Axiomatic design of the sandwich composite endplate for PEMFC in fuel cell vehicles

To fasten a fuel cell stack in a polymer electrolyte membrane fuel cell (PEMFC), two thick steel endplates have been used to maintain a proper contact pressure at the interfaces among gaskets, gas diffusion layer (GDL), membrane electrode assemblies (MEA), and bipolar plates. The proper contact pressure is required both to improve its energy efficiency by decreasing ohmic loss and to prevent leakage of fluid such as hydrogen, air, or coolant. Since the thick steel endplates are not only heavy, but also have high thermal conductivity and thermal inertia, which deteriorate the cold-start characteristics of fuel cell stack, a new development of the endplate with light weight and better thermal properties is necessary.In this work, to satisfy the two functional requirements, i.e. light weight and good cold-start characteristics, a sandwich construction composed of carbon fiber reinforced composite faces and a thermal insulation foam core was employed for the endplate. For the endplate design, the axiomatic design process and finite element analysis were used considering both structural and thermal characteristics of the endplate of a PEMFC.