Investigation on degradation mechanism of hydrogen-oxygen proton exchange membrane fuel cell under current cyclic loading

Hydrogen-oxygen proton exchange membrane fuel cell with good application prospect in the special occasions of space exploration and underwater navigation, its durability is still a key problem to be solved. In this research, current cyclic loading durability experiment of a hydrogen-oxygen proton exchange membrane fuel cell with an active area of 50 cm(2) was carried out. The performance degradation was characterized by polarization curves, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy. Finally, the decay of catalyst and membrane was evaluated by Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy and Transmission Electron Microscope. After 2500 loading cycles, it with a total performance degradation of 31.05% at 1200 mA cm(-2). The electrochemical active surface Area decreased by 61.6% and electrochemical Impedance increased by 33.04%. What' more, the catalyst layer in outlet area had been partially damaged, and its Pt particles have agglomerated and grown. More seriously, Pt particles had migrated and lost. The decay phenomenon was also found in the proton exchange membrane, in which element F, S and C were partially lost, especially element F. The findings reported here are expected to provide more insights into the effect of current loading on the decay of membrane electrode assembly. (C) 2021 Elsevier Ltd. All rights reserved.