Rapid diagnostics of characteristics and stability of fuel cells with proton-conducting electrolyte

Processes underlying the degrading of membrane-electrode assemblies of hydrogen-air fuel cells with Nafion 212 and MF-4SK membranes under the conditions of their accelerated stress testing and long-term life tests are analyzed. The cathode platinum catalyst corrosion was shown to be the main cause of the degrading of the fuel cell's kinetically controlled current-voltage characteristics; the corrosion is accompanied by the platinum nanoparticles' growth and the platinum ion partial transfer into the membrane. The overvoltage components of the membrane-electrode assembly and their changing during accelerated stress testing are determined. The voltage decrease at currents > 0.5 A/cm(2) is shown to be mainly caused by the transport and ohmic resistance growth. The transport resistance components are calculated; the dependence of the cathode active layer resistance on the platinum catalyst surface area is revealed.