POSITIVE ELECTRODE ACTIVE MATERIAL FOR SECONDARY BATTERY, AND SECONDARY BATTERY USING SAME

摘要

A positive electrode active material for a lithium-ion secondary battery that discharges high energy at lower cost, and is capable of minimizing a loss of capacity due to cycles is provided. A secondary battery that uses the positive electrode material is also provided. The positive electrode active material of the first embodiment is represented by the following formula (I): Lia(FexNiyMn2-x-y)04 (I) (In formula (I), 0.2 < x = 1.2, 0 < y < 0.5, and 0 = a = 1.2.) Furthermore, the positive electrode active material of the second embodiment is represented by the following formula (II): Lia(FexNiyMn2-x-y-zAz)O4 (II) (In formula (II), 0.2 = x = 1.2, 0 < y <0.5, 0 = a = 1.2, and 0 < z = 0.3.) A is at least one type of element selected from a group comprising Li, B, Na, Mg, Al, K and C.