Comparative analysis of circular and square end plates for a highly pressurized proton exchange membrane water electrolysis stack

End plates are located at both ends of a proton exchange membrane water electrolysis (PEMWE) stack. If the end plates are thin, clamping pressure is not uniform and the performance of PEMWE can deteriorate from leakage and high electrical contact resistance caused by the deformation of the thin end plates. In this study, end plates were designed to reduce the weight while clamping the stack uniformly by finite element analysis (FEA). The weights of the circular and square end plates were reduced compared to conventional end plates by 22.9% and 20.1%, respectively. The stress and strain distribution of square and circular end plates are analyzed using topology optimization. This analysis can improve the performance of the PEMWE by using new end plate designs verified by dummy cell stack simulation to maintain uniform pressure.