KR102415542B1 - Cathode active material slurry for solid electrolyte battery and cathode for solid electrolyte battery prepared therefrom - Google Patents

Abstract

The present invention provides a cathode active material; conductive material; solid electrolyte; electrolyte salts; and a dispersion medium for dispersing the positive active material, the conductive material, the solid electrolyte, and the electrolyte salt, which is dispersed by the dispersion medium and is present in a solid state at 15 to 25 ° C. Further comprising a plasticizer, wherein the plasticizer, when exposed to a temperature environment higher than the melting point of the plasticizer, changes into a liquid phase and penetrates into the cracks formed in the positive electrode active material. It relates to a positive electrode for an electrolyte battery.

Description

Cathode active material slurry for solid electrolyte battery and cathode for solid electrolyte battery prepared therefrom

The present invention relates to a positive electrode active material slurry for a solid electrolyte battery and a positive electrode for a solid electrolyte battery prepared therefrom, and more particularly, to a positive electrode active material slurry for a solid electrolyte battery capable of imparting ion conductivity to the inside of cracks formed in the positive electrode active material, and therefrom It relates to a prepared positive electrode for a solid electrolyte battery.

A lithium ion battery using a liquid electrolyte has a structure in which the negative electrode and the positive electrode are partitioned by a separator, so if the separator is damaged by deformation or external impact, a short circuit may occur, which may lead to the risk of overheating or explosion. Therefore, it can be said that the development of a solid electrolyte capable of securing safety in the field of lithium ion secondary batteries is a very important task.

Lithium secondary batteries using solid electrolytes have advantages in that battery safety is increased, electrolyte leakage can be prevented, so battery reliability is improved, and thin batteries can be easily manufactured. In addition, since lithium metal can be used as an anode, energy density can be improved. Accordingly, it is expected to be applied to small secondary batteries and high-capacity secondary batteries for electric vehicles, and thus is spotlighted as a next-generation battery.

On the other hand, the phenomenon that cracks are formed in the positive active material is one of the well-known causes of lifespan deterioration in typical lithium ion secondary batteries, it occurs from the beginning of the cycle, and it is known that it occurs under all conditions regardless of the type and potential of the active material. .

On the other hand, in the case of a solid electrolyte battery to which a solid electrolyte is applied, unlike a battery to which a liquid electrolyte is applied, it is impossible for the electrolyte to penetrate into the cracks of the cathode active material that occur during the cycle. For this reason, there is a problem in that a path necessary for ion conduction is cut off, and the lifespan of the battery is rapidly shortened.

Accordingly, the problem to be solved by the present invention is a positive electrode active material slurry for a solid electrolyte battery that allows the electrolyte to penetrate into cracks formed in the positive electrode active material, like a liquid electrolyte battery in a solid electrolyte battery system, and a positive electrode for a solid electrolyte battery prepared therefrom is to provide

According to an aspect of the present invention, a positive active material; conductive material; solid electrolyte; electrolyte salts; and a dispersion medium for dispersing the positive active material, the conductive material, the solid electrolyte, and the electrolyte salt, which is dispersed by the dispersion medium and is present in a solid state at 15 to 25 ° C. Further comprising a plasticizer, wherein the plasticizer, when exposed to a temperature environment equal to or higher than the melting point of the plasticizer, changes to a liquid phase and penetrates into the cracks formed in the positive electrode active material.

In this case, the plasticizer is ethylene carbonate (EC), polyethylene glycol (PEG) having a weight average molecular weight of 1,000 or more, succinonitrile (SN) and cyclic phosphate (CP). It may be any one selected from the group consisting of, or a mixture of two or more thereof.

And, the cathode active material slurry for a solid electrolyte battery, based on 100 parts by weight of the dispersion medium, 60 to 100 parts by weight of the cathode active material, 0.1 to 20 parts by weight of the conductive material, 1 to 50 parts by weight of the solid electrolyte, 0.01 parts by weight of the electrolyte salt to 25 parts by weight, and 0.1 to 30 parts by weight of the plasticizer.

In addition, the plasticizer may be dissolved in the cathode active material slurry for a solid electrolyte battery and dispersed in a liquid state, or may be dispersed in a solid state.

Meanwhile, according to another aspect of the present invention, it relates to a positive electrode for a solid electrolyte battery comprising a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, wherein the positive electrode active material layer is for a solid electrolyte battery according to the present invention There is provided a positive electrode for a solid electrolyte battery, characterized in that the positive electrode active material slurry is dried and the dispersion medium is removed.

And, according to another aspect of the present invention, it relates to a solid electrolyte battery comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode is the positive electrode for a solid electrolyte battery according to the present invention There is provided a solid electrolyte battery, characterized in that.

In addition, there is provided a battery module comprising the above-described solid electrolyte battery according to the present invention as a unit cell and a battery pack including the same.

According to an embodiment of the present invention, a specific plasticizer additionally provided in the positive electrode for a solid electrolyte battery penetrates into the crack of the positive electrode active material generated during the cycle of the solid electrolyte battery, and imparts ionic conductivity to the inside of the crack can do.

Accordingly, a path necessary for ion conduction due to the occurrence of cracks in the positive electrode active material is maintained, thereby preventing deterioration of the lifespan characteristics of the solid electrolyte battery.

In addition, since the plasticizer of the present application has high ionic conductivity, it is possible to further improve the output performance of the battery. In addition, the oxidation reactivity is higher than the potential used for the anode, so that it can be used stably in the anode.

The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical spirit of the present invention together with the above-described content of the present invention, so the present invention is limited to the matters described in those drawings It should not be construed as being limited.
1 is a graph showing the capacity retention rate of batteries according to Examples 1 and 2 and Comparative Examples.

Hereinafter, the present invention will be described in detail with reference to the drawings. 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. Based on the principle that there is, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Accordingly, the embodiments described in the present specification and the configurations described in the drawings are only the most preferred embodiment of the present invention, and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.

A cathode active material slurry for a solid electrolyte battery according to an aspect of the present invention includes a cathode active material; conductive material; solid electrolyte; electrolyte salts; and a dispersion medium for dispersing the positive active material, the conductive material, the solid electrolyte and the electrolyte salt, wherein the slurry is dispersed by the dispersion medium, and is at room temperature, that is, 15 to 25 ° C. It further comprises a plasticizer present in a solid state, wherein the plasticizer, when exposed to a temperature environment higher than the melting point of the plasticizer, changes to a liquid phase and penetrates into cracks formed in the positive electrode active material.

In general, cracks occur in the positive electrode active material during the cycle of the battery, and the plasticizer of the present application penetrates into the cracks during the cycle of the battery, thereby ions inside the crack as in the liquid electrolyte battery Conductivity can be provided. Accordingly, it is possible to prevent deterioration of the lifespan characteristics of the solid electrolyte battery.

The plasticizer exists in a solid state at room temperature, but any material that can change to a liquid phase at a high temperature can be used. Specifically, ethylene carbonate (EC), which has a melting point of about 37 ° C, and a melting point of about 35 ° C. Polyethylene glycol (PEG) having a phosphorus weight average molecular weight of 1,000 or more, succinonitrile (SN) having a melting point of about 57 ° C., and cyclic phosphate (CP) having a melting point of about 65 ° C. It may be any one selected from the group or a mixture of two or more thereof.

Meanwhile, propylene carbonate (PC) having a melting point of about -49 ° C, polyethylene glycol (PEG) having a weight average molecular weight of 600 or less, and polyethylene glycol dimethyl ether having a melting point of about -23 ° C. ether, PEGDME), dioctyl phthalate (DOP) with a melting point of about -50 ℃, and diethyl phthalate (DEP) with a melting point of about -4 ℃ exist in a liquid state at room temperature. It is difficult to apply as a plasticizer of the invention.

As an example of the plasticizer according to the present invention, the melting point of ethylene carbonate is about 37° C., and may exist in a liquid phase in the slurry during the preparation of the cathode active material slurry, so that it can be uniformly dispersed. Later, when the slurry is coated on the electrode current collector and dried, the dispersion medium is volatilized and removed, but ethylene carbonate remains without volatilization, and it changes to a solid phase at room temperature and is uniformly distributed around the positive electrode active material in the positive electrode.

In addition, as the solid electrolyte battery including the positive electrode prepared from the positive electrode active material slurry is exposed to a high temperature of 37° C. or higher through a high-temperature activation process, ethylene carbonate distributed around the positive electrode active material is changed to a liquid phase again, and the positive electrode electrode It reacts with the electrolyte salt in the interior, and thereafter exists in the liquid phase even at 37°C or lower. During the cycle of the battery, cracks occur in the cathode active material, and the ethylene carbonate penetrates into the cracks, thereby imparting ionic conductivity to the cracks as in the case of a liquid electrolyte battery. Accordingly, it is possible to prevent deterioration of the lifespan characteristics of the solid electrolyte battery.

The ethylene carbonate, which is used in a general non-aqueous electrolyte, can be applied to most batteries and has the advantage of no impurities. In particular, such ethylene carbonate has high ion conductivity, so that the output performance of the battery can be further improved. In addition, the oxidation reactivity (6.2 V) is higher than the potential used for the anode, so it can be used stably in the anode.

In addition to the ethylene carbonate, polyethylene glycol having a weight average molecular weight of 1,000 or more used as a plasticizer of the present application, succinonitrile (SN), and cyclic phosphate (CP), etc. are similar to the above-mentioned effects, such as ethylene carbonate. can exert

On the other hand, the cathode active material slurry for a solid electrolyte battery, based on 100 parts by weight of the dispersion medium, 60 to 100 parts by weight of the positive active material, 0.1 to 20 parts by weight of the conductive material, 1 to 50 parts by weight of the solid electrolyte, 0.01 parts by weight of the electrolyte salt to 25 parts by weight, and 0.1 to 30 parts by weight of the plasticizer.

If the content of the plasticizer is less than the numerical range, the effect is insignificant, and if it exceeds the numerical range, it becomes similar to a battery to which a liquid electrolyte is applied, and thus the safety improvement effect is insignificant, which is not preferable.

In addition, the plasticizer may be dissolved in the cathode active material slurry for a solid electrolyte battery and dispersed in a liquid state, or may be dispersed in a solid state.

On the other hand, the plasticizer has a property that may be absorbed by reacting with the solid electrolyte. Thereby, the solid electrolyte itself may be modified to improve performance.

However, in the present invention, absorption of the plasticizer into the solid electrolyte is prevented, and the plasticizer is directly present on the surface of the positive electrode active material rather than the solid electrolyte. To this end, during the preparation of the cathode active material slurry, the temperature condition may be set below the melting point of the plasticizer. For example, in the case of ethylene carbonate, the cathode active material slurry may be prepared at a temperature of 37 °C or less, preferably 0 to 25 °C, more preferably 0 to 10 °C. Accordingly, even when the plasticizer exists as a solid or is dissolved in the slurry and exists in a liquid state, the reactivity with the solid electrolyte is lowered, so that even when the electrode active material slurry is mixed, it is not absorbed into the solid electrolyte and individually in the slurry You can control it to exist. Thereafter, when a positive electrode is manufactured through the slurry, it exists in a solid state around the positive active material in the electrode, and exists in a liquid state around the positive active material after the high-temperature activation process, and subsequently during the cycle of the battery, It allows smooth penetration into the cracks formed in the positive electrode active material.

Meanwhile, in the present invention, any material that can be used as the positive electrode active material of a lithium secondary battery may be used as the positive electrode active material. For example, a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals; Formula Li _{1 + x} Mn _{2 - x} O ₄(herein, x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ Lithium manganese oxide, such as; lithium copper oxide (Li ₂ CuO ₂ ); vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; Ni site-type lithium nickel oxide represented by the formula LiNi _{1 - x} M _x O ₂ (wherein M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x = 0.01 to 0.3); Formula LiMn _{2 - x} M _x O ₂ (where M = Co, Ni, Fe, Cr, Zn or Ta and x = 0.01 to 0.1) or Li ₂ Mn ₃ MO ₈ (where M = Fe, Co, lithium manganese composite oxide represented by Ni, Cu or Zn; LiNi _x Mn _{2 - x} O ₄ A lithium manganese composite oxide having a spinel structure; LiMn ₂ O ₄ in which a part of Li in the formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , LiNi _{0 . 8} Co _{0 . 1} Mn _{0 . 1} O ₂ and the like. However, it is not limited only to these.

Meanwhile, when preparing the cathode active material slurry, a polymer binder may be further included depending on the type of solid electrolyte or desired performance, and the content that may be included is 1 to 20 parts by weight, preferably based on 100 parts by weight of the dispersion medium. It may be 1 to 10 parts by weight.

As the polymer binder, for example, polyvinylidene fluoride-hexafluoropropylene (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile (polyacrylonitrile), poly Various types of binders such as methyl methacrylate, styrene-butadiene rubber (SBR), and carboxyl methyl cellulose (CMC) may be used.

In addition, the conductive material is not particularly limited as long as it has conductivity without causing a chemical change in the battery. For example, graphite such as natural graphite or artificial graphite; carbon black, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; One or a mixture of two or more selected from conductive materials such as polyphenylene derivatives may be included.

In addition, it is preferable to use the solid electrolyte excellent in oxidation stability for the solid electrolyte of this invention. Since the solid electrolyte of the present invention mainly serves to transfer lithium ions within the electrode, any material having high ionic conductivity, for example, 10 ^-5 s/m or more, preferably 10 ^-4 s/m or more, may be used. It can be used, and is not limited to a specific component.

In this case, the solid electrolyte is a polymer solid electrolyte formed by adding a polymer resin to a solvated electrolyte salt, or a polymer containing an organic electrolyte containing an organic solvent and an electrolyte salt, an ionic liquid, a monomer or an oligomer, etc. in a polymer resin It may be a gel electrolyte, and further, it may be a sulfide-based solid electrolyte having high ionic conductivity or an oxide-based solid electrolyte having excellent stability.

In this case, 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 agitation. lysine (agitation lysine), polyester sulfide, polyvinyl alcohol, polyvinylidene fluoride, a polymer containing an ionic dissociation group, and the like. In addition, the polymer solid electrolyte is a polymer resin in which an amorphous polymer such as PMMA, polycarbonate, polysiloxane (pdms) and/or phosphazene is copolymerized as a comonomer in a PEO (polyethylene oxide) main chain, a branched copolymer, a comb polymer resin (comb-like polymer) and cross-linked polymer resin may be included, and may be a mixture of the above polymers.

In addition, the polymer gel electrolyte includes an organic electrolyte containing an electrolyte salt and a polymer resin, and the organic electrolyte contains 60 to 400 parts by weight based on the weight of the polymer resin. The polymer applied to the gel electrolyte is not limited to a specific component, but for example, polyether-based, PVC-based, PMMA-based, polyacrylonitrile (PAN), polyvinylidene fluoride (PVdF), polyvinyl fluoride poly(vinylidene fluoride-hexafluoro) propylene: PVdF-HFP and the like may be included. And it may be a mixture of the above polymers.

In addition, the electrolyte salt is an ionizable lithium salt and may be expressed as Li ⁺ X ⁻ . These lithium salts are preferably LiTFSI, LiCl, LiBr, LiI, LiClO ₄ , LiBF ₄ , LiB ₁₀ Cl ₁₀ , LiPF ₆ , LiAsF ₆ , LiSbF ₆ , LiAlCl ₄ , LiSCN, LiCF ₃ CO ₂ , LiCH ₃ SO ₃ , LiCF ₃ SO ₃ , LiN(SO ₂ CF ₃ ) ₂ , LiN(SO ₂ C ₂ F ₅ ) ₂ , LiC ₄ F ₉ SO ₃ , LiC(CF ₃ SO ₂ ) ₃ , (CF ₃ SO ₂ )·2NLi, It may be one selected from the group consisting of lithium chloroborate, lithium lower aliphatic carboxylate, lithium 4-phenyl borate, and combinations thereof. More preferably, it may be lithium bistrifluoromethanesulfonimide (LiTFSI).

In addition, the dispersion medium of the present invention can be used without any particular limitation as long as it is usually used in the preparation of the cathode active material slurry. Specifically, it may be isopropyl alcohol, N-methylpyrrolidone (NMP), acetone, and the like.

Meanwhile, according to another aspect of the present invention, it relates to a positive electrode for a solid electrolyte battery comprising a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, wherein the positive electrode active material layer is for a solid electrolyte battery according to the present invention It is characterized in that the cathode active material slurry is dried and the dispersion medium is removed.

A positive electrode is prepared by coating the positive electrode active material slurry for a solid electrolyte battery on a positive electrode current collector and drying it.

In this case, the coating method may use a known coating method such as slot die, gravure coating, spin coating, spray coating, roll coating, curtain coating, extrusion, casting, screen printing, or inkjet printing.

In addition, the drying of the cathode active material slurry may be drying while vaporizing the solvent by irradiating heat, E-beam, gamma rays, or UV (G, H, I-line) or the like.

Through this drying, the dispersion medium is volatilized and removed, but the remaining components including the plasticizer remain un volatilized, forming a positive electrode active material layer.

And, in the present invention, as the positive electrode current collector, an appropriate one may be used according to the polarity of the current collector electrode known in the field of secondary batteries as showing electrical conductivity such as a metal plate.

Meanwhile, the solid electrolyte battery according to another aspect of the present invention includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, wherein the positive electrode is the positive electrode for a solid electrolyte battery according to the present invention described above characterized.

In this case, in the solid electrolyte battery, through the charging/discharging process as described above, the plasticizer penetrates into the cracks formed in the positive electrode active material. Accordingly, ion conductivity can be imparted to the inside of the crack as in the case of the liquid electrolyte battery. As a result, it is possible to prevent deterioration of the lifetime characteristics of the solid electrolyte battery.

And, in the present invention, the negative electrode may be used without limitation as long as it can be used as a negative electrode active material of a lithium secondary battery as a negative electrode active material. For example, carbon such as non-graphitizable carbon and graphite-based carbon (natural graphite, artificial graphite); Li _x Fe ₂ O ₃ (0≤x≤1), Li _x WO ₂ (0≤x≤1), Sn _x Me _{1 - x} Me' _y O _z (Me: Mn, Fe, Pb, Ge; Me' : metal composite oxides such as Al, B, P, Si, elements of Groups 1, 2, and 3 of the periodic table, halogen; 0<x≤1;1≤y≤3;1≤z≤8); lithium metal; lithium alloy; silicon-based alloys; tin-based alloys; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , and metal oxides such as Bi ₂ O ₅ ; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; titanium oxide; One or two or more selected from lithium titanium oxide and the like may be used. In a specific embodiment, the negative active material may include a carbon-based material and/or Si.

In addition, the separator is interposed between the negative electrode and the positive electrode, and serves to electrically insulate the negative electrode and the positive electrode while allowing lithium ions to pass therethrough. The separator may be used as long as it is used as a polymer separator membrane used in a typical solid electrolyte battery field, and is not particularly limited.

Meanwhile, according to another aspect of the present invention, there is provided a battery module including the lithium secondary battery as a unit cell, a battery pack including the battery module, and a device including the battery pack as a power source.

Here, the specific example of the device may be an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage system, but is not limited thereto.

Hereinafter, the present invention will be described in more detail through examples, but the following examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

1. Example 1

(1) Preparation of anode

A binder solution was prepared by dissolving 2 parts by weight of PVDF as a binder in an acetonitrile solvent, and then 3 parts by weight of carbon black (Super C65) as a conductive material was added to the binder solution to prepare a mixed solution.

Then, 80 parts by weight of _NCM811 (LiNi _0.8 Co 0.1 Mn 0.1 _{O 2 ) as a} cathode active material, ₉ parts by weight of polyethylene oxide (PEO) as _a solid electrolyte, _and 5 parts by weight of LITFSI as an electrolyte salt in an environment of 60 ° C. After mixing in to prepare a uniform slurry, 1 part by weight of ethylene carbonate as a plasticizer was added to the mixed slurry in an environment of 10° C. and mixed, and a solvent was further added in consideration of the viscosity to prepare a cathode active material slurry.

The positive electrode active material slurry thus prepared was applied to an aluminum current collector having a thickness of 20 μm, and then vacuum dried at 120° C. for 24 hours to prepare a positive electrode.

Ethylene carbonate in the electrode after drying existed in a solid state.

(2) Preparation of battery

A coin-type half cell was manufactured using the prepared positive electrode and the lithium metal negative electrode. Specifically, a battery was manufactured by interposing a 50 μm thick polymer separator film (PEO + LiFSI, 20:1 (mol ratio)) between the positive electrode and the negative electrode.

2. Example 2

A positive electrode and a battery were prepared in the same manner as in Example 1 except that 9.5 parts by weight of polyethylene oxide was used instead of 9 parts by weight of polyethylene oxide as a solid electrolyte, and 0.5 parts by weight of succinonitrile was mixed instead of 1 part by weight of ethylene carbonate as a plasticizer. prepared. After drying, succinonitrile in the electrode was in a solid state.

3. Comparative Example

A positive electrode and a battery were manufactured in the same manner as in Example 1, except that ethylene carbonate was not included as a plasticizer.

4. Measurement of battery capacity retention

The batteries prepared in Examples 1 and 2 and Comparative Examples were stored at 60° C. for 10 minutes. Through this process, ethylene carbonate and succinonitrile contained in each of the batteries of Examples 1 and 2 were converted into liquid phases.

Thereafter, the batteries of Examples 1 and 2 and Comparative Examples were charged/discharged, and the capacity retention rate was measured and shown in FIG. 1 . At this time, at a temperature of 60 °C, charging/discharging was performed at 0.1 C, and the charging voltage was 4.25 V and the discharging voltage was 3.0 V.

Referring to FIG. 1 , as the charging/discharging of the batteries progressed, the batteries of the Examples had a higher capacity retention rate than the Comparative Examples, and as the number of cycles increased, the difference in the capacity retention rate showed a tendency to further increase.

As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and the technical spirit of the present invention and the following by those of ordinary skill in the art to which the present invention pertains It goes without saying that various modifications and variations are possible within the equivalent scope of the claims to be described.

Claims (9)

positive active material; conductive material; solid electrolyte; electrolyte salts; and a dispersion medium for dispersing the positive active material, the conductive material, the solid electrolyte, and the electrolyte salt, to a positive electrode active material slurry for a solid electrolyte battery,
The slurry further comprises a plasticizer present in a solid phase at 15 to 25 °C,
The plasticizer is dissolved by the dispersion medium in the slurry and dispersed in a liquid state, or is dispersed in a solid state and distributed around the cathode active material,
The plasticizer, when exposed to a temperature environment higher than the melting point of the plasticizer, changes into a liquid phase and penetrates into the cracks formed in the positive electrode active material. The method of claim 1,
The plasticizer is ethylene carbonate (EC), polyethylene glycol (PEG) having a weight average molecular weight of 1,000 or more, succinonitrile (SN) and cyclic phosphate (cyclic phosphate, CP) A cathode active material slurry for a solid electrolyte battery, characterized in that it is any one selected from or a mixture of two or more thereof. The method of claim 1,
The cathode active material slurry for a solid electrolyte battery, based on 100 parts by weight of the dispersion medium,
60 to 100 parts by weight of the positive active material,
0.1 to 20 parts by weight of the conductive material;
1 to 50 parts by weight of the solid electrolyte;
0.01 to 25 parts by weight of the electrolyte salt, and
The positive active material slurry for a solid electrolyte battery, characterized in that it contains 0.1 to 30 parts by weight of the plasticizer. delete It relates to a positive electrode for a solid electrolyte battery comprising a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector,
The positive electrode active material layer is a positive electrode for a solid electrolyte battery, characterized in that it is a result of drying the positive electrode active material slurry for a solid electrolyte battery according to any one of claims 1 to 3 and removing the dispersion medium. To a solid electrolyte battery comprising a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode,
The positive electrode is a solid electrolyte battery according to claim 5, characterized in that the positive electrode for the solid electrolyte battery. A battery module comprising the solid electrolyte battery according to claim 6 as a unit cell. A battery pack comprising the battery module according to claim 7 . In the method for preparing the positive electrode active material slurry for a solid electrolyte battery according to claim 1,
The method for preparing the cathode active material slurry for a solid electrolyte battery is that the cathode active material slurry is prepared at a temperature below the melting point of the plasticizer.

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