Lithium ion secondary battery
View Patent ↗The invention provides a lithium ion secondary battery comprising a positive electrode, a negative electrode and an electrolysis solution containing an aprotic solvent having an electrolyte dissolved in it, wherein the negative electrodes uses an amorphous carbon material as a negative electrode active material. The amorphous carbon material has (A) an average particle diameter (median size) of 7 μm to 20 μm inclusive as measured by a laser diffraction scattering method and (B) a particle size distribution as measured by a laser diffraction scattering method, in which distribution the ratio of particles of less than 3 μm in diameter is 1% by mass to 10% mass inclusive, and is free of an electrical conducting material.
1. A lithium ion secondary battery comprising
a positive electrode,
a negative electrode and
an electrolysis solution containing an aprotic solvent having an electrolyte dissolved in it, wherein said negative electrodes comprises an amorphous carbon material as a negative electrode active material,
wherein said amorphous carbon material has an average particle diameter (median size) of 7 μm to 20 μm inclusive as measured by a laser diffraction scattering method and a particle size distribution as measured by a laser diffraction scattering method, in which distribution a ratio of particles of less than 3 μm in a diameter is 1% by mass to 10% by mass inclusive, and is free of an electrical conducting material.
2. The lithium ion secondary battery according to claim 1 , wherein said amorphous carbon material has a weight change of less than 3% by weight as measured after 50 hours in an environment having a temperature of 40° C. and a humidity of 90%.
3. The lithium ion secondary battery according to claim 1 , wherein the lithium ion secondary battery is sealed up by a film wrap comprising a flexible film.
4. The lithium ion secondary battery according to claim 2 , wherein the lithium ion secondary battery is sealed up by a film wrap comprising a flexible film.