| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with improved charge/discharge characteristics, especially high rate discharge characteristics by using an amorphous composite oxide comprising tetra-valent tin and at least one element selected from among group 1 elements in the periodic table as a negative electrode material. SOLUTION: A composite oxide of a negative electrode material contains tetra-valent tin as a function element containing amorphous structure and relating to insertion/releasing of lithium, and at least one element selected from element from among the groups 1, 2, 13, 14, 15 in the periodic table, transition metals, and halogen elements. The composite oxide is preferably prepared through a sol-gel process. The fine particles of the composite oxide is preferably globular, in order to increase the filling density of an electrode material thin layer and the toughness of particles, and average particle size is 0.1-20 μm. The fine particles preferably have a BET specific surface area of at least 2 m<2> /g or more for enhancing the efficiency, even in quick charging/discharging. |
