水管理

Abstract(#br)In operation of hydrogen fuel cells for vehicle, carbon corrosion induced by frequent on/off operation significantly causes degradation of performance and durability of fuel cells, aggregating and losing Pt particles. It is critical to develop durable cathode and understand the mechanism of degradation in hydrogen fuel cells for commercialization. In this study, we prepared polydimethylsiloxane treated cathode, which is hydrophobic, for improving durability in hydrogen fuel cells. In addition, effect of hydrophobic cathode on durability was investigated by various analyses.

Abstract(#br)Microporous layers (MPLs) were prepared with different hydrophobic polymers to establish water management in polymer electrolyte membrane (PEM) fuel cells. Besides conventionally used polymers polytetrafluoroethylene (PTFE) and fluorinated ethylene propylene (FEP), two different molecular weights (MW) of polydimethylsiloxane (PDMS) polymer were used as hydrophobic materials in MPL. Membrane electrode assemblies (MEAs) having MPLs with low MW PDMS polymer exhibited the best fuel cell performance compared to the PTFE and FEP based ones.

摘要\n水管理在PEM燃料电池中仍然是一个具有挑战性的问题，许多研究者试图阐明液态水在细胞介质中的行为。通常选用气体扩散层( GDL )或微孔层( MPL )对其表面进行疏水性材料改性，以获得更好的除水能力。显然，本研究利用聚二甲基硅氧烷( PDMS )的疏水性和聚苯乙烯( PS ) -二氧化硅颗粒的粗糙度共同作用于MPL的含量，当PDMS-1 ( 3 % wt . )和PS-二氧化硅( 1 % wt . )颗粒的二元复配时，MPL的燃料电池性能最佳。该MPL的最高电流密度值为287.5 mA / cm2 ( @ 0.6 V )，对应于0.1 mg Pt / cm2催化剂负载量下的172 mW / cm2功率密度。对上述MPL的接触角和表面粗糙度分别测量为122°±4.7和2.63 µ m，假设最佳疏水性和表面粗糙度将此MPL与其他制备的MPL在PEM燃料电池性能上区别开来。