NON-AQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

A non-aqueous electrolyte secondary battery comprises a negative electrode having a negative electrode active material layer and a positive electrode having a positive electrode active material layer, wherein the negative electrode active material layer contains Si and the positive electrode active material layer contains a lithium-transition metal composite oxide containing Li and Co as constituent elements. The weight-based ratio of the amount of Co in the positive electrode to the amount of Si in the negative electrode (i.e., a Co/Si ratio) falls within the range from 0.3 to 5.5. Preferably, the content of Co in the lithium-transition metal composite oxide in the positive electrode active material layer is 10 to 40% by weight relative to the total amount of the transition metal contained in the composite oxide.