Combined experimental and molecular simulation study of arginine/PBI composite membranes for high- temperature fuel cells
DQ Zhang and XG Yu and F Zhang and WQ Liu and JY Miao and XJ Li, JOURNAL OF MATERIALS SCIENCE, 58, 1523-1537 (2023).
DOI: 10.1007/s10853-022-07807-3
High-temperature proton exchange membranes (HTPEMs) based on argininemodified phosphoric acid-doped polybenzimidazole (Arginine-PBI- PA) and poly(tetrafluoroethylene) phosphoric acid-doped polybenzimidazole (PTFEArginine-PBI-PA) were fabricated and characterized for fuel cell applications. Arginine as filler was used to prepare HTPEMs for the first time, and the Arginine-PBI-PA membrane exhibited an excellent proton conducting ability with 24.1 mS cm(-1) at 160 degrees C while maintaining mechanical strength. Furthermore, Arginine-PBI-PA composite membrane was also appropriate for membrane electrode assemblies (MEAs), and it exhibited better fuel cell performances (0.68 V@400 mA cm(-2)) compared with the PBI-PA membranes prepared. Molecular dynamics (MD) simulation revealed that the better electrochemical properties of Arginine-PBI-PA membranes over PBI-PA membranes were ascribed to the strong interactions between the basic sites and carboxyl groups of arginine and PA molecules, respectively. In addition, the higher proton conductivity for Arginine-PBI-PA membranes was attributed to the formation of a tighter H-bonding network and the interaction between arginine non-protonated oxygen (O) and PA protons (HPA).(GRAPHICS)
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