Investigation of polarization resistance of fuel cells by electrochemical impedance spectroscopy

Since a great deal of polarization resistance information of fuel cells is included in electrochemical impedance spectroscopy (EIS), it is an important method to characterize the performance of fuel cells. By analyzing EIS of fuel cells, all kinds of polarization resistances, such as ohmic, electrochemical and concentration polarization resistance, can be achieved. In the paper, various EIS of SOFC (Solid Oxide Fuel Cell) with typical shapes was analyzed and its equivalent circuit was presented, on which basis the polarization resistances of SOFC were calculated by fitting experiments data with complex impedance expressions. Compared with finding results just directly reading EIS curves, the results derived by this method are more rational and accurate.