Investigating the acceleration factors of proton exchange membrane fuel cell degradation

Abstract

In this work, a voltage square wave was used as accelerated stress test (AST) to assess the cathode catalyst durability in membrane electrode assemblies (MEAs) of the proton exchange membrane fuel cells (PEMFCs). The degradation of MEAs was investigated under square waves with dwell time of 3 s (SW-3 s) and 6 s (SW-6 s). AST conditions and the difference of impact between both ASTs conditions was calculated by using the degradation of electrochemical active surface area (ECSA) as an indicator. The platinum particle sizes of the cathode catalyst before and after the accelerated testing were characterized by transmission electron microscopy (TEM) and its correlation with ECSA was regarded. Finally, the loss of ECSA is used as an indicator to calculate the acceleration factor between AST and steady-state durability testing for 7500 h. The acceleration factor (fECSA) was estimated to be 150 by only regarding the ECSA.