Patent ID: 7799466
Filing Date: 2010-09-21
Classification: H01M,Y02E

Abstract:
1. A valve regulated lead acid battery having lightly gelled electrolyte comprising: (a) a container; (b) a positive plate and a negative plate disposed in the container; (c) an electrolyte-absorptive separator sandwiched in between the positive plate and the negative plate in the container; (d) a lightly gelled electrolyte providing electrolytic connection between the positive plate and the negative plate in the container, the light gelled electrolyte comprising: (e) a dilute sulfuric acid having a specific gravity of 1.28 to 1.34; and (f) an amount of fumed silica particles in the range of 0.1% to 3% of the electrolyte by weight; wherein the silica particles forms reversible pasty gel lumps in the pores of the separator during charging-discharging cycles, and the reversible gel lumps adjacent to the surface of the plates disrupt the growth of dendrites and prevent shedding of the active paste materials from the plate surfaces to provide a cycle life greater than 300 cycles at a minimal discharging time greater than 115 minutes.