Comparing Proton Conductivity of Polymer Electrolytes by Percent Conducting Volume

Proton conductivity is a critical property for polymer electrolytes used in fuel cells. Mass based water uptake and ion exchange capacity are typical characteristics used to make comparisons between polymer electrolytes, but have significant limitations when correlated to proton conductivity of different polymer electrolytes. In this paper, we report a length scale parameter, percent conducting volume, which is rather simply obtained from the chemical structure of polymer to compare proton conductivity of different polymer electrolytes. Morphological effects on proton conductivity at low relative humidity are also discussed using the percent conducting volume parameter