Electrochemical impedance spectroscopic characterization of impregnated La0.6Sr0.4Co0.2Fe0.8O3−δ cathode for intermediate-temperature SOFCs. (17th May 2018)

• Record Type: Journal Article
• Authors: Chen, Jing; Wan, Dongjin; Sun, Xuzhuo; Li, Bo; Lu, Mingxia
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 20(2018)
• Page Start: 9770
• Page End: 9776
• Publication Date: 2018-05-17
• Subjects: Impregnated cathode -- Polarization resistance -- Solid oxide fuel cell -- Rate-determining step -- Knudsen diffusion; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.03.223
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The electrochemical performance of the impregnated La0.6 Sr0.4 Co0.2 Fe0.8 O3−δ -Y2 O3 stabilized ZrO2 cathode (LSCF-YSZ) was studied with different amount of LSCF. Function as PO2, electrode resistance revealed that the rate-determining steps for oxygen reduction were changed with amount of LSCF loading. The rate-determining step is the charge transfer process for 12 wt% LSCF loading cathode. With the increasing amount of LSCF particles on the YSZ scaffold, the rate determining steps are the dissociation of oxygen molecules and adsorption-diffusion of oxygen atom for 20 wt% LSCF loading cathode. Accumulation of a great many LSCF particles on the YSZ scaffold makes the Knudsen diffusion of oxygen molecular of great importance for ORR. The rate-determining step is the Knudsen diffusion for 32 wt% LSCF loading cathode. The mean free path of oxygen molecules is about 0.22–0.27 μm at 1 atm and the temperature is between 600 and 800 °C. The appearance of inductive loop in the EIS for the cathode with high LSCF loading was possible influenced by the Knudsen diffusion process. Highlights: The inductive loop at high LSCF loading maybe affected by the Knudsen diffusion. The rate determining step for ORR changes with the increase of LSCF loadings. LSCF loading shows effect on the electrochemical performance of cathodes.