| 摘要 |
PURPOSE: To provide excellent battery characteristics such as a large capacity, high charging/discharging efficiency, a long cycle life, and a flat discharging voltage by forming the carbonaceous material used for a negative electrode with the mixture of two kinds of specific carbonaceous materials. CONSTITUTION: This lithium secondary battery is constituted of a negative electrode made of a carbonaceous material storing and releasing lithium ions, a positive electrode, and a nonaqueous electrolyte. The carbonaceous material is made of the mixture of two kinds of carbonaceous materials, and one of them is the graphitized mesophase pitch carbon fiber powder having the average fiber length of 10-100μm, the average fiber diameter of 4-15μm, and the spacing less than 0.338nm of the (002) plane by the X-ray diffraction method. The other carbonaceous material is the carbon powder made of artificial graphite or natural graphite and having the particle size distribution of 15μm or below at 70vol.% or above, the specific surface area less than 3.0m<2> /g, and the spacing less than 0.38nm of the (002) plane by the X-ray diffraction method. The weight ratio between two carbonaceous materials is set to 80-95:20-5. |
