Method for forming positive electrode active material particle

Abstract

A method for forming a lithium-rich positive electrode active material particle which enables high charge and discharge capacities and has a stable crystal structure is provided. The method for forming the positive electrode active material particle includes the steps of: mixing a lithium source and an M source (M is one or more selected from Mn, Ni, Co, Cr, Mo, Nb, V, Fe, Ti, and Ru) to form a first mixture; heating the first mixture at higher than or equal to 850° C. and lower than 950° C. to synthesize a first composite oxide; mixing the first composite oxide and an additive element source to form a second mixture; and heating the second mixture at higher than or equal to 850° C. and lower than or equal to 950° C. The additive element source includes a fluorine source and a magnesium source.

Dependencies are inferred from the claim text.