Krishnan, N. Nambi Joseph, Dickson Ngoc My Hanh Duong Konovalova, Anastasiia Jang, Jong Hyun Kim, Hyoung-Juhn Nam, Suk Woo Henkensmeier, Dirk 2024-01-20T00:02:35Z 2024-01-20T00:02:35Z 2021-09-03 2017-12 0376-7388 https://pubs.kist.re.kr/handle/201004/122026 Ionically crosslinked acid/base blend membranes of PBI-OO and a sulfonated polysulfone can be covalently crosslinked through aromatic sulfone groups, which form in a thermally induced Friedel-Crafts reaction. Here we systematically compare a series of blend membranes before and after curing. Even though the cured membranes have a lower phosphoric acid uptake even at increased doping time and temperature, they have an improved conductivity and therefore fuel cell performance than the ionically crosslinked membranes. For example, a covalently crosslinked blend membrane containing 5% of the acid component (c-BM 1) reached a conductivity of 260 mS/cm at 160 degrees C and a relative humidity of 5%, even though the PA uptake was just 266 wt%. In the fuel cell (H-2, air, 160 degrees C), this membrane yielded a peak power density of 452 mW cm(-2), about 100 mW cm(-2) above that of the commercial meta-PBI membrane. In a long term stability test, the ionically crosslinked membrane ucBM 1 already failed within 100 h, while the cured c-BM 1 membrane was much more stable. A cured membrane with less PA and higher amount of the acid blend component (c-BM 3) gave a stable performance for over 1000 h, proving that thermally induced sulfone crosslinking strongly increases the stability. English ELSEVIER SCIENCE BV Phosphoric acid doped crosslinked polybenzimidazole (PBI-OO) blend membranes for high temperature polymer electrolyte fuel cells Article 10.1016/j.memsci.2017.09.049 1 JOURNAL OF MEMBRANE SCIENCE, v.544, pp.416 - 424 JOURNAL OF MEMBRANE SCIENCE 544 416 424 N scie scopus 000412350900045 2-s2.0-85029722865 Engineering, Chemical Polymer Science Engineering Polymer Science Article DEGRADATION LINKING Polybenzimidazole Crosslinked membranes Friedel-Crafts reaction Phosphoric acid HT PEMFC