PURPOSE: To increase the discharge capacity and enhance the cyclic characteristics at a low cost by stabilizing the crystalline structure of a pos. electrode active substance.

CONSTITUTION: A non-aqueous secondary battery includes a neg. electrode 2 and a pos. electrode 1. The former uses lithium as active substance, while the latter contains an active substance which is expressed by LixMyNi1-yOz, where M is at least one of the metals Mg, V, Cr, Cu and the conditions shall be met such that 0<x<1.3, 0.02≤y≤0.5, 1.8<z<2.2.