Proton exchange membranes (PEM) are important components of proton exchange membrane fuel cells (PEMFC) which could potentially substitute fossil energy. The purpose of this study was to theoretically and experimentally study how the thermal conductivity of the PEM, Nafion 117, is related to water content and temperature. A thermal analyzer measured the thermal conductivity of dry Nafion 117 using the transient plane source (TPS) method. Results showed that, as predicted, the thermal ...