Comparison of Pb–Sm–Sn and Pb–Ca–Sn alloys for the positive grids in a lead acid battery

Abstract

The anodic behavior of Pb–0.73 wt.% Sm–0.63 wt.% Sn and Pb–0.088 wt.% Ca–0.63 wt.% Sn alloys in sulfuric acid solution has been studied using linear sweep voltammetry, impedance–time curves and cyclic voltammetry. The experimental results show that the samarium in the Pb–Sm–Sn alloy can inhibit the growth of the anodic corrosion layer (PbO 2) formed on the alloy. Moreover, the rate of the oxygen evolution at the Pb–Sm–Sn alloy electrode is lower than that at the Pb–Ca–Sn alloy electrode. 2V-200Ah VRLA batteries were separately manufactured using the Pb–Sm–Sn and Pb–Ca–Sn positive grids. The results of the test show that the capacity loss of the battery with the Pb–Sm–Sn positive grids is significantly less than that of the battery with the Pb–Ca–Sn positive grids.