Failure kinetics of ionomer membranes

The equivalence of the role of thermal fluctuations in the failure of fuel cell ionomer membranes is investigated in light of the kinetic theory of the strength of solids. Specifically, the activation energy of the membrane material is determined using two physically distinct methods, each exemplifying the role of thermal fluctuations. The failure kinetics of ionomer membranes is a function of the applied load as well as the temperature under which the membranes operate in a fuel cell. Time-to-failure data is thus generated for varied environmental conditions, and kinetic parameters are calculated by treatment using established methods. Separately, thermal decomposition data of the membrane material is generated for various heating rates, and the kinetic parameters so obtained are compared with those from the mechanically induced failure approach. The results from the two methods are found to confirm each other and may be used in the investigation of fracture modeling and lifetime prediction of fuel cell membranes.