The Effect of the Lead Alloy Hardening Process in Electric Vehicle Storage Batteries on Corrosion Resistance

Abstract

This study focuses on two types of precipitation in both ternary Pb‐Ca‐Sn alloys (up to 5 wt % Sn) and quaternary Pb‐Ca‐Sn‐Ag/In alloys (up to 0.5 wt % Ag/In) as well as on the nature and morphology of the precipitated phases and the hardening intensity. Several structural states are studied including gravity cast for grids, rolled, and as‐cast for strips. The corrosion behavior at the anodization potential of 1.5 V under overcharged battery conditions is determined in relation to both alloy composition and type of precipitation. A correlation between the mechanical properties of the alloys and their electrochemical behavior is clearly established. Thus, the Pb‐Ca‐Sn alloys with high tin contents (1–2 wt %) as well as the quaternary Pb‐Ca‐Sn‐Ag alloys, which harden following a continuous transformation, present a better corrosion resistance in overcharge conditions.