TY - JOUR
T1 - Protic ionic liquids immobilized in phosphoric acid-doped polybenzimidazole matrix enable polymer electrolyte fuel cell operation at 200 °C
AU - Skorikova, G.
AU - Rauber, D.
AU - Aili, David
AU - Martin, S.
AU - Li, Qingfeng
AU - Henkensmeier, D.
AU - Hempelmann, R.
PY - 2020
Y1 - 2020
N2 - Protic ionic liquids (PILs) based on the anion bis(trifluoromethanesulfonyl)imide were confined in polybenzimidazole (PBI) matrices. Quasi-solidified ionic liquid membranes (QSILMs) were fabricated and examined for mechanical and thermal stability. After doping in phosphoric acid (PA), the QSILMs exhibited conductivities of 30–60 mS cm−1 at 180 °C. Fluorescence microscopy was used to investigate the structure of the composite PBI membranes. Membrane-electrode assemblies, fabricated with PA doped QSILMs, were tested in a single fuel cell and exhibited a performance increase with increasing temperature up to 200 °C. The best performance was obtained for the membrane electrode assembly containing 50 mol% of diethyl-methyl-ammonium bis(trifluoromethylsulfonyl)imide confined in the phosphoric acid doped PBI matrix with closed porosity. It reached 0.32 W cm−2 at 200 °C and 900 mA cm−2 . The catalyst layer of the gas diffusion electrode impregnated with protic ionic liquid exhibited better long-term stability than the gas diffusion electrode impregnated with phosphoric acid within 100 h of operation at 200 °C and anhydrous conditions.
AB - Protic ionic liquids (PILs) based on the anion bis(trifluoromethanesulfonyl)imide were confined in polybenzimidazole (PBI) matrices. Quasi-solidified ionic liquid membranes (QSILMs) were fabricated and examined for mechanical and thermal stability. After doping in phosphoric acid (PA), the QSILMs exhibited conductivities of 30–60 mS cm−1 at 180 °C. Fluorescence microscopy was used to investigate the structure of the composite PBI membranes. Membrane-electrode assemblies, fabricated with PA doped QSILMs, were tested in a single fuel cell and exhibited a performance increase with increasing temperature up to 200 °C. The best performance was obtained for the membrane electrode assembly containing 50 mol% of diethyl-methyl-ammonium bis(trifluoromethylsulfonyl)imide confined in the phosphoric acid doped PBI matrix with closed porosity. It reached 0.32 W cm−2 at 200 °C and 900 mA cm−2 . The catalyst layer of the gas diffusion electrode impregnated with protic ionic liquid exhibited better long-term stability than the gas diffusion electrode impregnated with phosphoric acid within 100 h of operation at 200 °C and anhydrous conditions.
U2 - 10.1016/j.memsci.2020.118188
DO - 10.1016/j.memsci.2020.118188
M3 - Journal article
SN - 0376-7388
VL - 608
JO - Journal of Membrane Science
JF - Journal of Membrane Science
M1 - 118188
ER -