| 摘要 |
PROBLEM TO BE SOLVED: To prevent the loosening of a sealing part due to charging/discharging for preventing electrolyte leakage and to increase electrolyte leakage resistance by enlarging an electrode in the diameter direction so that the outer circumferential surface almost reaches the inner circumferential surface of a metal outer can. SOLUTION: An active material such as lithium titanate generating no volume change in charge/discharge and having spinel crystal structure is used in an electrode 1 which is enlarged in the diameter direction so that the outer circumferential surface 1a almost reaches the inner circumferential surface of a metal outer can 4. Or, in the case that an active material having crystal structure other than the spinel structure, the theoretical electric capacity of the other electrode 2 is made 90% or less of the electrode 1 enlarged in the diameter direction to reduce the volume change of the active material due to charging/ discharging. Thereby, the loosening of a sealing part due to charging/discharging is prevented, electrolyte leakage caused by the loosening of the sealing part is prevented, and by the enlarged electrode, electric capacity is increased. |
