In this work, perfluoropolyether (PFPE) functionalization was used as hydrophizing treatment for gas diffusion layers (GDLs) in polymer electrolyte membrane fuel cells (PEMFCs), instead of standard PTFE coatings, aiming to enhance the hydrophobicity of the gas diffusion media and to reduce the mass transfer limitations in the final device. Carbon cloth diffusion layers and carbon black were functionalized by decomposition of a PFPE peroxide. PFPE‐functionalized carbon black was employed in the preparation of an ink suitable for obtaining microporous layers (MPLs) by deposition onto macroporous backing layers. Dual‐layer gas diffusion media showing superhydrophobic behavior due to different hydrophobizing treatments were compared with conventional PTFE‐based materials, by testing in a single PEMFC working at two different temperatures and at low and high relative humidity conditions. Such tests demonstrated improved performances over conventional GDLs for pure PFPE‐based samples in terms of both overall electrical performance and reduced diffusive limitations in high current density conditions. The maximum output power achieved with the novel PFPE‐based compounds was 460 mW cm⁻² at 80 °C and relative humidity (RH) 100% while the best improvement (10%) with respect to conventional GDLs was realized at 80 °C and RH 60%.

中文翻译：

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在聚合物电解质膜燃料电池中具有增强性能的创新型全氟聚醚功能化气体扩散层

在这项工作中，全氟聚醚（PFPE）官能化被用作聚合物电解质膜燃料电池（PEMFCs）中气体扩散层（GDL）的加氢处理，而不是标准的PTFE涂层，旨在增强气体扩散介质的疏水性并减少最终设备中的传质限制。碳布扩散层和炭黑通过PFPE过氧化物的分解而官能化。PFPE功能化的炭黑用于制备适合通过沉积到大孔背衬层上以获得微孔层（MPL）的油墨。将由于不同的疏水处理而表现出超疏水行为的双层气体扩散介质与传统的PTFE基材料进行了比较，通过在单个PEMFC中进行测试，该PEMFC在两个不同的温度以及高低相对湿度条件下工作。此类测试证明了在纯电气性能和在高电流密度条件下减少的扩散限制方面，纯PFPE基样品的性能优于传统GDL。新型基于PFPE的化合物实现的最大输出功率为460 mW cm在80°C和相对湿度（RH）为100％时为^-2，而相对于常规GDL而言，在80°C和RH 60％时实现了最佳改进（10％）。