| 摘要 |
PROBLEM TO BE SOLVED: To improve charging/discharging efficiency, and to obtain an excellent cycle characteristic by using activated charcoal having a minimum pore diameter of the specific range length as a negative electrode current collector for holding lithium metal of a negative electrode provided together with a positive electrode and a nonaqueous electrolyte. SOLUTION: In a lithium secondary battery, a lithium ion permeable separator 3 is interposed between a positive electrode 1 and a negative electrode 2, these are wound, for example, in a spiral shape to be stored in a battery can 4, a nonaqueous electrolyte is reserved, and the battery can is sealed. Activated charcoal having a minimum pore diameter in a range of 5 to 16 Å is used as a negative electrode current collector of the negative electrode 2. The activated charcoal is desirably a fibered shape having a specific surface area of 960 to 2000 m2/g. A lithium ion enters a pore of the activated charcoal used as the negative electrode current collector in a solvent separated state to deposit lithium metal there to prevent formation of dendrites of the lithium metal to restrain reaction of the lithium metal and a solvent of the nonaqueous electrolyte to prevent reduction in charging/discharging efficiency to improve the cycle characteristic. |
