| 摘要 |
PROBLEM TO BE SOLVED: To provide a lithium ion secondary battery with a large charge/ discharge capacity to prevent a negative electrode from flaking even if charge/ discharge cycles are repeated. SOLUTION: A carbonic material with a surface interval of 0.34 mm or less, outward density of 90% or less the true density, and a specific surface area of 100 mm<2> or less by graphitizing an active carbon having a pore by activation treatment is manufactured, and this is used as a negative electrode. Thereby, since volume expansion when lithium ions are stored and also a large charge/discharge capacity of carbon is maintained, a lithium ion secondary battery with a large capacity whose cycle performance is improved can be provided. |
