Effect of magnesium sulfate on the electrochemical behavior of lead electrodes for lead acid batteries

The lead acid battery technology has undergone several modifications in the recent past, in particular, the electrode grid composition, oxide paste recipe with incorporation of foreign additives into the electrodes and similarly additives added in the electrolytes to improve electrical performance of the lead acid battery. In this paper, the electrochemical behavior of the lead electrodes with different weight/volume percentages (wt./v%) of MgSO4(0.0., 0.5., 1.0., 2.0., and 5.0) added into the electrolyte have been investigated with cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). The CV profile showed better redox behavior of the lead electrodes which was attributed to the increased active surface area of the electrode. Further studies of the gas evolution found a mixed trend and a considerable drop in the impedance as observed by LSV and EIS analysis as compared to the blank electrolyte solution. The influence of a modified electrolyte on the electrochemical activity of the lead electrodes is correlated and discussed.