Corrosion Assessment of a Lead-Based Composite in Sulfuric Acid Electrolytes

In this study, corrosion performances of the Pb-MnO2 composite in a sulfuric acid electrolyte solution at a wide range of anodic potentials were investigated. The protective effects of manganese ions as an additive to the electrolyte were also studied. An industrially supplied PbAg alloy was examined in some cases and the obtained results were used as benchmarks for comparison. Oxidation of these materials and properties of the formed anodic layers were examined using electrochemical techniques including electrochemical impedance spectroscopy, cyclic voltammetry, potentiostatic polarization, and linear sweep voltammetry. Scanning electron microscopy, x-ray diffraction, and Raman spectroscopy were used to characterize the anodic layers. The presence of MnO2 particles in the Pb-MnO2 caused the open-circuit potential of lead to increase from the PbSO4 potential region to the PbO potential region, contributing to different composition of the anodic layer and higher charge transfer resistances of the corrosion...