| 摘要 |
PURPOSE: To provide a Li secondary battery which is excellent in impact resistance and storage characteristics by improving the carbonaceous material of a negative electrode, and improving the filling density and the mechanical strength of the negative electrode. CONSTITUTION: A Li secondary battery (for instance, a coin type) is provided with a positive electrode 3, a negative electrode 5 containing carbon fiber which stores and discharges Li ions and to the surface of which a nonionic surfactant sticks, and a separator 4 impregnated with Li ion conductive electrolyte solution. Mesophase pitch raw material is fused and formed into fiber, which is made infusible, is graphitized at a temperature of about 2000 deg.C or less in inert gas, and is graphitized at about 1000 to 3200 deg.C so as to obtain the carbon fiber. A fiber diameter is set to 1 to 100μm, and a fiber length is set to about 1 to 100μm. Polyoxyethylene alkyl ether or the like is used as a nonionic surfactant, 0.01 to 0.1 percentage by weight of which is stuck to the carbon fiber. The electrolyte solution is prepared by dissolving about 0.5 to 1.5mol/l of lithium perchlorate as electrolyte in nonaqueous solvent such as ethylene carbonate. |
