CV and EIS Study of Hydrogen Fuel Cell Durability in Automotive Applications

The purpose of this paper was to investigate the main issues of the hydrogen fuel cell durability in relation to a possible application in the transportation sector. The experimental study was effected on a 500W Polymeric Electrolyte Membrane (PEM) stack, previously utilized as a power source in a fuel cell power train for scooter applications. The experimental characterization of the used stack, in terms of polarization curves and individual cell voltage acquisition, evidenced a significant total voltage decrease and a strong irregularity of individual cell voltage. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were used in order to investigate the possible causes of the stack performance loss. The results evidenced the role of catalyst particles sintering mechanism, associated with the reduction of electrochemical surface area (ECSA) and with the increase of the charge transfer resistance (Rct) observed in the fuel cell electrochemical interface. The possible role of the stack dynamic operation in cell durability was discussed in relation to the hybridization level between fuel cell generator and electric energy storage system.