<p>The membrane electrode assembly (MEA), as the core component of a fuel cell, faced the issue of liquid water accumulation in the cathode catalyst layer under high current density. This led to “water flooding,” which impeded oxygen transport and reduced cell performance. To address this, polytetrafluoroethylene (PTFE) was employed as a hydrophobic additive. Physical methods were used to improve its dispersion and prevent agglomeration, thereby constructing continuous hydrophobic channels to enhance gas diffusion and water removal. This study investigated the effect of PTFE content on the hydrophobicity of the catalyst layer and the overall cell performance to determine the optimal PTFE loading. Furthermore, the impact of cathode inlet gas humidity on output performance was explored. The results indicated that at a lower relative humidity of 40% RH, the performance of the hydrophobic MEA was close to that of the standard MEA. However, at a high humidity of 80% RH, the difference in polarization performance became more pronounced. The MEA with a 20 wt% PTFE content demonstrated the best performance, achieving current densities of 1033, 2220, and 4200 mA cm⁻² at 0.75 V, 0.65 V, and 0.5 V, respectively. This represented an improvement of 10.39%, 25.42%, and 18.31% compared to the standard MEA. Rational control of PTFE content and inlet gas humidity could significantly enhance gas transport efficiency in the catalyst layer, suppress the water flooding effect, and thereby optimize the overall performance of the fuel cell (Alam Rimon&#xa0;et al. in Energy Convers Manag: X 27:101102, 2025.&#xa0;<a href="https://doi.org/10.1016/j.ecmx.2025.101102">https://doi.org/10.1016/j.ecmx.2025.101102</a>). This research provided an experimental basis and theoretical reference for the design of high-performance MEAs (Kahraman and Akin in Energy Convers Manag 304:118244, 2024. <a href="https://doi.org/10.1016/j.enconman.2024.118244">https://doi.org/10.1016/j.enconman.2024.118244</a>).</p> Graphical Abstract <p></p>