ABSTRACT
Whereas lower antimony levels are preferred to reduce gassing. its complete elimination in grid alloys leads to a decay in the utilization factor with the charge-discharge cycle. As discussed later. the use of sufficient tin in antimony-free Pb-Ca-based alloys mitigates this problem. Antimony helps in fonning a fine and low-resistance lead oxide layer. and tin addition to low-antimony alloys helps stabilize capacity. The addition of phosphoric acid to the electrolyte in gel batteries (described later) has a beneficial effect on cycle stability. It reduces the fonnation of sulfate layers around the grid.
