Unraveling the Influence of Nafion Content on the Performance of Proton- Exchange Membrane Fuel Cells from the Perspective of Triple-Phase Boundary

CY Zhang and KD Hu and XR Liu and YX Qu and L Luo and XM Sun and ZB Zhuang and H Li, LANGMUIR, 40, 15520-15529 (2024).

DOI: 10.1021/acs.langmuir.4c01097

By combining molecular simulations and experimental measurements, the effect of the Nafion content on the performance of proton-exchange membrane fuel cells (PEMFCs) is explained from the perspective of the triple-phase boundary (TPB). The evaporation process of Nafion solvent is simulated on a triple-phase model to mimic the formation of the TPB, and the influence of the Nafion content on the TPB structure is investigated. When the Nafion content is 1.415 mg/m(2), the coverages of Nafion on both Pt particles and the carbon carrier are saturated at 42.1% and 32.7%, respectively. With the increase of Nafion content, the amount of water molecules around Pt particles is increased, and the surrounding O-2 content is decreased. The experimental PEMFC performance has confirmed such simulation results, which demonstrates a trend of enhancing first and then weakening with the increase of Nafion content and reaches a maximum with the Nafion content of 2.96 mg/m(2). Therefore, the correlation between the structure of the TPB and the cell's efficiency has been established at a molecular level, enabling enhancements in the design of the TPB morphology and an increase in PEMFC efficiency.

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