Life test of a high temperature PEM fuel cell prepared by electrospray

A life test has been conducted to a PBI-based membrane-electrode assembly (MEA) in which the anode and cathode catalyst layers were prepared by electrospray and results were compared with a previous study in which the catalyst layer was prepared by air-brushing. During the study, the average and local current density were continually monitored and several diagnostic techniques were periodically applied, including polarization curves, cyclic voltammetries, electrochemical impedance spectroscopy and computational fluid dynamics modelling (CFD). Results show that significantly better fuel cell performance is achieved by the electrosprayed MEA, by about 40%, as compared with the MEA prepared by traditional airbrushing with the same catalyst loading. According to the experimental measurements, the higher electrochemical active surface area and more favourable mass transport are the main responsible for the improved yield. Modelling estimations agree with experimental observations and corroborate better mass transport properties of the catalyst layer when using electrospray. This can be explained by a more appropriate morphology of the layer. No evidence of positive effects on the lifetime of the fuel cell was found out. At the end of the lifetest, the local concentrations of platinum (Pt) and phosphorus (P) in the degraded MEA were analysed and a correlation between Pt loading profile and local current distribution could be established. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.