A Comparison of Procedures Used in Assessing the Anodic Corrosion of Metal Matrix Composites and Lead Alloys for Use in Lead‐Acid Batteries

Abstract

The anodic corrosion of lead at 70°C in sulfuric acid was studied at a potential of 1.226V vs. where both the oxidation of lead to and the oxidation of water are thermodynamically possible. These parallel anodic reactions can be the cause of a decrease in the faradaic efficiency. The faradaic corrosion current efficiency can be defined as a fraction of the total charge passed which is used to transport metal ions into solution. The faradaic efficiency can affect the corrosion process in several ways. The most obvious of these is the corrosion time which increases with decreasing efficiency. The extent of corrosion was measured in terms of weight loss of lead and the current density of the corrosion layer. It is believed that some of the current is going towards oxygen evolution, which makes it inexact to use electrochemical capacities alone to predict accurately the corrosion rates for this system. Weight loss values are compared with those from Faraday's laws and data are presented on mass changes and corrosion currents.