Probing the Corrosion Rates of Novel Titanium Substrates in a Simulated PEM Fuel Cell Environment

Metallic bipolar plates are often used in proton exchange membrane fuel cells (PEMFCs) due to their facile manufacturing process, high electrical and thermal conductivity, and mechanical strength. [1] Titanium is particularly popular due to its corrosion-resistive properties which come from a naturally occurring passive oxide layer on its surface. However, the naturally occurring passive film cannot fully withstand the acidic environment of an operating PEMFC. And inherently, without this protective layer; corrosion will inevitably occur. [2] Thicker oxide layers can be formed on the surface by exposing the titanium to elevated temperatures in the presence of oxygen In this study, the corrosion resistance of commercially pure titanium with thermally grown oxidation layers and titanium directly coated with a commercial sub-oxide coating was investigated. The corrosion resistance of the various samples was examined with potentiostatic and potentiodynamic tests in sulfuric acid solution at various temperatures to simulate PEMFC conditions. The samples were also subjected to a novel accelerated stress test to evaluate long term durability under fuel cell vehicle startup and shutdown conditions. References [1] Wu, S., Yang, W., Yan, H., Zuo, X., Cao, Z., Li, H., Shi, M., & Chen, H. (2021). A review of modified metal bipolar plates for proton exchange membrane fuel cells. In International Journal of Hydrogen Energy (Vol. 46, Issue 12). [2] Yu, F., Wang, K., Cui, L., Wang, S., Hou, M., Xiong, F., Zou, R., Gao, P., Peng, H., & Liu, Z. (2022). Vertical-Graphene-Reinforced Titanium Alloy Bipolar Plates in Fuel Cells. Advanced Materials , 34 (21).