Use of Glass-Fabric/Epoxy End Plates in High Temperature Proton Exchange Membrane Fuel Cell to Reduce Startup Time

The end plates of fuel cell assemblies are used to support the inner stacks, reduce the contact pressure, and provide sealing between membrane-electrode assemblies. They therefore require sufficient mechanical strength to withstand the tightening pressure. The end plates must be stiff enough to resist large deformations, be light enough to ensure a high energy density, have stable electrochemical properties, and provide adequate electrical insulation. In the past, end plates were made from metals such as aluminum, titanium, and stainless steel alloys. However, due to large thermal losses and excessive weight, alternative materials are now being considered. This paper focuses on replacing the conventional stainless steel end plates of a high temperature proton exchange membrane fuel cell by those made of a glass-fiber/epoxy composite to decrease the startup time. To achieve this goal, following steps were performed. First, glass-fiber/epoxy composite specimens were fabricated to measure their mechanical properties. Then, a finite element analysis was performed using the measured material properties to confirm that the composite end plates could withstand the load conditions and to estimate the startup time. Finally, glass-fiber/epoxy composite end plates were fabricated, assembled, and tested to compare the startup time and generated voltage with the values obtained using stainless steel end plates.