KR102265976B1 - Electrode Assembly and Electrochemical device comprising the same - Google Patents

Abstract

The present invention provides an electrode assembly comprising a positive electrode, a negative electrode, and a composite solid electrolyte layer interposed between the positive electrode and the negative electrode, wherein the composite solid electrolyte layer includes: a first solid electrolyte part contacting both the negative electrode and the positive electrode; and a second solid electrolyte part in contact with the first solid electrolyte part and the positive electrode and spaced apart from the negative electrode, it provides an electrode assembly and an electrochemical device including the same.
The present invention prevents physical damage to the solid electrolyte layer, thereby preventing a short circuit between the positive electrode and the negative electrode.

Description

Electrode Assembly and Electrochemical Device Comprising the Same

The present invention relates to an electrode assembly and an electrochemical device including the same, and more particularly, to an electrode assembly including a solid electrolyte and an electrochemical device including the same.

Recently, interest in energy storage technology is increasing. Efforts for research and development of electrochemical devices are becoming more and more concrete as the field of application is expanded to the energy of mobile phones, camcorders and notebook PCs, and even electric vehicles. Electrochemical devices are receiving the most attention in this aspect, and among them, the development of rechargeable batteries that can be charged and discharged has become the focus of interest. Recently, in developing such batteries, new electrodes have been developed to improve capacity density and specific energy. and battery design research and development.

Among the currently applied secondary batteries, lithium secondary batteries developed in the early 1990s have a higher operating voltage and significantly higher energy density than conventional batteries such as Ni-MH, Ni-Cd, and sulfuric acid-lead batteries using aqueous electrolyte solutions. is gaining popularity as

For such a lithium secondary battery, a liquid electrolyte (electrolyte) such as a combustible organic solvent has been conventionally used. However, in a battery using a liquid electrolyte, there is a possibility of causing problems such as leakage of the electrolyte, ignition, and explosion.

In order to solve this problem and secure intrinsic safety, research on an All-Solid-State Secondary Battery that uses a solid electrolyte instead of a liquid electrolyte and consists of all other components in solid is being actively conducted. The all-solid-state battery is attracting attention as a next-generation lithium secondary battery in terms of safety, high energy density, high output, and simplification of the manufacturing process.

However, there is a problem in that a short circuit occurs due to the low strength of the solid electrolyte layer when manufacturing an electrode assembly to which such an all-solid-state battery is applied.

An object of the present invention is to provide an electrode assembly in which a short circuit between electrodes is prevented and physical damage to a solid electrolyte layer is prevented, and an electrochemical device including the same.

Other objects and advantages of the present invention will be understood by the following description. On the other hand, it will be easily understood that the objects and advantages of the present invention can be realized by means or methods described in the claims, and combinations thereof.

According to one aspect of the present invention in order to solve the above problems, there is provided an electrode assembly of the following embodiments.

The first embodiment is

An electrode assembly comprising a positive electrode, a negative electrode, and a composite solid electrolyte layer interposed between the positive electrode and the negative electrode,

The composite solid electrolyte layer may include: a first solid electrolyte part in contact with both the negative electrode and the positive electrode; and a second solid electrolyte part in contact with the first solid electrolyte part and the positive electrode and spaced apart from the negative electrode, it relates to an electrode assembly.

In the second embodiment, according to the first embodiment,

The second solid electrolyte portion is located on the outer peripheral surface of the positive electrode and relates to an electrode assembly, characterized in that formed to have a predetermined width inward from the end.

A third embodiment, according to the first or second embodiment,

It relates to an electrode assembly, characterized in that the area of the negative electrode is equal to or larger than the area of the composite solid electrolyte layer.

A fourth embodiment, according to any one of the first to third embodiments,

It relates to an electrode assembly, characterized in that the area of the negative electrode is larger than the area of the composite solid electrolyte layer.

A fifth embodiment, according to any one of the first to fourth embodiments,

The first solid electrolyte part relates to an electrode assembly, characterized in that it comprises at least one selected from the group consisting of a sulfide-based solid electrolyte and a polymer solid electrolyte as an electrolyte.

A sixth embodiment, according to any one of the first to fifth embodiments,

The sulfide-based solid electrolyte includes Li, X and S, wherein X includes at least one selected from the group consisting of P, Ge, B, Si, Sn, As, Cl, F, and I It relates to an electrode assembly.

A seventh embodiment, according to any one of the first to sixth embodiments,

The polymer solid electrolyte is a polyether-based polymer, a polycarbonate-based polymer, an acrylate-based polymer, a polysiloxane-based polymer, a phosphazene-based polymer, a polyethylene derivative, an alkylene oxide derivative, a phosphoric acid ester polymer, a poly agitation lysine, It relates to an electrode assembly comprising at least one selected from polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, and a polymer containing an ionic dissociation group.

The eighth embodiment, according to any one of the first to seventh embodiments,

The second solid electrolyte part relates to an electrode assembly, characterized in that it includes an oxide-based solid electrolyte as an electrolyte.

The ninth embodiment, according to the eighth embodiment,

The oxide-based solid electrolyte includes Li, A and O, wherein A is La, Zr, Ti, Al P, and I, characterized in that it includes at least one selected from the group consisting of P, and I will be.

According to another aspect of the present invention, an electrochemical device of the following embodiments is provided.

The tenth embodiment is

It relates to an electrochemical device including at least one electrode assembly of any one of the first to ninth embodiments into which the electrolyte is injected.

The eleventh embodiment, according to the tenth embodiment,

It relates to an electrochemical device, wherein the electrochemical device is a lithium secondary battery.

In the electrode assembly of the present invention, a second solid electrolyte part having high mechanical strength is disposed on the edge of the surface of the anode, and the second solid electrolyte part is spaced apart from the cathode. From these structural features, the electrode assembly according to the present invention can prevent a short circuit due to physical damage to the solid electrolyte layer.

1 is a perspective view schematically illustrating an electrode assembly according to an embodiment of the present invention.
2 is an exploded perspective view of FIG. 1 schematically illustrating an electrode assembly according to an embodiment of the present invention.
3 is a perspective view schematically illustrating an electrode assembly according to an embodiment of the present invention.
4 is an exploded perspective view of FIG. 3 schematically illustrating an electrode assembly according to an embodiment of the present invention.
5 is a perspective view schematically illustrating an electrode assembly according to an embodiment of the present invention.
6 is an exploded perspective view of FIG. 5 schematically illustrating an electrode assembly according to an embodiment of the present invention.
7 schematically illustrates a method of manufacturing an electrode assembly according to a specific embodiment of the present invention.

Hereinafter, the present invention will be described in detail. The terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor may properly define the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that there is. Accordingly, the configuration shown in the embodiments and drawings described in the present specification is merely the most preferred embodiment of the present invention and does not represent all the technical spirit of the present invention, so at the time of the present application, various It should be understood that there may be equivalents and variations.

In an electrode assembly used in an all-solid-state battery, the solid electrolyte layer serves as a separator that physically separates the positive and negative electrodes in the battery and as a safety device to prevent overheating of the battery. In addition, since the solid electrolyte layer can move lithium ions to the ion conductive layer, charging and discharging of the battery is possible.

In such an all-solid-state battery, since the strength of the positive electrode active material layer is greater than that of the solid electrolyte layer, physical damage to the solid electrolyte layer may occur due to the positive electrode active material layer during the manufacturing process of the electrode assembly, and between the positive electrode and the negative electrode due to the damaged solid electrolyte layer A short circuit may occur.

The present invention is to solve the above problems.

The present invention relates to an all-solid-state battery, and to an electrode assembly including a composite solid electrolyte layer and an electrochemical device including the same.

An electrode assembly according to an aspect of the present invention,

A positive electrode, a negative electrode, and a composite solid electrolyte layer interposed between the positive electrode and the negative electrode,

The composite solid electrolyte layer may include: a first solid electrolyte part in contact with both the negative electrode and the positive electrode; and a second solid electrolyte part in contact with the first solid electrolyte part and the positive electrode and spaced apart from the negative electrode.

First, the present invention will be described with reference to FIG. 1 .

1 is a perspective view schematically showing an electrode assembly 100 according to a specific embodiment of the present invention. FIG. 2 is an exploded perspective view of the electrode assembly of FIG. 1 .

The electrode assembly 100 according to a specific embodiment of the present invention includes a positive electrode 10 , a negative electrode 20 , and a composite solid electrolyte layer 50 interposed between the positive electrode and the negative electrode. The composite solid electrolyte layer 50 includes: a first solid electrolyte part 30 in contact with both the negative electrode and the positive electrode; and a second solid electrolyte part 40 in contact with the first solid electrolyte part and the positive electrode and spaced apart from the negative electrode.

In a specific embodiment of the present invention, the composite solid electrolyte layer 50 is interposed between the positive electrode and the negative electrode, and is used as a solid electrolyte layer in an all-solid-state battery. Since the electrode assembly according to the present invention does not include a liquid electrolyte and includes a solid electrolyte layer, problems such as electrolyte leakage or deterioration in flame retardancy do not occur.

In a specific embodiment of the present invention, the composite solid electrolyte layer 50 may be divided into a first layer and a second layer. However, this is only for easy explanation of the structure, and in reality, the first solid electrolyte part of the first layer and the first solid electrolyte part of the second layer are formed integrally without being separated.

The first layer includes the second solid electrolyte in the edge portion and the first solid electrolyte in the other portions. All of the outer peripheral portions of the second solid electrolyte may be connected to form a closed curve. In this case, the first layer may include the first solid electrolyte in an inner portion surrounded by the second solid electrolyte. In a specific embodiment of the present invention, the second solid electrolyte part may be cut off instead of a single closed curve, and may consist of a plurality of parts, and may be formed on a part of the rim. In this case, the portion where the second solid electrolyte is not formed may include the first solid electrolyte. On the other hand, the second layer is configured to cover the entire surface of one side of the first layer, and includes a first solid electrolyte.

In a specific embodiment of the present invention, the outer diameter of the second solid electrolyte portion is formed to coincide with the positive electrode when the electrode assembly is manufactured. As shown in FIG. 1 , the anode and the second solid electrolyte part are stacked without a step by making the horizontal and vertical lengths the same. That is, the second solid electrolyte portion may be formed in a shape consistent with the edge portion of the positive electrode.

In one specific embodiment of the present invention, the first layer faces the anode, and the second layer faces the cathode. The first and second floors may have the same or different heights.

The composite solid electrolyte layer 50 includes a first solid electrolyte part 30 and a second solid electrolyte part 40 . Both the first solid electrolyte part and the second solid electrolyte part are ion conductive layers that allow lithium ions to pass through, and are insulating layers that do not allow electrons to pass through. Therefore, since the electrode assembly according to the present invention includes the composite solid electrolyte layer, a short circuit that may occur when the positive electrode and the negative electrode come into contact with each other can be prevented, and the battery can be charged and discharged.

The pore diameter of the composite solid electrolyte layer may be generally 0.001 to 10 μm. In a specific embodiment of the present invention, the lower limit of the pore diameter may be 0.01 μm or more and 0.1 μm or more, and the upper limit of the pore diameter may be 7 μm or less, 5 μm or less, and a combination thereof. The thickness of the composite solid electrolyte layer may be generally 5 to 300 μm. In a specific embodiment of the present invention, the lower limit of the thickness may be 7 μm or more and 10 μm or more, and the lower thickness limit may be 200 μm or less and 150 μm or less. The composite solid electrolyte layer may have the same area as the positive electrode.

In a specific embodiment of the present invention, the positive electrode; The area of the anode and the composite solid electrolyte layer 50 interposed between the anode and the cathode may be formed to be the same. The composite solid electrolyte layer may have the same area, that is, in the case of a rectangular shape, the horizontal and vertical lengths may be the same, and each layer may be stacked so that the ends coincide without a step. In this way, by making the areas of the positive electrode, the negative electrode, and the composite solid electrolyte layer the same, the electrode assembly components, for example, the negative electrode, the positive electrode, and the solid electrolyte layer are continuously introduced in the electrode assembly manufacturing process, such as roll lamination, Physical damage to the electrode assembly due to meandering can be prevented.

The first solid electrolyte part 30 directly faces both the positive electrode 10 and the negative electrode 20 . In addition, the first solid electrolyte part directly faces the anode surface on which the second solid electrolyte part is not formed, and the inner end face of the second solid electrolyte part. That is, the first solid electrolyte part faces the positive electrode, the negative electrode, and the second solid electrolyte part. In this case, since the first solid electrolyte part is located only at the edge of the anode surface, the second solid electrolyte part may have a T-block shape in cross section of the first solid electrolyte part.

The first solid electrolyte part may include at least one selected from the group consisting of a sulfide-based solid electrolyte and a polymer solid electrolyte as an electrolyte.

The sulfide-based solid electrolyte may include Li, X and S, and X may include at least one selected from the group consisting of P, Ge, B, Si, Sn, As, Cl, F, and I. . However, it is not particularly limited thereto, and a sulfide-based compound commonly used as a solid electrolyte may be used without limitation. For example, the sulfide-based solid electrolyte is Li _{3 . 833} Sn _{0 . 833} As _{0 . 166} S ₄ , Li ₄ SnS ₄ , Li _{3 . 25 Ge 0 .25 P 0. 75 S} 4, Li 2 SP 2 S 0, B 2 S 3 -Li 2 S, xLi 2 S- (100-x) P 2 S 5 (x = 70 ~ 80), Li _{2 S-SiS 2 -Li 3 N} , Li 2 SP 2 S 5 -LiI, Li 2 S-SiS 2 -LiI, Li 2 SB 2 S 3 -LiI, and _{Thio-LISICON (Li 3. 25} Ge 0 .25 P _{0. 75} may comprise S ₄₎ of any one or a mixture of two or more of those selected from the group consisting of.

Since sulfide ions have high polarization and have small electrostatic attraction with lithium ions, sulfide-based solid electrolytes have high ionic conductivity. Therefore, by introducing the first solid electrolyte portion containing the sulfide-based solid electrolyte, it is possible to obtain a high output current of the electrochemical device.

The polymer solid electrolyte is, for example, a polyether-based polymer, a polycarbonate-based polymer, an acrylate-based polymer, a polysiloxane-based polymer, a phosphazene-based polymer, a polyethylene derivative, an alkylene oxide derivative, a phosphoric acid ester polymer, and a poly-edition lysine ( agitation lysine), polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, a polymer containing an ionic dissociation group, and the like. In a specific embodiment of the present invention, the polymer solid electrolyte is a polymer resin obtained by copolymerizing an amorphous polymer such as PMMA, polycarbonate, polysiloxane (pdms) and/or phosphazene as a comonomer in a PEO (polyethylene oxide) main chain. A branched copolymer, a comb-like polymer, and a cross-linked polymer resin may be included. However, the present invention is not particularly limited thereto, and a polymer solid electrolyte generally used as a solid electrolyte may be used without limitation.

The polymer solid electrolyte is any one selected from the group consisting of polyethylene oxide, polyethylene glycol, polypropylene oxide, polyphosphazene, polysiloxane, and copolymers thereof. Or it may be a mixture of two or more of these. Since the polymer solid electrolyte is chemically stable, it is safe even in the charging and discharging process. In addition, the polymer solid electrolyte is easy to handle, which is advantageous in the electrode assembly assembly process.

The first solid electrolyte unit may prevent a short circuit in the battery by using a sulfide-based solid electrolyte or a polymer solid electrolyte.

In a specific embodiment of the present invention, the first solid electrolyte part may further include an appropriate binder resin, additives, and the like, if necessary.

The second solid electrolyte part 40 is formed only on one layer, so it is spaced apart from the negative electrode 20 and does not physically come into direct contact with the negative electrode. The second solid electrolyte portion may be formed on an edge portion on the surface of the anode to have a predetermined width from the end in the inward direction. The width is sufficient as long as it can prevent physical damage due to an anode edge in an electrode assembly manufacturing process of lamination or the like.

In a specific embodiment of the present invention, the width may be 0.5 to 200㎛. Preferably, the width may be 0.5 μm or more, 1 μm or more, 10 μm or more, and 20 μm or more, respectively, and the width may be 200 μm or less, 150 μm or less, 100 μm or less, respectively, and a combination thereof . When the width of the second solid electrolyte part is within the above range, physical damage to the solid electrolyte layer that occurs during the manufacturing of the electrode assembly is prevented and at the same time, the area of the second solid electrolyte that faces the first solid electrolyte or the second solid electrolyte that faces the anode Since the area of the solid electrolyte is small, there is no deterioration in battery performance due to interfacial resistance.

In a specific embodiment of the present invention, the thickness of the second solid electrolyte portion may be 3 μm or less, 1 μm or less, 0.7 μm or less, or 0.6 μm or less. In a specific embodiment of the present invention, the thickness of the second solid electrolyte portion may be 0.1 μm or more, 0.3 μm or more, or 1 μm or more. In a specific embodiment of the present invention, the thickness of the second solid electrolyte portion may be a combination of each of the above-described upper and lower limits. When the thickness of the second solid electrolyte portion is within the above range, physical damage to the composite solid electrolyte layer by the edge portion of the positive electrode during the manufacturing process of the electrode assembly may be minimized.

As described above, the second solid electrolyte part may be positioned on the outer periphery of the surface of the anode to have a closed curve shape. On the other hand, in one specific embodiment of the present invention, the second solid electrolyte part may be an aggregate of several parts in which one closed curve is not integrally formed and is disconnected.

The second solid electrolyte may include an oxide-based solid electrolyte as an electrolyte.

The oxide-based solid electrolyte may include Li, A and O, and A may include at least one selected from the group consisting of La, Zr, Ti, Al, P and I. However, the present invention is not limited thereto, and oxide-based compounds commonly used as solid electrolytes may be used without limitation. For example, the oxide-based solid electrolyte is Li ₃ xLa _{2 /3- x} TiO ₃ (LLTO), Li ₇ La ₃ Zr ₂ O ₁₂ (LLZO), Li _{1 + x} Al _x Ti _{2 -X} (PO ₄ ) ₃ (LATP), Li _{1 + x} Al _x Ge _{2 -X} (PO ₄ ) ₃ (LAGP), Li _1.4 Zn(GeO ₄ ) ₄ , Li ₃ N, LIPON(Li _{3 + y} PO _{4 - x} N _x ) , and Li _{3 . 6} Si _{0 .6} P _{0. 4} O ₄ which is selected from the group consisting of one or may comprise a mixture of two or more of these.

Oxide-based solid electrolytes have higher mechanical strength than sulfide-based solid electrolytes or solid polymer electrolytes. Therefore, in the lamination process in which the components of the electrode assembly, for example, the positive electrode, the negative electrode, and the solid electrolyte layer are input and stacked, the composite solid electrolyte layer is physically damaged by the positive electrode edge portion when the electrode assembly is pressed. can be prevented in

In a specific embodiment of the present invention, the second solid electrolyte part may further include an appropriate binder resin, additives, and the like, if necessary.

Meanwhile, when designing an electrode assembly according to the related art, the areas of the positive electrode, the solid electrolyte layer, and the negative electrode are different, so that there is a difference in area between them. Typically, there was at least two area differences between the positive electrode and the solid electrolyte layer and between the negative electrode and the solid electrolyte layer.

On the other hand, referring to FIG. 1 , in the electrode assembly according to the present invention, since the areas of the positive electrode, the negative electrode, and the composite solid electrolyte layer are the same, there is no area difference. Accordingly, there is no loss of energy density due to the area difference, and energy density is improved compared to the conventional electrode assembly.

In another embodiment of the present invention, in the electrode assembly, the area of the negative electrode and the composite solid electrolyte layer may be the same, or the area of the positive electrode and the composite solid electrolyte layer may be the same. In this case, the electrode assembly may have a larger area of the negative electrode than the positive electrode. In a specific embodiment of the present invention, the area of the negative electrode may be greater than the area of the composite solid electrolyte layer, and the area of the composite solid electrolyte layer may be the same as the area of the positive electrode.

3 is a perspective view schematically showing an electrode assembly 100 according to a specific embodiment of the present invention. FIG. 4 is an exploded perspective view of the electrode assembly of FIG. 3 .

Referring to FIG. 3 , the electrode assembly 100 includes an anode 10 ; It includes a negative electrode 20 and a composite solid electrolyte layer 50 interposed between the positive electrode and the negative electrode. The composite solid electrolyte layer includes a second solid electrolyte part 40 that is in contact with the positive electrode and is spaced apart from the negative electrode, and includes a first solid electrolyte part 30 that is in contact with both the negative electrode and the positive electrode.

Referring back to FIG. 3 , in the electrode assembly 100 , the area of the negative electrode is larger than the area of the composite solid electrolyte layer, and the area of the composite solid electrolyte layer and the area of the positive electrode are the same. In the electrode assembly having this configuration, there is no area difference between the positive electrode and the composite solid electrolyte layer, only the area difference between the negative electrode and the composite solid electrolyte layer. Accordingly, energy loss due to a difference in area is reduced, and thus an electrode assembly having improved energy density may be provided.

In another embodiment of the present invention, the area of the negative electrode may be the same as the area of the composite solid electrolyte layer, and the area of the two may be larger than the area of the positive electrode.

5 is a perspective view schematically illustrating an electrode assembly 100 according to a specific embodiment of the present invention. 6 is an exploded perspective view of the electrode assembly of FIG. 5

Referring to FIG. 5 , the electrode assembly 100 includes an anode 10 ; It includes a negative electrode 20 and a composite solid electrolyte layer 50 interposed between the positive electrode and the negative electrode. The composite solid electrolyte layer includes a second solid electrolyte part 40 that is in contact with the positive electrode and is spaced apart from the negative electrode, and includes a first solid electrolyte part 30 that is in contact with both the negative electrode and the positive electrode.

When the composite solid electrolyte layer 50 of FIG. 5 is divided into a first layer and a second layer,

The first layer includes a second solid electrolyte in the form of a frame, and includes a first solid electrolyte in other portions. All of the frame portions made of the second solid electrolyte may be connected to form a closed curve. In this case, the first solid electrolyte may be included in the inner portion of the frame portion composed of the second solid electrolyte. In addition, a first solid electrolyte portion having a predetermined width may be further disposed on all or part of an outer portion of the frame portion composed of the second solid electrolyte. The first solid electrolyte part may be formed to enclose all or part of the frame part. In a specific embodiment of the present invention, the second solid electrolyte portion may be formed of a plurality of discontinuous portions rather than a single closed curve, and may be formed in a portion of the rim. In this case, the portion where the second solid electrolyte is not formed may include the first solid electrolyte. On the other hand, the second layer is configured to cover the entire surface of one side of the first layer, and includes a first solid electrolyte. Referring to FIG. 5 , the first solid electrolyte part may have a structure in which a frame-shaped groove having a predetermined width is dug inside the surface of the first solid electrolyte part.

In a specific embodiment of the present invention, the outer diameter of the second solid electrolyte portion is formed to coincide with the positive electrode when the electrode assembly is manufactured. As shown in FIG. 5 , the anode and the second solid electrolyte part are stacked without a step by making the horizontal and vertical lengths the same. That is, the second solid electrolyte portion may be formed in a shape consistent with the edge portion of the positive electrode. In a specific embodiment of the present invention, the first layer faces the anode, and the second layer faces the cathode. The first and second floors may have the same or different heights.

In the above description, the composite solid electrolyte layer has been described as being divided into one layer and two layers, but this is only for easy explanation of the structure, and in reality, the first solid electrolyte part of the first layer and the first solid electrolyte part of the second layer are separated. It is not formed as a single entity.

Referring back to FIG. 5 , in the electrode assembly 100 , the area of the negative electrode and the area of the composite solid electrolyte layer may be the same, and the area of the negative electrode and the composite solid electrolyte layer may be larger than the area of the positive electrode. That is, in the electrode assembly according to the present invention, only an area difference exists between the positive electrode and the composite solid electrolyte layer. In this case, energy loss due to the area difference is reduced. An electrode assembly having improved energy density of the electrode assembly may be provided.

The electrode assembly according to an aspect of the present invention may be manufactured by separately manufacturing the positive electrode, the second solid electrolyte part, the first solid electrolyte part, and the negative electrode, and then laminating them and laminating them. 7 schematically illustrates a method of manufacturing an electrode assembly according to a specific embodiment of the present invention.

In a specific embodiment of the present invention, the first solid electrolyte part is prepared in a flat plate shape in which a position where the second solid electrolyte part is disposed is not provided in advance, and the second solid electrolyte part is disposed in the first solid electrolyte part by pressurization. In this way, a composite solid electrolyte layer can be formed.

However, the method for manufacturing the electrode assembly according to an aspect of the present invention is not limited to the above methods, and is not particularly limited as long as it can manufacture the electrode assembly according to the present invention.

Meanwhile, another aspect of the present invention provides an electrochemical device including at least one electrode assembly described above.

The electrochemical device includes all devices that undergo an electrochemical reaction, and specific examples thereof include all kinds of primary, secondary batteries, fuel cells, solar cells, or capacitors such as super capacitor devices. In particular, a lithium secondary battery including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, or a lithium ion polymer secondary battery among the secondary batteries is preferable.

The positive electrode and the negative electrode to be applied together with the composite solid electrolyte layer of the present invention are not particularly limited, and the electrode active material layer may be prepared in the form of binding to the electrode current collector according to a conventional method known in the art.

In a specific embodiment of the present invention, the positive electrode may include a current collector and a positive active material layer formed on the surface of the current collector, and the positive active material layer may further include a positive active material, a solid electrolyte, a binder, and a conductive material. have.

The positive electrode current collector is generally made to have a thickness of 3 to 500 μm. The positive electrode current collector is not particularly limited as long as it has high conductivity without causing a chemical change in the battery, and for example, stainless steel, aluminum, nickel, titanium, fired carbon, or a surface of aluminum or stainless steel. Carbon, nickel, titanium, silver, etc. surface-treated may be used. In addition, the positive electrode current collector may increase the adhesive force of the positive electrode active material by forming fine irregularities on the surface thereof, and various forms such as a film, a sheet, a foil, a net, a porous body, a foam, and a nonwoven body are possible.

The positive active material is not particularly limited as long as it is a positive active material that can be used for a positive electrode of an electrochemical device. For example, the positive active material is LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiCoPO ₄ , LiFePO ₄ , LiNiMnCoO ₂ and LiNi _{1- xy- z} Co _x M1 _y M2 _z O ₂ (M1 and M2 are each independently Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, any one selected from the group consisting of Mg and Mo, x, y and z are each independently 0 ≤ 0 ≤ ≤ x < 0.5, 0 ≤ y < 0.5, 0 ≤ z < 0.5, and x+y+z ≤ 1) or a mixture of two or more thereof.

In a specific embodiment of the present invention, the negative electrode may include a current collector and a negative active material layer formed on the surface of the current collector, and the negative active material layer may include a negative active material, a solid electrolyte, a binder, and a conductive material. have.

The negative electrode current collector is generally made to have a thickness of 3 to 500 μm. Such a negative current collector is not particularly limited as long as it has high conductivity without causing a chemical change in the battery, and may be a foil made of copper, gold, nickel, or a copper alloy or a combination thereof.

The negative active material is not particularly limited as long as it is an anode active material that can be used for the negative electrode of the electrochemical device. For example, it may be a lithium adsorption material such as lithium metal or lithium alloy, carbon, petroleum coke, activated carbon, graphite, or other carbons.

The binder is a component that assists in bonding between the electrode active material and the conductive material and bonding to the current collector, and is typically added in an amount of 1 to 50 wt % based on the total weight of the positive electrode mixture. As such a binder, the high molecular weight polyacrylonitrile-acrylic acid copolymer may be used, but is not limited thereto. Other examples include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene ether polymer (EPDM), sulfonated EPDM, styrene butyrene rubber, fluororubber, various copolymers, and the like. However, it is not particularly limited thereto, and any binder component commonly used in electrochemical devices may be used without limitation.

As the conductive material, conventional ones used for manufacturing electrodes may be used, and non-limiting examples thereof include one or more selected from carbon nanotubes, acetylene black, carbon black, natural graphite, artificial graphite, Ketjen black, carbon fiber, and the like. it is a combination However, it is not particularly limited thereto, and as long as it is a conductive material commonly used in an electrochemical device, it may be used without limitation.

Claims (11)

An electrode assembly comprising a positive electrode, a negative electrode, and a composite solid electrolyte layer interposed between the positive electrode and the negative electrode,
The composite solid electrolyte layer may include: a first solid electrolyte part in contact with both the negative electrode and the positive electrode; and a second solid electrolyte part in contact with the first solid electrolyte part and the positive electrode and spaced apart from the negative electrode,
The first solid electrolyte part comprises at least one selected from the group consisting of a sulfide-based solid electrolyte and a polymer solid electrolyte as an electrolyte,
The second solid electrolyte part includes a solid electrolyte material, and the solid electrolyte material is an oxide-based solid electrolyte.
According to claim 1,
The second solid electrolyte portion is located on the outer peripheral surface of the positive electrode, characterized in that formed to have a predetermined width inward from the end, the electrode assembly.
According to claim 1,
The electrode assembly, characterized in that the area of the negative electrode is equal to or larger than the area of the composite solid electrolyte layer.
According to claim 1,
The electrode assembly, characterized in that the area of the negative electrode is larger than the area of the composite solid electrolyte layer.
delete According to claim 1,
The sulfide-based solid electrolyte includes Li, X and S, wherein X includes at least one selected from the group consisting of P, Ge, B, Si, Sn, As, Cl, F, and I to the electrode assembly.
According to claim 1,
The polymer solid electrolyte is a polyether-based polymer, a polycarbonate-based polymer, an acrylate-based polymer, a polysiloxane-based polymer, a phosphazene-based polymer, a polyethylene derivative, an alkylene oxide derivative, a phosphate ester polymer, a poly agitation lysine, An electrode assembly comprising at least one selected from polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, and a polymer containing an ionic dissociation group.
delete According to claim 1,
The oxide-based solid electrolyte includes Li, A and O, and A is La, Zr, Ti, Al P, and I, characterized in that it includes at least one selected from the group consisting of I, the electrode assembly.
An electrochemical device comprising at least one of the electrode assemblies of any one of claims 1 to 4, 6, 7 and 9 in which the electrolyte is injected.
11. The method of claim 10,
The electrochemical device is a lithium secondary battery.

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