Patent attributes
A non-aqueous electrolyte secondary battery is provided with a positive electrode, a negative electrode, a separator interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte, wherein positive electrode active material is a mixture of lithium-manganese composite oxide having spinel structure represented by a general formula Li1+zMn2O4 (wherein a relationship 0≦z≦0.2 is satisfied) and lithium-transition metal composite oxide represented by the general formula LiNi1−x−yCoxMnyO2 (wherein the relationships 0.5<x+y<1.0 and 0.1<y<0.6 are satisfied), and negative electrode active material is graphite coated with low crystalline carbon where whole or a part of a surface of first graphite material as a substrate is coated with second carbon material which is lower in crystallinity compared with the first graphite material.