Patent ID: 6428930
Filing Date: 2002-08-06
Classification: H01M,Y02E,Y02P

Abstract:
A lithium secondary battery comprising:a positive electrode having a positive electrode active material composed of a mixture of at least two reversible lithium intercalation materials, said mixture in which LiMn2O4 is mixed with LiCo0.5Ni0.5O2 which is a material showing a negative sign of heat generated by an entropy change at a potential of 3.0 V during charge and showing a positive sign of heat generated by an entropy change at a potential of 3.7 V or higher during charge, the potentials being determined with reference to a potential of lithium metal at 25Â° C., so that the weight ratio of LiMn2O4 to LiCo0.5Ni0.5O2 is in the range of from 2:8 to 6:4; a negative electrode having a negative electrode active material composed of a reversible lithium intercalation material; an electrolytic solution; a separator impregnated between said electroclytic electrode; and a battery can; wherein said positive and negative electrodes are spirally wound with said separator interposed therebetween, and enclosed in said battery can.