JP2007173014A - Nonaqueous electrolyte secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous secondary battery capable of restraining fall of battery capacity and swelling of a battery at repetition of charge/discharge cycles, and further, restraining increase of thickness of the abttery, even at charge/discharge at low temperature. <P>SOLUTION: In the nonaqueous electrolyte secondary battery 1 provided with a cathode 4, an anode 3, and electrolyte, the electrolyte is made up by containing chained diol sulfonic acid, cyclic sulfate dielectric or 1,3-propenesultone dielectric, and a chained sulfate compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and an electrolyte.

In recent years, portable electronic devices have been improved in performance and reduced in size and weight, and the use of non-aqueous electrolyte secondary batteries such as lithium ion batteries has increased as high-energy density batteries used in these electronic devices. Yes. A non-aqueous electrolyte secondary battery such as a lithium ion battery tends to have a reduced discharge capacity as it is repeatedly charged and discharged.
Therefore, Patent Document 1 discloses an invention of a non-aqueous electrolyte secondary battery in which a chain diol sulfonic acid is added to an electrolyte in order to prevent a decrease in discharge capacity when charging and discharging are repeated.
Further, Patent Document 2 discloses a non-electrolyte containing a chain diol sulfonic acid and a negative electrode containing graphite whose surface is partially or entirely covered with 0.5% by mass or more and 20% by mass or less of low crystalline carbon. An invention of a water electrolyte secondary battery is disclosed.
JP 2003-308876 A JP 2005-317389 A

  However, the non-aqueous electrolyte secondary battery of Patent Document 1 can suppress a decrease in discharge capacity when charging and discharging are repeated, but the problem is that the expansion of the negative electrode plate increases, so that the expansion of the battery increases. is there. Also, during initial charging, the chain diol sulfonic acid decomposes to form a thick film on the negative electrode surface, and the resistance of the negative electrode increases, so that lithium deposits on the negative electrode when charged at a low temperature and the thickness of the negative electrode There is a problem that the battery becomes thicker and the swelling of the battery becomes larger.

  In the case of the non-aqueous electrolyte secondary battery of Patent Document 2, as in the non-aqueous electrolyte secondary battery of Patent Document 1, the chain diol sulfonic acid decomposes during initial charging to form a thick film on the negative electrode surface. Therefore, there is a problem that when the battery is charged at a low temperature, lithium is deposited on the negative electrode, the thickness of the negative electrode is increased, and the swelling of the battery is increased.

  This invention is made | formed in view of such a situation, and the compound represented by Chemical formula (1) mentioned later, Chemical formula (2), Chemical formula (3), Chemical formula (4), and Chemical formula (5) is made into electrolyte. By adding at least one of the compounds represented by formula (6) and the compound represented by the chemical formula (6), it is possible to suppress a decrease in battery capacity and a swelling of the battery when the charge / discharge cycle is repeated. An object of the present invention is to provide a non-aqueous electrolyte secondary battery capable of suppressing an increase in battery thickness even after being charged and discharged at a low temperature.

A nonaqueous electrolyte secondary battery according to a first aspect of the present invention is a nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, and an electrolyte, wherein the electrolyte has the following chemical formula (1);
HO-R1-A (1)
(Wherein R1 is a hydrocarbon group that may contain an unsaturated bond, or a hydrocarbon group that may contain an unsaturated bond, part or all of which is substituted with a halogen element, and Has a structure represented by the following A1, A2 or A3):

  The following chemical formula (2);

(Wherein R2 and R3 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. ) Cyclic sulfate derivatives represented by
The following chemical formula (3);

(Wherein R4 and R5 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. ) Unsaturated cyclic sulfate derivatives represented by
The following chemical formula (4);

(Wherein R6 and R7 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. And a cyclic sulfate derivative represented by the following chemical formula (5):

(Wherein R8 to R10 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. At least one compound selected from 1,3-propene sultone derivatives represented by:
The following chemical formula (6);
R11-SO ₄ -R12 (6)
(Wherein R11 and R12 each independently represents the same or different alkyl group) and a chain-like sulfate ester compound.
The non-aqueous electrolyte secondary battery according to a second aspect is characterized in that the sulfate ester compound is at least one of dimethyl sulfate, diethyl sulfate, and ethyl methyl sulfate.

In this invention, the fall of the discharge capacity at the time of repeating charging / discharging can be suppressed by using the compound which concerns on Chemical formula (1) for electrolyte. By containing this compound, good SEI (Solid Electrolyte Interphase) is formed on the surface of the negative electrode active material, and the subsequent decomposition of the non-aqueous electrolyte on the negative electrode is suppressed. As a result, the capacity during the charge / discharge cycle is reduced. The decrease is considered to be small. When SEI is the first charge of lithium metal or carbon material in a non-aqueous electrolyte, the solvent in the electrolyte and components contained in the electrolyte are reduced and formed on the surface of the metal lithium or carbon material. A passive membrane. And SEI formed on the surface of metallic lithium or a carbon material works as a lithium ion conductive protective film, and the subsequent reaction between metallic lithium or carbon material and a solvent is suppressed.
When the compounds represented by the chemical formulas (2) to (5) are added to the electrolyte, a stable negative electrode protective film is formed on the negative electrode. Due to the compound represented by the chemical formula (1), the binding force of the binder of the negative electrode decreases or the binder itself expands, so that the electrode plate easily expands during expansion / contraction of the negative electrode plate due to charge / discharge. Tend to be. However, since a stable negative electrode protective film is formed on the negative electrode, the above-described expansion of the negative electrode plate due to the addition of the chemical formula (1) can be suppressed.

  The compound represented by the chemical formula (6) can suppress a decrease in discharge capacity when charging and discharging are repeated. The compound represented by the chemical formula (1) forms a thick film on the negative electrode surface to increase the resistance of the negative electrode. However, the chain sulfate ester compound does not form a film on the negative electrode surface, and is further represented by the chemical formula (1). Since the growth of the film caused by the decomposition of the generated compound is suppressed, the resistance of the negative electrode does not increase. When the compound of the chemical formula (6) is added, when the battery has a positive electrode active material that is a compound capable of occluding and releasing lithium, the charge acceptability of lithium at a low temperature is not lowered, and the deposition on the surface is suppressed. I can do it.

According to the first invention, it is possible to suppress a decrease in battery capacity and swelling of the battery when the charge / discharge cycle is repeated, and it is possible to suppress an increase in the thickness of the battery even after charging / discharging at a low temperature.
According to the second invention, an increase in the thickness of the battery can be suppressed even better even after charging and discharging at a low temperature.

Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof.
In the nonaqueous electrolyte secondary battery, the present invention includes the following chemical formula (1) in the nonaqueous electrolyte:
HO-R1-A (1)
(Wherein R1 is a hydrocarbon group that may contain an unsaturated bond, or a hydrocarbon group that may contain an unsaturated bond, part or all of which is substituted with a halogen element, and Has a structure represented by the following A1, A2 or A3):

  The following chemical formula (2);

A cyclic sulfate derivative represented by:
The following chemical formula (3);

An unsaturated cyclic sulfate derivative represented by:
The following chemical formula (4);

A cyclic sulfate derivative represented by the formula:

At least one compound of 1,3-propene sultone derivatives represented by:
The following chemical formula (6);
R11-SO ₄ -R12 (6)
And a chain sulfate ester compound represented by the formula:
However, in chemical formulas (2), (3), (4) and (5), R2 to R10 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, One or different alkoxy groups, same or different allyl groups, same or different aryl groups, same or different halogens, alkyl groups having the same or different halogens, allyls having the same or different halogens Or an aryl group having the same or different halogen.
In formula (6), R11 and R12 each independently represent the same or different alkyl group.

  The amount of the compound represented by the chemical formula (1) added to the entire nonaqueous electrolyte is preferably 0.001% by mass or more and 4% by mass or less. Even if the addition amount of the compound represented by the chemical formula (1) is less than 0.001% by mass described in Examples described later, the effect of the present invention is recognized. When the added amount of the compound exceeds 4% by mass, in the battery using this electrolyte, gas is generated at the time of initial charge, so that the internal pressure of the battery rises and the battery swells.

  The addition amount of at least one of the compounds represented by the chemical formulas (2), (3), (4) and (5) to the whole nonaqueous electrolyte is 0.01% by mass or more and 2% by mass or less. The lower limit is more preferably 0.1% by mass. When the addition amount is 0.01% by mass or more, the expected effect is remarkably obtained. When the addition amount exceeds 2% by mass, the irreversible capacity during the initial charge / discharge cycle is increased, which causes a problem that the initial capacity is decreased.

Examples of the chain sulfate ester compound represented by the chemical formula (6) include dimethyl sulfate, diethyl sulfate, ethyl methyl sulfate, methyl propyl sulfate, ethyl propyl sulfate, methyl phenyl sulfate, ethyl phenyl sulfate, phenyl propyl sulfate, and benzyl sulfate. Examples include methyl and benzylethyl sulfate. Of these, dimethyl sulfate, diethyl sulfate, and ethyl methyl sulfate are preferable.
The amount of the chain sulfate ester compound added to the whole non-aqueous electrolyte is preferably 0.05% by mass or more and 1% by mass or less, the lower limit is 0.1% by mass, and the upper limit is 0.5% by mass. Is more preferable. When the addition amount is 0.05% by mass or more, the expected effect is remarkably obtained. When the addition amount exceeds 1% by mass, in the battery using this electrolyte, gas is generated at the time of initial charging, so that the internal pressure of the battery rises and the battery swells.

When producing the non-aqueous electrolyte secondary battery of the present invention, the above-described non-aqueous electrolyte may be used to produce a battery by an ordinary method.
As a positive electrode active material used for the nonaqueous electrolyte secondary battery of the present invention, a composition formula Li _x MO ₂ or Li _y M ₂ O ₄ (where M is a transition metal, 0 ≦ A composite oxide represented by x ≦ 1, 0 ≦ y ≦ 2), an oxide having a tunnel-like hole, or a metal chalcogenide having a layered structure can be used. Specific examples thereof include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , Li ₂ Mn ₂ O _4, etc., and these may be used in combination. Moreover, when using a granular active material, it can produce, for example by forming the composite material which consists of an active material particle, a conductive support agent, and a binder on metal current collectors, such as aluminum.

Examples of the negative electrode active material include alloys of lithium with Al, Si, Pb, Sn, Zn, Cd, etc., transition metal oxides such as LiFe ₂ O ₃ , WO ₂ , MoO ₂ , graphite, carbon, etc. A carbon material, lithium nitride such as Li ₃ (Li ₃ N), a metal lithium foil, or a mixture thereof may be used. Moreover, when using a granular carbon material, it can produce, for example by forming the compound material which consists of an active material particle and a binder on metal collectors, such as copper. As the carbon material, natural graphite or artificial graphite (mesophase graphite such as MCMB or MCF) is preferably used, and mesophase graphite (MCMB or MCF) is more preferably used. Moreover, you may use what coat | covered the part or all of the surface of natural graphite with the low crystalline carbon whose crystallinity is lower than natural graphite.

  Non-aqueous electrolyte solvents include ethylene carbonate, vinylene carbonate, propylene carbonate, butylene carbonate, trifluoropropylene carbonate, γ-butyrolactone, sulfolane, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2- Nonaqueous solvents such as methyltetrahydrofuran, 3-methyl-1,3-dioxolane, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, methyl propyl carbonate, etc. These can be used alone or as a mixture thereof. Moreover, it may contain an appropriate amount of an additive such as a polymerization agent such as biphenyl or cyclohexylbenzene.

The nonaqueous electrolyte is used by dissolving the supporting salt in these nonaqueous solvents. Examples of the supporting salt include LiClO ₄ , LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiCF ₃ CO ₂ , LiCF ₃ SO ₃ , LiCF ₃ CF ₂ SO ₃ , LiCF ₃ CF ₂ CF ₂ SO ₃ , LiN (SO ₂ CF ₃ ). ₂ , LiN (SO ₂ CF ₂ CF ₃ ) ₂ , LiN (COCF ₃ ) ₂ , LiN (COCF ₂ CF ₃ ) ₂ , LiPF ₃ (CF ₂ CF ₃ ) ₃ , LiFOB (lithium difluorooxalate borate), and LiBOB A salt such as (lithium bisoxalate borate) or a mixture thereof can be used.

The non-aqueous electrolyte secondary battery of the present invention is usually composed of a combination of a positive electrode, a negative electrode, a separator and a non-aqueous electrolyte as its configuration. Examples of the separator include a porous polyolefin film and a porous polyvinyl chloride film. These porous polymer membranes or lithium ion or ion conductive polymer electrolyte membranes can be used alone or in combination.
In addition, the shape of the battery is not particularly limited, and the present invention is applicable to non-aqueous electrolyte secondary batteries having various shapes such as a square, cylindrical, long cylindrical, coin, button, and sheet batteries. Applicable.

The present invention will be described below with reference to preferred examples. However, the present invention is not limited to the examples, and can be appropriately modified and implemented without departing from the scope of the present invention. .
Example 1
FIG. 1 is a cross-sectional view of a nonaqueous electrolyte secondary battery (hereinafter referred to as a battery) according to the present invention. In FIG. 1, 1 is a battery, 2 is a flat wound electrode group, 3 is a negative electrode, 4 is a positive electrode, 5 is a separator, 6 is a battery case, 7 is a battery lid, 8 is a safety valve, 9 is a negative electrode terminal, and 10 is a negative electrode Lead. The flat wound electrode group 2 is obtained by winding a positive electrode 4 and a negative electrode 3 through a separator 5. The battery lid 7 has a negative electrode terminal 9 and a safety valve 8, the flat wound electrode group 2 is accommodated in the battery case 6, and the battery lid 7 and the battery case 6 are laser welded. The negative electrode terminal 9 is connected to the negative electrode lead 10, and the positive electrode 4 is connected to the battery case 6.

The positive electrode mixture was prepared by mixing 90% by mass of LiCoO ₂ as a positive electrode active material, 5% by mass of acetylene black as a conductive auxiliary agent, and 5% by mass of polyvinylidene fluoride (PVDF) as a binder. A paste was prepared by dispersing in 2-pyrrolidone (NMP). The prepared paste is uniformly applied to an aluminum current collector having a thickness of 20 μm and dried, and then the positive electrode is formed by compression molding with a roll press so that the density of the positive electrode mixture layer is 3.2 g / cm ^3. Produced.

The negative electrode mixture is a mixture of 97% by mass of a carbon material as a negative electrode active material, 1.5% by mass of carboxymethyl cellulose as a binder and 1.5% by mass of styrene butadiene rubber, and dispersed by adding distilled water as appropriate. The slurry was adjusted. The prepared slurry was uniformly applied to a 15 μm thick copper current collector, dried at 100 ° C. for 5 hours, and then compression-molded with a roll press so that the density of the negative electrode mixture layer was 1.4 g / cm ^3. As a result, a negative electrode was produced.

The carbon material is obtained by coating a part or all of the surface of natural graphite with low crystalline carbon having lower crystallinity than natural graphite (hereinafter referred to as coated graphite). The average plane spacing (d002) of the (002) plane by the diffraction method is 3.357 mm, and the intensity ratio (I1355 / I1580) of the peak near 1355 cm ^{−1 to} the peak near 1580 cm ⁻¹ by argon laser Raman is The crystallite size Lc and La obtained by X-ray diffraction by the Gakushin method was 100 nm or more. The coated graphite has an intensity ratio of a peak near 1355 cm ^{−1 to} a peak near 1580 cm ⁻¹ by an argon laser Raman of 1.03.

  The coated graphite is obtained by coating the surface of natural graphite with 10% by mass of low crystalline carbon based on the mass of natural graphite by a chemical vapor deposition method using toluene gas as a carbon raw material.

As the separator 5, a microporous polyethylene film having a thickness of about 20 μm was used. In the electrolyte, a table according to the chemical formula (1) is obtained by dissolving 1.1 mol / L of LiPF _{6 in} a mixed solvent having a volume ratio of ethylene carbonate (EC) and ethyl methyl carbonate (EMC) of 3: 7. 0.1% by mass of the compound C1 shown in FIG. 1, 0.5% by mass of PGLST (propylene glycol sulfate) shown in the following structural formula according to the chemical formula (2), and DEST (diethyl sulfate) according to the chemical formula (6) An electrolyte with 0.2% by mass added was used. The battery 1 has a width of 30 mm, a thickness of 4.2 mm, a height of 48 mm, and a capacity of 600 mAh.

(Example 2)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C2 shown in Table 1 according to the chemical formula (1) was added to the electrolyte.
(Example 3)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C3 shown in Table 1 according to the chemical formula (1) was added to the electrolyte.
Example 4
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C4 shown in Table 1 according to the chemical formula (1) was added to the electrolyte.
(Example 5)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C5 shown in Table 1 according to the chemical formula (1) was added to the electrolyte.

(Example 6)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C6 shown in Table 2 according to the chemical formula (1) was added to the electrolyte.

(Example 7)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of Compound C7 shown in Table 2 according to Chemical Formula (1) was added to the electrolyte.
(Example 8)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C8 shown in Table 2 related to the chemical formula (1) was added to the electrolyte.
Example 9
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of Compound C9 shown in Table 2 according to Chemical Formula (1) was added to the electrolyte.

(Example 10)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C10 shown in Table 3 according to the chemical formula (1) was added to the electrolyte.

(Example 11)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C11 shown in Table 3 according to the chemical formula (1) was added to the electrolyte.
(Example 12)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of the compound C12 shown in Table 3 according to the chemical formula (1) was added to the electrolyte.
(Example 13)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of Compound C13 shown in Table 3 according to Chemical Formula (1) was added to the electrolyte.
(Example 14)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of Compound C14 shown in Table 4 according to Chemical Formula (1) was added to the electrolyte.

(Example 15)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of Compound C15 shown in Table 4 according to Chemical Formula (1) was added to the electrolyte.

(Example 16)
Other than adding 0.1% by mass of compound C5 shown in Table 1 according to chemical formula (1) and 0.5% by mass of GLST (ethylene glycol sulfate) shown in the following structural formula according to chemical formula (2) to the electrolyte Produced the same battery as Example 1.

(Example 17)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of PRS (1,3-propene sultone) represented by the following structural formula according to chemical formula (5) was added to the electrolyte.

(Example 18)
A battery was prepared in the same manner as in Example 16 except that 0.5% by mass of BGLST (butylene glycol sulfate) represented by the following structural formula according to chemical formula (2) was added to the electrolyte.

Example 19
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of DMGLST (dimethyl glycol sulfate) represented by the following structural formula according to chemical formula (2) was added to the electrolyte.

(Example 20)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of VEST (vinyl ethylene glycol sulfate) represented by the following structural formula according to chemical formula (2) was added to the electrolyte.

(Example 21)
A battery was prepared in the same manner as in Example 16 except that 0.5% by mass of VST (vinylene glycol sulfate) represented by the following structural formula according to chemical formula (3) was added to the electrolyte.

(Example 22)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of TMST (trimethylene glycol sulfate) represented by the following structural formula according to chemical formula (4) was added to the electrolyte.

(Example 23)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of 2MTMST (2-methyltrimethylene glycol sulfate) represented by the following structural formula according to chemical formula (4) was added to the electrolyte.

(Example 24)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of 3MTMST (3-methyltrimethylene glycol sulfate) represented by the following structural formula according to chemical formula (4) was added to the electrolyte.

(Example 25)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of compound C7 and 0.5% by mass of GLST were added to the electrolyte.
(Example 26)
A battery was prepared in the same manner as in Example 25 except that 0.5% by mass of PRS was added to the electrolyte.
(Example 27)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of BGLST was added to the electrolyte.
(Example 28)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of DMGLST was added to the electrolyte.
(Example 29)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of VEST was added to the electrolyte.

(Example 30)
A battery was prepared in the same manner as in Example 25 except that 0.5% by mass of VST was added to the electrolyte.
(Example 31)
A battery was prepared in the same manner as in Example 25 except that 0.5% by mass of TMST was added to the electrolyte.
(Example 32)
A battery was produced in the same manner as in Example 25 except that 2% by mass of 2MTMST was added to the electrolyte.
(Example 33)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of 3MTMST was added to the electrolyte.

(Example 34)
A battery was prepared in the same manner as in Example 1 except that 0.1% by mass of compound C5, 0.5% by mass of PGLST, and 0.2% by mass of DMST (dimethyl sulfate) were added to the electrolyte.
(Example 35)
A battery was prepared in the same manner as in Example 34 except that 0.2% by mass of EMST (ethyl methyl sulfate) was added to the electrolyte.

(Example 36)
A battery was prepared in the same manner as in Example 34 except that 0.1% by mass of compound C7 was added to the electrolyte.
(Example 37)
A battery was prepared in the same manner as in Example 36 except that 0.2% by mass of EMST was added to the electrolyte.
(Example 38)
A battery was produced in the same manner as in Example 34 except that 0.5% by mass of GLST was added to the electrolyte.
(Example 39)
A battery was produced in the same manner as in Example 38 except that 0.2% by mass of EMST was added to the electrolyte.

(Example 40)
A battery was produced in the same manner as in Example 38 except that 0.1% by mass of compound C7 was added to the electrolyte.
(Example 41)
A battery was produced in the same manner as in Example 40 except that 0.2% by mass of EMST was added to the electrolyte.
(Example 42)
A battery was prepared in the same manner as in Example 34 except that 0.5 mass% of PRS was added to the electrolyte.
(Example 43)
A battery was prepared in the same manner as in Example 42 except that 0.2% by mass of EMST was added to the electrolyte.
(Example 44)
A battery was produced in the same manner as in Example 42 except that 0.1% by mass of compound C7 was added to the electrolyte.
(Example 45)
A battery was prepared in the same manner as in Example 44 except that 0.2% by mass of EMST was added to the electrolyte.

(Example 46)
A battery was prepared in the same manner as in Example 5 except that 0.001% by mass of compound C5 was added to the electrolyte.
(Example 47)
A battery was prepared in the same manner as in Example 5 except that 0.01% by mass of compound C5 was added to the electrolyte.

(Example 48)
A battery was prepared in the same manner as in Example 5 except that 0.5% by mass of compound C5 was added to the electrolyte.
(Example 49)
A battery was prepared in the same manner as in Example 5 except that 1% by mass of compound C5 was added to the electrolyte.
(Example 50)
A battery was prepared in the same manner as in Example 5 except that 2% by mass of compound C5 was added to the electrolyte.
(Example 51)
A battery was prepared in the same manner as in Example 5 except that 3% by mass of compound C5 was added to the electrolyte.
(Example 52)
A battery was prepared in the same manner as in Example 5 except that 4% by mass of Compound C5 was added to the electrolyte.

(Example 53)
A battery was prepared in the same manner as in Example 16 except that 0.001% by mass of compound C5 was added to the electrolyte.
(Example 54)
A battery was produced in the same manner as in Example 16 except that 0.01% by mass of compound C5 was added to the electrolyte.
(Example 55)
A battery was produced in the same manner as in Example 16 except that 0.5% by mass of compound C5 was added to the electrolyte.
(Example 56)
A battery was prepared in the same manner as in Example 16 except that 1% by mass of compound C5 was added to the electrolyte.
(Example 57)
A battery was prepared in the same manner as in Example 16 except that 2% by mass of the compound C5 was added to the electrolyte.
(Example 58)
A battery was prepared in the same manner as in Example 16 except that 3% by mass of compound C5 was added to the electrolyte.
(Example 59)
A battery was produced in the same manner as in Example 16 except that 4% by mass of the compound C5 was added to the electrolyte.

(Example 60)
A battery was produced in the same manner as in Example 17 except that 0.001% by mass of compound C5 was added to the electrolyte.
(Example 61)
A battery was prepared in the same manner as in Example 17 except that 0.01% by mass of compound C5 was added to the electrolyte.
(Example 62)
A battery was prepared in the same manner as in Example 17 except that 0.5% by mass of compound C5 was added to the electrolyte.
(Example 63)
A battery was prepared in the same manner as in Example 17 except that 1% by mass of compound C5 was added to the electrolyte.
(Example 64)
A battery was prepared in the same manner as in Example 17 except that 2% by mass of compound C5 was added to the electrolyte.
(Example 65)
A battery was prepared in the same manner as in Example 17 except that 3% by mass of compound C5 was added to the electrolyte.
Example 66
A battery was prepared in the same manner as in Example 17 except that 4% by mass of compound C5 was added to the electrolyte.

(Example 67)
A battery similar to that of Example 7 was produced, except that 0.001 mass of Compound C7 was added to the electrolyte.
(Example 68)
A battery was prepared in the same manner as in Example 7 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Example 69)
A battery was prepared in the same manner as in Example 7 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Example 70)
A battery was prepared in the same manner as in Example 7 except that 1% by mass of compound C7 was added to the electrolyte.
(Example 71)
A battery was prepared in the same manner as in Example 7 except that 2% by mass of compound C7 was added to the electrolyte.
(Example 72)
A battery was prepared in the same manner as in Example 7 except that 3% by mass of compound C7 was added to the electrolyte.
(Example 73)
A battery was prepared in the same manner as in Example 7 except that 4% by mass of Compound C7 was added to the electrolyte.

(Example 74)
A battery was produced in the same manner as in Example 25 except that 0.001 mass of compound C7 was added to the electrolyte.
(Example 75)
A battery was produced in the same manner as in Example 25 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Example 76)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Example 77)
A battery was produced in the same manner as in Example 25 except that 1% by mass of compound C7 was added to the electrolyte.
(Example 78)
A battery was produced in the same manner as in Example 25 except that 2% by mass of compound C7 was added to the electrolyte.
(Example 79)
A battery was produced in the same manner as in Example 25 except that 3% by mass of compound C7 was added to the electrolyte.
(Example 80)
A battery was produced in the same manner as in Example 25 except that 4% by mass of compound C7 was added to the electrolyte.

(Example 81)
A battery was produced in the same manner as in Example 26 except that 0.001 mass of compound C7 was added to the electrolyte.
(Example 82)
A battery was produced in the same manner as in Example 26 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Example 83)
A battery was prepared in the same manner as in Example 26 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Example 84)
A battery was produced in the same manner as in Example 26 except that 1% by mass of compound C7 was added to the electrolyte.
(Example 85)
A battery was produced in the same manner as in Example 26 except that 2% by mass of the compound C7 was added to the electrolyte.
(Example 86)
A battery was produced in the same manner as in Example 26 except that 3% by mass of compound C7 was added to the electrolyte.
(Example 87)
A battery was produced in the same manner as in Example 26 except that 4% by mass of compound C7 was added to the electrolyte.

(Example 88)
A battery similar to that of Example 36 was produced, except that 0.001 mass of Compound C7 was added to the electrolyte.
Example 89
A battery was produced in the same manner as in Example 36 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Example 90)
A battery was produced in the same manner as in Example 36 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Example 91)
A battery similar to that of Example 36 was produced, except that 1% by mass of compound C7 was added to the electrolyte.
(Example 92)
A battery was produced in the same manner as in Example 36 except that 2% by mass of the compound C7 was added to the electrolyte.
(Example 93)
A battery was produced in the same manner as in Example 36 except that 3% by mass of the compound C7 was added to the electrolyte.
(Example 94)
A battery was prepared in the same manner as in Example 36 except that 4% by mass of compound C7 was added to the electrolyte.

(Example 95)
A battery was produced in the same manner as in Example 37 except that 0.001 mass of compound C7 was added to the electrolyte.
Example 96
A battery was produced in the same manner as in Example 37 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Example 97)
A battery was produced in the same manner as in Example 37 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Example 98)
A battery was produced in the same manner as in Example 37 except that 1% by mass of compound C7 was added to the electrolyte.
Example 99
A battery was produced in the same manner as in Example 37 except that 2% by mass of compound C7 was added to the electrolyte.
(Example 100)
A battery was produced in the same manner as in Example 37 except that 3% by mass of the compound C7 was added to the electrolyte.
(Example 101)
A battery was produced in the same manner as in Example 37 except that 4% by mass of compound C7 was added to the electrolyte.

(Example 102)
A battery was prepared in the same manner as in Example 7 except that 0.1% by mass of PGLST was added to the electrolyte.
(Example 103)
A battery was prepared in the same manner as in Example 7 except that 1% by mass of PGLST was added to the electrolyte.
(Example 104)
A battery was prepared in the same manner as in Example 7 except that 2% by mass of PGLST was added to the electrolyte.

(Example 105)
A battery was produced in the same manner as in Example 25 except that 0.1% by mass of GLST was added to the electrolyte.
(Example 106)
A battery was produced in the same manner as in Example 25 except that 1% by mass of GLST was added to the electrolyte.
(Example 107)
A battery was produced in the same manner as in Example 25 except that 2% by mass of GLST was added to the electrolyte.

(Example 108)
A battery was prepared in the same manner as in Example 26 except that 0.1 mass% of PRS was added to the electrolyte.
(Example 109)
A battery was produced in the same manner as in Example 26 except that 1% by mass of PRS was added to the electrolyte.
(Example 110)
A battery was prepared in the same manner as in Example 26 except that 2% by mass of PRS was added to the electrolyte.

(Example 111)
A battery was prepared in the same manner as in Example 7 except that 0.05% by mass of DEST was added to the electrolyte.
(Example 112)
A battery was prepared in the same manner as in Example 7 except that 0.1% by mass of DEST was added to the electrolyte.
(Example 113)
A battery was prepared in the same manner as in Example 7 except that 0.5% by mass of DEST was added to the electrolyte.
(Example 114)
A battery was produced in the same manner as in Example 7 except that 1% by mass of DEST was added to the electrolyte.

(Example 115)
A battery was prepared in the same manner as in Example 36 except that 0.05% by mass of DMST was added to the electrolyte.
(Example 116)
A battery was produced in the same manner as in Example 36 except that 0.1% by mass of DMST was added to the electrolyte.
(Example 117)
A battery was produced in the same manner as in Example 36 except that 0.5% by mass of DMST was added to the electrolyte.
(Example 118)
A battery was prepared in the same manner as in Example 36 except that 1% by mass of DMST was added to the electrolyte.

(Example 119)
A battery was prepared in the same manner as in Example 37 except that 0.05% by mass of EMST was added to the electrolyte.
(Example 120)
A battery was prepared in the same manner as in Example 37 except that 0.1% by mass of EMST was added to the electrolyte.
(Example 121)
A battery was prepared in the same manner as in Example 37 except that 0.5% by mass of EMST was added to the electrolyte.
(Example 122)
A battery was prepared in the same manner as in Example 37 except that 1% by mass of EMST was added to the electrolyte.

(Example 123)
A battery was produced in the same manner as in Example 25 except that 0.05% by mass of DEST was added to the electrolyte.
(Example 124)
A battery was produced in the same manner as in Example 25 except that 0.1% by mass of DEST was added to the electrolyte.
(Example 125)
A battery was produced in the same manner as in Example 25 except that 0.5% by mass of DEST was added to the electrolyte.
(Example 126)
A battery was produced in the same manner as in Example 25 except that 1% by mass of DEST was added to the electrolyte.

(Example 127)
A battery was prepared in the same manner as in Example 40 except that 0.05% by mass of DMST was added to the electrolyte.
(Example 128)
A battery was produced in the same manner as in Example 40 except that 0.1% by mass of DMST was added to the electrolyte.
(Example 129)
A battery was produced in the same manner as in Example 40 except that 0.5% by mass of DMST was added to the electrolyte.
(Example 130)
A battery was prepared in the same manner as in Example 40 except that 1% by mass of DMST was added to the electrolyte.

(Example 131)
A battery was prepared in the same manner as in Example 41 except that 0.05% by mass of EMST was added to the electrolyte.
(Example 132)
A battery was produced in the same manner as in Example 41 except that 0.1% by mass of EMST was added to the electrolyte.
(Example 133)
A battery was produced in the same manner as in Example 41 except that 0.5% by mass of EMST was added to the electrolyte.
(Example 134)
A battery was prepared in the same manner as in Example 41 except that 1% by mass of EMST was added to the electrolyte.

(Example 135)
A battery was prepared in the same manner as in Example 26 except that 0.05% by mass of DEST was added to the electrolyte.
(Example 136)
A battery was produced in the same manner as in Example 26 except that 0.1% by mass of DEST was added to the electrolyte.
(Example 137)
A battery was produced in the same manner as in Example 26 except that 0.5% by mass of DEST was added to the electrolyte.
(Example 138)
A battery was produced in the same manner as in Example 26 except that 1% by mass of DEST was added to the electrolyte.

(Example 139)
A battery was produced in the same manner as in Example 44 except that 0.05 mass% of DMST was added to the electrolyte.
(Example 140)
A battery was produced in the same manner as in Example 44 except that 0.1% by mass of DMST was added to the electrolyte.
(Example 141)
A battery was produced in the same manner as in Example 44 except that 0.5% by mass of DMST was added to the electrolyte.
(Example 142)
A battery was produced in the same manner as in Example 44 except that 1% by mass of DMST was added to the electrolyte.

(Example 143)
A battery was prepared in the same manner as in Example 45 except that 0.05% by mass of EMST was added to the electrolyte.
(Example 144)
A battery was prepared in the same manner as in Example 45 except that 0.1% by mass of EMST was added to the electrolyte.
(Example 145)
A battery was prepared in the same manner as in Example 45 except that 0.5% by mass of EMST was added to the electrolyte.
(Example 146)
A battery was prepared in the same manner as in Example 45 except that 1% by mass of EMST was added to the electrolyte.

(Comparative Examples 1-15)
Comparative example in which 0.5% by mass of PGLST was added to the electrolyte without adding the compound of the chemical formula (6), and the types of the compounds of the chemical formula (1) were added corresponding to Examples 1 to 15, respectively. 1 to 15 batteries were produced.

(Comparative Examples 16-30)
Comparative example in which 0.5 mass% of PRS was added to the electrolyte without adding the compound of the chemical formula (6), and the types of the compounds of the chemical formula (1) were added corresponding to each of Examples 1 to 15. 16-30 batteries were produced.

(Comparative Example 31)
A battery was fabricated in the same manner as in Example 1 without adding any of the compound of the chemical formula (1), the compounds of the chemical formulas (2) to (5), and the compound of the chemical formula (6) to the electrolyte.

(Comparative Example 32)
A battery was prepared in the same manner as in Comparative Example 5 except that 0.001% by mass of compound C5 was added to the electrolyte.
(Comparative Example 33)
A battery was prepared in the same manner as in Comparative Example 5 except that 0.01% by mass of Compound C5 was added to the electrolyte.
(Comparative Example 34)
A battery was prepared in the same manner as in Comparative Example 5 except that 0.5% by mass of compound C5 was added to the electrolyte.
(Comparative Example 35)
A battery was prepared in the same manner as in Comparative Example 5 except that 1% by mass of Compound C5 was added to the electrolyte.
(Comparative Example 36)
A battery was prepared in the same manner as in Comparative Example 5 except that 2% by mass of Compound C5 was added to the electrolyte.
(Comparative Example 37)
A battery was prepared in the same manner as in Comparative Example 5 except that 3% by mass of compound C5 was added to the electrolyte.
(Comparative Example 38)
A battery was prepared in the same manner as in Comparative Example 5 except that 4% by mass of Compound C5 was added to the electrolyte.

(Comparative Example 39)
A battery was prepared in the same manner as in Comparative Example 7, except that 0.001% by mass of compound C7 was added to the electrolyte.
(Comparative Example 40)
A battery was prepared in the same manner as in Comparative Example 7, except that 0.01% by mass of compound C7 was added to the electrolyte.
(Comparative Example 41)
A battery was prepared in the same manner as in Comparative Example 7, except that 0.5% by mass of compound C7 was added to the electrolyte.
(Comparative Example 42)
A battery was produced in the same manner as in Comparative Example 7, except that 1% by mass of compound C7 was added to the electrolyte.
(Comparative Example 43)
A battery was prepared in the same manner as in Comparative Example 7, except that 2% by mass of compound C7 was added to the electrolyte.
(Comparative Example 44)
A battery was prepared in the same manner as in Comparative Example 7, except that 3% by mass of compound C7 was added to the electrolyte.
(Comparative Example 45)
A battery was prepared in the same manner as in Comparative Example 7, except that 4% by mass of Compound C7 was added to the electrolyte.

(Comparative Example 46)
A battery was produced in the same manner as in Comparative Example 20, except that 0.001% by mass of compound C5 was added to the electrolyte.
(Comparative Example 47)
A battery was prepared in the same manner as in Comparative Example 20, except that 0.01% by mass of compound C5 was added to the electrolyte.
(Comparative Example 48)
A battery was prepared in the same manner as in Comparative Example 20, except that 0.5% by mass of compound C5 was added to the electrolyte.
(Comparative Example 49)
A battery was prepared in the same manner as in Comparative Example 20, except that 1% by mass of compound C5 was added to the electrolyte.
(Comparative Example 50)
A battery was produced in the same manner as in Comparative Example 20, except that 2% by mass of compound C5 was added to the electrolyte.
(Comparative Example 51)
A battery was prepared in the same manner as in Comparative Example 20, except that 3% by mass of compound C5 was added to the electrolyte.
(Comparative Example 52)
A battery was prepared in the same manner as in Comparative Example 20, except that 4% by mass of compound C5 was added to the electrolyte.

(Comparative Example 53)
A battery was produced in the same manner as in Comparative Example 22 except that 0.001 mass% of compound C7 was added to the electrolyte.
(Comparative Example 54)
A battery was prepared in the same manner as in Comparative Example 22 except that 0.01% by mass of compound C7 was added to the electrolyte.
(Comparative Example 55)
A battery was prepared in the same manner as in Comparative Example 22 except that 0.5% by mass of compound C7 was added to the electrolyte.
(Comparative Example 56)
A battery was prepared in the same manner as in Comparative Example 22 except that 1% by mass of compound C7 was added to the electrolyte.
(Comparative Example 57)
A battery was prepared in the same manner as in Comparative Example 22 except that 2% by mass of compound C7 was added to the electrolyte.
(Comparative Example 58)
A battery was prepared in the same manner as in Comparative Example 22 except that 3% by mass of compound C7 was added to the electrolyte.
(Comparative Example 59)
A battery was prepared in the same manner as in Comparative Example 22 except that 4% by mass of compound C7 was added to the electrolyte.

The batteries of these Examples and Comparative Examples were subjected to the following 25 ° C. charge / discharge cycle test and 0 ° C. cycle test.
(25 ° C charge / discharge cycle test)
First, 5 batteries of each example and comparative example were prepared, and charged at a constant current / constant voltage for 3 hours at a current of 600 mA and at a current of 600 mA at an ambient temperature of 25 ° C., and up to a voltage of 3 V at a current of 600 mA. Discharge was performed and the initial discharge capacity was measured. Thereafter, the same charge and discharge was repeated 500 cycles, the discharge capacity at the 500th cycle was measured, the capacity retention rate (%) was calculated, and the average value of 5 cells was obtained. Here, the capacity retention is the ratio (%) of the discharge capacity at the 500th cycle to the initial discharge capacity. The test results are shown in the table.

(0 ° C cycle test)
First, 5 batteries of each example and comparative example were prepared, and charged at a constant current / constant voltage for 3 hours at a current of 600 mA and at a current of 600 mA at an ambient temperature of 25 ° C., and up to a voltage of 3 V at a current of 600 mA. Discharge was performed, and the initial discharge capacity and initial battery thickness were measured. Thereafter, the same charge / discharge cycle was repeated 20 cycles at an ambient temperature of 0 ° C. After the end of the cycle, the sample was left for 5 hours or more at an ambient temperature of 25 ° C., then charged at a current of 600 mA to a voltage of 4.2 V at a constant current / constant voltage for 3 hours, and discharged at a current of 600 mA to a voltage of 3 V. After the test, the thickness increment (mm) was calculated, and the average value of 5 cells was obtained. The thickness increment is a difference (mm) obtained by subtracting the initial battery thickness from the battery thickness after the test. The test results are shown in Tables 5-12.

The batteries of Comparative Examples 1 to 30 in Table 6 to which the compound of Chemical Formula (6) was not added had a capacity compared to the batteries of Examples 1 to 45 in Tables 5 and 6 to which the compound was added. Retention rate is inferior and thickness increment is greatly inferior.
The compound represented by the chemical formula (1) forms a thick film on the negative electrode surface to increase the resistance of the negative electrode, but the chain sulfate ester compound represented by the chemical formula (6) does not form a film on the negative electrode surface. Furthermore, since the growth of the film caused by the decomposition of the compound represented by the chemical formula (1) is suppressed, the resistance of the negative electrode does not increase. When the compound of the chemical formula (6) is added, lithium charge acceptability at a low temperature does not decrease, and precipitation of lithium on the negative electrode surface can be suppressed. Therefore, an increase in battery thickness can be suppressed even after charging / discharging at a low temperature.
Moreover, the battery of the comparative example 31 which has not added the compound of Chemical formula (1) and the compound of Chemical formula (2)-(5) is also inferior in capacity retention compared with the battery of an Example. It turns out that the fall of the battery capacity after repeating charging / discharging is suppressed by adding the compound of Chemical formula (1) and the compound of Chemical formula (2)-(5).

  Although R1 of the compound which concerns on Chemical formula (1) of Example 1 and 5 and Example 2 and 6 is the same and A is different, all have a favorable test result. However, Examples 5 and 6 using A3 are superior in capacity retention after cycling to Examples 1 using A1 and Example 2 using A2. This is presumably because A3 contains more oxygen than A1 or A2 in its structure, and thus the properties of the negative electrode film formed during initial charging become more stable.

  As in Examples 3, 4 and 8, R1 of the compound according to chemical formula (1) may contain an unsaturated bond. When the unsaturated bond is included, it is considered that a negative electrode and a more stable film are formed. Further, as in Examples 4, 7, 8, 9, 10, 11, 12, the side chain of R1 of compound C according to chemical formula (1) may be lengthened or plural. When the side chain is made long or plural, the surface active effect is increased, so that the affinity between the separator and the electrolyte is improved, the electrolyte solution easily penetrates into the electrode plate, and the initial capacity is increased. However, if the side chain is lengthened, the viscosity of the electrolyte may increase when the compound C according to the chemical formula (1) is added to the electrolyte, and the charge / discharge performance may be deteriorated. Is preferably 8 or less.

  R1 of compound C according to chemical formula (1) may be halogenated. When an electron withdrawing halogen is added, it is difficult to oxidize and is easily reduced. Since it is difficult to oxidize, the oxidative decomposition reaction on the positive electrode is suppressed, and the decrease in charge / discharge cycle characteristics (capacity retention) due to the deposition of decomposition products on the positive electrode surface is suppressed. In addition, since it is easy to be reduced, a stable inorganic coating such as LiF or LiCl containing halogen is formed on the negative electrode. In order to suppress the reductive decomposition reaction of other electrolytes, the initial charge / discharge efficiency is improved, and the discharge The capacity is thought to increase.

  As shown in Tables 7 to 9 below, Examples 46 to 101 in which the compound of the chemical formula (6) was added were compared with Comparative Examples 32 to 59 in which the compound was not added, and the capacity retention after 500 cycles. And the increase in thickness after the low-temperature cycle is suppressed. However, when the addition amount of the compound of the chemical formula (1) is small and when the addition amount is large, the capacity retention after the cycle tends to decrease, and the thickness increment slightly increases. When the amount of the compound represented by the chemical formula (1) is small, the coating film formed on the negative electrode is thin, the electrolytic solution is easily decomposed with the cycle, the capacity is reduced, and gas is generated during decomposition. So the bulge also increases. When the amount of the compound represented by the chemical formula (1) is large, the viscosity of the electrolytic solution is increased and the diffusion of lithium ions is hindered, so that the charge / discharge efficiency is lowered and the capacity is reduced during the cycle. In addition, since the coating formed on the negative electrode is thick, the lithium acceptability during low-temperature charging is reduced and swelling is increased.

As shown in Table 10 below, when this compound was added (Examples 102 to 110), regardless of the type of the compounds of the chemical formulas (2) to (5), when not added (Comparative Example 31) As compared with, the capacity retention after the cycle is improved, and the increase in thickness after the low temperature cycle is suppressed. This cyclic sulfate ester is considered to form a good film during initial charging. Even when an unsaturated bond is included as in PRS, since a stable coating film is formed with the negative electrode, the decomposition of the nonaqueous electrolyte on the negative electrode surface is suppressed, and the capacity retention after cycling is good.
When the addition amount of this compound is changed to 0.1 to 2% by mass, it can be seen that better results are obtained when the addition amount is 0.5 to 1% by mass, regardless of the type.

As shown in the following Tables 11 and 12, regardless of the type of the compound of the chemical formula (6), when this compound was added (Examples 111 to 146), when it was not added (Comparative Examples 7 and 22) As compared with, the capacity retention after the cycle is improved, and the increase in thickness after the low temperature cycle is suppressed.
When the addition amount of this compound is changed to 0.05 to 1% by mass, better results are obtained when the addition amount is 0.1 to 0.5% by mass, regardless of the type of the compound. I understand that.

  In the above examples, the electrolyte solvent is described as a mixed solvent of EC and EMC. However, when the ratio of cyclic carbonate and chain carbonate is changed, or when PC is used as the cyclic carbonate, DMC is used as the chain carbonate. Alternatively, the same tendency was observed when DEC was used, and the same tendency was observed when γ-butyrolactone was used instead of the chain carbonate. A similar tendency was observed when the concentration of the supporting salt was changed. Moreover, the same effect was acquired even if it used together with various additives (For example, polymeric agents, such as biphenyl and cyclohexylbenzene, etc.).

Moreover, the compound which concerns on the compound which concerns on Chemical formula (1), and the compound which concerns on Chemical formula (2)-(5) is not limited to the compound in the Example mentioned above.
The alkyl group that can be taken by R2 to R10 of the compounds according to the chemical formulas (2) to (5) is preferably an alkyl group having 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group. Etc. can be used. As the aryl group serving as a substituent for the alkyl group, a phenyl group, a naphthyl group, an anthranyl group, and the like can be used, and a phenyl group is preferable. Moreover, as a halogen atom which becomes a substituent of an alkyl group, it is possible to use a fluorine atom, a chlorine atom, or a bromine atom. A plurality of these substituents may be substituted with an alkyl group, or both an aryl group and a halogen atom may be substituted.

  The compound of the chemical formula (6) is not limited to dimethyl sulfate, diethyl sulfate, ethyl methyl sulfate, but methyl propyl sulfate, ethyl propyl sulfate, methyl phenyl sulfate, ethyl phenyl sulfate, phenyl propyl sulfate, benzyl methyl sulfate, benzyl ethyl sulfate, etc. May be used. However, it is preferable to use dimethyl sulfate, diethyl sulfate, or ethyl methyl sulfate in which R11 and R12 have 1 or 2 carbon atoms because the increase in the thickness of the battery can be further suppressed even after charging and discharging at a low temperature. .

  Only one type of each group of compounds may be selected and used, or two or more types may be used in combination.

It is sectional drawing of the nonaqueous electrolyte secondary battery which concerns on this invention.

Explanation of symbols

1 battery (non-aqueous electrolyte secondary battery)
2 Flat wound electrode group 3 Negative electrode 4 Positive electrode 5 Separator 6 Battery case 7 Battery lid 8 Safety valve 9 Negative electrode terminal 10 Negative electrode lead

Claims (2)

In a non-aqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, and an electrolyte,
The electrolyte has the following chemical formula (1);
HO-R1-A (1)
(Wherein R1 is a hydrocarbon group that may contain an unsaturated bond, or a hydrocarbon group that may contain an unsaturated bond, part or all of which is substituted with a halogen element, and Has a structure represented by the following A1, A2 or A3):

The following chemical formula (2);

(Wherein R2 and R3 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. ) Cyclic sulfate derivatives represented by
The following chemical formula (3);

(Wherein R4 and R5 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. ) Unsaturated cyclic sulfate derivatives represented by
The following chemical formula (4);

(Wherein R6 and R7 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. And a cyclic sulfate derivative represented by the following chemical formula (5):

(Wherein R8 to R10 are each independently a hydrogen atom, the same or different alkyl group, the same or different vinyl group, the same or different alkoxy group, the same or different allyl group, the same One or different aryl groups, the same or different halogen, an alkyl group having the same or different halogen, an allyl group having the same or different halogen, or an aryl group having the same or different halogen. At least one compound of 1,3-propene sultone derivatives represented by:
The following chemical formula (6);
R11-SO ₄ -R12 (6)
(Wherein R11 and R12 each independently represent the same or different alkyl group) and a chain sulfate ester compound represented by the nonaqueous electrolyte secondary battery.   The non-aqueous electrolyte secondary battery according to claim 1, wherein the sulfate ester compound is at least one of dimethyl sulfate, diethyl sulfate, and ethyl methyl sulfate.

Images