Kirkebaek, Andreas Aili, David Henkensmeier, Dirk Jensen, Jens Oluf Li, Qingfeng 2024-01-20T00:01:32Z 2024-01-20T00:01:32Z 2021-09-03 2017-12 1438-7492 https://pubs.kist.re.kr/handle/201004/121968 Polybenzimidazole membranes imbibed with phosphoric acid can support high proton conductivity at 120-200 degrees C, and have therefore emerged as the state-of-the-art electrolytes for fuel cells operating in this temperature range. This work presents a novel and operationally simple methodology for preparing mechanically robust covalent network polybenzimidazole membranes containing up to 95 wt% phosphoric acid. Diamino-terminal pre-polymers of different chain lengths are first prepared, followed by addition of a trifunctional carboxylic acid. The crude solutions are cast and subsequently heat treated at up to 230 degrees C, yielding free-standing membranes of networked polybenzimidazole with high proton conductivity at up to 180 degrees C and encouraging fuel cell performance. English WILEY-V C H VERLAG GMBH Gel Electrolytes of Covalent Network Polybenzimidazole and Phosphoric Acid by Direct Casting Article 10.1002/mame.201700347 1 MACROMOLECULAR MATERIALS AND ENGINEERING, v.302, no.12 MACROMOLECULAR MATERIALS AND ENGINEERING 302 12 N scie scopus 000417894700011 2-s2.0-85037995054 Materials Science, Multidisciplinary Polymer Science Materials Science Polymer Science Article HIGH-TEMPERATURE PEMFC MEMBRANE FUEL-CELLS POLYMER ELECTROLYTE HYPERBRANCHED POLYBENZIMIDAZOLES MOLECULAR-WEIGHT BLEND MEMBRANES CROSS-LINKING HT-PEFC PBI CONDUCTIVITY direct casting fuel cell HT-PEMFC polybenzimidazole polymer electrolyte