关键词: 质子交换膜燃料电池, 接触电阻, 电池锁紧力, 膜电极, 寿命性能

Abstract: The lifetime performance was investigated by assembling the single cell of PEMFC under a series of holding forces ranging from 0.45 to 11.3 MPa and reassembled under optimal holding force.The polarization and power density curves were obtained during different periods of operating time up to 2000 hours and the fuel cell catalyst activation regions in the polarization curves were analyzed to evaluate the electrochemical kinetic parameters.The results revealed that the holding forces affected not only the internal contact resistances,but also the kinetic parameters which might be caused by the change of the MEA microstructures.The apparent degradation observed at higher current densities after 2000 h lifetime test under the optimal holding force of 3.2 MPa was due mainly to the increases of the catalyst particle sizes.However,the agglomeration in the particle sizes of cathode catalyst after 2000 h lifetime test at 3.2 MPa was less severe than that without optimal assembly force control.

Key words: proton exchange membrane fuel cell, contact resistance, assembly force, membrane electrode assembly, lifetime performance