Positive electrode for lithium secondary battery, and lithium secondary battery using the same

A positive electrode, for use in a lithium secondary battery, comprising a positive electrode current collector, and a positive electrode film carried on the positive electrode current collector, wherein

• the positive electrode film contains, as a positive electrode active material, two or more kinds of lithium-containing compounds having exothermic initiation temperatures different from each other,
• at least one kind of the two or more kinds of lithium-containing compounds has the exothermic initiation temperature of 300° C. or higher,
• a content of the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher is increased in a thickness direction of the positive electrode film from an outermost layer of the positive electrode film toward the positive electrode current collector, and
• said lithium-containing compound having the exothermic initiation temperature of 300° C. or higher is a lithium nickel manganese cobalt oxide represented by the chemical formula Lia Ni 1−(b+c)MnbCocO2 where a, b, and c satisfy 1 ≦a ≦1.2, 0.1≦b ≦0.5, and 0 1 ≦c ≦0.5
• in a portion of the positive electrode film, closest to the positive electrode current collector, the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher and the lithium-containing compound other than the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher are contained, and a content of the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher is larger than a content of the lithium-containing compound other than the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher, and
• in an outer mixture layer, the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher and the lithium-containing compound other than the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher are contained, and a content of the lithium-containing compound other than the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher is larger than a content of the lithium-containing compound having the exothermic initiation temperature of 300° C. or higher.