Hydrophilic Channel Volume Behavior on Proton Transport Performance of Proton Exchange Membrane in Fuel Cells

Inadequate water balance causes water flooding in a fuel cell, leading to performance degradation. The hydrophilic channel volume is crucial to the proton conductivity of PEM, especially under a high water concentration gradient. Herein, the volume of the hydrophilic channel was controlled and optimized through adjusting the collocation of resins with different side-chain lengths, with the length acting as a key parameter for the in-depth research on the proton conductivity performance of PEMs. Membranes with different hydrophilic channel volumes were prepared and suggested that the volume of the hydrophilic channel boosted as the increase of the length gap between the matched side chains, which would benefit to proton conductivity of membrane. This study provides guidance for the structural design of proton exchange membrane with cell-flooding resistance and efficient proton conduction at a high water concentration gradient.