| 摘要 |
[Problem] To provide a lithium ion secondary battery having excellent high-rate discharge characteristics. [Solution] Excellent high-rate discharge characteristics are obtained by a lithium ion secondary battery in which a compound represented by Lia(NixCoyAl1-x-y)O2 (where 0.95≦a≦1.05, 0.5≦x≦0.9, 0.05≦y≦0.2, and 0.7≦x+y≦1.0) is used as a positive electrode active material in a positive electrode, the positive electrode has an electrode density of 3.75 to 4.1 g/cm3, and the positive electrode has a BET specific surface area of 1.3 to 3.5 m2/g as an electrode. |
