Impedance of Solid Oxide Fuel Cell LSM/YSZ Composite Cathodes

A number of lanthanum strontium manganate/yttria-stabilized zirconia (LSM/YSZ) composite electrodes are produced with varying composition and processing parameters. The composites are investigated using impedance spectroscopy. General trends related to the oxygen reduction process are extracted from the impedance data. Literature concerning kinetic studies of LSM/YSZ electrodes and related systems is reviewed and compared to new experimental data. From this it is found that at least five processes affect the impedance. Going from high to low frequency, these processes are (i), (ii) two geometry-related contributions interpreted as transport across LSM/YSZ interfaces and through the YSZ of the composite. (iii) a process reflecting competitive reaction steps such as bond breaking and surface diffusion, (iv) gas diffusion in a stagnant gas layer above the electrode structure. and (v) an activation process (inductive) presumably located at the triple phase boundary of electrode, electrolyte, and gas phase.

[1]  H. Tagawa,et al.  Kinetic studies on the reaction at the La0.6Ca0.4MnO3/YSZ interface, as an SOFC air electrode , 1989 .

[2]  H. Yoo,et al.  Microstructural Changes in a Polycrystalline, Semiconducting Oxide under DC Electric Fields , 1998 .

[3]  M. Mogensen,et al.  Performance/structure correlation for composite SOFC cathodes , 1996 .

[4]  Stuart B. Adler,et al.  Electrode Kinetics of Porous Mixed‐Conducting Oxygen Electrodes , 1996 .

[5]  J. MacManus‐Driscoll,et al.  Oxygen tracer diffusion in undoped lanthanum manganites , 1999 .

[6]  M. Odgaard,et al.  SOFC cathode kinetics investigated by the use of cone shaped electrodes: The effect of polarization and mechanical load , 1996 .

[7]  Tohru Kato,et al.  Oxygen reduction sites and diffusion paths at La0.9Sr0.1MnO3âx/yttria-stabilized zirconia interface for different cathodic overvoltages by secondary-ion mass spectrometry , 2000 .

[8]  Junichiro Mizusaki,et al.  Reaction Kinetics and Microstructure of the Solid Oxide Fuel Cells Air Electrode La0.6Ca0.4MnO3 / YSZ , 1991 .

[9]  M. Kleitz,et al.  Electrocatalysis and inductive effects at the gas, Pt/stabilized zirconia interface , 1987 .

[10]  Sukhvinder P.S. Badwal,et al.  Zirconia-based solid electrolytes: microstructure, stability and ionic conductivity , 1992 .

[11]  Mogens Bjerg Mogensen,et al.  Gas Diffusion Impedance in Characterization of Solid Oxide Fuel Cell Anodes , 1999 .

[12]  A. Hammouche,et al.  Impedance spectroscopy analysis of La1 − xSritxMnO3-yttria-stabilized zirconia electrode kinetics , 1995 .

[13]  Wolfgang Göpel,et al.  Active Reaction Sites for Oxygen Reduction in La0.9Sr0.1,MnO3/YSZ Electrodes , 1995 .

[14]  M. Mogensen,et al.  ac Impedance study of the oxygen reduction mechanism on La1−xSrxMnO3 in solid oxide fuel cells , 1993 .

[15]  S. Badwal,et al.  Yttria-zirconia: Effect of microstructure on conductivity , 1987 .

[16]  Oxygen reduction on lanthanum strontium manganites investigated by the use of cone shaped electrodes , 1997 .

[17]  Mogens Bjerg Mogensen,et al.  Characterisation of composite SOFC cathodes using electrochemical impedance spectroscopy , 1999 .

[18]  San Ping Jiang,et al.  The electrochemical performance of LSM/zirconia–yttria interface as a function of a-site non-stoichiometry and cathodic current treatment , 1999 .

[19]  T. Jacobsen,et al.  Dynamics of the YSZ-Pt interface , 1997 .

[20]  Henricus J.M. Bouwmeester,et al.  Electrode Properties of Sr‐Doped LaMnO3 on Yttria‐Stabilized Zirconia II. Electrode Kinetics , 1997 .

[21]  H. Bouwmeester,et al.  Electrode Properties of Sr‐Doped LaMnO3 on Yttria‐Stabilized Zirconia I. Three‐Phase Boundary Area , 1997 .

[22]  Jürgen Fleig,et al.  Inhomogeneous current distributions at grain boundaries and electrodes and their impact on the impedance , 1998 .

[23]  B. Boukamp,et al.  Oxygen transfer properties of ion-implanted yttria-stabilized zirconia , 1992 .

[24]  M. J. Jørgensen,et al.  Durability test of SOFC cathodes , 2000 .

[25]  A. Hammouche,et al.  Electrocatalytic Properties and Nonstoichiometry of the High Temperature Air Electrode La1 − x Sr x MnO3 , 1991 .

[26]  M. Mogensen,et al.  Manganite-zirconia composite cathodes for SOFC: Influence of structure and composition , 1995 .

[27]  Andy Horsewell,et al.  Microstructural and microchemical characterization of the interface between La0.85Sr0.15MnO3 and Y2O3-stabilized ZrO2 , 1994 .

[28]  Ludwig J. Gauckler,et al.  La2Zr2O7 formation and oxygen reduction kinetics of the La0.85Sr0.15MnyO3, O2(g)|YSZ system , 1998 .

[29]  S. Barnett,et al.  Oxygen transfer processes in (La,Sr)MnO3/Y2O3-stabilized ZrO2 cathodes: an impedance spectroscopy study , 1998 .

[30]  T. Jacobsen,et al.  A model for the frequency dispersion of the impedance of compressed powders of ionic conductors , 1989 .

[31]  Svein Sunde,et al.  Monte Carlo Simulations of Polarization Resistance of Composite Electrodes for Solid Oxide Fuel Cells , 1996 .

[32]  M. Nishiya,et al.  LaMnO3 air cathodes containing ZrO2 electrolyte for high temperature solid oxide fuel cells , 1992 .

[33]  Brian E. Conway,et al.  Modern Aspects of Electrochemistry , 1974 .

[34]  B. Boukamp.  A Nonlinear Least Squares Fit procedure for analysis of immittance data of electrochemical systems , 1986 .

[35]  S. Sunde.  Calculations of impedance of composite anodes for solid oxide fuel cells , 1997 .