Double cross-linked 3D layered PBI proton exchange membranes for stable fuel cell performance above 200 °C.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38649702.
- Also identified by DOI 10.1038/s41467-024-47627-4 and PMC identifier 11035571.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Phosphoric acid doped proton exchange membranes often experience performance degradation above 200 °C due to membrane creeping and phosphoric acid evaporation, migration, dehydration, and condensation. To address these issues, here we present gel-state polybenzimidazole membranes with double cross-linked three-dimensional layered structures via a polyphosphoric acid sol-gel process, enabling stable operation above 200 °C. These membranes, featuring proton-conducting cross-linking phosphate bridges and branched polybenzimidazole networks, effectively anchor and retain phosphoric acid molecules, prevent 96% of its dehydration and condensation, improve creep resistance, and maintain excellent proton conductivity stability. The resulting membrane, with superior through-plane proton conductivity of 0.348 S cm-1, delivers outstanding peak power densities ranging from 1.20-1.48 W cm-2 in fuel cells operated at 200-240 °C and a low voltage decay rate of only 0.27 mV h-1 over a 250-hour period at 220 °C, opening up possibilities for their direct integration with methanol steam reforming systems.