| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery in which charge/discharge effect is sharply enhanced by containing the specified ratio of cobalt and boron in a lithium - ickel composite oxide which is a positive active material for the nonaqueous electrolyte secondary battery. SOLUTION: An active material represented by a formula of Li (Ni1-y Coy )1-z Bz O2 (wherein x, y, z represent the composition ratio of Ni, Co, B, 0.1y<=z<=0.05y+0.026, y≠0, 0<z<=0.03) obtained by adding cobalt and boron to a lithium - nickel composite oxide is used in a positive electrode of a nonaqueous electrolyte secondary battery. A carbon material (such as coke and graphite) capable of doping and undoping lithium ions is used in a negative electrode, and a solution prepared by dissolving an electrolyte such as LiCLO4 in a nonaqueous solvent, such as propylene carbonate, is used as a nonaqueous electrolyte. The nonaqueous electrolyte secondary battery with high charge/ discharge efficiency and high energy density is obtained. |
