Journal article
Synthesis and properties of poly(aryl sulfone benzimidazole) and its copolymers for high temperature membrane electrolytes for fuel cells
Department of Energy Conversion and Storage, Technical University of Denmark1
Proton conductors, Department of Energy Conversion and Storage, Technical University of Denmark2
Energy and Materials, Department of Chemistry, Technical University of Denmark3
Functional organic materials, Department of Energy Conversion and Storage, Technical University of Denmark4
Newcastle University5
Department of Chemistry, Technical University of Denmark6
Northeastern University7
Poly(aryl sulfone benzimidazole) (SO2PBI) and its copolymers with poly[2,2′-p-(phenylene)-5,5′-bibenzimidazole] (pPBI), termed as Co-SO2PBI, were synthesized with varied feeding ratios of 4,4′-sulfonyldibenzoic acid (SDBA) to terephthalic acid (TPA). Incorporation of the stiff para-phenylene and flexible aryl sulfone linkages in the macromolecular structures resulted in high molecular weight copolymers with good solubility.
The chemical stability towards radical oxidation was improved for SO2PBI and its copolymer membranes due to the electron-withdrawing sulfone functional groups. Upon acid doping, the membrane swelling was reduced and the mechanical strength was improved, as compared with their meta structured analogues.
At an acid doping level of 11 mol H3PO4 per average molar repeat unit, the Co-20%SO2PBI membrane exhibited a tensile strength of 16 MPa at room temperature and an H2-air fuel cell peak power density of 346 mW cm−2 at 180 °C at ambient pressure. Durability tests with the membrane under a constant current density of 300 mA cm−2 at 160 °C showed a degradation rate of 6.4 μV h−1 during a period of 2400 h, which was significantly lower than that for meta PBI membranes with a similar acid doping level.
Language: | English |
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Publisher: | The Royal Society of Chemistry |
Year: | 2012 |
Pages: | 11185-11195 |
ISSN: | 13645501 and 09599428 |
Types: | Journal article |
DOI: | 10.1039/c2jm30217a |
ORCIDs: | Li, Qingfeng , Cleemann, Lars Nilausen , Jensen, Jens Oluf and Bjerrum, Niels |