Numerical study of the effects of operating voltage on the degradation of membrane electrodes of PEMFC
To study the effect of operating voltage on the degradation of membrane electrodes of proton exchange membrane fuel cell(PEMFC)under long-term stable operation conditions,a coupled multi-physics field PEMFC model including carbon corrosion,Pt oxidation,dissolution and ionomer degradation is established for numerical simulation.The results show that as the operating voltage increases,the Pt dissolution and carbon corrosion rates in the cathode catalytic layer accelerate.After 500 h,the oxidized area of the Pt surface increases significantly.The radius of the agglomerates in CCL and the concentration of sulfonic acid groups in the proton exchange membrane decrease drastically,and the recession area is mainly concentrated in the cathode inlet and the degree of the recession is increased drastically at a high voltage.When the cell is operated at 0.8 V for 500 h,the thickness of CCL and membrane at the cathode inlet decreased significantly by 13.62%and 35.30%,respectively.The electrochemcial active surface area of CCL and the ionic conductivity of the membrane decreased by 59.9%and 6.9%,respectively,and the equivalent weight of the membrane increased by 7.4%,and the above indexes declined drastically in the first 100 h,and then gradually stabilized.The conclusion can provide a guideline for the optimization of membrane electrode material design and control strategy.
国家科技期刊平台
NSTL
万方数据
