Characterization and Electrochemical Performance of Composite BSCF Cathode for Intermediate-temperature Solid Oxide Fuel Cell |
Yu-Mi Kim, Pattaraporn Kim-Lohsoontorn, Joong-Myeon Bae |
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST);Department of Chemical Engineering, Mahidol University;Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST); |
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Abstract |
The composite barium strontium cobalt ferrite (BSCF) cathodes were investigated in the intermediate temperature range of solid oxide fuel cells (SOFCs). The characteristics and electrochemical performances of composited BSCF/samarium doped ceria (SDC); BSCF/gadolinium doped ceria (GDC); and BSCF/SDC/GDC were compared to single BSCF cathode. The BSCF used in this study were synthesized using glycine nitrate process and mechanically mixing was used to fabricate a composite cathode. Using a composite form, the thermal expansion coefficient (TEC) could be reduced and BSCF/SDC/GDC exhibited the lowest TEC value at $18.95{ imes}10^{-6}K^{-1}$. The electrochemical performance from half cells and single cells exhibited nearly the same trend. All the composite cathodes gave higher electrochemical performance than the single BSCF cathode (0.22 $Wcm^{-2}$); however, when two kinds of electrolyte were used (BSCF/SDC/GDC, 0.36$Wcm^{-2}$), the electrochemical performance was lower than when the BSCF/SDC (0.45 $Wcm^{-2}$) or BSCF/GDC (0.45 $Wcm^{-2}$) was applied as cathode ($650^{circ}C$, 97%$H_2$/3%$H_2O$ to the anode and ambient air to the cathode). |
Key Words:
Composite electrode, Cathode, Anode-supported solid oxide fuel cell, Barium strontium cobalt ferrite, Gadolinium doped ceria, Samarium doped ceria |
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