Fuel Cell Gas Diffusion Layer Patterned Water Repellent Coating

The patent applies water repellent selectively to specific regions rather than uniformly across the entire macroporous layer. By using a coating head that deposits water repellent only in certain areas, the patent maintains water-repellent properties where needed while preserving pore size and gas diffusion pathways in other regions, thus resolving the contradiction between water repellency and pore size maintenance

The patent uses partial action by applying water repellent to only a portion of the macroporous layer surface rather than the entire surface. This selective application provides sufficient water-repellent performance for water discharge while avoiding excessive water repellent accumulation that would clog pores and reduce gas diffusion performance

The patent implements local quality by concentrating water repellent application in specific regions rather than distributing it uniformly across the entire macroporous layer. This localized approach ensures adequate water-repellent performance in areas where water discharge is needed while maintaining high gas diffusion performance in areas where water repellent is not applied, thus resolving the contradiction between water-repellent performance and gas diffusion performance

The patent applies partial action by using a controlled amount of water repellent in specific areas rather than applying excessive water repellent throughout the entire layer. This partial application achieves the necessary water-repellent effect for effective water discharge while avoiding the performance degradation that would result from excessive water repellent content affecting gas diffusion