Lithium-transition metal oxide powder and method of producing the same, positive electrode active material for lithium ion battery, and lithium ion secondary battery

Abstract

There is provided a lithium-transition metal oxide powder with a coating layer containing lithium niobate formed on a part or the whole part of a surface of a lithium-transition metal oxide particle and having a low powder compact resistance, and a positive electrode active material for a lithium ion battery containing the lithium-transition metal oxide powder. Specifically, there is provided the lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with a part or the whole part of a surface coated with a coating layer containing lithium niobate, wherein a carbon-content is 0.03 mass % or less.

1 . A method of producing a lithium-transition metal oxide powder composed of a lithium-transition metal oxide particle with a part or the whole part of a surface coated with a coating layer containing lithium niobate, comprising:
 mixing an aqueous solution containing a niobium compound and a lithium compound, and a lithium-transition metal oxide powder, to obtain a mixture;   removing a water of the mixture, to obtain a powder in which the niobium compound and the lithium compound are adhered to the surface of the lithium-transition metal oxide powder; and   applying a heat treatment to the powder at 300° C. or more and 700° C. or less.   
     
     
         2 . A method of producing the lithium-transition metal oxide powder according to  claim 1 , wherein the niobium compound is a complex niobate. 
     
     
         3 . A method of producing the lithium-transition metal oxide powder according to  claim 2 , wherein the complex niobate is a peroxo complex ([Nb(O 2 ) 4 ] 3− ) of niobium oxide, or the complex niobate having oxalic acid in ligands.