Experimental assessment of proton exchange membrane fuel cell performance degradations during emulated start-up/shut-down phases

Abstract

Start-Up/Shut-Down phases in PEM Fuel Cell system has paid particular attention because of the well-identified reverse current mechanism leading to harsh corrosion environment within the Cathode Catalyst Layer. In this work, an experimental ageing test is designed to assess a comprehensive investigation of electrochemical properties degradations and thus influence on cell performances during the Start-Up phase. An Accelerated Stress Test protocol is designed to mimic and cycle the cathodic potential profile during the H2|Air front propagation along anodic channel. A sensitivity analysis is performed on the maximum cathodic potential and the exposure time parameters. Results divulge that lowering maximum potential by a dummy load application and lowering exposure time by accelerating H2 feeding during Start-Up phases are promising mitigation strategies. Moreover, this paper reports a promising effect by scanning the cathodic potential above 1.0 V for conditioning carbon support and optimizing cell performance at high current densities.