Discharge behaviour of electro-deposited lead and lead dioxide electrodes on carbon in aqueous sulfuric acid

Lead and lead dioxide electrodes on carbon are prepared by electro-deposition and subsequent electro-oxidation. Their behaviour as lead/acid battery electrodes is studied. It is found that while the oxidation of lead to lead sulfate is diffusion controlled, the reduction of lead dioxide to lead sulfate is a surface process. The efficiencies of both the reactions vary with sulfuric acid concentration, and each passes through a maximum. Unlike the lead dioxide electrode, the discharge capacity of the lead electrode is found to depend heavily on the discharge rate. The current-voltage characteristics of a prototype cell that consists of two electro-deposited electrodes improve with an increase in the acid concentration.