Method for producing cathode, and method for producing oxide solid-state battery

Patent metadata

Field	Value
Publication number	US-10950862-B2
Application number	US-201715837119-A
Country	US
Kind code	B2
Filing date	Dec 11, 2017
Priority date	Jan 25, 2017
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A method for producing a cathode that can lower a sintering temperature is provided. The method comprises: acid-treating particles of a lithium containing composite oxide that has a layered rock-salt structure; obtaining a mixture by mixing the acid-treated particles with a lithium salt whose melting point is lower than that of the lithium containing composite oxide; and heating and sintering the mixture.

First claim

What is claimed is:

1. A method for producing a cathode, the method comprising:
obtaining a lithium containing composite oxide that has a layered rock-salt structure;
determining the melting point of the lithium containing composite oxide;
acid-treating particles of the lithium containing composite oxide;
obtaining a lithium salt whose melting point is lower than that of the lithium containing composite oxide;
obtaining a mixture by mixing the acid-treated particles with the lithium salt; and
heating and sintering the mixture,
wherein the lithium salt is a combination of lithium formate and lithium acetate.

2. The method according to claim 1 ,
wherein the lithium salt further comprises lithium nitrate.

3. The method according to claim 1 ,
wherein in said sintering the mixture, the mixture is heated either while or after pressurized.

4. The method according to claim 1 ,
wherein a molar ratio of the lithium formate to the lithium acetate (lithium formate/lithium acetate) in the mixture is 1/3 to 3.

5. The method according to claim 1 ,
wherein an amount of the lithium salt in the mixture is 1 part by mass to 100 parts by mass per 100 parts by mass of the acid-treated particles in the mixture.

6. The method according to claim 1 ,
wherein the lithium salt has a melting point lower than 250° C.

7. A method for producing an oxide solid-state battery, the method comprising:
obtaining a lithium containing composite oxide that has a layered rock-salt structure;
determining the melting point of the lithium containing composite oxide,
acid-treating particles of the lithium containing composite oxide;
obtaining a lithium salt whose melting point is lower than that of the lithium containing composite oxide;
obtaining a mixture by mixing the acid-treated particles with the lithium salt;
obtaining a layered body by layering a layer that comprises the mixture, and a layer of an oxide solid electrolyte;
determining a reaction temperature at which the mixture reacts with the oxide solid electrolyte;
selecting a heating temperature that is greater than or equal to the melting point of the lithium salt and lower than the reaction temperature; and
heating the layered body at the temperature, and sintering the mixture on a surface of the layer of the oxide solid electrolyte,
wherein the lithium salt is a combination of lithium formate and lithium acetate.

8. The method according to claim 7 , wherein
the oxide solid electrolyte contains garnet type lithium lanthanum zirconate, and
the heating temperature is no less than the melting point of the lithium salt, and lower than 600° C.

9. The method according to claim 7 ,
wherein a molar ratio of the lithium formate to the lithium acetate (lithium formate/lithium acetate) in the mixture is 1/3 to 3.

10. The method according to claim 7 ,
wherein an amount of the lithium salt in the mixture is 1 part by mass to 100 parts by mass per 100 parts by mass of the acid-treated particles in the mixture.

11. The method according to claim 7 ,
wherein the lithium salt has a melting point lower than 250° C.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kawakami Masatsugu
• Ohta Shingo

Classifications

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M4/1391 Primary

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title