Metal-supported solid oxide fuel cells with barium-containing in-situ cathodes

Abstract

Materials containing barium (Ba), such as SmBa(0.5)Sr(0.5)Co(2)O(5-d)/Ce(0.9)Gd(0.1)O(1.9) (SBSC50) and Ba(0.5)Sr(0.5)Co(0.8)Fe(0.2)O(3-d) (BSCF), are considered for use as an in-situ cathode in metal-supported solid oxide fuel cells (SOFCs). The electrochemical properties and sintering behavior of these materials are investigated in terms of area specific resistances (ASRs), I-V-P characteristics and microstructure. The properties of in-situ cathodes comprised of SBSC50 and BSCF are compared with those of conventional cathodes, such as La(0.8)Sr(0.2)MnO(3-d) (LSM). La(0.8)Sr(0.2)FeO(3-d) (LSF). La(0.6)Sr(0.4)Co(0.2)Fe(0.8)O(3-d) (LSCF) and Sm(0.5)Sr(0.5)CoO(3-d)/Ce(0.8)Sm(0.2)O(1.9) (SSC40). Impedance spectroscopy analysis using Nyquist and Bode plots and microstructure analysis is conducted to understand the reason behind electrochemical performance differences between in-situ cathodes and sintered cathodes. From this analysis, we are also able to verify the electrochemical behavior of well-defined in-situ cathodes. SBSC50 and BSCF are the incorporated in our metal-supported cells without the use of any additional sintering process. The metal-supported cells are successfully fabricated using a high temperature sinter-joining process and we fail to detect any defects or deformation after fabrication. At an operating temperature of 800 degrees C, metal-supported cells with SBSC50 and BSCF cathodes exhibit maximum power densities of 0.50 Wcm(-2) and 0.65 Wcm(-2), respectively. (C) 2010 Elsevier B.V. All rights reserved.