Abstract:This study is mainly on electrochemical performance testing, electrochemical impedance spectroscopy (EIS) testing and contact pressure distribution testing with a fuel cell stack of 15 cells, systematically study the influence of assembly force to the electrochemical performance of fuel cell stack. Experiment results show that the assembly force and loading type have influence on the internal ohmic impedance and pressure distribution, and bolt assembly is negative to the high power output of fuel cell performance. The results indicate improvement of fuel cell performance and uniformity of contact pressure should non only consider the assembly force, but also more attention to the uniform loading type and optimization of end plate structure.