: Chao-Yang Wang, Ugur Pasaogullari
: Ugur Pasaogullari, Chao-Yang Wang
: Modeling and Diagnostics of Polymer Electrolyte Fuel Cells
: Springer-Verlag
: 9780387980683
: 1
: CHF 115.60
:
: Physikalische Chemie
: English
: 397
: Wasserzeichen/DRM
: PC/MAC/eReader/Tablet
: PDF
This volume, presented by leading experts in the field, covers the latest advances in diagnostics and modeling of polymer electrolyte fuel cells, from understanding catalyst layer durability to start-up under freezing conditions.
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Preface6
Contents8
List of Contributors, MAE 4915
Modern Aspects of Electrochemistry18
1 Durability of PEM Fuel Cell Membranes19
1 Summary19
2 Review of PEM Fuel Cell Degradation Phenomena and Mechanisms20
3 Membrane Degradation24
3.1. Stress in Membrane and MEAs25
3.2. Mechanical Characterization of Membranes29
3.3. Chemical Degradation Processes33
3.4. Mechanical Degradation Processes36
3.5. Interactions of Chemical and Mechanical Degradation44
4 Accelerated Testing and Life Prediction49
4.1. Accelerated Degradation Testing and Degradation Metrics49
4.2. Progressive Degradation Model of Combined Effects53
5 Mitigation57
Acknowledgments60
References60
2 Modeling of Membrane-Electrode-Assembly Degradation in Proton-Exchange-Membrane Fuel Cells -- Local H2 Starvation and Start--Stop Induced Carbon-Support Corrosion63
1 Introduction63
2 Kinetic Model67
2.1. Electrode Kinetics67
2.2. Local H2 Starvation Model72
2.3. Start--Stop Model75
3 Coupled Kinetic and Transport Model78
3.1. Model Description78
3.2. Local H2 Starvation Simulation81
3.3. Start--Stop Simulation90
4 Pseudo-Capacitance Model94
4.1. Mechanism Description94
4.2. Model Description96
4.3. The Pseudo-capacitive Effect98
5 Summary and Outlook99
Acknowledgments101
List of Symbols101
References103
3 Cold Start of Polymer Electrolyte Fuel Cells107
1 Introduction107
2 Equilibrium Purge Cold Start113
2.1. Equilibrium Purge114
2.2. Isothermal Cold Start115
2.3. Proton Conductivity at Low Temperature115
2.4. Effects of Key Parameters118
2.4.1. Initial Membrane Water Content118
2.4.2. Startup Current Density121
2.4.3. Startup Temperature124
2.5. ORR Kinetics at Low Temperatures125
2.6. Short-Purge Cold Start128
3 Water Removal During Gas Purge129
3.1. Introduction130
3.2. Purge Curve132
3.3. Two Characteristic Parameters for Water Removal133
3.4. Stages of Purge135
3.5. Effect of Key Parameters136
3.5.1. Purge Cell Temperature136
3.5.2. Purge Gas Flow Rate139
3.5.3. Matching Two Parameters141
3.6. HFR Relaxation142
4 Concluding Remarks144
References145
4 Species, Temperature, and Current Distribution Mapping in Polymer Electrolyte Membrane Fuel Cells147
1 Introduction147
2 Species Distribution Mapping148
2.1. Species and Properties of Interest148
2.1.1. Hydrogen148
2.1.2. Oxygen148
2.1.3. Water148
2.1.4. Contaminants and Diluents149
2.1.5. Pressure Drop149
2.1.6. Flow Distribution150
2.2. Methodology and Results150
2.2.1. Pressure Drop Measurement150
2.2.2. Gas Composition Analysis151
2.2.3. Neutron Imaging153
2.2.4. Magnetic Resonance Imaging156
2.2.5. X-ray Imaging158
2.2.6. Optically Transparent Fuel Cells159
2.2.7. Embedded Sensors165
2.2.8. Other Methods166
2.3. Design Implications167
3 Temperature Distribution Mapping170
3.1. Methodology and Results171
3.1.1. IR Transparent Fuel Cells171
3.1.2. Embedded Sensors172
3.2. Design Implications173
4 Current Distribution Mapping174
4.1. Methodology and Results174
4.1.1. Partial MEA174
4.1.2. Segmented Cells175
4.1.3. Other Methods181
4.2. Design Implications183
5 Concluding Remarks184
References185
5 High-Resolution Neutron Radiography Analysis of Proton Exchange Membrane Fuel Cells193
1 Introduction193
2 Neutron Radiography Facility Layout And Detectors195
2.1. Neutron Sources and Radiography Beamlines195
2.2. Neutron Imaging Detectors199
3 Water Metrology with Neutron Radiography202
3.1. Neutron Attenuation Coefficient of Water, µw202
3.2. Sources of Uncertainties in Neutron Radiography205
3.2.1. Counting Statistics206
3.2.2. Beam Hardening208
3.2.3. Background Subtraction208
3.2.4. Changes in the Total Neutron Scattering from Water Absorbed in the Membrane209
3.2.5. Image Spatial Resolution210
4 Recent In Situ High-Resolution Neutron Radiography Experiments of PEMFCs213
4.1. Proof-of-Principle Experiments213
4.2. In Situ, Steady-State Through-Plane Water Content214
4.3. Dynamic Through-Plane Mass Transport Measurements215
5 Conclusions216
Acknowledgments217
References217
6 Magnetic Resonance Imaging and Tunable Diode Laser Absorption Spectroscopy for In-Situ Water Diagnostics in Polymer Electrolyte Membrane Fuel Cells219
1 Introduction219
2 Magnetic Resonance Imaging (MRI): As a Diagnostic Tool for In-Situ Visualization of Water Content Distribution in PEMFC s 220
2.1. Basic Principle of MRI220
2.2. MRI System Hardware for PEMFC Visualization224
2.3. MRI Signal Calibration for Water Content in PEM227
2.4. In Situ Visualization of Water in PEMFC Using MRI227
3 Tunable Diode Laser Absorption Spectroscopy (TDLAS): As a Diagnostic Tool for In-Situ Detection of Water Vapor Concentration in PEMFC s 231
3.1. Basic Principle of TDLAS231
3.2. TDLAS System Hardware for Water Vapor Measurement232
3.3. TDLAS Signal Calibration for Measurement of Water Vapor Concentration234
3.4. In Situ Measurement of Water Vapor in PEMFC Using TDLAS237
4 Summary240
References240
7 Characterization of the Capillary Properties of Gas Diffusion Media243
1 Introduction243