State-of-the-Art Membranes and Ionomers for High Temperature Polymer Electrolyte Membrane Fuel Cells
발표자
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초록
내용
Phosphonated polymers have been proposed as anhydrous proton conductors for fuel cells. However, anhydride formation of phosphonic acid functional groups lowers proton conductivity and prevents its use in the fuel cell applications. Here, we report a poly(2,3,5,6-tetrafluorostyrene-4-phosphonic acid), PWN , which does not undergo anhydride formation, thus maintains protonic conductivity above 200 °C. We used the phosphonated polymer, PWN, in fuel cell electrodes with an ion-pair coordinated membrane in a membrane electrode assembly which showed peak power densities of 1,130 mW cm-2 at 160 °C and 1,740 mW cm-2 at 240 °C under H2/O2 conditions, significantly outperforming other HT-PEMFCs. Furthermore, blending PWN with Nafion ionomer gave a protonated phosphonic acid ionomer, which showed even greater performance under heavy-duty mobility conditions. Our result demonstrates a pathway to utilizing phosphonated polymers for high-performance fuel cells under hot and dry operating conditions for large-scale mobility applications.