Chemical and Materials Engineering Vol. 3(2), pp. 17 - 22
DOI: 10.13189/cme.2015.030201
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Effect of Tin Addition on the Corrosion Behavior of Lead-Calcium-Tin Grids in Lead-Acid Batteries


Lourdes Patricia L. Carreon , Michelle Angelica A. de Guzman *, Stan Kristian G. Ejera , Alyssa C. Ong
Department of Mining, Metallurgical and Materials Engineering, University of the Philippines-Diliman, Philippines

ABSTRACT

Pb-Ca-Sn alloys are used as grids in lead-acid batteries with Ca concentrations that range from 0.03-0.05 wt.%. Grids that contain 0.03 wt.% Ca have been proven to be resistant to corrosion, making them the ideal alloys for positive and negative grids of stationary batteries. Additives such as Sn have been added to improve the corrosion resistance, the electrochemical and the mechanical properties of the battery. This study aims to determine the effect of Sn coating on the corrosion behavior and the service life of Pb-Ca-Sn grids. The corrosion behavior was determined using weight loss method. Three batteries, each one composed of six corrosion cells, were prepared. Four positive plates, namely one control grid and three experimental grids, comprise each corrosion cell. The grids were submerged in sulfuric acid (H2SO4) with a specific gravity of 1.28 and charged with 1.25 A. Energy dispersive x-ray spectroscopy (EDX) was used to determine the composition of the grids and surface morphology was examined using scanning electron microscopy (SEM). Single factor analysis of variance (ANOVA) at 95% confidence level, suggests that the amount of Sn coating significantly affects the corrosion behavior of the grids. Results show that corrosion resistance of grids greatly improves with increasing thickness of Sn coating.

KEYWORDS
Corrosion, Corrosion Rate, Electrodeposition, Pb-Ca-Sn Alloy, Weight Loss Method

Cite this paper
Lourdes Patricia L. Carreon , Michelle Angelica A. de Guzman , Stan Kristian G. Ejera , Alyssa C. Ong (2015). Effect of Tin Addition on the Corrosion Behavior of Lead-Calcium-Tin Grids in Lead-Acid Batteries. Chemical and Materials Engineering, 3 , 17 - 22. doi: 10.13189/cme.2015.030201.