JP6673785B2 - Solid electrolyte composition, solid electrolyte-containing sheet and all-solid secondary battery, and method for producing solid electrolyte-containing sheet and all-solid secondary battery - Google Patents

Description

  The present invention relates to a solid electrolyte composition, a solid electrolyte containing sheet and an all-solid secondary battery, and a method for producing a solid electrolyte containing sheet and an all solid secondary battery.

A lithium ion secondary battery is a storage battery having a negative electrode, a positive electrode, and an electrolyte sandwiched between the negative electrode and the positive electrode, and capable of charging and discharging by reciprocating lithium ions between the two electrodes. Conventionally, organic electrolytes have been used as electrolytes in lithium ion secondary batteries. However, the organic electrolyte is liable to leak, and overcharging or overdischarging may cause a short circuit inside the battery and cause ignition, and further improvement in reliability and safety is required.
Under such circumstances, an all-solid secondary battery using an inorganic solid electrolyte instead of an organic electrolyte has been receiving attention. All-solid-state rechargeable batteries are composed of solid negative electrode, electrolyte and positive electrode, which can greatly improve safety and reliability, which are the issues of batteries using organic electrolytes, and also enable long life. It will be. Further, the all-solid-state secondary battery can have a structure in which the electrode and the electrolyte are directly arranged and arranged in series. Therefore, a higher energy density can be achieved as compared with a secondary battery using an organic electrolyte, and application to an electric vehicle, a large storage battery, and the like is expected.

  Due to the advantages described above, the development of an all-solid-state secondary battery as a next-generation lithium-ion battery is underway. For example, Patent Document 1 discloses a sulfide solid electrolyte material, a tertiary amine; an ether; a thiol; a functional group having 3 or more carbon atoms bonded to a carbon atom of an ester group and a carbon atom bonded to an oxygen atom of an ester group having 4 carbon atoms. A method for producing an all-solid battery using a slurry containing an ester having the above functional group; and a dispersion medium comprising at least one ester having a benzene ring bonded to a carbon atom of the ester group is described. Patent Document 2 discloses that all solids including forming a solid electrolyte layer or an electrode active material layer using a slurry using a first solvent and a second solvent having a boiling point higher than that of the first solvent. A method for manufacturing a battery is described.

JP 2012-212652 A JP 2012-243472 A

  In recent years, the development of all solid state secondary batteries has been rapidly progressing. As the development progresses, there is an increasing demand for the performance of the all-solid secondary battery such as suppression of resistance and improvement of cycle characteristics. As a result of repeated studies by the present inventors to respond to such demands, the uniformity of the distribution of solid particles such as inorganic solid electrolytes in each layer constituting the all-solid secondary battery is improved, and the connection between the solid particles is improved. It has become clear that increasing the adhesion is an important factor in suppressing the resistance of the all-solid secondary battery and improving the cycle characteristics.

  The present invention can be used to form a solid electrolyte layer or an electrode layer of an all solid state secondary battery, whereby the uniformity of distribution of solid particles in each layer and the binding between solid particles can be increased to a desired level, As a result, it is an object of the present invention to provide a solid electrolyte composition that can effectively suppress the resistance of an all-solid secondary battery and realize excellent cycle characteristics. Another object of the present invention is to provide a solid electrolyte-containing sheet using the solid electrolyte composition and an all-solid secondary battery using the solid electrolyte-containing sheet. Another object of the present invention is to provide a method for producing a solid electrolyte-containing sheet and a method for producing an all-solid secondary battery using the solid electrolyte composition.

  The present inventors have further studied and found that, in a solid electrolyte composition containing an inorganic solid electrolyte and its dispersion medium, by using a specific heterocyclic compound as a dispersion medium, solid particles do not settle and disperse. (Improving dispersion stability), the solid electrolyte-containing sheet formed using this solid electrolyte composition has a uniform distribution of solid particles, excellent binding between solid particles, It has been found that an excellent electric conductivity is exhibited, and that the all-solid secondary battery using the solid electrolyte-containing sheet has low electric resistance and excellent cycle characteristics. The present invention has been further studied based on these findings, and has been completed.

式中、αは４〜１０員のヘテロ環を示し、Ｘ^１１は酸素原子を示し、Ｙ^１１およびＹ^１２は、各々独立に環α構成原子を示し、Ｒ^１１およびＲ^１２は、各々独立に置換基を示し、ｎ１は０または１である。Ｒ^Ｄ０は環α構成原子と結合している置換基を示し、ｄ０は０以上の整数を示す。ｄ０が２以上の場合、複数のＲ^Ｄ０は同じでも異なってもよく、隣接する環α構成原子に結合するＲ^Ｄ０同士が互いに結合して、環を形成してもよい。ただし、αは５員の芳香族性のヘテロ環ではない。

式中、Ｙ^１３およびＹ^１４は、各々独立に環α^２構成原子を示し、Ｒ^１３、Ｒ^１４、Ｒ^Ｄ１およびｄ１は、式（Ｓ−０）におけるＲ^１１、Ｒ^１２、Ｒ^Ｄ０およびｄ０とそれぞれ同義である。ｎ２およびｎ３は、１である。α^２は４〜１０員のヘテロ環を示し、Ｘ^０１は、窒素原子、リン原子、硫黄原子、ケイ素原子、ヒ素原子もしくはセレン原子、または、窒素原子、リン原子、硫黄原子、ケイ素原子、ヒ素原子もしくはセレン原子を含有する２価の基を示す。ただし、α^２は５員の芳香族性のヘテロ環ではない。
That is, the above problem was solved by the following means.
<1> An inorganic solid electrolyte (A) having ion conductivity of a metal belonging to Group 1 or 2 of the periodic table and a heterocyclic ring represented by the following formula (S-0) or (S-1) A compound (B) and a dispersion medium (C) having a LogP value of 2.0 or more, wherein the dispersion medium (C) is a ketone compound, an alcohol compound, a halogen compound, a hydrocarbon compound, an aromatic compound, an amine compound, A solid electrolyte composition which is an ester compound or a carbonate compound.

In the formula, α represents a 4- to 10-membered heterocyclic ring, X ¹¹ represents an oxygen atom, Y ¹¹ and Y ¹² each independently represent a ring α-constituting atom, and R ¹¹ and R ¹² each independently represent Represents a substituent, and n1 is 0 or 1. R ^D0 represents a substituent bonded to the ring α-constituting atom, and d0 represents an integer of 0 or more. When d0 is 2 or more, a plurality of R ^D0s may be the same or different, and R ^D0s bonded to adjacent ring α-constituting atoms may be bonded to each other to form a ring. However, α is not a 5-membered aromatic heterocycle.

^{Wherein, Y 13} and ^{Y 14} are each independently a ring alpha ² constituting ^{atom, R 13, R 14, R} D1 and d1 are, ^R 11 in the formula ^{(S-0), R 12} , R D0 and d0 Is synonymous with each. n2 and n3 are 1 . α ² represents a 4- to 10-membered heterocyclic ring, and X ⁰¹ represents a nitrogen atom, phosphorus atom, sulfur atom, silicon atom, arsenic atom or selenium atom, or nitrogen atom, phosphorus atom, sulfur atom, silicon atom, arsenic atom. It represents a divalent group containing an atom or a selenium atom. However, alpha ² is not a 5-membered aromatic heterocycle.

式中、βは５〜８員のヘテロ環を示し、Ｘ^２０は酸素原子を示し、Ｙ^２１およびＹ^２２は、各々独立に環β構成原子を示し、Ｒ^２１およびＲ^２２は、各々独立に置換基を示す。Ｒ^Ｄ２０は、環β構成原子と結合している置換基を示し、ｄ２０は０以上６以下の整数を示す。ｄ２０が２以上の場合、複数のＲ^Ｄ２０は同じでも異なってもよく、隣接する環β構成原子に結合するＲ^Ｄ２０同士が互いに結合して、環を形成してもよい。ただし、βは５員の芳香族性のヘテロ環ではない。

式中、β^２は５〜８員のヘテロ環を示し、Ｘ^２１は窒素原子、硫黄原子、−ＮＨ−または−Ｓ（Ｏ_２）−を示し、Ｙ^２３およびＹ^２４は、各々独立に環β^２構成原子を示し、Ｒ^２３およびＲ^２４は各々独立に置換基を示す。Ｒ^Ｄ２１は、環β^２構成原子と結合している置換基を示し、ｄ２１は０以上６以下の整数を示す。ｄ２１が２以上の場合、複数のＲ^Ｄ２１は同じでも異なってもよく、隣接する環β^２構成原子に結合するＲ^Ｄ２１同士が互いに結合して、環を形成してもよい。ただし、β ^２ は５員の芳香族性のヘテロ環を示さない。
<2> The solid electrolyte composition according to <1>, wherein the heterocyclic compound (B) is represented by the following formula (S-20) or (S-21).

In the formula, β represents a 5- to 8-membered heterocyclic ring, X ²⁰ represents an oxygen atom, Y ²¹ and Y ²² each independently represent a ring β-constituting atom, and R ²¹ and R ²² each independently represent Shows a substituent. R ^D20 represents a substituent bonded to a ring β-constituting atom, and d20 represents an integer of 0 or more and 6 or less. When d20 is 2 or more, a plurality of ^RD20s may be the same or different, and ^RD20s bonded to adjacent ring β-constituting atoms may be bonded to each other to form a ring. However, β is not a 5-membered aromatic heterocycle.

In the formula, β ² represents a 5- to 8-membered heterocyclic ring, X ²¹ represents a nitrogen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and Y ²³ and Y ²⁴ each independently represent a ring. β ² represents a constituent atom, and R ²³ and R ²⁴ each independently represent a substituent. R ^D21 represents a substituent attached with the ring beta ² constituting atom, d21 represents an integer of 0 to 6. If d21 is 2 or more, plural R ^D21 may be the same or different, bonded to each other R ^D21 bonded to the adjacent ring beta ² constituent atoms together may form a ring. However, beta ² do not exhibit aromatic 5-membered heterocycle.

式中、Ｘ^３１ およびＸ^３３は各々独立に、酸素原子、硫黄原子、−ＮＨ−または−Ｓ（Ｏ_２）−を示し、Ｒ^３１〜Ｒ ^３４ 、Ｒ ^３７ およびＲ^３８は各々独立に、フッ素原子、塩素原子、臭素原子、ヨウ素原子、炭素数１〜３のアルキル基、炭素数１〜３のアルコキシ基または炭素数２〜３のアルケニル基を示す。
アルキル基、アルコキシ基およびアルケニル基は、フッ素原子、塩素原子および／または臭素原子を有してもよい。
<3> The solid electrolyte composition according to <2>, wherein the heterocyclic compound (B) is represented by any of the following formulas (S-31) , (S-32), and (S-34).

In the formula, X ³¹ and X ³³ each independently represent an oxygen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and R ³¹ to R ³⁴ , R ³⁷ and R ³⁸ each independently represent fluorine It represents an atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkenyl group having 2 to 3 carbon atoms.
Alkyl, alkoxy and alkenyl groups may have a fluorine, chlorine and / or bromine atom.

<4 > The solid electrolyte composition according to any one of <1> to <3>, wherein the dispersion medium (C) having a LogP value of 2.0 or more is a hydrocarbon compound or an aromatic compound.
< 5 > The solid electrolyte composition according to any one of <1> to <4> , wherein the viscosity of the dispersion medium (C) having a LogP value of 2.0 or more at 30 ° C is 0.8 mPa · S or more.
< 6 > The one according to any one of < 1 > to < 5 >, wherein the mass ratio of the dispersion medium (C) having a LogP value of 2.0 or more to the heterocyclic compound (B) is 1: 4 to 1: 100. Solid electrolyte composition.
< 7 > The solid electrolyte composition according to any one of <1> to < 6 >, containing the polymer particles (D).
< 8 > The solid electrolyte composition according to any one of <1> to < 7 >, wherein the inorganic solid electrolyte (A) is represented by the following formula (1).
_{L a1 M b1 P c1 S d1} A e1 formula (1)
In the formula, L represents an element selected from Li, Na and K. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al and Ge. A represents an element selected from I, Br, Cl and F. a1 to e1 indicate the composition ratio of each element, and a1: b1: c1: d1: e1 satisfies 1 to 12: 0 to 5: 1: 2 to 12: 0 to 10.
< 9 > The solid electrolyte composition according to any one of <1> to < 8 >, containing the active material (E).
< 10 > The solid electrolyte composition according to < 9 >, wherein the active material (E) is a metal oxide.

< 11 > A solid electrolyte-containing sheet having a layer formed of the solid electrolyte composition according to any one of <1> to <10> ,
A solid electrolyte-containing sheet wherein the content of the heterocyclic compound (B) in the layer is from 1 ppm to 10,000 ppm.

<12 > An all-solid secondary battery including a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer,
An all-solid secondary battery in which at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is the solid electrolyte-containing sheet according to < 11> .
< 13 > A method for producing a solid electrolyte-containing sheet, comprising applying the solid electrolyte composition according to any one of <1> to < 10 > on a substrate and forming a film.
< 14 > A method for manufacturing an all-solid secondary battery, which manufactures an all-solid secondary battery through the manufacturing method according to < 13 >.

In this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.
In this specification, when simply describing “acryl” or “(meth) acryl” means methacryl and / or acryl. Further, when simply described as “acryloyl” or “(meth) acryloyl”, it means methacryloyl and / or acryloyl.

  The solid electrolyte composition of the present invention has excellent dispersion stability, and can be used for forming a solid electrolyte layer or an electrode layer of an all-solid secondary battery to effectively improve the uniformity of distribution of solid particles and the binding property between solid particles. , The resistance of the obtained all-solid-state secondary battery can be suppressed, and the cycle characteristics can be improved. In addition, the solid electrolyte-containing sheet of the present invention is excellent in uniformity of distribution of solid particles in a layer and excellent in binding between solid particles, and can realize excellent ionic conductivity between solid particles. Further, the all-solid secondary battery of the present invention has low resistance and excellent cycle characteristics. Furthermore, according to the method for producing a solid electrolyte-containing sheet and the method for producing an all-solid secondary battery of the present invention, the solid electrolyte-containing sheet and the all-solid secondary battery of the present invention having the above-described characteristics can be produced.

FIG. 1 is a longitudinal sectional view schematically illustrating an all solid state secondary battery according to a preferred embodiment of the present invention. It is a longitudinal cross-sectional view which shows typically the all solid state secondary battery (coin battery) produced in the Example.

<Preferred embodiment>
FIG. 1 is a cross-sectional view schematically illustrating an all solid state secondary battery (lithium ion secondary battery) according to a preferred embodiment of the present invention. The all-solid-state secondary battery 10 of the present embodiment includes a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5 in this order as viewed from the negative electrode side. . Each layer is in contact with each other and has a laminated structure. By adopting such a structure, during charging, electrons (e ⁻ ) are supplied to the negative electrode side, and lithium ions (Li ⁺ ) are accumulated therein. On the other hand, at the time of discharging, lithium ions (Li ⁺ ) accumulated in the negative electrode are returned to the positive electrode side, and electrons are supplied to the operating portion 6. In the illustrated example, an electric bulb is used for the operating portion 6, and this is turned on by discharge. The solid electrolyte composition of the present invention can be preferably used as a molding material for the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer. Further, the solid electrolyte-containing sheet of the present invention is suitable as the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer.
In this specification, a positive electrode active material layer (hereinafter, also referred to as a positive electrode layer) and a negative electrode active material layer (hereinafter, also referred to as a negative electrode layer) may be collectively referred to as an electrode layer or an active material layer.

  The thicknesses of the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 are not particularly limited. In consideration of general battery dimensions, the thickness is preferably 10 to 1,000 μm, and more preferably 20 μm or more and less than 500 μm. In the all solid state secondary battery of the present invention, it is more preferable that at least one of the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 has a thickness of 50 μm or more and less than 500 μm.

<Solid electrolyte composition>
The solid electrolyte composition of the present invention comprises an inorganic solid electrolyte (A) having ion conductivity of a metal belonging to Group 1 or 2 of the periodic table, and a compound represented by the following formula (S-0) or (S-1). )) And a heterocyclic compound (B) represented by
Hereinafter, for example, "inorganic solid electrolyte (A)", such as "inorganic solid electrolyte", describes the components contained in or can be contained in the solid electrolyte composition of the present invention without reference numerals. There is.

(Inorganic solid electrolyte (A))
The inorganic solid electrolyte is an inorganic solid electrolyte, and the solid electrolyte is a solid electrolyte capable of moving ions inside the solid electrolyte. Since it does not contain an organic substance as a main ion conductive material, it is an organic solid electrolyte (a polymer electrolyte represented by polyethylene oxide (PEO) and the like; an organic represented by lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) and the like) Electrolyte salt). Further, since the inorganic solid electrolyte is a solid in a steady state, it is not normally dissociated or released into cations and anions. In this regard, it is clearly distinguished from inorganic electrolyte salts (such as LiPF ₆ , LiBF ₄ , LiFSI, and LiCl) in which cations and anions are dissociated or released in the electrolyte solution or the polymer. The inorganic solid electrolyte is not particularly limited as long as it has ion conductivity of a metal belonging to Group 1 or 2 of the periodic table, and generally has no electron conductivity.

  In the present invention, the inorganic solid electrolyte has ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table. As the inorganic solid electrolyte, a solid electrolyte material applied to this type of product can be appropriately selected and used. Representative examples of the inorganic solid electrolyte include (i) a sulfide-based inorganic solid electrolyte and (ii) an oxide-based inorganic solid electrolyte. In the present invention, a sulfide-based inorganic solid electrolyte is preferably used because a better interface can be formed between the active material and the inorganic solid electrolyte.

(I) Sulfide-based inorganic solid electrolyte The sulfide-based inorganic solid electrolyte contains a sulfur atom (S), has ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and And a compound having an electronic insulating property are preferable. The sulfide-based inorganic solid electrolyte preferably contains at least Li, S, and P as elements and has lithium ion conductivity, but depending on the purpose or case, other than Li, S, and P, may be used. It may contain an element.
Since the solid electrolyte composition of the present invention has better ion conductivity among sulfide-based inorganic solid electrolytes, it may contain a lithium ion-conductive inorganic solid electrolyte satisfying the composition represented by the following formula (1). preferable.

_{L a1 M b1 P c1 S d1} A e1 formula (1)

In the formula, L represents an element selected from Li, Na and K, and Li is preferable. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al and Ge. A represents an element selected from I, Br, Cl and F. a1 to e1 indicate the composition ratio of each element, and a1: b1: c1: d1: e1 satisfies 1 to 12: 0 to 5: 1: 2 to 12: 0 to 10. a1 is further preferably 1 to 9, and more preferably 1.5 to 7.5. b1 is preferably 0 to 3, and more preferably 0 to 1. d1 is further preferably 2.5 to 10, and more preferably 3.0 to 8.5. e1 is further preferably 0 to 5, more preferably 0 to 3.

  The composition ratio of each element can be controlled by adjusting the compounding amount of the raw material compound when producing the sulfide-based inorganic solid electrolyte as described below.

The sulfide-based inorganic solid electrolyte may be non-crystalline (glass) or crystallized (glass-ceramic), or may be partially crystallized. For example, Li-PS-based glass containing Li, P and S, or Li-PS-based glass ceramic containing Li, P and S can be used.
Examples of the sulfide-based inorganic solid electrolyte include lithium sulfide (Li ₂ S), phosphorus sulfide (for example, diphosphorus pentasulfide (P ₂ S ₅ )), elemental phosphorus, elemental sulfur, sodium sulfide, hydrogen sulfide, and lithium halide (for example, LiI, LiBr, LiCl) and at least two or more raw materials among the sulfides (for example, SiS ₂ , SnS, GeS ₂ ) of the element represented by M can be produced.

In Li-P-S based glass and Li-P-S based glass ceramics, the ratio of Li ₂ S and _P 2 _{S 5 is,} Li 2 _S: at a molar ratio of P 2 _{S 5,} preferably 60:40 90:10, more preferably 68:32 to 78:22. By setting the ratio of Li ₂ S and P ₂ S ₅ to this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity can be preferably 1 × 10 ⁻⁴ S / cm or more, more preferably 1 × 10 ⁻³ S / cm or more. Although there is no particular upper limit, it is practical that it is 1 × 10 ⁻¹ S / cm or less.

As examples of specific sulfide-based inorganic solid electrolytes, combinations of raw materials are shown below. For example, Li ₂ S—P ₂ S ₅ , Li ₂ S—P ₂ S ₅ —LiCl, Li ₂ S—P ₂ S ₅ —H ₂ S, Li ₂ S—P ₂ S ₅ —H ₂ S—LiCl, Li _{2 S-LiI-P 2 S} 5, Li 2 S-LiI-Li 2 O-P 2 S 5, Li 2 S-LiBr-P 2 S 5, Li 2 S-Li 2 O-P 2 S 5, Li _{2 S-Li 3 PO 4 -P} 2 S 5, Li 2 S-P 2 S 5 -P 2 O 5, Li 2 S-P 2 S 5 -SiS 2, Li 2 S-P 2 S 5 -SiS 2 _{-LiCl, Li 2 S-P 2} S 5 -SnS, Li 2 S-P 2 S 5 -Al 2 S 3, Li 2 S-GeS 2, Li 2 S-GeS 2 -ZnS, Li 2 S-Ga 2 _{S 3, Li 2 S-GeS} 2 -Ga 2 S 3, Li 2 S-GeS 2 -P 2 S 5 _{Li 2 S-GeS 2 -Sb 2} S 5, Li 2 S-GeS 2 -Al 2 S 3, Li 2 S-SiS 2, Li 2 S-Al 2 S 3, Li 2 S-SiS 2 -Al 2 S _{3, Li 2 S-SiS 2} -P 2 S 5, Li 2 S-SiS 2 -P 2 S 5 -LiI, Li 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -Li 4 SiO 4, Li ₂ S—SiS ₂ —Li ₃ PO ₄ , Li ₁₀ GeP ₂ S _{12 and the} like. However, the mixing ratio of each raw material does not matter. As a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition, for example, an amorphization method can be mentioned. Examples of the amorphization method include a mechanical milling method, a solution method, and a melt quenching method. This is because processing at normal temperature becomes possible, and the manufacturing process can be simplified.

(Ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte contains an oxygen atom (O), has ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and And a compound having an electronic insulating property are preferable.

Specific compounds, for example _Li xa _La ya TiO ₃ [xa = 0.3~0.7, ya = 0.3~0.7] _{(LLT), Li xb La yb} Zr zb M bb mb O _nb ( ^Mbb is at least one element of Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In and Sn, xb satisfies 5 ≦ xb ≦ 10, and yb satisfies 1 ≦ yb ≦ 4, zb satisfies 1 ≦ zb ≦ 4, mb satisfies 0 ≦ mb ≦ 2, nb satisfies 5 ≦ nb ≦ 20), Li _{xc Byc} M ^cc _zc O _nc (M ^cc is C, S, Al, Si, Ga, Ge, In and Sn are at least one or more elements, xc satisfies 0 ≦ xc ≦ 5, yc satisfies 0 ≦ yc ≦ 1, and zc satisfies 0 ≦ zc ≦ met 1, nc satisfies 0 ≦ nc ≦ 6.), Li xd ( _{l, Ga) yd (Ti,} Ge) zd Si ad P md O nd ( provided that, 1 ≦ xd ≦ 3,0 ≦ yd ≦ 1,0 ≦ zd ≦ 2,0 ≦ ad ≦ 1,1 ≦ md ≦ 7, ^{_{3 ≦ nd ≦ 13), Li}} (3-2xe) M ee xe D ee O (xe represents a number of 0 to ^{0.1, .D ee M ee} is representative of a divalent metal atom is a halogen atom or Represents a combination of two or more halogen atoms.), Li _xf Si _yf O _zf (1 ≦ xf ≦ 5, 0 <yf ≦ 3, 1 ≦ zf ≦ 10), Li _xg S _yg O _zg (1 ≦ xg ≦ 3, 0 <yg ≦ 2, 1 ≦ zg ≦ 10), Li ₃ BO ₃ —Li ₂ SO ₄ , Li ₂ O—B ₂ O ₃ —P ₂ O ₅ , Li ₂ O—SiO ₂ , Li ₆ BaLa _{2 ta 2 O 12, Li 3 PO} (4-3 / 2w) N w (w is w <1), LI ICON (Lithium super ionic conductor) type _Li 3.5 _Zn 0.25 GeO ₄ having a crystal structure, _La 0.55 _Li 0.35 TiO ₃ and _Li 0.33 _La 0.55 TiO ₃ having a perovskite crystal structure , LiTi ₂ P ₃ O ₁₂ having a NASICON (Natrium superionic conductor) type crystal structure, Li _{1 + xh + yh} (Al, Ga) _xh (Ti, Ge) _2-xh Si _yh P _3-yh O ₁₂ (where 0 ≦ xh ≦ 1, 0 ≦ yh ≦ 1), and Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ) having a garnet type crystal structure. Further, a phosphorus compound containing Li, P and O is also desirable. For example, lithium phosphate (Li ₃ PO ₄ ), LiPON in which a part of oxygen of lithium phosphate is substituted by nitrogen, LiPOD ¹ (D ¹ is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr , Nb, Mo, Ru, Ag, Ta, W, Pt, Au, etc.). Further, LiA ¹ ON (A ¹ is at least one selected from Si, B, Ge, Al, C, Ga, and the like) can also be preferably used.

  The volume average particle diameter of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. The upper limit is preferably 100 μm or less, more preferably 50 μm or less. The average particle diameter of the inorganic solid electrolyte particles is measured according to the following procedure. A 1% by weight dispersion of inorganic solid electrolyte particles is prepared in a 20 mL sample bottle using water (heptane in the case of a substance unstable to water). The dispersion sample after dilution is irradiated with 1 kHz ultrasonic wave for 10 minutes and used immediately after the test. Using this dispersion sample, data was taken 50 times using a quartz cell for measurement at a temperature of 25 ° C. using a laser diffraction / scattering type particle size distribution analyzer LA-920 (manufactured by HORIBA) to obtain volume average particles. Get the diameter. For other detailed conditions and the like, refer to the description of JISZ8828: 2013 “Particle Size Analysis-Dynamic Light Scattering Method” as necessary. Five samples are prepared for each level, and the average value is adopted.

The content of the inorganic solid electrolyte in the solid component in the solid electrolyte composition is 100% by mass of the solid component when considering the reduction of the interface resistance and the maintenance of the reduced interface resistance when used in an all-solid secondary battery. The content is preferably 5% by mass or more, more preferably 10% by mass or more, and particularly preferably 20% by mass or more. From the same viewpoint, the upper limit is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and particularly preferably 99% by mass or less.
The inorganic solid electrolyte may be used alone or in combination of two or more.
In this specification, the solid content (solid component) refers to a component that does not disappear by volatilization or evaporation when a drying treatment is performed at 140 ° C. for 6 hours in a nitrogen atmosphere. Typically, it refers to components other than the heterocyclic compound (B) and the dispersion medium described below.

(Heterocyclic compound (B))
The solid electrolyte composition of the present invention contains the heterocyclic compound (B) represented by the following formula (S-0) or (S-1), and contains the heterocyclic compound represented by the formula (S-1). Is preferred.

In the formula, α represents a heterocyclic ring, X ¹¹ represents an oxygen atom, Y ¹¹ and Y ¹² each independently represent a ring α-constituting atom, R ¹¹ and R ¹² each independently represent a substituent, n1 is 0 or 1. R ^D0 represents a substituent bonded to the ring α-constituting atom, and d0 represents an integer of 0 or more. When d0 is 2 or more, a plurality of R ^D0s may be the same or different, and R ^D0s bonded to adjacent ring α-constituting atoms may be bonded to each other to form a ring.

Ring α may be an aliphatic or aromatic hetero ring, but is preferably a 4- to 10-membered ring, more preferably a 5- to 8-membered ring, and particularly preferably a 5- to 6-membered ring.
Y ¹¹ and Y ¹² are preferably carbon atoms.
As ring α-constituting atoms other than X ¹¹ , Y ¹¹ and Y ¹² , a carbon atom and an oxygen atom are preferred, and a carbon atom is more preferred.
As the ring α, specifically, an oxetane ring, a furan ring, a dioxolane ring, a tetrahydrofuran ring, a pyran ring, a tetrahydropyran ring, a 1,3-dioxane ring, a 1,4-dioxane ring, a hexamethylene oxide ring, an oxycyclo Heptatriene rings are preferred, and furan rings or tetrahydrofuran rings are more preferred.
d0, when the ring members of the ring alpha and m _alpha, an integer satisfying _{0 ≦ d0 ≦ 2 (m α} -1) -1-n1, preferably an integer of 0 to 8.
n1 is preferably 1.

The substituents represented by R ¹¹ and R ¹² are not particularly limited, but include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and an alkyl group (having preferably 1 to 24 carbon atoms, more preferably 1 to 12 carbon atoms, and 1 to 6 carbon atoms. Are more preferred.), An alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 6), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14), and an aralkyl group. (The number of carbon atoms is preferably 7 to 23, more preferably 7 to 15.), an aryloxy group (the number of carbon atoms is preferably 6 to 22, more preferably 6 to 14, and particularly preferably 6 to 10), and aralkyloxy. Groups (preferably having 7 to 23 carbon atoms, more preferably 7 to 15 carbon atoms, and particularly preferably 7 to 11 carbon atoms), and alkyloxyalkyl groups (preferably having 2 to 24 carbon atoms and more preferably 2 to 12 carbon atoms). And particularly preferably 2 to 6), an alkoxy group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, more preferably 1 and 2, particularly preferably 1), a hydroxy group and an amino group. (The number of carbon atoms is preferably 0 to 8, more preferably 1 to 6, and particularly preferably 2 to 4.), carboxy, sulfonic, and oxo (= O) are preferred. Among them, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkenyl group having 2 to 3 carbon atoms are preferable. An alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 3 carbon atoms or an alkoxy group having 1 to 2 carbon atoms is more preferable, and a chlorine atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 2 carbon atoms is preferable. More preferred are a methyl group, an ethyl group and a methoxy group. Note that R ¹¹ and R ¹² are respectively bonded to Y ¹¹ and Y ¹² via a single bond or a double bond.

R ^D0 is bonded to the ring α-constituting atom via a single bond or a double bond. Among R ^D0 , an alkyl group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, and particularly preferably 1 to 6) and an alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 6) Preferred), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14), an aralkyl group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15), and an alkyloxy group ( The number of carbon atoms is preferably from 1 to 24, more preferably from 1 to 12, particularly preferably from 1 to 6, and an aryloxy group (the number of carbon atoms is preferably from 6 to 22, more preferably from 6 to 14, particularly preferably from 6 to 10). Aralkyloxy group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15 and particularly preferably 7 to 11), and alkyloxyalkyl group (preferably having 2 to 24 carbon atoms, and having 2 to 1 carbon atoms). 2 is more preferable, and 2 to 6 are particularly preferable.), A hydroxy group, an amino group, a carboxy group, a sulfonic acid group or an oxo group (（O) is preferable. Among them, an alkyl group having 1 or 2 carbon atoms, an alkenyl group having 2 carbon atoms, an alkyloxy group having 1 to 2 carbon atoms, and an alkyloxyalkyl group having 2 to 4 carbon atoms are preferable, and an alkyl group having 1 to 3 carbon atoms. Alternatively, an alkoxy group having 1 to 2 carbon atoms is more preferable, and a methyl group, an ethyl group or a methoxy group is particularly preferable.
In addition, it is also preferable that a part of the substituents represented by R ¹¹ , R ¹² and R ^D0 is substituted by a halogen atom (preferably, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom).

The ring formed by combining a plurality of ^RD0s with each other is not particularly limited, but is preferably an aromatic ring having 6 to 12 carbon atoms or an aliphatic ring having 3 to 12 carbon atoms.

^{Wherein, Y 13} and ^{Y 14} are each independently a ring alpha ² constituting ^{atom, R 13, R 14, R} D1 and d1 are, ^R 11 in the formula ^{(S-0), R 12} , R D0 and d0 Is synonymous with each. n2 and n3 are each independently 0 or 1. α ² represents a heterocyclic ring, X ⁰¹ represents a nitrogen atom, a phosphorus atom, a sulfur atom, a silicon atom, an arsenic atom or a selenium atom, or a nitrogen atom, a phosphorus atom, a sulfur atom, a silicon atom, an arsenic atom or a selenium atom. Shows the divalent group contained.

The ring α ² may be an aliphatic or aromatic hetero ring, but is preferably a 4- to 10-membered ring, more preferably a 5- to 8-membered ring, and particularly preferably a 5- to 6-membered ring.
Y ¹³ and Y ¹⁴ are each independently preferably a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, and a silicon atom, more preferably a carbon atom, a nitrogen atom, and an oxygen atom, and particularly preferably a carbon atom.
The X ^01, Y ¹³ and Y ¹⁴ than ring alpha ^{2-constituting} atom, a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom, silicon atom and selenium atom include preferably a carbon atom, a nitrogen atom, an oxygen atom is more Preferred are carbon and / or nitrogen atoms.
The ring alpha ^2, specifically, a thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, imidazole ring, imidazoline ring, pyrazole ring, pyrazoline ring, pyrazolidine ring, pyridine ring, piperidine ring, pyrazine ring, piperazine ring, Preferable examples include a pyrimidine ring, a pyridazine ring, an oxazole ring, a thiazole ring, a morpholine ring and a thiazine ring, and a thiophene ring, a pyrrole ring, a pyridine ring, a piperidine ring or a pyrimidine ring are more preferable.
d1, when the ring members of the ring alpha ² and m _{[alpha] 2,} an integer satisfying _{0 ≦ d1 ≦ 2 (m α2} -1) -n2-n3, preferably an integer of 0 to 8.
n2 and n3 are preferably 1.

The atom represented by X ⁰¹ is preferably a nitrogen atom or a sulfur atom, and more preferably a nitrogen atom.
Examples of the divalent group represented by _{^{X 01, -S (= O)}} 2 - 2 divalent group having a sulfur atom such as, -SiR- (R is a hydrogen atom, an alkoxy group (preferably 1 to 3 carbon atoms ) Or a divalent group having a silicon atom, such as an alkyl group (preferably having 1 to 3 carbon atoms).

  As the heterocyclic compound (B) represented by the above formula (S-0) or (S-1), a heterocyclic compound represented by the following formula (S-20) or (S-21) is preferable. More preferably, it is a heterocyclic compound represented by (S-21). By having a substituent on the hetero ring-constituting atom bonded to the hetero atom constituting the hetero ring, the reaction between the hetero ring compound (B) and the inorganic solid electrolyte is effectively suppressed, and the ionic conduction of the inorganic solid electrolyte is suppressed. This is because a decrease in the degree can be effectively prevented.

In the formula (S-20), β represents a 5- to 8-membered heterocyclic ring, X ²⁰ represents an oxygen atom, Y ²¹ and Y ²² each independently represent a ring β-constituting atom, and R ²¹ and R ²² Each independently represents a substituent. R ^D20 represents a substituent bonded to a ring β-constituting atom, and d20 represents an integer of 0 or more and 5 or less. When d20 is 2 or more, a plurality of ^RD20s may be the same or different, and ^RD20s bonded to adjacent ring β-constituting atoms may be bonded to each other to form a ring.

Y ²¹ and Y ²² have the same meanings as Y ¹¹ and Y ¹² in the formula (S-0), respectively, and their preferable ranges are also the same.
R ²¹ and R ²² are preferably a fluorine atom, a chlorine atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. Among them, a chlorine atom, an alkyl group having 1 to 3 carbon atoms or an alkoxy group having 1 to 2 carbon atoms is preferable, and a methyl group, an ethyl group or a methoxy group is particularly preferable. Note that R ²¹ and R ²² are respectively bonded to Y ¹¹ and Y ¹² via a single bond or a double bond.
Each has the same meaning as R ¹¹ and R ¹² in the above formula (S-0), and the preferred range is also the same.
Further, the substituent represented by R ^D20 has the same meaning as the substituent represented by R ^D0 in formula (S-0), and the preferred range is also the same.
Ring β may be an aliphatic or aromatic hetero ring, but is preferably a 5- to 6-membered ring.
The ring β-constituting atoms other than X ²⁰ , Y ²¹ and Y ²² have the same meanings as the ring α-constituting atoms other than X ¹¹ , Y ¹¹ and Y ¹² , and the preferred ranges are also the same.
Specific examples of the ring β are preferably specific examples of the ring α.
d20 is an integer that satisfies 0 ≦ d20 ≦ 2 ( _mβ− 3) +2, where mβ is the number of members of the ring _β, and is preferably an integer of 0 to 6.

In formula (S-21), β ² represents a 5- to 8-membered heterocyclic ring, X ²¹ represents a nitrogen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and Y ²³ and Y ²⁴ represent , Each independently represents a ring β ² -constituting atom, and R ²³ and R ²⁴ each independently represent a substituent. R ^D21 represents a substituent attached with the ring beta ² constituting atom, d21 represents an integer of 0 to 6. If d21 is 2 or more, plural R ^D21 may be the same or different, bonded to each other R ^D21 bonded to the adjacent ring beta ² constituent atoms together may form a ring.

X ²¹ is preferably a nitrogen atom or —NH—.
Y ²³ and Y ²⁴ have the same meanings as Y ¹¹ and Y ¹² in the formula (S-0), respectively, and their preferable ranges are also the same.
R ²³ and R ²⁴ have the same meanings as R ¹¹ and R ¹² in the formula (S-0), respectively, and their preferable ranges are also the same.
Further, the substituent represented by R ^D21 has the same meaning as the substituent represented by R ^D0 in Formula (S-0), and the preferred range is also the same.
Ring β ² may be an aliphatic or aromatic hetero ring, but is preferably a 5- to 6-membered ring.
X ^{21, Y 23} and ^{Y 24} ring beta ² constituting atoms other than ^are X ^{01, Y 13} and ^{Y 14} same meanings as ring alpha ² constituting atoms other than, the preferred range is also the same.
Specific examples of the ring β ² include preferably specific examples of the ring α ² .
d21, when the ring members of the ring beta ² and m _.beta.2, an integer satisfying _{0 ≦ d21 ≦ 2 (m β2} -3) +2, preferably an integer of 0 to 6.

  The heterocyclic compound (B) represented by the above formula (S-20) or (S-21) has the following formulas (S-31) to (S-31) in order to reduce the boiling point and suppress the reaction with the inorganic solid electrolyte. -34) A heterocyclic compound represented by any of the above is preferable, and a heterocyclic compound represented by the formula (S-31) is particularly preferable.

In the formula, X ^{31 to} X ³³ each independently represent an oxygen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and R ^{31 to} R ³⁸ each independently represent a fluorine atom, a chlorine atom, or a bromine. It represents an atom, an iodine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms, or an alkenyl group having 2 to 3 carbon atoms.
The alkyl group, alkoxy group and alkenyl group in R ^{31 to} R ³⁸ may have a fluorine atom, a chlorine atom and / or a bromine atom.

X ^{31 to} X ³³ are more preferably an oxygen atom, a sulfur atom and —NH—.

Hereinafter, specific examples of the heterocyclic compound (B) used in the present invention will be described, but the present invention is not limited thereto. In addition, THF represents tetrahydrofuran.
2,5-dimethyl THF, 2-methyl THF, 2-ethyl piperidine, 2,6-dimethyl piperidine, 2,5-dimethyl thiophene, 2,6-lutidine, 2,5-dimethoxy THF, 2,5-dimethyl pyrrole , 2,5-dimethyl furan, thiophene, 2,6-dichloropyridine, 4,6-dimethyl pyrimidine, 2-methylimidazole, ethylene carbonate, .gamma.-butyrolactone, .gamma. Bareroraku tons and trimethylene carbonate.

(Dispersion medium (C))
The solid electrolyte composition of the present invention preferably contains a dispersion medium (C) having a LogP value of 2 or more, preferably 2.4 or more, in order to maintain the ionic conductivity of the inorganic solid electrolyte higher. The LogP value is a value calculated by ChemBioDraw (trade name) Version: 12.9.2.076 manufactured by PerkinElmer. The upper limit of the LogP value is not particularly limited, but is practically 10 or less.
Hereinafter, the dispersion medium (C) having a LogP value of 2 or more is simply referred to as “dispersion medium (C)”. Examples of such a dispersion medium (C) include ketone compounds, alcohol compounds, halogen compounds, hydrocarbon compounds, aromatic compounds, amine compounds, ester compounds, and carbonate compounds. In the present invention, hydrocarbon compounds and aromatic compounds are preferred because of low reactivity with the inorganic solid electrolyte, and cyclooctane, cycloheptane, cyclohexane, tetralin and mesitylene are particularly preferred.

  Specific examples of the ketone compound include dibutyl ketone (LogP value: 3.18, boiling point: 186 ° C).

  Specific examples of the alcohol compound include 1-octanol (Log P value: 2.64, boiling point: 195 ° C.).

  Specific examples of the halogen compound include 1-chloropentane (LogP value: 2.61, boiling point: 108 ° C) and perfluorononane (LogP value: 6.42, boiling point: 125 ° C).

  The hydrocarbon compound is a compound composed of carbon atoms and hydrogen atoms, and may be a chain or a cyclic structure. As for carbon number, 3-24 are preferred, 4-18 are more preferred, and 6-12 are especially preferred. A double bond or a triple bond may be appropriately formed, but when it exhibits aromaticity, it is not included in the hydrocarbon compound. The ring formed is preferably a 5- to 8-membered ring. C5-24 are preferable, C6-12 are preferable, and C6-9 are especially preferable.

  Specific examples of the hydrocarbon compound include cyclohexane (LogP value: 2.50, boiling point: 81 ° C), cycloheptane (LogP value: 2.92, boiling point: 118 ° C), cyclooctane (LogP value: 3.34, Boiling point: 149 ° C), Hexane (LogP value: 3.00, Boiling point: 69 ° C), Heptane (LogP value: 3.42, Boiling point: 98 ° C), Octane (LogP value: 3.84, Boiling point: 125 ° C) And nonane (Log P value: 4.25, boiling point: 151 ° C.).

  Specific examples of the aromatic compound include toluene (Log P value: 2.52, boiling point: 111 ° C.), xylene (Log P value: 3.01, boiling point: 140 ° C.), mesitylene (Log P value: 3.50, boiling point: 165 ° C) and tetralin (Log P value: 3.34, boiling point: 207 ° C).

  Specific examples of the amine compound include tributylamine (LogP value: 3.97, boiling point: 216 ° C) and diisopropylethylamine (LogP value: 3.99, boiling point: 127 ° C).

  Specific examples of the ester compound include butyl butyrate (Log P value: 2.27, boiling point: 165 ° C.).

  Specific examples of the carbonate compound include bis (2,2,2-trifluoroethyl) carbonate (Log P value: 2.5, boiling point: 118 ° C.).

It is preferable that the heterocyclic compound (B) and the dispersion medium (C) are mixed when mixed at a mass ratio described below in order to improve dispersibility.
The term “mixing” means that under a normal temperature (25 ° C.) and normal pressure (760 mmHg) environment, a plurality of types of dispersion media are uniformly mixed even when each contains 5% by mass or more. Uniform mixing means that after mixing, the mixture is transparent even after 24 hours and is not separated. Transparent means that the haze is 10 mg / L or less as measured by a haze meter (trade name: NDH 4000, manufactured by Nippon Denshoku Industries Co., Ltd.). The haze meter is measured under the conditions of JIS K7136 using a D65 light source with an optical path length of 10 mm.

  Although the boiling point of the heterocyclic compound (B) is not particularly limited, it is preferably 30C to 220C, more preferably 70C to 130C. The boiling point of the dispersion medium (C) is not particularly limited, but is preferably from 60 ° C to 240 ° C, and more preferably from 90 ° C to 170 ° C.

  Although the viscosity of the dispersion medium (C) used in the present invention is not particularly limited, it is preferably 0.8 mPa · S or more at 30 ° C. in order to effectively suppress sedimentation of solid components in the solid electrolyte composition which is a slurry. Preferably, it is 0.9 mPa · S or more. There is no particular upper limit, but 1,000,000 mPa · S or less is practical. The viscosity of the dispersion medium (C) used in the present invention can be measured by the method described in the section of Examples below.

  In the solid electrolyte composition of the present invention, the mass ratio of the heterocyclic compound (B) to the dispersion medium (C) is not particularly limited, but the mass of the heterocyclic compound (B): the mass of the dispersion medium (C) is 1: It is preferably in the range of 4 to 1: 100, more preferably 1: 6 to 1:50, and particularly preferably 1: 8 to 1:30. This is because, by being in this range, the dispersion stability can be improved while further suppressing the reaction between the heterocyclic compound (B) and the inorganic solid electrolyte (A).

  In addition, each of the heterocyclic compound (B) and the dispersion medium (C) may be used alone or in combination of two or more. As the heterocyclic compound (B) and the dispersion medium (C) used in the present invention, for example, commercially available products can be used.

In the present specification, the expression of a compound (for example, when the compound is referred to as a suffix) is used to include the compound itself, its salt, and its ion. Further, it is meant to include a derivative partially changed by introducing a substituent within a range in which a desired effect is exhibited.
In the present specification, a substituent that is not specified as substituted or unsubstituted (the same applies to a linking group) means that the group may have an appropriate substituent. This is synonymous with a compound for which no substitution or no substitution is specified.

(Polymer particles (D))
The solid electrolyte composition of the present invention may contain a binder, and preferably may contain polymer particles. More preferably, it may contain polymer particles containing a macromonomer component.
The binder used in the present invention is not particularly limited as long as it is an organic polymer.
The binder that can be used in the present invention is not particularly limited, and for example, a binder made of a resin described below is preferable.

Examples of the fluorinated resin include polytetrafluoroethylene (PTFE), polyvinylene difluoride (PVdF), and a copolymer of polyvinylene difluoride and hexafluoropropylene (PVdF-HFP).
Examples of the hydrocarbon thermoplastic resin include polyethylene, polypropylene, styrene butadiene rubber (SBR), hydrogenated styrene butadiene rubber (HSBR), butylene rubber, acrylonitrile butadiene rubber, polybutadiene, and polyisoprene.
Examples of the acrylic resin include various (meth) acrylic monomers, (meth) acrylamide monomers, and copolymers (preferably, copolymers of acrylic acid and methyl acrylate) of monomers constituting these resins. Can be
Further, copolymers with other vinyl monomers are also preferably used. Examples include a copolymer of methyl (meth) acrylate and styrene, a copolymer of methyl (meth) acrylate and acrylonitrile, and a copolymer of butyl (meth) acrylate, acrylonitrile and styrene. In the present specification, the copolymer may be any of a statistical copolymer and a periodic copolymer, and is preferably a block copolymer.
Examples of other resins include polyurethane resin, polyurea resin, polyamide resin, polyimide resin, polyester resin, polyether resin, polycarbonate resin, and cellulose derivative resin.
Among them, a fluorine-containing resin, a hydrocarbon-based thermoplastic resin, an acrylic resin, a polyurethane resin, a polycarbonate resin, and a cellulose derivative resin are preferable, and an acrylic resin and a polyurethane resin are particularly preferable.
These may be used alone or in combination of two or more.

  The shape of the binder is not particularly limited, and may be particulate or irregular in the all-solid secondary battery, and is preferably particulate.

  In addition, a commercial item can be used for the binder used for this invention. Moreover, it can also be prepared by a conventional method.

The water concentration of the binder used in the present invention is preferably 100 ppm (by mass) or less.
Further, the binder used in the present invention may be used in a solid state or in a state of a polymer particle dispersion or a polymer solution.

  The weight average molecular weight of the binder used in the present invention is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 30,000 or more. Although the upper limit is substantially 1,000,000 or less, an embodiment in which a binder having a mass average molecular weight in this range is crosslinked is also preferable.

-Measurement of molecular weight-
In the present invention, the molecular weight of the binder refers to the mass average molecular weight unless otherwise specified, and is measured by gel permeation chromatography (GPC) in terms of standard polystyrene. The measurement method is basically a value measured by the method of the following condition 1 or condition 2 (priority). However, an appropriate eluent may be appropriately selected and used depending on the kind of the binder.

(Condition 1)
Column: Two TOSOH TSKgel Super AWM-H (trade name) are connected.
Carrier: 10 mM LiBr / N-methylpyrrolidone Measurement temperature: 40 ° C
Carrier flow rate: 1.0 mL / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector

(Condition 2) Priority column: A column connected with TOSOH TSKgel Super HZM-H (trade name), TOSOH TSKgel Super HZ4000 (trade name), and TOSOH TSKgel Super HZ2000 (trade name) is used.
Carrier: tetrahydrofuran Measurement temperature: 40 ° C
Carrier flow rate: 1.0 mL / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector

The content of the binder in the solid electrolyte composition is 0.01% by mass in a solid component of 100% by mass in consideration of the reduction of the interface resistance and the maintenance of the reduced interface resistance when used in an all-solid secondary battery. % Or more, more preferably 0.1% by mass or more, still more preferably 1% by mass or more. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and still more preferably 3% by mass or less, from the viewpoint of battery characteristics.
In the present invention, the mass ratio of the total mass (total amount) of the inorganic solid electrolyte and the active material to the mass of the binder [(the mass of the inorganic solid electrolyte + the mass of the active material) / the mass of the binder] is 1,000 to 1. A range is preferred. This ratio is more preferably from 500 to 2, and even more preferably from 100 to 10.

  In the present invention, the binder is preferably polymer particles (D) insoluble in the dispersion medium (C) from the viewpoint of dispersion stability of the solid electrolyte composition. Here, “the polymer particles (D) are insoluble particles in the dispersion medium (C)” means that the average particle diameter is 5 nm or more even when added to the dispersion medium at 30 ° C. and allowed to stand for 24 hours. 10 nm or more is preferable, and 30 nm or more is more preferable.

(Active material (E))
The solid electrolyte composition of the present invention may contain an active material (E) capable of inserting and releasing ions of a metal element belonging to Group 1 or Group 2 of the periodic table. Hereinafter, the active material (E) is also simply referred to as an active material.
Examples of the active material include a positive electrode active material and a negative electrode active material, and a metal oxide (preferably a transition metal oxide) as a positive electrode active material, or a metal oxide or Sn, Si, Al, and a negative electrode active material. A metal that can form an alloy with lithium, such as In, is preferable.
In the present invention, a solid electrolyte composition containing an active material (a positive electrode active material or a negative electrode active material) may be referred to as an electrode composition (a positive electrode composition or a negative electrode composition).

−Positive electrode active material−
The positive electrode active material which may be contained in the solid electrolyte composition of the present invention is preferably one capable of reversibly inserting and releasing lithium ions. The material is not particularly limited as long as it has the above characteristics, and may be a transition metal oxide, an organic substance, an element such as sulfur, which can be combined with Li, or a composite of sulfur and a metal.
Among them, a transition metal oxide is preferably used as the positive electrode active material, and a transition metal oxide containing a transition metal element M ^a (at least one element selected from Co, Ni, Fe, Mn, Cu, and V). Are more preferred. In addition, the transition metal oxide includes an element M ^b (an element of the first (Ia) group, an element of the second (IIa) group, Al, Ga, In, Ge, Sn, Pb, Sb, Nb, Bi, Si, P or B). The mixing amount, 0~30mol% is preferred for the amount of the transition metal element ^{M a (100mol%).} Those synthesized by mixing such that the molar ratio of Li / Ma becomes 0.3 to 2.2 are more preferable.
Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt type structure, (MB) a transition metal oxide having a spinel type structure, (MC) a lithium-containing transition metal phosphate compound, (MD) And (ME) lithium-containing transition metal silicate compounds.

(MA) As specific examples of the transition metal oxide having a layered rock salt type structure, LiCoO ₂ (lithium cobaltate [LCO]), LiNiO ₂ (lithium nickelate), LiNi _0.85 Co _0.10 Al _0.05 O ₂ (lithium nickel cobalt aluminum oxide [NCA]), LiNi _1/3 Co _1/3 Mn _1/3 O ₂ (lithium nickel manganese cobalt oxide [NMC]), LiNi _0.8 Co _0.1 Mn _0.1 O ₂ (high nickel nickel manganese cobalt oxide [NMC]) and LiNi _0.5 Mn _0.5 O ₂ (lithium manganese nickel oxide).
(MB) As specific examples of the transition metal oxide having a spinel structure, LiMn ₂ O ₄ (LMO), LiCoMnO _4, Li ₂ FeMn ₃ O ₈ , Li ₂ CuMn ₃ O ₈ , Li ₂ CrMn ₃ O _8, and Li 2 ₂ NiMn ₃ O ₈ .
Examples of (MC) lithium-containing transition metal phosphate compounds include olivine-type iron phosphates such as LiFePO ₄ and Li ₃ Fe ₂ (PO ₄ ) ₃ , iron pyrophosphates such as LiFeP ₂ O ₇ , and LiCoPO _4. And monoclinic nasicon-type vanadium phosphate salts such as Li ₃ V ₂ (PO ₄ ) ₃ (lithium vanadium phosphate).
(MD) as the lithium-containing transition metal halogenated phosphate compound, for _example, Li 2 FePO ₄ F such fluorinated phosphorus iron _salt, Li 2 MnPO ₄ hexafluorophosphate manganese salts such as F and _Li 2 CoPO ₄ F And the like, such as cobalt fluorophosphates.
(ME) Examples of the lithium-containing transition metal silicate compound include Li ₂ FeSiO ₄ , Li ₂ MnSiO _4, and Li ₂ CoSiO ₄ .
In the present invention, a transition metal oxide having a (MA) layered rock salt type structure is preferred, LCO or NMC is more preferred, and NMC is particularly preferred.

  The shape of the positive electrode active material is not particularly limited, but is preferably particulate. The volume average particle diameter (sphere equivalent average particle diameter) of the positive electrode active material is not particularly limited. For example, it can be 0.1 to 50 μm. In order to make the positive electrode active material have a predetermined particle size, a normal pulverizer or a classifier may be used. The positive electrode active material obtained by the firing method may be used after washing with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent. The volume average particle diameter (sphere equivalent particle diameter) of the positive electrode active material particles can be measured using a laser diffraction / scattering type particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA).

The positive electrode active material may be used alone or in combination of two or more.
When the positive electrode active material layer is formed, the mass (mg) (weight per unit area) of the positive electrode active material per unit area (cm ² ) of the positive electrode active material layer is not particularly limited. It can be determined appropriately according to the designed battery capacity.

  The content of the positive electrode active material in the solid electrolyte composition is not particularly limited, and is preferably 10 to 95% by mass, more preferably 30 to 90% by mass, and further preferably 50 to 85% by mass based on 100% by mass of the solid content. Preferably, 55 to 80% by mass is particularly preferable.

-Negative electrode active material-
The negative electrode active material which the solid electrolyte composition of the present invention may contain is preferably one capable of reversibly inserting and releasing lithium ions. The material is not particularly limited as long as it has the above characteristics, carbonaceous materials, metal oxides such as tin oxide, silicon oxide, metal composite oxides, lithium alone and lithium alloys such as lithium aluminum alloy, and , Sn, Si, Al and In, and other metals that can form an alloy with lithium. Among them, a carbonaceous material or a lithium composite oxide is preferably used from the viewpoint of reliability. Further, as the metal composite oxide, it is preferable that lithium can be inserted and extracted. The material is not particularly limited, but preferably contains titanium and / or lithium from the viewpoint of high current density charge / discharge characteristics.

  The carbonaceous material used as the negative electrode active material is a material substantially composed of carbon. For example, various synthetics such as petroleum pitch, carbon black such as acetylene black (AB), graphite (artificial graphite such as natural graphite and vapor-grown graphite), and PAN (polyacrylonitrile) -based resin and furfuryl alcohol resin. A carbonaceous material obtained by firing a resin can be used. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA (polyvinyl alcohol) -based carbon fiber, lignin carbon fiber, glassy carbon fiber, and activated carbon fiber , Mesophase microspheres, graphite whiskers and flat graphite.

  As the metal oxide and the metal composite oxide applied as the negative electrode active material, an amorphous oxide is particularly preferable, and chalcogenite which is a reaction product of a metal element and an element of Group 16 of the periodic table is also preferably used. Can be The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays having a broad scattering band having an apex in a range of 20 ° to 40 ° in 2θ value, and a crystalline diffraction line. May be provided.

Among the compound group consisting of the above-mentioned amorphous oxide and chalcogenide, an amorphous oxide of a metalloid element and a chalcogenide are more preferable. , Ga, Si, Sn, Ge, Pb, Sb and Bi are particularly preferably oxides composed of one kind alone or a combination of two or more kinds thereof, and chalcogenides. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , _{Sb 2 O 3, Sb 2 O} 4, Sb 2 O 8 Bi 2 O 3, Sb 2 O 8 Si 2 O 3, Bi 2 O 4, SnSiO 3, GeS, SnS, SnS 2, PbS, PbS 2, Sb 2 S ₃ , Sb ₂ S ₅ and SnSiS ₃ are preferred. Further, these may be a composite oxide with lithium oxide, for example, Li ₂ SnO ₂ .

It is also preferable that the negative electrode active material contains a titanium atom. More specifically, Li ₄ Ti ₅ O ₁₂ (lithium titanate [LTO]) is excellent in rapid charge / discharge characteristics due to small volume fluctuation at the time of occlusion and release of lithium ions. This is preferable in that the life of the battery can be improved.

  In the present invention, it is also preferable to use a Si-based negative electrode. Generally, a Si negative electrode can occlude more Li ions than a carbon negative electrode (such as graphite and acetylene black). That is, the storage amount of Li ions per unit mass increases. Therefore, the battery capacity can be increased. As a result, there is an advantage that the battery driving time can be extended.

  The shape of the negative electrode active material is not particularly limited, but is preferably particulate. The average particle diameter of the negative electrode active material is preferably from 0.1 to 60 μm. In order to obtain a predetermined particle size, a usual pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibration ball mill, a satellite ball mill, a planetary ball mill, a swirling air jet mill, a sieve, and the like are suitably used. At the time of pulverization, wet pulverization in the presence of water or an organic solvent such as methanol can also be performed if necessary. Classification is preferably performed to obtain a desired particle size. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be performed both in a dry type and a wet type. The average particle diameter of the negative electrode active material particles can be measured by a method similar to the method for measuring the volume average particle diameter of the positive electrode active material described above.

  The chemical formula of the compound obtained by the above calcination method can be calculated from inductively coupled plasma (ICP) emission spectroscopy as a measuring method, and from the mass difference between powder before and after calcination as a simple method.

The negative electrode active material may be used alone or in combination of two or more.
When forming the negative electrode active material layer, the mass (mg) (basis weight) of the negative electrode active material per unit area (cm ² ) of the negative electrode active material layer is not particularly limited. It can be determined appropriately according to the designed battery capacity.

  The content of the negative electrode active material in the solid electrolyte composition is not particularly limited, and is preferably from 10 to 90% by mass, more preferably from 20 to 80% by mass, based on 100% by mass of the solid content.

The surfaces of the positive electrode active material and the negative electrode active material may be covered with another metal oxide. Examples of the surface coating agent include metal oxides containing Ti, Nb, Ta, W, Zr, Al, Si or Li. Specific examples include titanate spinel, tantalum-based oxide, niobium-based oxide, lithium niobate-based compound, and the like. Specifically, Li ₄ Ti ₅ O ₁₂ , Li ₂ Ti ₂ O ₅ , and LiTaO ₃ , LiNbO ₃ , LiAlO ₂ , Li ₂ ZrO ₃ , Li ₂ WO ₄ , Li ₂ TiO ₃ , Li ₂ B ₄ O ₇ , Li ₃ PO ₄ , Li ₂ MoO ₄ , Li ₃ BO ₃ , LiBO ₂ , Li ₂ CO ₃ , Li ₂ SiO ₃ , SiO ₂ , TiO ₂ , ZrO ₂ , Al ₂ O ₃ , B ₂ O _{3 and the} like.
The surface of the electrode containing the positive electrode active material or the negative electrode active material may be surface-treated with sulfur or phosphorus.
Further, the surface of the particles of the positive electrode active material or the negative electrode active material may be subjected to a surface treatment with an active ray or an active gas (plasma or the like) before and after the surface coating.

(Dispersant)
The solid electrolyte composition of the present invention may contain a dispersant. By adding a dispersant, when the content of either the electrode active material or the inorganic solid electrolyte is large, or when the particle size is small and the surface area increases, the aggregation is suppressed, and a uniform active material layer and solid electrolyte are formed. Layers can be formed. As the dispersant, those commonly used in all solid-state secondary batteries can be appropriately selected and used. Generally, compounds intended for particle adsorption and steric repulsion and / or electrostatic repulsion are preferably used.

(Lithium salt)
The solid electrolyte composition of the present invention may contain a lithium salt.
The lithium salt is not particularly limited, and for example, lithium salts described in paragraphs 0082 to 0085 of JP-A-2015-088486 are preferable.
The content of the lithium salt is preferably 0 parts by mass or more, more preferably 5 parts by mass or more based on 100 parts by mass of the inorganic solid electrolyte. As a maximum, 50 mass parts or less are preferred, and 20 mass parts or less are more preferred.

(Conduction aid)
The solid electrolyte composition of the present invention may contain a conductive aid. There is no particular limitation on the conductive assistant, and a general conductive assistant can be used. For example, electron conductive materials such as graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, Ketjen black, furnace black, amorphous carbon such as needle coke, vapor-grown carbon fibers and carbon nanotubes Carbon fibers such as graphene and fullerene; metal powders such as copper and nickel; metal fibers; and conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and polyphenylene derivatives. May be used. One of these may be used, or two or more of them may be used.

(Preparation of solid electrolyte composition)
The solid electrolyte composition of the present invention can be prepared, for example, by dispersing the inorganic solid electrolyte (A) in the heterocyclic compound (B) and forming a slurry.
The slurry can be formed by mixing the inorganic solid electrolyte (A) and the heterocyclic compound (B) using various mixers. The mixing device is not particularly limited, and examples thereof include a ball mill, a bead mill, a planetary mixer, a blade mixer, a roll mill, a kneader, and a disk mill. The mixing conditions are not particularly limited. For example, when a ball mill is used, mixing is preferably performed at 150 to 700 rpm (rotation per minute) for 1 to 24 hours.
When preparing a solid electrolyte composition containing components such as a dispersion medium (C), a binder, an active material, and a particle dispersant, the solid electrolyte composition may be added and mixed simultaneously with the above-described inorganic solid electrolyte (A) dispersion step. Alternatively, they may be separately added and mixed.

[All-solid secondary battery sheet]
The solid electrolyte-containing sheet of the present invention comprises an inorganic solid electrolyte (A) having ion conductivity of a metal belonging to Group 1 or 2 of the periodic table and the above-mentioned formula (S-0) or (S-1). It has a layer containing the heterocyclic compound (B) represented by 1 ppm or more and 10000 ppm or less based on the total mass.

  The solid electrolyte-containing sheet of the present invention can be suitably used for an all-solid secondary battery, and includes various embodiments depending on the use. For example, a sheet preferably used for a solid electrolyte layer (also referred to as a solid electrolyte sheet for an all-solid secondary battery), a sheet preferably used for an electrode or a laminate of an electrode and a solid electrolyte layer (an electrode sheet for an all-solid secondary battery) And the like. In the present invention, these various sheets may be collectively referred to as an all-solid secondary battery sheet.

The sheet for an all-solid secondary battery is a sheet having a solid electrolyte layer or an active material layer (electrode layer), such as a sheet having a solid electrolyte layer or an active material layer (electrode layer) on a substrate. . The sheet for an all-solid secondary battery may have other layers as long as it has a base material and a solid electrolyte layer or an active material layer. It is classified as an electrode sheet for the next battery. Examples of the other layers include a protective layer, a current collector, a coat layer (a current collector, a solid electrolyte layer, and an active material layer).
Examples of the solid electrolyte sheet for an all-solid secondary battery include a sheet having a solid electrolyte layer and a protective layer on a base material in this order.
The substrate is not particularly limited as long as it can support the solid electrolyte layer, and examples thereof include the materials described below for the current collector, and sheets (plates) such as organic materials and inorganic materials. Examples of the organic material include various polymers, and specifically, polyethylene terephthalate, polypropylene, polyethylene, cellulose, and the like. Examples of the inorganic material include glass and ceramic.

The layer thickness of the solid electrolyte layer of the sheet for an all-solid secondary battery is the same as the layer thickness of the solid electrolyte layer described in the above-described all-solid secondary battery of the present invention.
This sheet is obtained by forming (coating and drying) the solid electrolyte composition of the present invention on a base material (which may be through another layer) and forming a solid electrolyte layer on the base material. Can be
Here, the solid electrolyte composition of the present invention can be prepared by the above method.

The electrode sheet for an all-solid-state secondary battery of the present invention (also simply referred to as “electrode sheet”) is an electrode sheet having an active material layer on a metal foil as a current collector. This electrode sheet is usually a sheet having a current collector and an active material layer. However, an embodiment having a current collector, an active material layer and a solid electrolyte layer in this order, and a current collector, an active material layer, and a solid electrolyte An embodiment having a layer and an active material layer in this order is also included.
The layer thickness of each layer constituting the electrode sheet is the same as the above-described layer thickness of the all-solid secondary battery of the present invention.
The electrode sheet is obtained by forming a solid electrolyte composition containing the active material of the present invention on a metal foil (coating and drying) to form an active material layer on the metal foil. The method for preparing the solid electrolyte composition containing the active material is the same as the method for preparing the solid electrolyte composition, except that the active material is used.

[All-solid secondary battery]
The all solid state secondary battery of the present invention has a positive electrode, a negative electrode facing the positive electrode, and a solid electrolyte layer between the positive electrode and the negative electrode. The positive electrode has a positive electrode active material layer on a positive electrode current collector. The negative electrode has a negative electrode active material layer on a negative electrode current collector.
At least one of the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer is preferably formed using the solid electrolyte composition of the present invention.
The active material layer and / or the solid electrolyte layer formed of the solid electrolyte composition are preferably the same as those in the solid content of the solid electrolyte composition with respect to the contained component species and the content ratio thereof.
Hereinafter, a preferred embodiment of the present invention using polymer particles will be described with reference to FIG. 1, but the present invention is not limited to this.

(Positive electrode active material layer, solid electrolyte layer, negative electrode active material layer)
In the all-solid secondary battery 10, one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is formed using the solid electrolyte composition of the present invention.
That is, when the solid electrolyte layer 3 is formed of the solid electrolyte composition including the polymer particles of the present invention, the solid electrolyte layer 3 includes the inorganic solid electrolyte, the polymer particles, and the formula (S-0) or ( It contains 1 to 10,000 ppm of the heterocyclic compound (B) represented by S-1) in the total mass. The solid electrolyte layer usually does not contain a positive electrode active material and / or a negative electrode active material. In the solid electrolyte layer 3, it is considered that the polymer particles exist between the inorganic solid electrolyte and the solid particles such as the active material contained in the adjacent active material layer. Therefore, the interfacial resistance between the solid particles is reduced, and the binding property is increased.

When the positive electrode active material layer 4 and / or the negative electrode active material layer 2 are formed using the solid electrolyte composition including the polymer particles of the present invention, the positive electrode active material layer 4 and the negative electrode active material layer 2 It contains a positive electrode active material or a negative electrode active material, and further contains an inorganic solid electrolyte, polymer particles, and a heterocyclic compound (B) represented by the above formula (S-0) or (S-1) in an amount of 1 ppm or more based on the total mass. 10000 ppm or less. When the active material layer contains an inorganic solid electrolyte, ionic conductivity can be improved. It is considered that polymer particles exist between the solid particles in the active material layer. Therefore, the interfacial resistance between the solid particles is reduced, and the binding property is increased.
The inorganic solid electrolyte and the polymer particles contained in the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 may be the same or different from each other.

  In the present invention, any one of the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer in the all-solid secondary battery includes the inorganic solid electrolyte and the above formula (S-0) or (S-1). It is produced using a solid electrolyte composition containing the heterocyclic compound (B) represented by For this reason, the binding property between solid particles can be improved, and as a result, good cycle characteristics in an all-solid secondary battery can also be realized.

[Current collector (metal foil)]
The positive electrode current collector 5 and the negative electrode current collector 1 are preferably electronic conductors.
In the present invention, one or both of the positive electrode current collector and the negative electrode current collector may be simply referred to as a current collector.
Materials for forming the positive electrode current collector include, in addition to aluminum, aluminum alloy, stainless steel, nickel and titanium, etc., a material obtained by treating the surface of aluminum or stainless steel with carbon, nickel, titanium or silver (forming a thin film). Are preferred, and among them, aluminum, stainless steel and aluminum alloy are more preferred.
Aluminum, copper, copper alloy, stainless steel, nickel and titanium, etc., as well as aluminum, copper, copper alloy or stainless steel surface treated with carbon, nickel, titanium or silver Preferably, aluminum, copper, copper alloy and stainless steel are more preferred.

As the shape of the current collector, a film sheet is usually used, but a net, a punched material, a lath, a porous material, a foam, a molded product of a fiber group, and the like can also be used.
The thickness of the current collector is not particularly limited, but is preferably 1 to 500 μm. In addition, it is preferable that the surface of the current collector be provided with irregularities by surface treatment.

  In the present invention, between or outside each layer of the negative electrode current collector, the negative electrode active material layer, the solid electrolyte layer, the positive electrode active material layer and the positive electrode current collector, a functional layer or member is appropriately interposed or provided. May be. Each layer may be composed of a single layer, or may be composed of multiple layers.

(Housing)
The basic structure of the all-solid secondary battery can be manufactured by arranging the above layers. Depending on the application, the battery may be used as it is as an all-solid secondary battery, but in order to form a dry battery, it is further sealed in an appropriate housing. The housing may be made of metal or resin (plastic). When a metallic material is used, for example, a material made of an aluminum alloy or stainless steel can be used. It is preferable that the metallic casing is divided into a casing on the positive electrode side and a casing on the negative electrode side, and electrically connected to the positive electrode current collector and the negative electrode current collector, respectively. It is preferable that the housing on the positive electrode side and the housing on the negative electrode side are joined and integrated via a gasket for preventing short circuit.

[Production of sheet containing solid electrolyte]
In the solid electrolyte-containing sheet of the present invention, the solid electrolyte composition of the present invention is formed (coated and dried) on a substrate (which may be through another layer), and the solid electrolyte layer or active layer is formed on the substrate. It is obtained by forming a substance layer (coating dried layer).
According to the above aspect, a sheet for an all-solid secondary battery that is a sheet having a substrate and a coating and drying layer can be produced. Here, the applied dry layer refers to a layer formed by applying the solid electrolyte composition of the present invention and drying the heterocyclic compound (B) and the dispersion medium (C).
In addition, for the steps of coating and the like, the method described in the production of an all-solid secondary battery below can be used.

The content of the heterocyclic compound (B) in the solid electrolyte-containing sheet of the present invention can be measured by the following method.
The solid electrolyte-containing sheet is punched out in a 20 mm square, and immersed in heavy tetrahydrofuran in a glass bottle. The eluate obtained is filtered through a syringe filter and quantitatively operated by gas chromatography. The correlation between the peak area of gas chromatography and the amount of solvent is determined by preparing a calibration curve.

[Manufacture of all-solid secondary battery and electrode sheet for all-solid secondary battery]
The production of the all-solid secondary battery and the electrode sheet for the all-solid secondary battery can be performed by a conventional method. Specifically, an all-solid secondary battery and an electrode sheet for an all-solid secondary battery can be manufactured by forming each of the above layers using the solid electrolyte composition of the present invention and the like. The details will be described below.

The all-solid-state secondary battery of the present invention is manufactured by a method including a step of applying the solid electrolyte composition of the present invention on a metal foil serving as a current collector and forming (forming) a coating film. it can.
For example, a solid electrolyte composition containing a positive electrode active material is applied as a positive electrode material (a positive electrode composition) on a metal foil serving as a positive electrode current collector to form a positive electrode active material layer, and an all-solid secondary A positive electrode sheet for a battery is prepared. Next, a solid electrolyte composition for forming a solid electrolyte layer is applied on the positive electrode active material layer to form a solid electrolyte layer. Further, a solid electrolyte composition containing a negative electrode active material is applied as a negative electrode material (a negative electrode composition) on the solid electrolyte layer to form a negative electrode active material layer. Obtaining an all-solid secondary battery with a structure in which a solid electrolyte layer is sandwiched between a positive electrode active material layer and a negative electrode active material layer by stacking a negative electrode current collector (metal foil) on the negative electrode active material layer Can be. If necessary, this can be sealed in a housing to obtain a desired all-solid secondary battery.
In addition, by reversing the method of forming each layer, a negative electrode active material layer, a solid electrolyte layer, and a positive electrode active material layer are formed on the negative electrode current collector, and the positive electrode current collector is stacked to manufacture an all-solid secondary battery. You can also.

Another method is as follows. That is, a positive electrode sheet for an all-solid secondary battery is prepared as described above. In addition, a solid electrolyte composition containing a negative electrode active material is applied as a negative electrode material (a negative electrode composition) on a metal foil serving as a negative electrode current collector to form a negative electrode active material layer. A negative electrode sheet for a battery is produced. Next, a solid electrolyte layer is formed on one of the active material layers of these sheets as described above. Further, the other of the positive electrode sheet for an all-solid secondary battery and the negative electrode sheet for an all-solid secondary battery is laminated on the solid electrolyte layer such that the solid electrolyte layer and the active material layer are in contact with each other. Thus, an all-solid secondary battery can be manufactured.
Another method is as follows. That is, a positive electrode sheet for an all-solid secondary battery and a negative electrode sheet for an all-solid secondary battery are prepared as described above. Separately from this, a solid electrolyte composition is applied on a substrate to produce a solid electrolyte sheet for an all-solid secondary battery comprising a solid electrolyte layer. Further, the positive electrode sheet for an all-solid secondary battery and the negative electrode sheet for an all-solid secondary battery are laminated so as to sandwich the solid electrolyte layer peeled off from the base material. Thus, an all-solid secondary battery can be manufactured.

  An all-solid secondary battery can also be manufactured by a combination of the above forming methods. For example, as described above, a positive electrode sheet for an all-solid secondary battery, a negative electrode sheet for an all-solid secondary battery, and a solid electrolyte sheet for an all-solid secondary battery are respectively produced. Next, on the negative electrode sheet for an all-solid secondary battery, after laminating the solid electrolyte layer peeled from the substrate, it is possible to produce an all-solid secondary battery by bonding the positive electrode sheet for the all-solid secondary battery. it can. In this method, the solid electrolyte layer may be laminated on the positive electrode sheet for an all-solid secondary battery, and bonded to the negative electrode sheet for an all-solid secondary battery.

(Formation of each layer (film formation))
The method for applying the solid electrolyte composition is not particularly limited, and can be appropriately selected. Examples include coating (preferably wet coating), spray coating, spin coating, dip coating, slit coating, stripe coating, and bar coating.
At this time, the solid electrolyte composition may be subjected to a drying treatment after each application, or may be subjected to a drying treatment after multi-layer application. The drying temperature is not particularly limited. The lower limit is preferably at least 30 ° C, more preferably at least 60 ° C, even more preferably at least 80 ° C. The upper limit is preferably 300 ° C. or lower, more preferably 250 ° C. or lower, and further preferably 200 ° C. or lower. By heating in such a temperature range, the dispersion medium can be removed and a solid state can be obtained. Further, it is preferable because the temperature is not set too high and each member of the all solid state secondary battery is not damaged. Thereby, in the all-solid secondary battery, excellent overall performance can be exhibited and good binding properties can be obtained.

After preparing the applied solid electrolyte composition or the all-solid secondary battery, it is preferable to pressurize each layer or the all-solid secondary battery. It is also preferable to apply pressure in a state where the respective layers are stacked. Examples of the pressurizing method include a hydraulic cylinder press. The pressure is not particularly limited, and is generally preferably in the range of 50 to 1500 MPa.
Further, the applied solid electrolyte composition may be heated simultaneously with pressurization. The heating temperature is not particularly limited, and is generally in the range of 30 to 300 ° C. Pressing can be performed at a temperature higher than the glass transition temperature of the inorganic solid electrolyte.
Pressurization may be performed in a state where the coating solvent or the dispersion medium is dried in advance, or may be performed in a state where the solvent or the dispersion medium remains.
In addition, each composition may be applied simultaneously, and the application and drying press may be performed simultaneously and / or sequentially. After coating on separate substrates, they may be laminated by transfer.

The atmosphere during pressurization is not particularly limited, and may be any of air, dry air (dew point −20 ° C. or lower), and inert gas (for example, argon gas, helium gas, and nitrogen gas).
As for the pressing time, a high pressure may be applied in a short time (for example, within several hours), or a medium pressure may be applied for a long time (one day or more). In the case of an all-solid secondary battery other than the all-solid secondary battery sheet, for example, in the case of an all-solid secondary battery, an all-solid secondary battery restraint (such as a screw tightening pressure) can be used to keep applying a moderate pressure.
The pressing pressure may be uniform or different with respect to a pressure-receiving portion such as a sheet surface.
The pressing pressure can be changed according to the area and the film thickness of the pressure-receiving part. The same part can be changed stepwise with different pressures.
The press surface may be smooth or rough.

(Initialization)
It is preferable that the all-solid-state secondary battery manufactured as described above be initialized after manufacturing or before use. The initialization is not particularly limited. For example, the initialization can be performed by performing initial charge and discharge in a state where the press pressure is increased, and then releasing the pressure until the general use pressure of the all solid state secondary battery is reached.

[Use of all-solid-state secondary battery]
The all solid state secondary battery of the present invention can be applied to various uses. Although there is no particular limitation on the application mode, for example, when mounted on an electronic device, for example, a notebook computer, a pen input computer, a mobile computer, an electronic book player, a mobile phone, a cordless phone handset, a pager, a handy terminal, a mobile fax, and a mobile phone Copy, portable printer, headphone stereo, video movie, LCD television, handy cleaner, portable CD, mini disk, electric shaver, transceiver, electronic organizer, calculator, portable tape recorder, radio, backup power supply, memory card, and the like. Other consumer applications include automobiles (electric vehicles, etc.), electric vehicles, motors, lighting fixtures, toys, game machines, road conditioners, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder massagers, etc.). . Furthermore, it can be used for various military purposes and space applications. Further, it can be combined with a solar cell.

According to the preferred embodiment of the present invention, the following applications are derived.
[1] An all-solid secondary battery in which at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer contains a lithium salt.
[2] An all-solid secondary battery in which a solid electrolyte layer is formed by wet coating a slurry in which a lithium salt and a sulfide-based inorganic solid electrolyte are dispersed with a heterocyclic compound (B) and a dispersion medium (C) to form a film. Production method.
[3] A solid electrolyte composition containing an active material for producing an all-solid secondary battery.
[4] An electrode sheet for a battery formed by applying the solid electrolyte composition on a metal foil and forming a film.
[5] A method for producing a battery electrode sheet in which the solid electrolyte composition is applied on a metal foil to form a film.

  As described in the above preferred embodiments [2] and [5], the preferred methods for producing the all-solid secondary battery and the battery electrode sheet of the present invention are both wet processes. Thereby, even in a region where the content of the inorganic solid electrolyte in at least one of the positive electrode active material layer and the negative electrode active material layer is as low as 10% by mass or less, the adhesion between the active material and the inorganic solid electrolyte is increased, and an efficient ion conduction path is provided. , And an all-solid-state secondary battery having a high energy density per battery mass (Wh / kg) and a high power density (W / kg) can be manufactured.

The all-solid-state secondary battery refers to a secondary battery in which the positive electrode, the negative electrode, and the electrolyte are all solid. In other words, it is distinguished from an electrolyte type secondary battery using a carbonate-based solvent as an electrolyte. Among them, the present invention is based on an inorganic all-solid secondary battery. The all-solid-state secondary battery includes an organic (polymer) all-solid-state secondary battery using a polymer compound such as polyethylene oxide as an electrolyte, and an inorganic all-solid-state battery using the above-described Li-PS-based glass, LLT, or LLZ. It is classified into secondary batteries. Note that application of an organic compound to an inorganic all-solid secondary battery is not hindered, and an organic compound can be used as a binder or an additive for a positive electrode active material, a negative electrode active material, and an inorganic solid electrolyte.
An inorganic solid electrolyte is distinguished from an electrolyte (polymer electrolyte) using the above-described polymer compound as an ion conductive medium, and an inorganic compound serves as an ion conductive medium. Specific examples include the above-mentioned Li-PS-based glass, LLT and LLZ. The inorganic solid electrolyte does not emit cations (Li ions) per se, but exhibits an ion transport function. On the other hand, a material serving as a supply source of ions that release cations (Li ions) by being added to the electrolyte or the solid electrolyte layer may be referred to as an electrolyte. This is referred to as an “electrolyte salt” or a “supporting electrolyte” when distinguishing it from the electrolyte as the ion transport material described above. Examples of the electrolyte salt include LiTFSI.
In the present invention, the term “composition” means a mixture in which two or more components are uniformly mixed. However, it is sufficient that substantially uniformity is maintained, and aggregation or uneven distribution may occur in a part as long as a desired effect is obtained.

  Hereinafter, the present invention will be described in more detail based on examples. It should be noted that the present invention is not construed as being limited thereto. In the following examples, “parts” and “%” representing compositions are based on mass unless otherwise specified. Further, "-" used in the table means that the composition in the row is not contained.

[Examples and Comparative Examples]
<Synthesis of Binder B-1 (Preparation of Binder B-1 Dispersion)>
Heptane (200 parts by mass) was added to a 1-L three-necked flask equipped with a reflux condenser and a gas introduction cock, nitrogen gas was introduced at a flow rate of 200 mL / min for 10 minutes, and then the temperature was raised to 80 ° C. To this, 150 parts by mass of a liquid prepared in a separate container (ethyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.), methacryloylated poly-n-butyl acrylate oligomer at one end (mass average molecular weight: 13,000, trade name: AB) -6, a liquid obtained by mixing 60 parts by mass (solid content) of Toa Gosei Chemical Industry Co., Ltd. and 2.0 parts by mass of a polymerization initiator V-601 (trade name, manufactured by Wako Pure Chemical Industries) at 30 ° C. for 1 hour. ) Was added dropwise over 2 hours, and the mixture was stirred at 80 ° C for 2 hours. Thereafter, 1.0 g of V-601 was added to the obtained mixture, and the mixture was further stirred at 90 ° C for 2 hours. By diluting the obtained solution with heptane, a dispersion of a binder B-1 as polymer particles was obtained. The solid concentration was 34.8%, and the mass average molecular weight was 123,000.

-Measurement method-
<Method of measuring solid content>
The solid concentration of the dispersion of the binder B-1 was measured based on the following method.
About 1.5 g of the dispersion liquid of the binder B-1 was weighed in an aluminum cup having a diameter of 7 cmΦ, and the weighed value to the third decimal place was read. Subsequently, it was heated and dried at 90 ° C. for 2 hours and subsequently at 140 ° C. for 2 hours under a nitrogen atmosphere. The mass of the residue in the obtained aluminum cup was measured, and the solid content concentration was calculated by the following equation. The measurement was performed five times, and the average of three times except for the maximum value and the minimum value was adopted.
Solid content concentration (%) = Amount of residue in aluminum cup (g) / dispersion of binder B-1 (g)

<Synthesis of sulfide-based inorganic solid electrolyte>
As a sulfide-based inorganic solid electrolyte, T.I. Ohtomo, A .; Hayashi, M .; Tatsusumisago, Y .; Tsuchida, S .; HamGa, K .; Kawamoto, Journal of Power Sources, 233, (2013), pp. 231-235 and A.I. Hayashi, S .; Hama, H .; Morimoto, M .; Tatsusumisago, T .; Minami, Chem. Lett. , (2001), pp872-873, a Li-PS-based glass was synthesized.

Specifically, in a glove box under an argon atmosphere (dew point -70 ° C.), 2.42 g of lithium sulfide (Li ₂ S, manufactured by Aldrich, purity> 99.98%) and diphosphorus pentasulfide (P ₂ S) 3.90 g ( ₅ , Aldrich, purity> 99%) were weighed and placed in a mortar. Li ₂ S and P ₂ S ₅ were in a molar ratio of Li ₂ S: P ₂ S ₅ = 75: 25. On an agate mortar, mixing was performed for 5 minutes using an agate pestle.
66 g of zirconia beads having a diameter of 5 mm were charged into a 45-mL zirconia container (manufactured by Fritsch), the entire mixture was charged, and the container was sealed under an argon atmosphere. A container was set on a planetary ball mill P-7 (trade name) manufactured by Fritsch Co., Ltd., and mechanical milling was performed at 25 ° C. and a rotation speed of 510 rpm for 20 hours to obtain a yellow powdered sulfide-based inorganic solid electrolyte (Li-PS). (Based glass Li ₃ PS ₄ , also referred to as “LPS”) 6.20 g was obtained. The volume average particle size was 15 μm.

<Preparation of solid electrolyte composition S-1>
180 zirconia beads having a diameter of 5 mm were charged into a 45 mL zirconia container (manufactured by Fritsch), and 4.95 g of the LPS synthesized above and the binder B-1 dispersion were mixed with a binder B-1 (solid component mass) of 0.25 g / ml. The heterocyclic compound (B) was added in such an amount that the total mass with the heptane of the dispersion liquid of the binder B-1 was 17.0 g. Thereafter, the container was set in a planetary ball mill P-7 manufactured by Fritsch Co., and mixing was continued at a temperature of 25 ° C. and a rotation speed of 300 rpm for 2 hours to obtain a solid electrolyte composition S-1.

Solid electrolyte compositions S-2 to S-11, S-13, S-14, and S-18 are manufactured in the same manner as in the solid electrolyte composition S-1 except that the compositions are changed to those shown in Table 1 below. ~ S-21 and T-1 to T-3 were prepared. In addition, about the dispersion medium (C), it added so that it might become the mass ratio of Table 1.

LPS: Sulfide-based inorganic solid electrolyte synthesized above B-1: Binder synthesized above B-2: Hydrogenated styrene-butadiene rubber (trade name: DYNARON1321P manufactured by JSR) [Non-particulate in the composition. ]
2,5-dimethyl THF: 2,5-dimethyl tetrahydrofuran 2-methyl THF: 2-methyl tetrahydrofuran 2,5-dimethoxy THF: 2,5-dimethoxy tetrahydrofuran TBA: tri-n-butylamine mass ratio: heterocyclic compound (B) And the ratio of dispersion medium (C) (mass of heterocyclic compound (B): mass of dispersion medium (C))
The dispersion medium contained a total of 17.0 g of any of the solid electrolyte compositions.
In addition, heptane (*) represents heptane derived from the dispersion liquid of the binder B-1. No. Heptane of the solid electrolyte composition of S-5 was the same as heptane derived from the binder dispersion, It represents the total amount of heptane charged during the preparation of the solid electrolyte composition of S-5. The composition of S-6,9~ 11, 1 4 Contact and 19 is similar.

<Method of measuring viscosity of dispersion medium (C)>
The viscosity of the dispersion medium (C) was measured by measuring at 30 ° C. using an Ubbelohde viscometer (trade name: Ubbelohde viscometer number 2, manufactured by Kusano Chemical Co., Ltd.).

<Evaluation of dispersion stability (settling property)>
The solid electrolyte composition was added to a glass test tube having a diameter of 10 mmΦ and a height of 8 cm up to a height of 6 cm, allowed to stand at 25 ° C. for 1 hour, and then measured for the height of the separated supernatant. evaluated. The evaluation criterion “3” or more passes. The results are shown in Table 2 below.
-Evaluation criteria-
5: supernatant height / total height <0.07
4: 0.07 ≦ height of supernatant / height of total volume <0.15
3: 0.15 ≦ supernatant height / total height <0.3
2: 0.3 ≦ height of supernatant / height of total volume <0.5
1: 0.5 ≦ the height of the supernatant / the height of the total amount [total amount: the total amount of the solid electrolyte composition as a slurry, and the supernatant: the supernatant liquid generated by the solid components of the solid electrolyte composition settling out]

(Example of manufacturing solid electrolyte sheet for all-solid secondary battery)
Each of the solid electrolyte compositions obtained above was applied on an aluminum foil having a thickness of 20 μm using an applicator (trade name: SA-201 Baker type applicator, manufactured by Tester Sangyo Co., Ltd.), and heated at 80 ° C. for 2 hours to obtain a solid electrolyte. The composition was dried. Thereafter, the dried solid electrolyte composition was heated and pressed at a temperature of 120 ° C. and a pressure of 600 MPa for 10 seconds using a heat press machine, and the solid electrolyte sheet No. for each all-solid-state secondary battery was heated. 101 to 111, 113, 114, 118 to 121 and c11 to c13 were obtained. The thickness of the solid electrolyte layer was 100 μm.
The following tests were performed on the prepared solid electrolyte sheet for an all-solid secondary battery, and the results are shown in Table 2 below. In Table 2, in the solid electrolyte sheet No. for the all solid state secondary battery, Of the sheet No. It is described.

<Measurement of ionic conductivity>
The solid electrolyte sheet for an all-solid secondary battery obtained above was cut into a disc shape having a diameter of 14.5 mm, and the solid electrolyte sheet 12 for an all-solid secondary battery was placed in a 2032 type coin case 11 shown in FIG. . Specifically, an aluminum foil (not shown in FIG. 2) cut into a disk shape having a diameter of 15 mm is brought into contact with the solid electrolyte layer, and a spacer and a washer (both not shown in FIG. 2) are incorporated. It was put in the coin case 11. By crimping the 2032 type coin case 11, a jig 13 for measuring ion conductivity was produced.

The ionic conductivity was measured using the ionic conductivity measuring jig obtained above. Specifically, in a 30 ° C. constant temperature bath, AC impedance was measured at a voltage amplitude of 5 mV and a frequency of 1 MHz to 1 Hz using 1255B FREQUENCY RESPONSE ANALYZER (trade name) manufactured by SOLARTRON. Thus, the resistance in the film thickness direction of the sample was obtained and calculated by the following equation (1). The evaluation criterion “3” or more passes. The results are shown in Table 2 below.
Ion conductivity (mS / cm) =
1000 × sample thickness (cm) / (resistance (Ω) × sample area (cm ² )) formula (1)
-Evaluation criteria-
5: 0.4 mS / cm or more 4: 0.3 mS / cm or more and less than 0.4 mS / cm 3: 0.2 mS / cm or more and less than 0.3 mS / cm 2: 0.1 mS / cm or more and less than 0.2 mS / cm 1: Less than 0.1 mS / cm

<Evaluation of binding property>
A solid electrolyte sheet for an all-solid secondary battery is cut into a disk having a diameter of 15 mm, and the surface portion (observation area 500 μm × 500 μm) of the solid electrolyte layer in the cut sheet is inspected by an optical microscope for inspection (Eclipse Ci (trade name), Nikon And the presence or absence of cracks, cracks, and cracks in the solid electrolyte layer, and the presence or absence of peeling of the solid electrolyte layer from the aluminum foil (current collector) were evaluated according to the following evaluation criteria. Evaluation criteria "2" or higher are passed. The results are shown in Table 2 below.
-Evaluation criteria-
5: No defect (chip, crack, crack, peeling) was observed.
4: The area of the defective portion is more than 0% and not more than 20% of the total area to be observed. 3: The area of the defective portion is more than 20% and not more than 40% of the entire area to be observed. Is more than 40% and less than 70% of the total area to be observed 1: The area of the defective portion is more than 70% of the total area to be observed

As is clear from Table 2, the solid electrolyte compositions that do not satisfy the requirements of the present invention failed in dispersion stability. In addition, the solid electrolyte sheet for an all-solid secondary battery formed from the solid electrolyte composition not satisfying the requirements of the present invention failed the binding property. The inorganic solid electrolyte has low solubility in THF. It is considered that the binding property was unacceptable in c13. In addition, No. In c11 and c13, the ionic conductivity was rejected.
In contrast, all of the solid electrolyte compositions of the present invention were excellent in dispersion stability. The solid electrolyte sheet for an all-solid secondary battery formed using the solid electrolyte composition of the present invention passed the ionic conductivity and the binding property.

<Preparation of positive electrode composition U-1>
180 zirconia beads having a diameter of 5 mm are put into a 45-mL zirconia container (manufactured by Fritsch), 2.9 g of LPS, 0.1 g of binder B-1 dispersion liquid, and 0.1 g of binder B-1 (solid component mass). The heterocyclic compound (B) was added in such an amount that the total mass of the binder B-1 dispersion and heptane was 22 g. Thereafter, the container was set in a planetary ball mill P-7 (trade name) manufactured by Fritsch, and the mixture was stirred at 25 ° C. at 300 rpm for 2 hours. Thereafter, 7.0 g of NMC (manufactured by Nippon Chemical Industry Co., Ltd.) was charged as an active material, and similarly, a container was set in a planetary ball mill P-7, and mixing was continued for 15 minutes at 25 ° C. and a rotation speed of 100 rpm to obtain a positive electrode composition. The product U-1 was obtained.

  Positive electrode compositions U-2 to U-11 and V-1 to V-3 were prepared in the same manner as in the positive electrode composition U-1, except that the composition was changed to the composition shown in Table 3 below.

<Notes in the table>
NMC: LiNi _1/3 Co _1/3 Mn _1/3 O ₂ (lithium nickel manganese cobaltate)
LPS: Sulfide-based inorganic solid electrolyte synthesized above B-1: Binder synthesized above B-2: Hydrogenated styrene-butadiene rubber (DYNARON1321P manufactured by JSR)
2,5-dimethyl THF: 2,5-dimethyl tetrahydrofuran 2-methyl THF: 2-methyl tetrahydrofuran TBA: tri-n-butylamine mass ratio: ratio of heterocyclic compound (B) to dispersion medium (C) (heterocyclic compound (B) mass: Dispersion medium (C) mass)
The dispersion medium contained a total of 22 g of any of the solid electrolyte compositions.

<Preparation of positive electrode sheet for all-solid secondary battery>
The composition U-1 for a positive electrode obtained above was applied on a 20-μm-thick aluminum foil using a baker-type applicator (trade name: SA-201, manufactured by Tester Sangyo Co., Ltd.), and heated at 80 ° C. for 2 hours to prepare a composition for a positive electrode. The material was dried. Thereafter, the dried positive electrode composition U-1 was heated (80 ° C.) while applying pressure (600 MPa, 1 minute) using a heat press machine to obtain an all-solid two-layer material having a positive electrode active material layer having a thickness of 80 μm. A positive electrode sheet for a secondary battery was prepared.
Next, the solid electrolyte composition S-1 was applied on the obtained positive electrode active material layer using the above-mentioned baker-type applicator, and heated at 80 ° C. for 2 hours to dry the solid electrolyte composition. Thereafter, using a heat press, the dried solid electrolyte composition S-1 was heated (80 ° C.) and pressurized (600 MPa, 10 seconds) to form an all-solid electrolyte having a 30 μm-thick solid electrolyte layer. A positive electrode sheet for a secondary battery was prepared.

<Preparation of all solid state secondary battery>
The positive electrode sheet for an all-solid secondary battery obtained above was cut into a disk shape having a diameter of 14.5 mm, placed in a stainless steel 2032 type coin case 11 incorporating a spacer and a washer, and cut into 15 mmφ on the solid electrolyte layer. Stacked indium foil. After further laminating a stainless steel foil thereon, the 2032 type coin case 11 is swaged to form an all solid secondary battery No. shown in FIG. 201 was produced.
The all-solid-state secondary battery manufactured as described above has a layer configuration shown in FIG.
All solid-state secondary batteries No. 1 and 2 except that the compositions for forming the positive electrode active material layer and the solid electrolyte layer were respectively changed to the compositions shown in Table 4 below. In the same manner as in No. 201, the all solid state secondary battery No. 202 to 211 and c21 to c23 were produced.

<Evaluation of resistance>
The resistance of the all-solid secondary battery obtained above was evaluated using a charge / discharge evaluation device TOSCAT-3000 (trade name) manufactured by Toyo System Co., Ltd. Charging was performed at a current density of 0.1 mA / cm ² until the battery voltage reached 3.6 V. The discharge was performed at a current density of 0.2 mA / cm ² until the battery voltage reached 2.5 V. This was repeated, and the battery voltage after the discharge of 5 mAh / g (electric quantity per 1 g of active material mass) at the third cycle was read according to the following criteria to evaluate the resistance. The higher the battery voltage, the lower the resistance. The evaluation criterion “3” or more passes. The results are shown in Table 4 below.

<Evaluation criteria>
5: 3.4 V or more 4: 3.2 V or more and less than 3.4 V 3: 2.9 V or more and less than 3.2 V 2: Less than 2.9 V 1: Cannot be charged and discharged

<Evaluation of discharge capacity retention rate (cycle characteristics)>
The discharge capacity retention rate of the all-solid secondary battery obtained above was measured using a charge / discharge evaluation device TOSCAT-3000 (trade name) manufactured by Toyo System Corporation. Charging was performed at a current density of 0.1 mA / cm ² until the battery voltage reached 3.6 V. The discharge was performed at a current density of 0.1 mA / cm ² until the battery voltage reached 2.5 V. Initialization was performed by repeating charge and discharge for three cycles under the above conditions. The discharge capacity in the first cycle after the initialization was set to 100%, and the number of cycles when the discharge capacity retention ratio reached 80% was evaluated based on the following criteria. The evaluation criterion “3” or more passes. The results are shown in Table 4 below.
6: 300 cycles or more 5: 180 cycles or more and less than 300 cycles 4: 100 cycles or more and less than 180 cycles 3: 60 cycles or more and less than 100 cycles 2: 20 cycles or more and less than 60 cycles 1: less than 20 cycles

<Notes in the table>
Dispersion stability: Shows the dispersion stability of the positive electrode composition.
The negative electrode layer is an indium foil.

  The content of the heterocyclic compound (B) in the sheets constituting each layer was 1 ppm or more and 10000 ppm or less based on the total mass of all the sheets. Note that the content ratio was measured by the above-described method.

As is clear from Table 4, No. 1 does not satisfy the requirements of the present invention. Each of the positive electrode compositions V-1 to V-3 failed the dispersion stability. In addition, the positive electrode layer and the solid electrolyte layer were formed using the positive electrode composition and the solid electrolyte composition that did not satisfy the requirements of the present invention. The cycle characteristics of the all solid state secondary batteries c21 to c23 were rejected.
On the other hand, No. 1 satisfying the requirements of the present invention. All of the compositions for positive electrodes of U-1 to 6, 8, and 9 were excellent in dispersion stability. Further, the positive electrode layer and the solid electrolyte layer were formed using the positive electrode composition and the solid electrolyte composition satisfying the requirements of the present invention. All of the solid-state secondary batteries 201 to 206, 208, and 209 had acceptable levels of resistance and cycle characteristics.
In particular, no. From the results of 203 and 207, in the heterocyclic compound (B) represented by the formula (S-0), the resistance was further suppressed by having a substituent on two of the heterocyclic constituent atoms bonded to the heteroatom, and It can be seen that the characteristics have been further improved. In addition, No. From the results of 208 and 210, in the heterocyclic compound (B) represented by the formula (S-1), the resistance is more suppressed by having a substituent on two of the heterocyclic constituent atoms bonded to the heteroatoms, and It can be seen that the characteristics have been further improved.
In addition, No. No. 209 for the all solid state secondary battery. The result of the all-solid-state secondary battery of No. 208 was excellent because the heterocyclic compound (B) represented by the formula (S-1) had a methyl group contained in the heterocyclic constituent atom bonded to the heteroatom more than a chlorine atom. This is considered to be due to low reactivity with the inorganic solid electrolyte.

Sheet No. of Table 2 In the solid electrolyte compositions 101 to 111, 113 and 114 , tests were carried out in the same manner except that Li _0.33 La _0.55 TiO ₃ was used instead of LPS. As a result, it was confirmed that excellent performance was exhibited.
In addition, except that Li _0.33 La _0.55 TiO ₃ was used instead of LPS, the battery Nos. It was confirmed that the manufactured all-solid-state secondary battery exhibited excellent performance in the same manner as the all-solid-state secondary batteries 201 to 211.

DESCRIPTION OF SYMBOLS 1 Negative electrode current collector 2 Negative electrode active material layer 3 Solid electrolyte layer 4 Positive electrode active material layer 5 Positive electrode collector 6 Working part 10 All solid secondary battery 11 2032 type coin case 12 Sheet for all solid secondary battery 13 Ion conductivity Measurement jig or all-solid secondary battery

Claims (14)

An inorganic solid electrolyte (A) having ion conductivity of a metal belonging to Group 1 or 2 of the periodic table; and a heterocyclic compound (B) represented by the following formula (S-0) or (S-1) ) And a dispersion medium (C) having a LogP value of 2.0 or more, wherein the dispersion medium (C) is a ketone compound, an alcohol compound, a halogen compound, a hydrocarbon compound, an aromatic compound, an amine compound, or an ester compound. Or a solid electrolyte composition which is a carbonate compound.

In the formula, α represents a 4- to 10-membered heterocyclic ring, X ¹¹ represents an oxygen atom, Y ¹¹ and Y ¹² each independently represent a ring α-constituting atom, and R ¹¹ and R ¹² each independently represent Represents a substituent, and n1 is 0 or 1. R ^D0 represents a substituent bonded to the ring α-constituting atom, and d0 represents an integer of 0 or more. When d0 is 2 or more, a plurality of R ^D0s may be the same or different, and R ^D0s bonded to adjacent ring α-constituting atoms may be bonded to each other to form a ring. However, α is not a 5-membered aromatic heterocycle.

^{Wherein, Y 13} and ^{Y 14} each independently represent a ring alpha ² constituting ^{atom, R 13, R 14, R} D1 and d1 are the ^{R 11, R 12, R D0} and d0 in formula (S-0) Each is synonymous. n2 and n3 are 1 . α ² represents a 4- to 10-membered heterocyclic ring, and X ⁰¹ represents a nitrogen atom, phosphorus atom, sulfur atom, silicon atom, arsenic atom or selenium atom, or nitrogen atom, phosphorus atom, sulfur atom, silicon atom, arsenic atom. It represents a divalent group containing an atom or a selenium atom. However, alpha ² is not a 5-membered aromatic heterocycle. The solid electrolyte composition according to claim 1, wherein the heterocyclic compound (B) is represented by the following formula (S-20) or (S-21).

In the formula, β represents a 5- to 8-membered heterocyclic ring, X ²⁰ represents an oxygen atom, Y ²¹ and Y ²² each independently represent a ring β-constituting atom, and R ²¹ and R ²² each independently represent Shows a substituent. R ^D20 represents a substituent bonded to a ring β-constituting atom, and d20 represents an integer of 0 or more and 6 or less. When d20 is 2 or more, a plurality of ^RD20s may be the same or different, and ^RD20s bonded to adjacent ring β-constituting atoms may be bonded to each other to form a ring. However, β is not a 5-membered aromatic heterocycle.

In the formula, β ² represents a 5- to 8-membered heterocyclic ring, X ²¹ represents a nitrogen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and Y ²³ and Y ²⁴ each independently represent a ring. β ² represents a constituent atom, and R ²³ and R ²⁴ each independently represent a substituent. R ^D21 represents a substituent attached with the ring beta ² constituting atom, d21 represents an integer of 0 to 6. If d21 is 2 or more, plural R ^D21 may be the same or different, bonded to each other R ^D21 bonded to the adjacent ring beta ² constituent atoms together may form a ring. However, β ² is not a 5-membered aromatic heterocycle. The solid electrolyte composition according to claim 2, wherein the heterocyclic compound (B) is represented by any of the following formulas (S-31), (S-32), and (S-34).

In the formula, X ³¹ and X ³³ each independently represent an oxygen atom, a sulfur atom, —NH— or —S (O ₂ ) —, and R ^{31 to} R ³⁴ , R ³⁷ and R ³⁸ each independently represent fluorine It represents an atom, a chlorine atom, a bromine atom, an iodine atom, an alkyl group having 1 to 3 carbon atoms, an alkoxy group having 1 to 3 carbon atoms or an alkenyl group having 2 to 3 carbon atoms.
The alkyl group, the alkoxy group and the alkenyl group may have a fluorine atom, a chlorine atom and / or a bromine atom.   The solid electrolyte composition according to any one of claims 1 to 3, wherein the dispersion medium (C) having a LogP value of 2.0 or more is a hydrocarbon compound or an aromatic compound.   The solid electrolyte composition according to any one of claims 1 to 4, wherein the dispersion medium (C) having a LogP value of 2.0 or more has a viscosity at 30 ° C of 0.8 mPa · S or more.   The solid electrolyte composition according to any one of claims 1 to 5, wherein a mass ratio of the dispersion medium (C) having a LogP value of 2.0 or more to the heterocyclic compound (B) is 1: 4 to 1: 100. Stuff.   The solid electrolyte composition according to any one of claims 1 to 6, comprising a polymer particle (D). The solid electrolyte composition according to any one of claims 1 to 7, wherein the inorganic solid electrolyte (A) is represented by the following formula (1).
_{L a1 M b1 P c1 S d1} A e1 formula (1)
In the formula, L represents an element selected from Li, Na and K. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al and Ge. A represents an element selected from I, Br, Cl and F. a1 to e1 indicate the composition ratio of each element, and a1: b1: c1: d1: e1 satisfies 1 to 12: 0 to 5: 1: 2 to 12: 0 to 10.   The solid electrolyte composition according to any one of claims 1 to 8, further comprising an active material (E).   The solid electrolyte composition according to claim 9, wherein the active material (E) is a metal oxide. A solid electrolyte-containing sheet having a layer formed of the solid electrolyte composition according to any one of claims 1 to 10,
A solid electrolyte-containing sheet wherein the content of the heterocyclic compound (B) in the layer is from 1 ppm to 10,000 ppm. An all-solid secondary battery including a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer,
An all-solid secondary battery in which at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is the solid electrolyte-containing sheet according to claim 11.   A method for producing a solid electrolyte-containing sheet, comprising applying the solid electrolyte composition according to any one of claims 1 to 10 onto a substrate and forming a film. A method for manufacturing an all-solid secondary battery, which manufactures an all-solid secondary battery through the manufacturing method according to claim 13.

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