A Woodpecker-Inspired Assembly Methodology for a Proton Exchange Membrane Fuel Cell with Uniform Contact Pressure on the Bipolar Plate

The contact pressure between bipolar plates in proton exchange membrane fuel cells (PEMFCs) is nonlinearly distributed, because of the bolt assembly. This nonlinearity in the contact pressure distribution can be amplified under vibration, and the convex point on the rough surface of a membrane electrode assembly (MEA) is equivalent to a Hertz contact. Under the friction effect, a transient current is generated and the bipolar plate corrodes suddenly, resulting in hydrogen and oxygen leakage. This study proposes a woodpecker inspired assembly PEMFC based on a hyoid-shaped wave spring (WIA-PEMFC), to achieve uniform contact pressure on the bipolar plates under both static and dynamic conditions. Then, the effectiveness of WIA-PEMFC was verified via finite element simulations and experiments. Compared with that of conventional assembly methods, the nonuniformity of the contact pressure can be reduced by up to 60%. Additionally, the electrical performance of WIA-PEMFC was also tested, and the results revealed a significant improvement in the electrical performance. Moreover, WIA-PEMFCs boast high reliability, low cost, and zero emissions due to the lack of energy supply equipment, which can facilitate the engineering development of PEMFC stacks with high reliability and high efficiency.