“…The membranes need to be hydrated to maintain high proton conductivity and ensure adequate fuel cell performance. However, excess water in the electrodes can result in electrode flooding, which prevents electrochemical reactions from occurring and reduces performance, thus a careful balance must be maintained [6][7][8][9][10][11][12][13][14][15][16][17]. In this respect, the gas diffusion layer (GDL) which is in contact with catalyst layer is one of the critical components of a fuel cell that has the ability to influence the system performance because its basic functions are transporting the reactant gas from the flow channel to the catalyst layer, draining liquid water from the catalyst layer to the flow channel, conducting electrons with low resistance, and keeping the membrane in a wet condition at low humidity.…”