Composite active material, all solid state battery, and method for producing composite active material

摘要

A main object of the present invention is to provide a composite active material provided with a coating layer having satisfactory electron conductivity. The object is attained by providing a composite active material including an active material and a coating layer that is formed on the surface of the active material and contains a carbonaceous material and an ion conductive oxide, wherein the elemental carbon concentration of the coating layer surface is 17.0 atm % or more.

主权项

1. A method for producing a composite active material that is comprised of an active material and a coating layer, wherein the coating layer is formed on a surface of the active material and is comprised of a carbonaceous material and an ion conductive oxide, the method comprising:
a preparation step of preparing a coating liquid containing at least one alkoxide compound that serves as a raw material for the carbonaceous material and a raw material for the ion conductive oxide; a coating film forming step of applying the coating liquid on the surface of the active material to thereby form a coating film on the surface; and a heat treatment step of subjecting the coating film to a heat treatment to thereby form the coating layer, wherein
a thickness of the coating layer is in a range of 2 nm to 100 nm,each of the preparation, coating film forming, and heat treatment steps is carried out in an atmosphere, anda water content in the coating liquid and a water content in an atmosphere of each step is adjusted to suppress hydrolysis of the alkoxide and to make a surface of the coating layer have an elemental carbon concentration be in a range of 17.0 atm % to 36.7 atm %.