Microstructural Optimization of Anode-Supported Solid Oxide Fuel Cells by a Comprehensive Microscale Model

The microstructural optimization of two-layer cathodes in anode-supported solid oxide fuel cells SOFCs was numerically performed by a comprehensive microscale model developed by the authors. The single-cell performances of anode-supported SOFCs, recently reported by Zhao and Virkar, were studied to provide the detailed information on the electrochemical processes occurring in the SOFCs. Good agreements between the numerical and experimental results were observed which also ensured the validity of the present calculation. The dependence of the electrochemical reaction and the mass transport on the particle size of each layer in two-layer cathodes was then studied. The optimal microstructure for two-layer cathodes was determined as a mean particle diameter of 0.5 m and a thickness of 15 m for cathode functional layers, and a mean particle diameter of 4.0 ma nd a thickness of 85 m for cathode current collector layers. The stack-cell performances of anode-supported SOFCs were also studied by fully considering the effect of interconnect rib geometry, e.g., the contact resistance, in-plane ohmic loss, and nonuniformity of current generation. Based on the simulation results, the geometrical criterion for interconnect rib geometry to obtain better performance was discussed.

[1]  Doris Sebold,et al.  Optimisation of processing and microstructural parameters of LSM cathodes to improve the electrochemical performance of anode-supported SOFCs , 2005 .

[2]  Toshio Oshima,et al.  Estimation of the Co-ordination number in a Multi-Component Mixture of Spheres , 1983 .

[3]  Svein Sunde,et al.  Calculation of Conductivity and Polarization Resistance of Composite SOFC Electrodes from Random Resistor Networks , 1995 .

[4]  R. Herbin,et al.  Three-dimensional numerical simulation for various geometries of solid oxide fuel cells , 1996 .

[5]  Anil V. Virkar,et al.  The role of electrode microstructure on activation and concentration polarizations in solid oxide fuel cells , 2000 .

[6]  A. Virkar,et al.  Dependence of polarization in anode-supported solid oxide fuel cells on various cell parameters , 2005 .

[7]  Yann Bultel,et al.  Theoretical optimisation of a SOFC composite cathode , 2005 .

[8]  L. A. Chick,et al.  Diffusion Limitations in the Porous Anodes of SOFCs , 2003 .

[9]  U. Anselmi-Tamburini,et al.  Electrical properties of Ni / YSZ cermets obtained through combustion synthesis , 1998 .

[10]  Suttichai Assabumrungrat,et al.  Oxygen transport through LSM/YSZ/LaAlO system for use of fuel cell type reactor , 2005 .

[11]  E. A. Mason,et al.  Gas Transport in Porous Media: The Dusty-Gas Model , 1983 .

[12]  R. Krishna,et al.  The Maxwell-Stefan approach to mass transfer , 1997 .

[13]  S. Jiang,et al.  H2 oxidation on Ni/Y–TZP cermet electrodes – polarisation behaviour , 1999 .

[14]  P. Gupta,et al.  Rigidity and conductivity percolation thresholds in particulate composites , 1995 .

[15]  S. Deevi,et al.  Opportunity of metallic interconnects for solid oxide fuel cells: a status on contact resistance , 2003 .

[16]  M. Kaviany.  Principles of heat transfer in porous media , 1991 .

[17]  F. Lange,et al.  Relation between percolation and particle coordination in binary powder mixtures , 1991 .

[18]  L. Gauckler,et al.  The Electrochemistry of Ni Pattern Anodes Used as Solid Oxide Fuel Cell Model Electrodes , 2001 .

[19]  James Larminie,et al.  Fuel Cell Systems Explained , 2000 .

[20]  F. Tietz,et al.  Simplified processing of anode-supported thin film planar solid oxide fuel cells , 2005 .

[21]  D. Jeon,et al.  A random resistor network analysis on anodic performance enhancement of solid oxide fuel cells by penetrating electrolyte structures , 2005 .

[22]  S. Jiang,et al.  Issues on development of (La,Sr)MnO3 cathode for solid oxide fuel cells , 2003 .

[23]  M. Fowler,et al.  Performance comparison of Fick’s, dusty-gas and Stefan–Maxwell models to predict the concentration overpotential of a SOFC anode , 2003 .

[24]  J. Young,et al.  Thermodynamic and transport properties of gases for use in solid oxide fuel cell modelling , 2002 .

[25]  Subhash C. Singhal,et al.  Estimation of Charge-Transfer Resistivity of La0.8Sr0.2MnO3 Cathode on Y 0.16Zr0.84 O 2 Electrolyte Using Patterned Electrodes , 2005 .

[26]  Werner Lehnert,et al.  Correlated Resistor Network Study of Porous Solid Oxide Fuel Cell Anodes , 1997 .

[27]  M. Kaviany,et al.  Principles of Heat Transfer , 2001 .

[28]  N. Minh.  Ceramic Fuel Cells , 1993 .

[29]  S. Chan,et al.  Anode Micro Model of Solid Oxide Fuel Cell , 2001 .

[30]  V. Antonucci,et al.  Micro-modelling of solid oxide fuel cell electrodes , 1998 .

[31]  Paola Costamagna,et al.  Effect of composition on the performance of cermet electrodes. Experimental and theoretical approach , 2002 .

[32]  Khiam Aik Khor,et al.  Cathode Micromodel of Solid Oxide Fuel Cell , 2004 .