| 摘要 |
PROBLEM TO BE SOLVED: To pressurize a polar plate group without increasing the number of battery components and to suppress local charging/discharging reaction in a polar plate surface by setting a battery inner pressure lower than the atmospheric pressure. SOLUTION: Argon gas is supplied into a square type battery container 4 under a pressure lower than the atmospheric pressure. As a result, the surfaces opposite the polar plate surface os positive and negative electrode plates 1 and 2 are elastically deformed inside, a pressure is applied on a polar plate group and thereby the polar plate group is fixed. Thus, local charging/ discharging stress in a polar plate surface and the increase of internal resistance are suppressed. But a battery inner pressure is preferably set in the range of 450 to 610 mmHg. If a pressure higher than 610 mmHg is set, a pressing force is insufficient and thus a sufficient effect is not provided. Under a pressure lower than 450 mmHg, an excessive pressure is applied on the electrode surface, an electrolyte holding amount is reduced and an active material using rate is reduced. |
