Evaluation of PbSn Alloys Corrosion Inhibition Using Tin and PbO₂ Coatings

Abstract

One of the main failure modes in Lead-Acid Batteries (LAB) is corrosion at the positive plate. This problem has increased significantly the number of warranty claims, becoming a significant loss for this industry. Attempts to prevent corrosion in LABs include the application coatings of metallic oxides in the positive plate. In this work the use of tin and PbO2 as anti-corrosion coatings is explored. The coatings were prepared by electroless deposition and electrodeposition using current pulses. Corrosion rate of grid samples was determined, with and without coating, from Tafel plots. It was found that electrodeposited tin coated grids had the highest corrosion inhibition. On the other hand, electroless tin deposits had the lowest corrosion inhibition activity showing a higher corrosion rate than the uncoated alloy.