| abstract |
(57) [Summary] [PROBLEMS] In a lithium secondary battery using a lithium manganese oxide having a spinel structure capable of inserting and extracting lithium in a positive electrode, when the lithium secondary battery is charged or discharged or stored in a charged state, Dissolution of manganese from lithium manganese oxide is suppressed, and a lithium secondary battery having excellent storage characteristics can be obtained. SOLUTION: In a lithium secondary battery using a lithium manganese oxide having a spinel structure capable of inserting and extracting lithium in a positive electrode 1, a surface of the lithium manganese oxide is coated with boron oxide and lithium cobalt composite oxide. Or a coating in which a first coating using boron oxide and a second coating using lithium cobalt composite oxide are formed on the surface of the above-mentioned lithium manganese oxide. did. |