Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing the same, positive electrode for nonaqueous electolyte

Abstract

An object of the present invention is to provide a positive electrode active material for a nonaqueous electrolyte secondary battery etc. which are capable of suppressing the generation of gas during charge by suppressing a reaction between a positive electrode and an electrolyte decomposition product moved from a negative electrode and a reaction between the positive electrode and the electrolyte, and which are thereby capable of significantly improving battery characteristics such as cycling characteristics. The positive electrode active material includes a compound composed of sodium, fluorine, and erbium and adhered to a surface of lithium cobalt oxide, and can be produced by adding, while adjusting pH, an aqueous solution prepared by dissolving erbium nitrate pentahydrate to a suspension containing lithium cobalt oxide and sodium fluoride.