Electrochemical studies of sealed lead-acid battery electrode reactions

Abstract

From these investigations, it can be concluded that the addition of H?PO? (phosphoric acid) at a concentration of approximately 20 g/L to the H?SO? electrolyte of a sealed lead-acid battery-featuring a low-antimonial lead positive grid and an antimony-free negative grid-offers the following advantages:

Reduced corrosion rate of lead and lead alloys (Pb, Pb–Ca–Sn, and Pb–Sb–Se) accompanied by decreased hydrogen evolution. Lower open-circuit corrosion rate of lead and the above alloys. Mitigation of Sb(III) effects, which otherwise increase both the corrosion rate and hydrogen evolution on Pb, Pb–Ca–Sn, and Pb–Sb–Se alloys.

Importantly, these benefits are achieved without adversely affecting the desired electrode reaction (Pb/Pb²?). When combined with other known positive effects of this additive on the performance of the positive electrode, these findings suggest that incorporating H?PO? into the electrolyte of sealed lead-acid batteries can significantly minimize current limitations and enhance overall battery performance.