Investigation of processes in a lead-acid battery

The kinetics and mechanism of surface processes which take place on lead electrodes, as well as lead-antimony alloy electrodes in sulphate acidic electrolyte, have been investigated using cyclic voltammetry and impedance spectroscopy. Surface film characterization and solid state transitions taking place between the potential of lead (II) sulphate formation and oxygen evolution, have also been studied. It was found, in comparison with the pure lead electrode, that antimony present in the alloy catalyzes the transition of tetragonal lead (II) oxide to nonstoichiometric PbOn oxide and orthorhombic α-phase of PbO2 in the anodic (corrosion) layer, while it inhibits the formation of conducting β-PbO2 phase. This causes an expansion of the discharging region as well as an increase in the capacity of the positive electrode in the lead-acid battery.