| 摘要 |
PURPOSE:To suppress an increase of internal resistance of a battery to a minimum limit and improve its heavy load discharge characteristic, by increasing the thickness of a separator in the electrode group spirally wound with a zinc negative electrode at the latter half side of the winding along its lengthwise direction. CONSTITUTION:An electrode group 2 is spirally wound between web-like positive electrodes 3, for instance, nickel electrodes and negative electrodes 4 made of zinc through the interposition of separators 5 and constructed. The thickness of the separator 5 is arranged in such a manner as to be larger at the latter half side than at the first half side of the winding along its lengthwise direction. A difference of the thickness is constructed in such a method that, for instance, a sheet of separator is used at the first half side with two sheets at the latter half side or that a sheet of tapered separator is used with its thickness larger at its latter half side. In this way, adherent pressures between plates can be equalized at the first and latter half sides to prevent a partial location of electrolyte, decrease the growth of a zinc dendrite, further prevent an internal short-circuit by the thickness of the separator at the latter half side susceptible of growing the above described dendrite thus to improve the heavy load discharge characteristic. |
