| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium secondary battery with high output and long life by suppressing drop in voltage in high rate discharging. SOLUTION: Lithium manganate of 87 wt.% having an average particle size of 20 μm, 4 wt.% carbon material having an average particle size of 3 μm, 4 wt.% graphite having an average particle size of 1 μm are mixed, 5 wt.% polyvinylidene fluoride and N-methyl pyrrolidone are added to the mixture, they are kneaded to prepare slurry having a viscosity of 50,000 mPa.s, and the obtained slurry is uniformly applied to an aluminum foil, dried at 200 deg.C for 10 min to prepare almost a uniform positive mix layer. Dispersions in which 10% graphite is dispersed in a PVDF solution are thinly applied to the surface of the positive mix layer, dried at 120 deg.C for 30 min to form a carbon rich layer. Reaction of electrons with lithium ions on the surface of a positive electrode is made smooth, and the resistance is reduced. |
