Influence of Crack Formation at the Catalyst Layer and Membrane Interface on the Performance of Pemfc

Abstract

Temperature and humidity cycling during frequent startup-shutdown of proton exchange membrane (PEM) fuel cell (PEMFC) can lead to crack formation in the catalyst layer (CL) or even at the interface between the CL and PEM, decreasing the effective activation area and degrading the fuel cell performance. This study develops a two-dimensional PEMFC model to investigate the effect of CL/PEM interface crack (delamination) on the mass transport and performance of PEMFC. The results show that both the crack length and position have significant influence on the cell performance. Higher current density causes more pronounced inhibition of the electrochemical reaction in PEMFC by the length and position of crack. The presence of crack leads to an uneven distribution of cell current density, and the performance of the cell decreases with the increase of the crack length due to decreased activation area. As for the crack position effect with the same crack length, it has the greatest impact on the cell performance and leads to the worst cell performance when the crack is near the inlet, compared to other positions near the outlet or in the middle of the rib.

Keywords: interface crack, delamination, electrochemical reaction, oxygen mass fraction, Proton exchange membrane fuel cell