Experimental Study on Durability of the Carbon-Based Support in Proton-Exchange Membrane Fuel Cells 2022-01-5068

Durability is a key technical challenge for the commercialization and scale-up of proton-exchange membrane fuel cells (PEMFCs). It is difficult to screen and optimize the material rapidly due to the limitation of time and multifactor influencing mechanism of the normal-speed durability test. In this study, microstructural analysis and various characterization methods were used to study the degradation of the Pt/C (Platinum/Carbon) catalyst support during accelerated stress tests (ASTs) utilizing triangular wave voltammetry (TWV) in the range of 1.0-1.5 V. The voltage at the rated current decreased from 0.6168 V to 0.5483 V (~10% loss) after 1500 TWV cycles and was <0.2 V (72.88% loss) after 15,000 cycles. Increasing the number of TWV cycles was accompanied by an increase in the charge and mass transfer resistance and decrease in the electrochemically active surface area (ECSA) of the cathode. Microstructural analysis indicated that the thickness of the cathodic catalyst layer significantly decreased at the anode and cathode gas inlets as well as at the center of the membrane electrode assembly (MEA) owing to the severe corrosion of the carbon-based support. In this study, it is worth noting that in view of the full lifetime of the fuel cell performance variation, the effect of AST on carbon-based supports durability is not linear to the increase of AST cycles. which presents a curve with “rapid—slow—rapid” three stages, while the voltage decline rate presents a “bathtub”-like curve, which will provide some new references to the research of carbon-based support corrosion.