| 摘要 |
PROBLEM TO BE SOLVED: To improve reduction of the discharge load characteristic by providing a positive electrode active material, a negative electrode active material, and a binder contained in these active materials, and setting the film thickness of the binder on the surface of at least one active material of both active materials to a specific value or below. SOLUTION: A film thickness of a binder on the surface of an active material is set to 15 nm or below. The binder at both electrodes connects active material grains together, so that the active material grains are not dispersed and serves to maintain the binding property of the electrodes. The film thickness of the binder stuck to the surface of the active material is adjusted so as to improve the discharge capacity at high load on at least one electrode. Polyvinylidene fluoride(PVDF), cellulose, styrene butadiene rubber(SBR), or nitrile butadiene rubber(NBR) is used for the binder, a Cu foil with the film thickness of 10-20 μm is used for a negative electrode current collector, and an Al foil with a film thickness of 10-20 μm is used for a positive electrode current collector. |
