NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND METHOD OF MANUFACTURING THE SAME

摘要

A mixed positive electrode active material is used. The mixed positive electrode active material is obtained by mixing a layered oxide whose initial charge-discharge efficiency when lithium metal is used for a counter electrode is less than 100% (hereinafter referred to as a first layered oxide) and a layered oxide whose initial charge-discharge efficiency is 100% or more (hereinafter referred to as a second layered oxide). Examples of the first layered oxide include Li1+aMnxCoyNizO2. A sodium oxide such as LiANaBMnXCoYNiZO2 other than a layered compound from which lithium is previously extracted by acid treatment or the like can be used as the second layered oxide whose initial charge-discharge efficiency is 100% or more. A layered oxide obtained by replacing (ion exchange) sodium in the foregoing LiANaBMnXCoYNiZO2 with lithium can be also used as the second layered oxide.