CYCLIC CORROSION OF THE LEAD-ACID-BATTERY POSITIVE

Simulated deep discharge cycling of a lead-acid battery positive, using a linear potential sweep technique, was performed on pure and antimonial lead electrodes in sulfuric acid electrolyte with and without phosphoric acid additive. Discharge capacity, depth of corrosion, corrosion product morphology, adhesion between the substrate and corrosion product, and distribution of antimony, phosphorus, and sulfur in the corrosion product layer were monitored. Results indicated that the cyclic corrosion process occurring at the lead/lead dioxide electrode interface was controlled by the corrosion product layer consisting of an inner layer dominated by α-PbO2 and an overlapping outer layer dominated by βPbO2. Presence of antimony in the alloy was noted to improve the adhesion between the grid substrate and the inner layer, integrity of the inner layer, and interparticle bonding of lead dioxide particles. Phosphoric acid additive in electrolyte was noted to alter the structure of corrosion product layer resulting in improved adhesion between the grid and the inner layer and between the inner and outer layer. © 1979, The Electrochemical Society, Inc. All rights reserved.