초록 |
Modern electrochemical energy conversion devices require more advanced proton conductors for their broad applications. Phosphonated polymers have been proposed as anhydrous proton conductors for fuel cells. However, the anhydride formation of phosphonic acid functional groups lowers proton conductivity and this prevents the use of phosphonated polymers in fuel cell applications. Here, we report a poly(2,3,5,6-tetrafluorostyrene-4-phosphonic acid) that does not undergo anhydride formation and thus maintains protonic conductivity above 200 °C. We use the phosphonated polymer in fuel cell electrodes with an ion-pair coordinated membrane in a membrane electrode assembly to exceed current benchmarks in HT-PEMFC power density performance. Moreover, through protonation of the phosphonic acid through blending with a perfluorosulfonic acid ionomer showed even high peak/rated power density performance and durability under heavy duty large scale automotive extreme conditions. Through optimization of membrane and ionomer technology, we demonstrate comparable performance and durability for HT-PEMFCs on par with current high performance LT-PEMFCs. |