METHOD FOR JUDGING QUALITY OF LITHIUM NICKEL COMPOSITE OXIDE AND POSITIVE ELECTRODE USING LITHIUM NICKEL COMOPOSITE OXIDE

摘要

A positive electrode active material quality judgment method that can easily and accurately judge the quality of a positive electrode active material used in a non-aqueous electrolyte secondary cell without having to complete the positive electrode. The positive electrode active material quality judgment method includes: heating a positive electrode active material mainly made of a lithium nickel composite oxide to a temperature x (° C.) of 200° C. or higher and 1500° C. or lower; measuring the amount of carbon dioxide gas occurring from the heating; and the positive electrode active material as a suitable positive electrode active material when the positive electrode active material satisfies formulas 1 and 2: y<(0.27x−51)/1000000(200≦̸x<400)  formula 1 y<57/1000000(400≦̸x≦̸1500)  formula 2 where x is the heating temperature x (° C.) and y is the amount of carbon dioxide gas (mole/g) occurring per 1 g of the positive electrode active material in the heating to the heating temperature x (° C.).