PURPOSE: To lengthen the life of a battery by assembling unformed plates manu factured by immersing in a specified solution through a retainer, and performing in-container formation in a limited volume of sulfuric acid.
CONSTITUTION: When an unformed plate is manufactured by filling lead oxide paste in a lead alloy grid and by immersing in a sulfuric acid having a specified concentration, PbO is uniformly converted into PbSO4 from the surface to the inside of the coated layer, resulting in volume expansion. A plate group obtained by assembling the unformed plates together with a retainer under compression is accommodated into a container. A specified volume, which needs for a com pleted battery, of sulfuric acid having a specified concentration is poured in a container, and water equivalent to 10∼30% of this specified volume is addition ally poured, then in-container formation is performed. The conversion of PbSO4 into PbO2 by formation results in volume shrinkage, and uniform pores and specific surface area are increased, and in addition fine PbO2 crystals gather to form a large skeleton crystal. By retainer effect by which the collapse of active material is decreased by close contact between the active material and the retainer, the discharge duration and the life of a battery are increased.
SAITO SHINJI
MIURA ASAHIKO
MATSUBAYASHI SATOSHI
KOMAKI AKIO
HAYAKAWA TAKUMI
Next Patent: MANUFACTURE OF PLATE FOR SEALED ALKALINE STORAGE BATTERY