JP2012226944A - Electrode of solid electrolyte battery including sulfur and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrode in a solid state battery with a solid sulfide electrolyte layer which can suppress deterioration in reaction resistance after a durability test under severe conditions; and a method for producing the same.SOLUTION: In an electrode of a solid state battery with a solid sulfide electrolyte layer, the surface in which a thin film or particles 3 that comprise a cathode active material composing at least one portion of the electrode come into contact with a solid sulfide electrolyte 6 is laminated with a coat layer 5 comprising LiTiOobtained by not using an organic compound including a carbonyl group in the production process. A method for producing the above-mentioned electrode comprises a step of preparing LiTiOor a precursor solgel solution thereof from a starting raw material which can provide LiTiOin a solvent under the absence of the organic compound including the carbonyl group.

Description

  The present invention relates to an electrode for a novel solid electrolyte battery and a method for producing the same, and more particularly to an electrode for a solid battery having a solid sulfide electrolyte layer capable of suppressing deterioration of reaction resistance in the solid battery and a method for producing the same.

In recent years, lithium batteries have been put into practical use as batteries having high voltage and high energy density. Due to the expansion of the use of lithium batteries in a wide range of fields and the demand for high performance, various studies have been conducted to further improve the performance of lithium batteries.
Among them, the use of non-flammable electrolytes compared to the conventional non-aqueous electrolyte type lithium batteries eliminates the need for flammable electrolytes, so the safety is high, the degree of freedom of the cell shape is high, the degree of freedom of the structure is increased, and the number of auxiliary devices Therefore, it is expected that the solid state battery will be put to practical use.

However, in order to realize the practical application of solid state batteries, various improvements such as the creation of a solid electrolyte capable of providing high capacity and high output and / or the creation of electrodes capable of realizing high electrode utilization efficiency are required. is there.
A solid sulfide electrolyte such as Li ₂ S—P ₂ S ₅ has been proposed as one of the technologies capable of realizing the high capacity and high output of this solid battery.
However, it is known that a solid battery using a solid sulfide electrolyte such as Li ₂ S—P ₂ S ₅ described above deteriorates battery characteristics after durability. One possible cause of the deterioration in battery characteristics after endurance is that the positive electrode active material and the solid sulfide electrolyte are directly connected at the interface between the positive electrode active material and the solid sulfide electrolyte constituting at least a part of the electrode. It is considered that a reaction occurs by contact and an insulating layer is formed to reduce the charge transfer conductivity of lithium ions and increase the reaction resistance of the solid state battery.

Various studies have been made to suppress reaction resistance in a solid state battery using this solid sulfide electrolyte.
For example, in a solid state battery, in order to prevent a reaction from occurring at the interface between the positive electrode active material and the solid sulfide electrolyte layer and forming a high resistance reaction layer at the interface, the surface of the positive electrode active material or the solid sulfide Attempts have been made to form a reaction suppression layer on the electrolyte surface. In order to form this reaction suppression layer, it has been proposed to use lithium niobate, lithium titanate, lithium phosphate, etc., all of which are effective for suppressing the initial reaction, but have a low maintenance rate. It was inferior in durability.

For this reason, in order to suppress reaction resistance in a solid state battery, a solid electrode having long-term durability has been studied.
For example, in Non-Patent Document 1, a Li ₂ O—TiO ₂ film is covered with an all-solid lithium secondary battery in which a LiCoO ₂ electrode of a solid battery using a solid sulfide electrolyte is covered with a Li ₂ O—TiO ₂ film. It is described that the interfacial resistance of a solid state battery can be reduced as compared with an all solid state lithium secondary battery that has not been used. As a specific example, a starting material capable of providing ethanol, acetylacetone, Li ₂ Ti ₂ O ₅ as a solvent, and a sol prepared from TiO ₂ are mixed with LiCoO ₂ particles, dried, and calcined at 350 ° C. for 30 minutes. The positive electrode prepared by mixing the obtained Li ₂ Ti ₂ O ₅ and TiO ₂ -coated LiCoO ₂ and a solid sulfide electrolyte has been shown to reduce interfacial resistance after charge-discharge at room temperature.

Journal of Power Sources 195 (2010) 599-603

Thus, Li ₂ Ti ₂ O ₅ coated LiCoO ₂ obtained by mixing a sol prepared from an organic solvent, a starting material capable of providing Li ₂ Ti ₂ O ₅ and acetylacetone with LiCoO ₂ particles, drying and firing, and A positive electrode made of a solid sulfide electrolyte can give durability at room temperature, but an electrode of a solid battery that can suppress deterioration of reaction resistance after durability under severe conditions is not known.
Accordingly, an object of the present invention is to provide an electrode in a solid state battery having a solid sulfide electrolyte layer capable of suppressing deterioration of reaction resistance after endurance under severe conditions.
Furthermore, the objective of this invention is providing the manufacturing method of the electrode in the solid battery which has a solid sulfide electrolyte layer which can suppress the deterioration of reaction resistance after the endurance on severe conditions.

The present invention relates to an electrode of a solid battery having a solid sulfide electrolyte layer, wherein a surface of a thin film or particle made of a positive electrode active material constituting at least a part of the electrode is in contact with a solid sulfide electrolyte in the production process. It is laminated by coating layers consisting of Li ₂ Ti ₂ O ₅ obtained without using an organic compound containing a group relates to the electrode.

The present invention also relates to a method of manufacturing a solid battery electrode having a solid sulfide electrolyte layer,
Preparing a thin film or particles made of a positive electrode active material constituting at least a part of the electrode;
A step of preparing Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof in the absence of an organic compound containing a carbonyl group from a starting material capable of providing Li ₂ Ti ₂ O ₅ in a solvent; and from the positive electrode active material A step of forming a coating layer of Li ₂ Ti ₂ O ₅ by coating the Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof on the surface of the thin film or particle that comes into contact with the solid sulfide electrolyte, drying and firing The manufacturing method.
In the present specification, the durability under severe conditions means a test for storage for 1 month or more in a temperature environment of 60 ° C. or more.
Moreover, in this specification, reaction resistance means the reaction resistance in the impedance analysis calculated | required by the measuring method explained in full detail in the column of the below-mentioned Example.

ADVANTAGE OF THE INVENTION According to this invention, the electrode in the solid battery which has a solid sulfide electrolyte layer which can suppress the deterioration of reaction resistance after the endurance on severe conditions can be obtained.
Further, according to the present invention, it is possible to easily obtain an electrode in a solid state battery having a solid sulfide electrolyte layer capable of suppressing deterioration of reaction resistance after endurance under severe conditions.

FIG. 1 is a partially enlarged schematic view of an electrode of a solid state battery according to an embodiment of the present invention. FIG. 2 is a partially enlarged schematic view of an electrode of a solid state battery according to another embodiment of the present invention. FIG. 3 is an X-ray diffraction diagram of Li ₂ Ti ₂ O ₅ obtained in the example. FIG. 4 is a graph showing the change over time in reaction resistance of the solid state batteries having the solid sulfide electrolyte layers obtained in Examples and Comparative Examples under a storage environment at 60 ° C.

In particular, in the present invention, the following embodiments can be mentioned.
1) The electrode, wherein the electrode is a thin film electrode in which a surface in contact with a solid sulfide electrolyte of a thin film made of a positive electrode active material constituting at least a part of the electrode is laminated by the coat layer.
2) A positive electrode mixture in which the electrode is in contact with a solid sulfide electrolyte of particles made of a positive electrode active material constituting at least a part of the electrode, and the particles laminated with the coat layer and the solid sulfide electrolyte. The electrode, which is a powder electrode formed by molding powder.
3) The electrode, wherein the positive electrode active material is lithium cobalt oxide (LiCoO ₂ ).
4) the solid sulfide electrolyte _layer, the electrode made of _{Li 2 S-P 2 S 5} .
5) The Li ₂ Ti ₂ O ₅ or its precursor sol-gel solution is coated on the surface of the thin film made of the positive electrode active material in contact with the solid sulfide electrolyte by a spin coater, dried and fired, and Li ₂ Ti ₂ O ₅ The said manufacturing method which forms the coating layer of.
6) the solid sulfide electrolyte layer before depositing the positive electrode active on material, said manufacturing method comprising the step of forming a coating layer of the Li ₂ Ti ₂ O _5.

In the present invention, the surface in contact with the solid sulfide electrolyte of the thin film or particles of the positive electrode active material constituting at least a part of the electrode of the solid battery having the solid sulfide electrolyte layer contains a carbonyl group in the production process. It is necessary to be an electrode laminated by a coating layer made of Li ₂ Ti ₂ O ₅ obtained without using a compound, and this can suppress deterioration of reaction resistance after endurance under severe conditions. .

The electrode of the solid battery having the solid sulfide electrolyte layer of the present invention is, for example,
Preparing a thin film or particles comprising a positive electrode active material constituting at least part of an electrode of a solid battery having a solid sulfide electrolyte layer;
A step of preparing Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof in the absence of an organic compound containing a carbonyl group from a starting material capable of providing Li ₂ Ti ₂ O ₅ in a solvent; and from the positive electrode active material The surface of the particles or thin film in contact with the solid sulfide electrolyte is coated with the Li ₂ Ti ₂ O ₅ or its precursor sol-gel solution, dried and fired to form a Li ₂ Ti ₂ O ₅ coating layer. It can obtain by the manufacturing method containing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIG. 1, the electrode 1 of the solid battery according to the embodiment of the present invention has a surface 4 in contact with the solid sulfide electrolyte of the thin film 2 made of the positive electrode active material constituting at least a part of the electrode. This is a thin film electrode 8 formed by laminating a coat layer 5 made of Li ₂ Ti ₂ O ₅ obtained without using an organic compound containing a group.

Further, in the solid battery electrode 1 according to another embodiment of the present invention, the surface 4 of the particle 3 made of the positive electrode active material constituting at least a part of the electrode is in contact with the solid sulfide electrolyte, and contains a carbonyl group in the production process. Powder electrode formed by molding positive electrode composite powder 7 composed of particles 3 and solid sulfide electrolyte 6 laminated by coating layer 5 composed of Li ₂ Ti ₂ O ₅ obtained without using an organic compound Nine.

Although the theoretical elucidation that the electrode of the solid battery having the solid sulfide electrolyte layer of the present invention can suppress the deterioration of the reaction resistance after endurance under severe conditions has not yet been made sufficiently, it is composed of the positive electrode active material. The surface of the thin film or particle in contact with the solid sulfide electrolyte is laminated by a coating layer made of Li ₂ Ti ₂ O ₅ obtained without using an organic compound containing a carbonyl group in the production process. ₂ Ti in the coating layer made of ₂ Ti ₂ O ₅ is firmly bonded to O atoms, and the structure can be maintained without drawing O atoms to S in the solid sulfide electrolyte, and 2) the solid sulfide electrolyte even in contact with the Li ₂ Ti ₂ O _5, it is _Li 2 _Ti 2 _{O 5} obtained by using an organic compound containing a carbonyl group such as acetyl acetone in the manufacturing process have been stacked In some cases, the carbonyl group does not remain in the coating layer during durability under severe conditions, so that the reaction between S and the carbonyl group in the solid sulfide electrolyte molecule, that is, the reaction in which the COO bond is replaced with S. It is thought that this is because no occurs.

The organic compound containing the carbonyl group, for example, acetylacetone, is a substance generally used in the sol-gel reaction in the manufacturing process of the conventional solid battery electrode. In the technique described in Non-Patent Document 1, Li ₂ Ti is used. It is considered that it is used for controlling the thickness of the coating layer made of ₂ O ₅ .
In the present invention, without using an organic compound containing a carbonyl group, for example, acetylacetone, the Li ₂ Ti ₂ O ₅ or its precursor sol-gel is formed on the surface of the thin film made of the positive electrode active material in contact with the solid sulfide electrolyte. A coating layer having a uniform thickness can be formed by coating the solution with a spin coater, drying and firing to form a coating layer of Li ₂ Ti ₂ O ₅ .

Alternatively, in the present invention, without using an organic compound containing a carbonyl group, for example, acetylacetone, for example, a particle composed of the positive electrode active material and a sol-gel solution containing the Li ₂ Ti ₂ O ₅ or a precursor thereof at a low concentration They were mixed, dried and calcined to _Li 2 _Ti several times a step of forming a coating layer of 2 _{O 5,} for example, by repeating 2-5 times, the surface in contact with the solid sulfide electrolyte, the _Li 2 _Ti 2 O A coat layer of ₅ uniform thickness can be formed.

In the production method of the present invention, a step of preparing particles or a thin film made of a positive electrode active material constituting at least a part of an electrode of a solid battery having a solid sulfide electrolyte layer,
A step of preparing Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof in the absence of an organic compound containing a carbonyl group from a starting material capable of providing Li ₂ Ti ₂ O ₅ in a solvent; and from the positive electrode active material A step of forming a coating layer of Li ₂ Ti ₂ O ₅ by coating the Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof on the surface of the thin film or particle that comes into contact with the solid sulfide electrolyte, drying and firing Including.
The thin film or particles made of the positive electrode active material may contain any component, for example, an ion conductor, for improving the performance of the electrode of the present invention and a solid state battery using the electrode.

The thin film or particles made of the positive electrode active material constituting at least a part of the electrode of the solid battery having the solid sulfide electrolyte layer can be prepared from the positive electrode active material by any method.
The solvent is not particularly limited as long as it is an organic compound not containing a carbonyl group, and examples thereof include alcohols such as ethanol, methanol, isopropanol, and ethers such as THF.

The starting materials that can provide the Li ₂ Ti ₂ O ₅ include lithium alkoxides such as lithium ethoxide, lithium methoxide, lithium propoxide, lithium butoxide, and titanium tetraalkoxides such as titanium tetramethoxide and titanium. Examples thereof include tetraethoxide, titanium tetraisopropoxide, and titanium tetrabutoxide.
The lithium alkoxide and titanium tetraalkoxide can be used in equimolar amounts.

  The sol-gel solution is coated, dried and fired by coating by impregnation or spin coating, drying at room temperature, air or inert atmosphere, for example, nitrogen at 200 to 350 ° C. at 0.3 to 1 It can be carried out by baking with heating for about an hour.

As the positive electrode active material in the present invention, lithium cobaltate (Li _x CoO ₂ ), lithium nickelate (Li _x NiO ₂ ), nickel manganese lithium cobaltate (Li _{1 + x} Ni _1/3 Mn _1/3 Co _1/3 O ₂ ), lithium cobaltate nickel (LiCo _0.3 Ni _0.7 O ₂ ), lithium manganate (Li _x Mn ₂ O ₄ ), lithium titanate (Li _4/3 Ti _5/3 O ₄ ), lithium manganese acid compound _{(Li 1 + x M y Mn} 2-x-y O 4; M = Al, Mg, Fe, Cr, Co, Ni, Zn), lithium titanate _(Li x _TiO y), phosphate metal lithium (LiMPO ₄ , M = Fe, Mn, Co , Ni), vanadium oxide _{(V 2 O} 5), molybdenum oxide (MoO3), titanium sulfide _(TiS 2), Titanium cobalt nitride (LiCoN), lithium silicon nitride (LiCoN), lithium metal, lithium alloy (LiM, M = Sn, Si, Al, Ge, Sb, P), lithium storable intermetallic compound (MgxM, M = Sn, Ge, Sb, or XySb, X = In, Cu, Mn) and derivatives thereof.
In particular, Li _x CoO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , Li _x Ni _1/2 Mn _1/2 O ₂ , Li _x Ni _1/3 Co _1/3 Mn _1/3 O ₂ , Li _x [Ni _y Li _{1 / 3-2y / 3} ] O ₃ (0 ≦ x ≦ 1, 0 <y <1/2) and lithium or transition metal of these lithium transition metal oxides were substituted with other elements Lithium transition metals, especially LiCoO _2, are mentioned as positive electrode active materials.

Examples of the solid sulfide electrolyte in the present invention include Li ₂ S—SiS ₂ , LiI—Li ₂ S—SiS ₂ , liI-li ₂ S—P ₂ S ₅ , LiI—Li ₂ S—B ₂ S ₃ , Li _{3. PO 4 -Li 2 S-Si 2} S, Li 3 PO 4 -Li 2 S-SiS 2, LiPO 4 -Li 2 S-SiS, LiI-Li 2 S-P 2 O 5, LiI-Li 3 PO 4 - Examples thereof include sulfide-based amorphous solid electrolytes such as P ₂ S ₅ , Li ₃ PS ₄ and Li ₂ S—P ₂ S ₅ , and preferably Li ₂ S—P ₂ S ₅ .

The Li ₂ S—P ₂ S ₅ can be obtained from lithium sulfide and diphosphorus pentasulfide and / or simple phosphorus and simple sulfur. For example, these raw materials are melt-reacted and then rapidly cooled or the raw materials are used. It can be obtained by heat-treating sulfide glass obtained by processing by a mechanical milling method. The mixing molar ratio of lithium sulfide to diphosphorus pentasulfide or simple phosphorus and simple sulfur is usually 50:50 to 80:20, preferably 60:40 to 75:25, and preferably Li ₂ S: P _2. S ₅ = 70: 30~75: is about 25 (mole ratio).

The electrode of the present invention may contain an ion conductor component in addition to the above components.
The lithium ion conductor needs to be a material that does not react with the active material contained in the granulated body and the solid electrolyte that is another component contained in the electrode. For example, LiTi ₂ (PO ₄ ) ₃ Or oxide-based amorphous such as Li ₂ O—B ₂ O ₃ —P ₂ O ₅ , Li ₂ O—SiO ₂ , Li ₂ O—B ₂ O ₃ , Li ₂ O—B ₂ O ₃ —ZnO quality solid _{electrolyte, LiI-Li 2 S-P} 2 S 5, LiI-Li 2 S-B 2 S 3, Li 3 PO 4 -Li 2 S-Si 2 S, Li 3 PO 4 -Li 2 S-SiS 2 _{, LiPO 4 -Li 2 S-SiS} , LiI-Li 2 S-P 2 O 5, LiI-Li 3 PO 4 -P 2 S 5, Li 3 PS 4, Li 2 sulfides such _S-P 2 _{S 5} Amorphous solid electrolyte, LiNbO ₃ , a Rui _{Li 1.3 Al 0.3 Ti 0.7 (PO} 4) 3, Li 1 + x + y A x Ti 2-x Si y P 3-y O 12 (A = Al or Ga, 0 ≦ x ≦ 0.4 , 0 <y ≦ 0.6), [(B _1/2 Li _1/2 ) _1−z C _z ] TiO ₃ (B = La, Pr, Nd, Sm, C = Sr or Ba, 0 ≦ x ≦ _{0.5), Li 5 La 3 Ta} 2 O 12, Li 7 La 3 Zr 2 O 12, Li 6 BaLa 2 Ta 2 O 12, Li 3 PO (4-3 / 2w) N w (w <1), Li-containing containing at least one element selected from crystalline oxides such as Li _3.6 Si _0.6 P _0.4 O ₄ and niobium such as oxynitrides, tantalum, silicon, phosphorus and boron and lithium _{compounds, LiI, LiI-Al 2 O} 3, LiN 3, Li 3 N-L Such as I-LiOH, and the like.

In order to obtain a solid battery using the electrode of the solid battery of the present invention, a thin film type electrode obtained by the present invention is applied to the positive electrode, a solid sulfide electrolyte is laminated, and an electrode other than the electrode of the present invention is applied to the negative electrode. Can be made.
Alternatively, for example, a solid battery is prepared by placing a solid sulfide electrolyte into a cell, pressing it, producing a pellet of a solid sulfide electrolyte layer that functions as a separator, and then providing the electrode of the present invention and a negative electrode composite powder. It can be produced by putting the material powder on both sides of the solid sulfide electrolyte layer and pressing it.
Further, in the solid battery, first, the positive electrode mixture powder and the negative electrode mixture powder capable of providing the electrode of the present invention are pressed and pelletized to form positive and negative electrodes, and a solid sulfide electrolyte layer is formed between both electrodes. It can be made by forming.

Examples of the present invention will be described below.
The following examples are for illustrative purposes only and are not intended to limit the invention.
In each of the following examples, reaction resistance was measured by the following method. In addition, the following method is an illustration, Comprising: The method which those skilled in the art consider that is equivalent can be used similarly.
Reaction resistance measurement method: AC impedance method Reaction resistance measurement device: Toyo Technica, Solartron Li ₂ Ti ₂ O ₅ obtained in the examples was measured and identified using the following XRD device.
XRD measuring device: Rigaku, Smart Lab

Example 1
1 hour in a glass bottle in which ethanol (10 mL, Wako Pure Chemical Industries, Ltd.), lithium ethoxide (1 mmol, High Purity Chemical Laboratories) and titanium tetraisopropoxide (1 mmol, High Purity Chemical Laboratories) were replaced with nitrogen. The mixture was stirred and mixed with a magnetic stirrer to prepare a Li ₂ Ti ₂ O ₅ precursor sol-gel solution by a sol-gel reaction.
Lithium cobaltate thin film surface, the _Li 2 _Ti 2 _{O 5} precursor sol-gel solution a spin coater (Mikasa Co., MS-A100) were coated at 5000 rpm, 10 seconds at. After drying, it was baked at 350 ° C. for 0.5 hour to form a Li ₂ Ti ₂ O ₅ coat layer to obtain a positive electrode.
For _Li 2 _Ti 2 _{O 5} coating layer formed by performing identification by XRD, it was confirmed. An X-ray diffraction pattern of Li ₂ Ti ₂ O ₅ is shown in FIG.

An all-solid battery was fabricated using the obtained thin film electrode as a positive electrode, 75Li ₂ S-25P ₂ S ₅ which is a solid sulfide electrolyte as a separator, and Li-In foil as a negative electrode.
Impedance measurement of the obtained all-solid-state battery was performed at the initial stage and at 60 ° C. endurance test (storage conditions: 60 ° C. environment, OCV, for 1 month) (= resistance after a predetermined time in the endurance test / initial resistance) The change with time was determined.
The obtained results are shown together with other results in FIG.

Comparative Example 1
Ethanol (10 mL, Wako Pure Chemical Industries, Ltd.), lithium ethoxide (1 mmol, High Purity Chemical Laboratories), titanium tetraisopropoxide (1 mmol, High Purity Chemical Laboratories) and acetylacetone (1 mmol, Wako Pure Chemical Industries, Ltd.) In a glass bottle substituted with nitrogen, the mixture was stirred and mixed with a magnetic stirrer for 1 hour to prepare a Li ₂ Ti ₂ O ₅ precursor sol-gel solution by a sol-gel reaction.
A positive electrode and an all-solid-state battery were obtained in the same manner as in Example 1 except that this Li ₂ Ti ₂ O ₅ precursor sol-gel solution was used.
The measurement results of this all solid state battery are shown together with other examples in FIG.

Comparative Example 2
Ethanol (487 g, Wako Pure Chemical Industries, Ltd.), lithium ethoxide (0.59 mol, High Purity Chemical Research Laboratories) and titanium tetraisopropoxide (0.74 mol, High Purity Chemical Research Laboratories) are mixed, and sol-gel A Li ₂ Ti ₂ O ₅ precursor sol-gel solution was prepared by the reaction.
A positive electrode and an all-solid battery were obtained in the same manner as in Example 1 except that this Li ₄ Ti ₅ O ₁₂ precursor sol-gel solution was used.
The measurement results of this all solid state battery are shown together with other examples in FIG.

The result of FIG. 4 shows that the electrode in the solid battery having the solid sulfide electrolyte layer of the present invention is laminated by a coating layer made of Li ₂ Ti ₂ O ₅ obtained using an organic compound containing a carbonyl group in the production process. It was confirmed that the deterioration of reaction resistance could be suppressed after endurance under severe conditions as compared with the electrode formed and the electrode laminated with the coating layer made of Li ₄ Ti ₅ O ₁₂ .

  According to the present invention, a highly durable solid battery electrode for a solid battery can be obtained, and a highly durable solid battery electrode for a solid battery can be easily obtained according to the present invention.

A solid battery electrode 2 positive active material embodiment of one invention thin film 3 electrode active contact with the material consisting of particles 4 solid sulfide electrolyte surface 5 Li ₂ Ti ₂ O ₅ consisting coat layer 6 solid sulfide electrolyte 7 Positive electrode composite powder 8 Compact electrode

Claims (8)

An electrode of a solid battery having a solid sulfide electrolyte layer, wherein a surface of a thin film or particle made of a positive electrode active material constituting at least a part of the electrode and contacting the solid sulfide electrolyte contains a carbonyl group in the production process laminated by coating layers consisting of Li ₂ Ti ₂ O ₅ obtained without using an organic compound formed by the electrode.   2. The electrode according to claim 1, wherein the electrode is a thin film electrode in which a surface in contact with a solid sulfide electrolyte of a thin film made of a positive electrode active material constituting at least a part of the electrode is laminated by the coat layer.   The positive electrode mixture powder in which the surface of the electrode that is in contact with the solid sulfide electrolyte of the positive electrode active material constituting at least a part of the electrode is formed of the particles and the solid sulfide electrolyte laminated by the coat layer The electrode according to claim 1, which is a compacted electrode formed by molding. The electrode according to claim 1, wherein the positive electrode active material is lithium cobalt oxide (LiCoO ₂ ). The electrode according to claim 1, wherein the solid sulfide electrolyte layer is made of Li ₂ S—P ₂ S ₅ . A method for producing an electrode of a solid battery having a solid sulfide electrolyte layer, comprising:
Preparing a particle or thin film comprising a positive electrode active material constituting at least a part of the electrode;
A step of preparing Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof in the absence of an organic compound containing a carbonyl group from a starting material capable of providing Li ₂ Ti ₂ O ₅ in a solvent; and from the positive electrode active material A step of forming a coating layer made of Li ₂ Ti ₂ O ₅ by coating the Li ₂ Ti ₂ O ₅ or a precursor sol-gel solution thereof on the surface of the thin film or particle to be in contact with the solid sulfide electrolyte, drying and firing The said manufacturing method including. The surface of the thin film made of the positive electrode active material in contact with the solid sulfide electrolyte is coated with the Li ₂ Ti ₂ O ₅ or its precursor sol-gel solution by a spin coater, dried and fired to coat Li ₂ Ti ₂ O ₅ The manufacturing method of Claim 6 which forms a layer. Before coating the solid sulfide electrolyte layer on the positive electrode active on material, comprising the step of forming a coating layer of the Li ₂ Ti ₂ O _5, The method according to claim 7.

Images