Lithium secondary battery

Abstract

To provide a lithium secondary battery excellent in the life characteristic and the power density. A lithium secondary battery, comprising: a positive electrode capable of intercalating and deintercalating lithium; and an negative electrode capable of intercalating and deintercalating lithium, wherein the positive electrode contains a manganese-containing positive electrode active material of a spinel structure and an oxide that coats the surface of this positive electrode active material, wherein the oxide contains a metallic element, wherein the metallic element forms a solid solution with the positive electrode active material, and wherein the atomic concentration of the metallic element is approximately 0 at depths of from 50 to 100 nm from an external surface of the negative electrode.

1 . A lithium secondary battery comprising:
 a positive electrode capable of intercalating and deintercalating lithium; and   a negative electrode capable of intercalating and deintercalating lithium,   wherein the positive electrode comprises a manganese-containing positive electrode active material of a spinel structure represented by a general formula Li a Mn b M c O 4 , where, 1.0≦a≦1.15, 1.8≦b≦1.94, 0.01≦c≦0.10, a+b+c=3, and M is a substitutional element, and is one or more elements selected from the group consisting of Mg, Ni, and Cu, and an oxide coating a surface of the positive electrode active material,   wherein the oxide coating the surface of the positive electrode active material contains first atoms of at least one metallic element selected from the group consisting of Al, Co, and Fe, and   wherein second atoms of the at least one metallic element form a solid solution with the positive electrode active material.