Corrosion Behavior of Pure Aluminum in the Simulated and Real Environments for Use as a Bipolar Plate Component in Polymer Electrolyte Membrane Fuel Cells

Abstract

Due to oxygen- or hydrogen-rich environments, metallic bipolar plates in proton exchange membrane (PEM) fuel cells (FCs) are extremely prone to corrosion. In this work, the corrosion behavior of pure aluminum (Al) and its correlation between the simulated and real environments in the PEM FC were investigated, where the word “real” means the recovered solutions that were collected from the cathode and anode of the PEM FC during the 500 h of single-cell power generation test. The single-cell power generation test was performed for 500 h using graphite, bare Al, and TiN-SBR-coated Al as the reaction gas isolating plates for use as bipolar plates in the PEM FC. The corrosion rate of pure Al was calculated after immersion in different solutions, such as distilled water, sulfate ions, fluoride ions, and their combined solutions. The electrochemical behavior of pure Al was evaluated by polarization tests, which showed that the higher corrosion resistance was found in the solutions with higher pHs. Corrosion morphology, surface roughness, structures of corrosion products, and elemental compositions in simulated and real environments were measured and examined. The results revealed that higher and lower amounts of oxide layers as corrosion products were found for the presence of fluoride and sulfate ions, respectively, in the tested solutions. In addition, the study of the cathode and anode sides of used bipolar plates before and after the single-cell power generation test reports that the light and whitish corrosion products were captured on the anode side, and interestingly, almost no corrosion layers were seen on the cathode side of the bipolar plates after PEM FC operation. Thus, it was suggested that Al can be considered one of the most suitable materials for use as bipolar plates in a PEM FC, where the higher voltage and improved corrosion resistance were found using TiN-SBR-coated Al plates.

Corrosion behavior and surface structure analysis of pure aluminum immersed in fluoride‐sulfate solutions simulating polymer electrolyte membrane fuel cell‐produced water

“…Here, we just used the Al BPs without any coating performance and accomplished the experiments, though some of the researchers also found and mentioned the use and suitability of coated BPs in PEMFC. In addition, further research was performed along with the cell operation on coated Al BPs using surface modification methods for PEMFC by Jahan et al [40]. It is also believed that one of the main policies for improving the durability and performance of the PEMFC is to design and find cheaper BPs with high corrosion resistance.…”

“…In addition, further research was performed along with the cell operation on coated Al BPs using surface modification methods for PEMFC by Jahan et al. [40]. It is also believed that one of the main policies for improving the durability and performance of the PEMFC is to design and find cheaper BPs with high corrosion resistance.…”