POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERY, ITS MANUFACTURING METHOD, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY USING IT

摘要

PROBLEM TO BE SOLVED: To provide a positive electrode active material excelling in thermal stability and having high charge-discharge capacity.

SOLUTION: In this manufacturing method of this positive electrode active material formed of powder of a lithium composite oxide Li1+zNi1-x-yCoxTiyO2, where 0.10≤x≤0.21, 0.03≤y≤0.08 and -0.05≤z≤0.10, an alkaline solution is added in a mixture aqueous solution of a nickel salt and a cobalt salt and a sulfuric acid aqueous solution of titanyl sulfate to coprecipitate hydroxides of nickel, cobalt and titanium in a condition at 50-80°C and at pH of 10-12.5; an obtained composite hydroxide Ni1-x-yCoxTiy(OH)2(where 0.10≤x≤0.21 and 0.03≤y≤0.08) is heat-treated at a temperature not lower than 300°C and below 900°C; and an obtained nickel-cobalt-titanium composite oxide is mixed with a lithium compound and heat treated at a temperature of 650-850°C.

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