Heat and mass transfer performance of proton exchange membrane fuel cells with electrode of anisotropic thermal conductivity

Proton exchange membrane fuel cells (PEMFCs) are widely used because they are clean, efficient, and renewable. However, many advanced electrode materials have distinct characteristics in different dimensions, and the anisotropy of thermal conductivity can significantly influences the performance of PEMFCs. In this study, the coupling characteristics of heat transfer and catalysis by a PEMFC are systematically analyzed using an anisotropic electrode thermal conductivity model. The results revealed that the anisotropy in the through-plane direction of the electrode thermal conductivity exhibited a more significant influence than in other directions. Specifically, the heat generated in the cathode electrode during the electrochemical process was the primary heat source in the PEMFC, and the molar concentration distributions of liquid water and oxygen on the electrode surface also varied at different operational temperatures. Moreover, the output performance of the PEMFC could be effectively improved through appropriate anisotropic thermal conductivity in the through-plane direction at a low operational temperature. However, the improvement of the electrochemical reaction is limited under high operational temperature conditions, owing to a decrease in transition region of proton conductivity. Overall, this study shows a new strategy of improving the performance of PEMFCs by reasonably design the electrode materials with anisotropic thermal conductivity. (c) 2021 Elsevier Ltd. All rights reserved.