Investigation of a Method of Evaluating Proton Transport Resistance in PEFC Catalyst Layers

Abstract

Since there is no method to directly measure proton conductivity in the catalyst layer in PEFC even though proton conduction in the catalyst layer is one of the critical factors for high performance and durability. A method to directly measure proton transport resistance in the catalyst layers was investigated by sandwiching a sample layer by two Nafion® membranes to block electron transfer, and two gas diffusion electrodes to reduce gas diffusion resistance, in this study. Direct current was applied to the system in the hydrogen atmosphere, and measurements for proton transport resistance were performed in various sample layers. As a result, proton transport resistance in sample layers was successfully evaluated, and such measurements lead to improvement of current-voltage performance of PEFC.