Effect of As, Cu and Sb impurities on performance of Pb‐Ca‐Sn grids of lead‐acid batteries

Abstract

The performance of Pb‐Ca‐Sn grids of lead‐acid batteries made from recycled lead in 4 M H2SO4 in the absence and presence of traces of Cu, As and Sb, as potential impurities in the recycling process at 0.1% level, is investigated by electrochemical methods. The study includes the effect of each impurity and impurities combined on the alloy corrodibility, the efficiency of PbO2 formation, the rate of the self‐discharge and the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The results show that individual impurity enhances the corrosion resistance but increases the anode corrosion and the self‐discharge rate. Impurities play opposite effects on hydrogen evolution reaction and oxygen evolution reaction either individually or combined. Concerning water loss problem, the harmful effect of individual impurity on increasing oxygen evolution reaction is compensated by their suppression of hydrogen evolution reaction. The impurities combined suppress effectively both hydrogen evolution reaction and oxygen evolution reaction relative to alloy without any impurity. Sb has the highest harmful effects on oxygen evolution reaction and the self‐discharge but it is the best in the suppression of hydrogen evolution reaction. The impurities combined relatively improve the general corrosion resistance, the anode corrosion resistance and the self‐discharge. The study supports higher tolerance levels of Cu, As and Sb in Pb‐Ca‐Sn grids, especially when present combined, than the recommended levels in the industry standards.

Water Loss Predictive Tests in Flooded Lead‐Acid Batteries

“…Such tests, carried out on full size cell, are developed in constant current or constant voltage mode for at least one day or more (weeks/months), and in most cases the applied or collected potential is limited to the cell potential without discriminate the positive potential from the negative potential in the overcharging period. On the other hand, the water consumption effect in reduced size configuration is mainly detected through Cyclic Voltammetry (CV) or Linear Sweep Voltammetry (LSV) using a third electrode (reference), in order to investigate the reactions governing the water consumption of the single plate (either negative or positive) or to determine the inhibition and the retarding behaviour toward the H 2 /O 2 evolution caused by additives/contaminants in electrolyte and plate compositions [16–21] . Non‐conventional designs, namely reduced size cell, are used also for the gas quantification during floating water consumption tests, where the Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are detected by the volume variation and the monitoring of vented gas rate [19,22–29] .…”

Rapid Electrochemical Assessment of the Leady Oxide Recovered from Spent Lead Pastes: A Case Study on the Effect of Iron and Antimony Doping

“…Sb has effects on oxygen evolution reaction and the selfdischarge. 25 The reuse of the final leady oxide product as the starting material of PAMs and NAMs in new LABs demands a thorough study on the impact of these impurities.…”