POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, MANUFACTURING METHOD THEREOF, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY ARRANGED BY USE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a positive electrode active material which has good thermal stability and a high charge/discharge capacity when used as a positive electrode material of a nonaqueous electrolyte secondary battery.SOLUTION: A lithium nickel composite oxide is expressed by the following general formula: LiNiMO(x satisfies (4-Z)x≥0.75, where Z is an average valence of Ni, and M represents at least one additive element which is 3.375 or larger in average valence of the whole M). The lithium nickel composite oxide is obtained by a manufacturing method which comprises: (1) a crystallization step for obtaining the complex hydroxide, NiM(OH)by adding an alkali liquid solution to a mixed aqueous solution of a salt of Ni and a salt of M; (2) a sintering step for mixing the complex hydroxide with a lithium compound so that the mole ratio given by Li/(Ni+M) becomes 1.00-1.15 and then, sintering the resultant mixture at a temperature of 700-1000°C; and (3) a water-rinse step for rinsing the resultant lithium nickel composite oxide with water.SELECTED DRAWING: Figure 1