Advancements in Multilayer Coatings on Aluminium Alloy-Based Bipolar Plates for PEMFC Application

Abstract

Fuel cells represent a revolutionary and sustainable approach to energy conversion, offering a clean alternative to traditional combustion-based power generation. These electrochemical devices convert the chemical energy of a fuel, typically hydrogen, directly into electricity. The fundamental working principle involves the electrochemical reaction between hydrogen and oxygen, facilitated by a catalyst, to produce electricity, water, and heat as byproducts in Proton Exchange Membrane (PEMFC). This strategic use of aluminum (Al) alloy for Bipolar plates (Bp) aligns with the industry's commitment to advancing materials and design methodologies, ultimately promoting the optimization of fuel cell technology in terms of performance, durability, and economic feasibility. This comprehensive review investigates recent progress in the development of multilayer coatings tailored for Al alloy-Bp in PEMFCs. Al alloys are a preferred substrate material due to their cost-effectiveness, lightweight nature, and high thermal conductivity. However, challenges such as corrosion, electrical conductivity, and interfacial contact resistance have spurred extensive research into innovative coating solutions. The review critically examines various coating materials, deposition techniques, and performance evaluation methods aimed at addressing the challenges associated with al alloy Bp. Special emphasis is placed on corrosion-resistant coatings, conductive layers, and interfacial modifiers. The assessment encompasses both established technologies and cutting-edge approaches, including nanocomposite coatings, self-healing materials, and advanced characterization methods. By synthesizing and analyzing existing literature, this review provides a comprehensive overview for researchers, engineers, and policymakers involved in advancing PEMFC technology. The findings underscore the crucial role of multilayer coatings in augmenting the performance and longevity of al alloy-based Bp, offering valuable insights to guide further research and development in the pursuit of efficient and durable fuel cell systems. In comparing the aluminum grades Al-356, Al-5052, Al-6061, and Al-7075, it is observed that Al 5052 exhibits lower corrosion density, providing greater efficiency compared to other aluminum grades. In the case of Al 356, the potentiostatic result yields a lower value than that of other aluminum grades. Consequently, these findings suggest a tendency for favorable corrosion resistance and electrodeposition in both Al 5052 and Al 356, making them noteworthy choices in applications requiring these particular material characteristics.