A non-aqueous secondary battery comprising a negative electrode made of an active negative electrode material capable of intercalating/deintercalating lithium ion, a positive electrode made of spinnel type lithium manganese oxide as a main active positive electrode material and an electrolyte containing a non-aqueous solvent is characterized in that said positive electrode comprises lithium cobalt oxide in admixture with spinnel type lithium manganese oxide having crystal lattices partially substituted by magnesium or aluminum and said non-aqueous solvent comprises vinylene carbonate incorporated therein.