| 摘要 |
[Problem] To provide a nonaqueous electrolyte secondary battery which is suppressed in deterioration of cycle characteristics even in cases where a high-rate charging process is included, and has high capacity retention rate. [Solution] A nonaqueous electrolyte secondary battery of the present invention contains, as a positive electrode active material, lithium nickel cobalt manganese oxide (LiNixCoyMn1-x-yO2, wherein 0.3 < x < 0.6 and 0.2 < y < 0.4) and lithium cobaltate or lithium cobaltate to which a different element is added. The nonaqueous electrolyte of this nonaqueous electrolyte secondary battery contains at least one compound that is selected from the group consisting of adiponitrile, glutaronitrile, succinonitrile, malononitrile and oxalonitrile in an amount of 0.05-0.3% by mass, and at least one compound that is selected from the group consisting of 1, 2-dioxane, 1, 3-dioxane and 1, 4-dioxane in an amount of 0.1-3.0% by mass. |
