Effect of corrossion on the electrical conductivity of metals and polymer composite

Abstract

Applications of a metallic bipolar plate in a proton exchange membrane fuel cell (PEMFC) are currently being developed in the market. The main challenge for metal usage is the effect of corrosion on the overall performance of a PEMFC. The materials used in this study are stainless steel 316L (SS316L), aluminum 6061, titanium, compressed graphite, and graphite/CNTs/epoxy nanocomposite. The materials and its measurements were studied using digital multimeter to obtain the conductivity of the material, potentiostatic test to determine the corrosion rate, pH meter to determine the pH level of the sulfuric acid, and microscope to study the topography surface of the corrosion material before and after the corrosion test. Results show that aluminum corrosion is the fastest and the most severe, followed by SS316L, titanium, compressed graphite, and graphite/CNTs/epoxy nanocomposite. Corrosion decreases the electrical conductivity of the material and the pH level of sulfuric acid, consequently making the material dull and coarse. Metal plates face more severe corrosion problems compared with compressed graphite and graphite/CNTs/epoxy nanocomposite. Despite the corrosion problems it creates, metal use is low cost, easy to fabricate, light, and has good heat and electric conductivity. Hence, the development of the metallic bipolar plate shows high potential, and its modification is encouraged. © 2012 Penerbit UTM Press.