Leveraging the interactions between ionomer and catalyst can increase the performance of proton exchangemembrane fuel cells.The impacts of the equivalent weight(EW)of perfluorosulfonic acid-based ionomers on the plati...Leveraging the interactions between ionomer and catalyst can increase the performance of proton exchangemembrane fuel cells.The impacts of the equivalent weight(EW)of perfluorosulfonic acid-based ionomers on the platinum group metal-free electrode structure and fuel cell performance have not been fully explored.Four membrane electrode assemblies(MEAs)were prepared by using a commercial Fe-N-C catalyst,two perfluorosulfonic acid ionomers with different EWs,that is,Aquivion 720(A720)and Nafion 1100(N1100),and two ionomer-tocatalyst(I/C)ratios.The four MEAswere characterized to understand the impact of the ionomer EW and content on the capacitance,proton conductivity,and mass transport on the cathode.The mass transport resistance was measured for the first time using a new oxygen reduction reaction limiting current method enabling to couple the effects of oxygen diffusion with liquid water generation.Low EW ionomer combined with a moderate I/C results in improved performance due to its enhanced proton conductivity.However,when used at high I/C,it can cause severewater flooding at high current density due to the enhanced liquid water uptake,especially at high relative humidity,resulting in lower catalyst utilization and higher mass transport resistance.展开更多
基金National Renewable Energy Laboratory for the U.S.Department of Energy(DOE)under Contract No.DE-AC36-08GO28308Argonne National Laboratory is managed for the U.S.Department of Energy by the University of Chicago Argonne,LLC,also under contract DE-AC-02-06CH11357+1 种基金supported by the U.S.Department of Energy,Office of Energy Efficiency and Renewable Energy,Hydrogen and Fuel Cell Technologies Office(HFTO).This research used resources of the Advanced Photon Source(APS)a U.S.Department of Energy Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DE-AC02-06CH11357.
文摘Leveraging the interactions between ionomer and catalyst can increase the performance of proton exchangemembrane fuel cells.The impacts of the equivalent weight(EW)of perfluorosulfonic acid-based ionomers on the platinum group metal-free electrode structure and fuel cell performance have not been fully explored.Four membrane electrode assemblies(MEAs)were prepared by using a commercial Fe-N-C catalyst,two perfluorosulfonic acid ionomers with different EWs,that is,Aquivion 720(A720)and Nafion 1100(N1100),and two ionomer-tocatalyst(I/C)ratios.The four MEAswere characterized to understand the impact of the ionomer EW and content on the capacitance,proton conductivity,and mass transport on the cathode.The mass transport resistance was measured for the first time using a new oxygen reduction reaction limiting current method enabling to couple the effects of oxygen diffusion with liquid water generation.Low EW ionomer combined with a moderate I/C results in improved performance due to its enhanced proton conductivity.However,when used at high I/C,it can cause severewater flooding at high current density due to the enhanced liquid water uptake,especially at high relative humidity,resulting in lower catalyst utilization and higher mass transport resistance.
