Characterization of a Prismatic SOFC Stack by AC Impedance Spectroscopy

Thursday, November 11, 2010: 12:30 PM
Grand Ballroom H (Marriott Downtown)
Ying Zhu, Wenhua H. Zhu and Bruce J. Tatarchuk, Center for Microfibrous Materials, Department of Chemical Engineering, Auburn University, Auburn, AL

Impedance spectra of a prismatic solid oxide fuel cell (SOFC) stack, consisting of five (61 cm2) single planar SOFC cells, were obtained at 800C and varying operating conditions. The contributions of chemical and physical processes occurring on the electrodes and in the electrolyte of the stack to the output cell impedance were determined by equivalent circuit (EC) diagram modeling. The EC diagram was proposed based on our previous investigations on small sized button cells (2 cm2), brushed with reference electrodes. The EC elements were attributed to certain cell processes; its validity was verified by changing stack load current (in the range between OCV and 150 mA/cm2) and anode fuel gas compositions. Combined with previous button cell investigation, our work provides useful information for SOFC scaling up, stack diagnostics and designing process controls.

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See more of this Session: Fuel Cell Technology
See more of this Group/Topical: Fuels and Petrochemicals Division