The influences of silver and zinc addition on the electrochemical performances of the Pb-Ca-Sn Grids for lead acid batteries

The silver and zinc addition on the electrochemical performances of the Pb-Ca-Sn Grids were investigated. The corrosion film structure, phase composition and electrochemical performances of Pb - 0.08 wt.% Ca - 1.2 wt.% Snalloy, Pb - 0.08 wt.% Ca - 1.2 wt.% Sn - 0.03 wt.% Ag alloy and Pb - 0.08wt.% Ca - 1.2 wt.% Sn - 0.06 wt.% Zn alloy in a 1.28 g/mL of H2SO4 solution were studied by SEM observation, metallographic study, XRD, CV test and Constant DC discharge. It was found that the corrosion film of the alloy Pb - 0.08 wt.% Ca - 1.2 wt.% Sn appears as flaky crystal structure, while with the addition of 0.03% Ag and 0.06% Zn into Pb - 0.08 wt.% Ca - 1.2 wt.% Sn, the corrosion film being transformed into the crystalline columnar, compact structure. XRD analysis shows that the relative diffraction density of PbO2 increases with the addition of Agand Zn. The capacity loss of the battery with the Pb-Ca-Sn-Zn grids is significant less than that with the Pb-Ca-Sn-Ag and Pb-Ca-Sn grids, and the life of battery with the Pb-Ca-Sn-Zn grids is longer than that with the Pb-Ca-Sn-Ag and Pb-Ca-Sn grids. The addition of Zn into Pb-Ca-Sn alloy can obviously improve the corrosion resistance of the alloy and form a new positive grid material for the lead-acid battery.