Ishihara Perovskite Oxide for Solid Oxide Fuel Cells

1. Auflage 2009
ISBN: 978-0-387-77708-5
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 302 Seiten

Reihe: Fuel Cells and Hydrogen Energy

Fuel cell technology is quite promising for conversion of chemical energy of hydrocarbon fuels into electricity without forming air pollutants. There are several types of fuel cells: polymer electrolyte fuel cell (PEFC), phosphoric acid fuel cell (PAFC), molten carbonate fuel cell (MCFC), solid oxide fuel cell (SOFC), and alkaline fuel cell (AFC). Among these, SOFCs are the most efficient and have various advantages such as flexibility in fuel, high reliability, simple balance of plant (BOP), and a long history. Therefore, SOFC technology is attracting much attention as a power plant and is now close to marketing as a combined heat and power generation system. From the beginning of SOFC development, many perovskite oxides have been used for SOFC components; for example, LaMnO -based oxide for the cathode and 3 LaCrO for the interconnect are the most well known materials for SOFCs. The 3 current SOFCs operate at temperatures higher than 1073 K. However, lowering the operating temperature of SOFCs is an important goal for further SOFC development. Reliability, durability, and stability of the SOFCs could be greatly improved by decreasing their operating temperature. In addition, a lower operating temperature is also beneficial for shortening the startup time and decreasing energy loss from heat radiation. For this purpose, faster oxide ion conductors are required to replace the conventional Y O -stabilized ZrO 2 3 2 electrolyte. A new class of electrolytes such as LaGaO is considered to be 3 highly useful for intermediate-temperature SOFCs.

Autoren/Hrsg.

Ishihara, Tatsumi

Inhaltsverzeichnis

1;Preface;6
2;Contents;8
3;Contributors;15
4;Structure and Properties of Perovskite Oxides;17
4.1;1.1 Introduction;17
4.2;1.2 Structure of Perovskite Oxides;18
4.3;1.3 Typical Properties of Perovskite Oxides;23
4.4;1.4 Preparation of Perovskite Oxide;28
4.5;1.5 Perovskite Oxides for Solid Oxide Fuel Cells (SOFCs);31
4.6;References;32
5;Overview of Intermediate-Temperature Solid Oxide Fuel Cells;33
5.1;2.1 Introduction;33
5.2;2.2 Characteristic Features of Solid Oxide Fuel Cells;34
5.2.1;2.2.1 Merits and Demerits of SOFCs;34
5.2.2;2.2.2 Issues for Intermediate-Temperature SOFCs;36
5.2.2.1;2.2.2.1 Electrolytes and Conversion Efficiency;37
5.2.2.2;2.2.2.2 Cathode;41
5.2.2.2.1;Relationship with YSZ and Cr Poisoning;41
5.2.2.2.2;Compatibility with LSGM;44
5.2.2.3;2.2.2.3 Anode;44
5.2.2.3.1;Nickel Anode;45
5.2.2.3.2;Nickel Anode with LSGM Electrolyte;47
5.2.2.3.3;Oxide Anodes;48
5.2.2.4;2.2.2.4 Metal Interconnects;48
5.2.3;2.2.3 Stack Design;51
5.3;2.3 Development of Intermediate Temperature SOFC Stacks/Systems;52
5.3.1;2.3.1 Kyocera/Osaka Gas;52
5.3.2;2.3.2 Mitsubishi Materials Corporation;53
5.3.3;2.3.3 Micro SOFCs by TOTO;54
5.4;2.4 Perspective;54
5.4.1;2.4.1 Applications;54
5.4.2;2.4.2 Fuel Flexibility and Reliability in Relationship to Intermediate-Temperature SOFCs;57
5.4.3;2.4.3 Hybrid Systems;57
5.5;2.5 Summary;58
5.6;References;58
6;Ionic Conduction in Perovskite-Type Compounds;60
6.1;3.1 Introduction;60
6.2;3.2 Conduction Behavior of Perovskite-Type Compounds;61
6.3;3.3 Early Studies on Ionic Conduction in Perovskite-Type Oxides;64
6.4;3.4 Oxide Ion Conduction;67
6.5;3.5 Proton Conduction;70
6.6;3.6 Lithium Ion Conduction;74
6.7;3.7 Halide Ion Conduction;75
6.8;3.8 Silver Ion Conduction;76
6.9;References;77
7;Oxide Ion Conductivity in Perovskite Oxide for SOFC Electrolyte;79
7.1;4.1 Introduction;79
7.2;4.2 Oxide Ion Conductivity in Oxide;80
7.3;4.3 Oxide Ion Conductivity in Perovskite Oxides;82
7.4;4.4 LaGaO3-Based Oxide Doped with Sr and Mg (LSGM) as a New Oxide Ion Conductor;85
7.4.1;4.4.1 Effects of Dopant for La and Ga Site;85
7.4.2;4.4.2 Transition Metal Doping Effects on Oxide Ion Conductivity in LSGM;88
7.5;4.5 Basic Properties of the LSGM Electrolyte System;91
7.5.1;4.5.1 Phase Diagram of La-Sr-Ga-Mg-O;91
7.5.2;4.5.2 Reactivity with SOFC Component;91
7.5.3;4.5.3 Thermal Expansion Behavior and Other Properties;92
7.5.4;4.5.4 Behavior of Minor Carrier;93
7.5.5;4.5.5 Diffusivity of Oxide Ion;96
7.6;4.6 Performance of a Single Cell Using LSGM Electrolyte;98
7.7;4.7 Preparation of LaGaO3 Thin-Film Electrolytes for Application at Temperatures Lower Than 773 K;101
7.8;4.8 Oxide Ion Conductivity in the Perovskite-Related Oxides;103
7.9;4.9 Summary;106
7.10;References;106
8;Diffusivity of the Oxide Ion in Perovskite Oxides;108
8.1;5.1 Introduction;108
8.1.1;5.1.1 Definitions of Diffusion Coefficients;109
8.1.2;5.1.2 The Oxygen Tracer Diffusion Coefficient;109
8.1.3;5.1.3 The Surface Exchange Coefficient;111
8.1.4;5.1.4 Defect Chemistry and Oxygen Transport;112
8.1.5;5.1.5 Defect Equilibria;112
8.2;5.2 Diffusion in Mixed Electronic-Ionic Conducting Oxides (MEICs);115
8.2.1;5.2.1 Effect of A-Site Cation on Oxygen Diffusivity;116
8.2.2;5.2.2 The Effect of B-Site Cation on Oxygen Diffusivity;117
8.2.3;5.2.3 The Effect of A-Site Cation Vacancies on Oxygen Diffusivity;118
8.2.4;5.2.4 Temperature Dependence of the Oxygen Diffusion Coefficient;118
8.2.5;5.2.5 The Effect of Oxygen Pressure;121
8.3;5.3 Oxygen Diffusion in Ionic Conducting Perovskites;121
8.4;5.4 Oxygen Diffusion in Perovskite-Related Materials;123
8.5;5.5 Correlations Between Oxygen Diffusion Parameters;123
8.6;5.6 Conclusions;125
8.7;References;126
9;Structural Disorder, Diffusion Pathway of Mobile Oxide Ions, and Crystal Structure in Perovskite-Type Oxides and Related Materials;130
9.1;6.1 Introduction;130
9.2;6.2 High-Temperature Neutron Powder Diffractometry;131
9.3;6.3 Data Processing for Elucidation of the Diffusion Paths of Mobile Oxide Ions in Ionic Conductors: Rietveld Analysis, Maximum Entropy Method (MEM), and MEM-Based Pattern Fitting (MPF);133
9.4;6.4 Diffusion Path of Oxide Ions in the Fast Oxide Ion Conductor (La0.8Sr0.2)(Ga0.8Mg0.15Co0.05)O2.8 [10];134
9.4.1;6.4.1 Introduction;134
9.4.2;6.4.2 Experiments and Data Processing;134
9.4.3;6.4.3 Results and Discussion;135
9.5;6.5 Diffusion Path of Oxide Ions in an Oxide Ion Conductor, La0.64(Ti0.92Nb0.08)O2.99, with a Double Perovskite-Type Structure [11];139
9.5.1;6.5.1 Introduction;139
9.5.2;6.5.2 Experiments and Data Processing;139
9.5.3;6.5.3 Results and Discussion;140
9.6;6.6 Crystal Structure and Structural Disorder of Oxide Ions in Cathode Materials, La0.6Sr0.4CoO3-delta and La0.6Sr0.4Co0.8Fe0.2O3-delta, with a Cubic Perovskite-Type Structure [12, 13];144
9.6.1;6.6.1 Introduction;144
9.6.2;6.6.2 Experiments and Data Processing;144
9.6.3;6.6.3 Results and Discussion;145
9.6.3.1;6.6.3.1 Crystal Structure and Disorder of La0.6Sr0.4CoO3-delta;145
9.6.3.2;6.6.3.2 Crystal Structure and Disorder of La0.6Sr0.4Co0.8Fe0.2O3-delta;147
9.7;6.7 Structural Disorder and Diffusion Path of Oxide Ions in a Doped Pr2NiO4-Based Mixed Ionic-Electronic Conductor (Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4+delta with a K2NiF4-Type Structure [15];150
9.7.1;6.7.1 Introduction;150
9.7.2;6.7.2 Experiments and Data Processing;151
9.7.3;6.7.3 Results and Discussion;151
9.8;6.8 Conclusions;154
9.9;References;156
10;Perovskite Oxide for Cathode of SOFCs;159
10.1;7.1 Introduction;159
10.2;7.2 Properties Required for a Cathode Material;160
10.2.1;7.2.1 Catalytic Activity;160
10.2.2;7.2.2 Electronic Conductivity;161
10.2.3;7.2.3 Oxygen Transport (Bulk or Surface);163
10.2.4;7.2.4 Chemical Stability and Compatibility;164
10.2.5;7.2.5 Morphological Stability;164
10.3;7.3 General Description of Cathode Reaction and Polarization;165
10.3.1;7.3.1 Oxygen Electrode Process;165
10.3.2;7.3.2 Equivalent Circuit for a Cathode-Electrolyte Interface;166
10.4;7.4 Cathode for High-Temperature SOFC: (La, Sr)MnO3;168
10.4.1;7.4.1 Transport Properties and Electrochemical Reaction;168
10.4.2;7.4.2 Chemical and Morphological Stability of LSM;170
10.5;7.5 Cathode for Intermediate-Temperature SOFC: (La, Sr)CoO3, (La, Sr)(Co, Fe)O3;172
10.5.1;7.5.1 General Features of Co-Based Perovskite Cathode;172
10.5.2;7.5.2 Electrochemical Reaction of a Model Electrode: A (La,Sr)CoO3 Dense Film;173
10.5.3;7.5.3 Electrochemical Response of (La, Sr)CoO3 on Zirconia with and Without Ceria Interlayer;175
10.6;7.6 Summary;176
10.7;References;177
11;Perovskite Oxide Anodes for SOFCs;179
11.1;8.1 Introduction;179
11.2;8.2 Anode Materials for SOFCs;180
11.3;8.3 Perovskite Chemistry;181
11.4;8.4 Doping, Nonstoichiometry, and Conductivity;182
11.5;8.5 Perovskite Anode Materials;185
11.6;8.6 A(B,B’)O3 Perovskites;189
11.7;8.7 Tungsten Bronze Anode Materials;190
11.8;8.8 Anode Materials for All-Perovskite Fuel Cells;191
11.9;8.9 Conclusions;192
11.10;References;192
12;Intermediate-Temperature Solid Oxide Fuel Cells Using LaGaO3;195
12.1;9.1 Introduction;195
12.2;9.2 Cell Development;196
12.2.1;9.2.1 Electrolyte;196
12.2.1.1;9.2.1.1 Doped Lanthanum Gallate;196
12.2.2;9.2.2 Anode;197
12.2.2.1;9.2.2.1 Nickel/Rare Earth Metal-Doped Ceria Cermet;197
12.2.3;9.2.3 Cathode;200
12.2.3.1;9.2.3.1 Strontium-Doped Samarium Cobaltite;201
12.2.3.2;9.2.3.2 Lanthanum-Doped Barium Cobaltite;201
12.3;9.3 Stack Development;202
12.4;9.4 Module Development;204
12.4.1;9.4.1 A 1-kW Class Single-Stack Module;204
12.4.2;9.4.2 A 10-kW Class Multi-Stack Module;207
12.5;9.5 System Development;208
12.6;9.6 Stack Modeling;210
12.7;References;214
13;Quick-Start-Up Type SOFC Using LaGaO3-Based New Electrolyte;216
13.1;10.1 Introduction;216
13.2;10.2 Micro-Tubular Cell Development;217
13.3;10.3 Rapid Thermal Cycling;222
13.4;10.4 Fuel Flexibility;222
13.5;10.5 Stack Development;225
13.6;10.6 Summary;227
13.7;References;227
14;Proton Conductivity in Perovskite Oxides;228
14.1;11.1 Introduction;228
14.2;11.2 Proton Conductivity in Acceptor-Doped Perovskites;230
14.2.1;11.2.1 Protons in Oxides;230
14.2.2;11.2.2 Hydration of Acceptor-Doped Perovskites;230
14.2.3;11.2.3 Proton Diffusion;233
14.2.4;11.2.4 Charge Mobility and Conductivity of Protons;235
14.2.5;11.2.5 Proton Conductivity in Acceptor-Doped Simple Perovskites, ABO3;236
14.2.6;11.2.6 Effects of Defect-Acceptor Interactions;239
14.2.7;11.2.7 Grain Boundaries;240
14.3;11.3 Proton Conduction in Inherently Oxygen-Deficient Perovskites;241
14.3.1;11.3.1 Hydration of Ordered Oxygen Deficiency;241
14.3.2;11.3.2 Nomenclature and Hydration of Disordered Intrinsic Oxygen Deficiency;242
14.3.3;11.3.3 Order-Disorder Reactions Involving Hydrated Inherently Oxygen-Deficient Perovskites (Oxyhydroxides);243
14.4;11.4 Hydration of Undoped Perovskites;244
14.5;11.5 Proton Conductivity in Selected Classes Of Non-Perovskite Oxides and Phosphates;244
14.6;11.6 Developments of Proton-Conducting SOFCs;247
14.7;11.7 Conclusions;248
14.8;References;249
15;Proton Conduction in Cerium- and Zirconium-Based Perovskite Oxides;253
15.1;12.1 Introduction;253
15.2;12.2 Conductivity;255
15.3;12.3 Activation/Deactivation of Electrodes;257
15.4;12.4 Stability;258
15.5;12.5 Dopant;261
15.6;12.6 Proton Hole Mixed Conduction;265
15.7;References;268
16;Mechanisms of Proton Conduction in Perovskite-Type Oxides;270
16.1;13.1 Introduction;270
16.2;13.2 Proton Sites;271
16.3;13.3 Mechanisms of Proton Conduction (Undoped, Cubic Perovskites);273
16.4;13.4 Complications (Symmetry Reduction, Doping, Mixed Site Occupancy);277
16.5;13.5 Implications for the Development of Proton-Conducting Electrolytes for Fuel Cell Applications;279
16.6;References;280
17;Intermediate-Temperature SOFCs Using Proton-Conducting Perovskite;282
17.1;14.1 Introduction;282
17.2;14.2 Preparation of Fuel Cells;286
17.3;14.3 Characterization of Fuel Cells;286
17.4;14.4 Operation and Evaluation of Fuel Cells;288
17.5;14.5 Conclusion;291
17.6;References;292
18;LaCrO3-Based Perovskite for SOFC Interconnects;293
18.1;15.1 Introduction;293
18.2;15.2 Sintering Properties and Chemical Compatibility with the Other Components;294
18.3;15.3 Electronic Conductivity;295
18.4;15.4 Defect Chemistry and Oxygen Electrochemical Leak;297
18.5;15.5 Lattice Expansion During Reduction and Temperature Change;301
18.6;15.6 Mechanical Strength;301
18.7;15.7 Summary;302
18.8;References;303
19;Index;305