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Preface | |
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Durability of Polymer Electrolyte Fuel Cells: Status and Targets | |
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Background | |
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Durability Targets for PEFC Technology | |
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United States Office of Energy Efficiency and Renewable Energy | |
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European Hydrogen and Fuel Cell-Technology Platform | |
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Japanese New Energy and Industrial Technology Development Organization | |
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Concluding Remarks | |
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Acronyms and Abbreviations | |
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Membrane Durability: Physical and Chemical Degradation | |
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Introduction | |
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Background | |
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Performance-Durability Trade-offs | |
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Accelerated Durability Testing and Failure Analysis | |
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Chemical Degradation | |
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Background | |
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Initiation: Oxidants | |
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End Chain Degradation Pathways | |
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Acid Site Degradation Pathways | |
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Mitigation of Chemical Degradation | |
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Chemical Durability of Hydrocarbon-based PEMs | |
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Mechanical Degradation | |
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Background | |
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Initiation: Hygrothermal Mechanical Stress | |
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Membrane Strength | |
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Membrane Fracture Toughness | |
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Mitigation of Mechanical Degradation | |
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Combined Chemical and Mechanical Degradation | |
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Membrane Shorting | |
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Backgroundp64 | |
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Compression Induced Soft Shorts | |
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Voltage Induced Hard Shorts | |
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Thermal-Electrical Analysis | |
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Mitigation of Membrane Shorting | |
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Summary and Future Challenges | |
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Acknowledgments | |
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Glossary | |
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Acronyms | |
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Nomenclature | |
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Electrochemical Degradation: Electrocatalyst and Support Durability | |
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Introduction | |
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The Catalyst Layer | |
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Practical Targets for Electrocatalyst Activity, Cost and Durability | |
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Significant Literature | |
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Catalyst Durability | |
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Support Durability | |
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Contamination | |
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Sub-zero Operation | |
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Experimental Set-up and Diagnostic Techniques | |
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Experimental Set-up | |
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Diagnostic Techniques | |
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Results and Discussion | |
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Ex-situ Pt Dissolution Measurements | |
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In-situ Catalyst Degradation Under Automotive Operation | |
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Durability of PEMFC Stacks in Vehicles | |
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Summary and Future Challenges | |
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Acknowledgments | |
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Nomenclature | |
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Gas Diffusion Media and their Degradation | |
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Introduction | |
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Fabrication of Woven and Non-Woven GDLs | |
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Manufacturers of GDLs | |
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GDL Properties and their Characterization | |
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Surface Morphology and Fiber Structure | |
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Porosity and Gases and Water Transport | |
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Electrical Conductivity and Contact Resistance | |
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Thermal Conductivity and Contact Resistance | |
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Hydrophobicity | |
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Mechanical Characteristics | |
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Other GDL Characteristics | |
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The Degradation Mechanisms of GDLs | |
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Electrochemical Degradation | |
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Mechanical Degradation | |
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Thermal Degradation | |
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Conclusions | |
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Bipolar Plate Durability and Challenges | |
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Introduction | |
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Literature Survey of Metallic Bipolar Plate Technology | |
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Non-coated Metals | |
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Coated Metals | |
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Amorphous Alloys | |
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Composite Plates | |
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Methods, and Approaches | |
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Interfaciai Contact Resistance (ICR) Measurement Setup | |
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Accelerated Corrosion Resistance Test Cell Setup | |
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Results and Discussion | |
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Interfacial Contact Resistance (ICR) Measurements | |
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Accelerated Corrosion Resistance Test | |
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Effect of Roughness | |
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Summary | |
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Freeze Damage to Polymel Electrolyte Fuel Cells | |
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Introduction | |
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Computational Model Efforts | |
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Modes of Degradation | |
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Membrane | |
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Catalyst Layer Damage | |
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Loss of Electrochemical Surface Area | |
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DM Fracture and Loss of Hydrophobicity | |
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Methods of Freeze Damage Mitigation | |
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Damage Mitigation via Material Choice and Design | |
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Comments on ProperConditions for Experimental Testing of Freeze/Thaw | |
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Summary and Future Outlook | |
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Acronyms | |
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Experimental Diagnostics and Durability Testing Protocols | |
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Introduction | |
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General Comments on Diagnostic Test Procedures | |
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Polarization-change Curve | |
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Key Limiting Cases of Polarization-Change Curves | |
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Analyzing Actual Polarization-Change Curves | |
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Isolating the Components Responsible for Performance Loss | |
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Catalytic Activity Losses | |
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Ohmic Losses | |
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Reactant Mass-Transport Losses | |
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Leaks | |
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Accelerated Test Protocols | |
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Nomenclature and Abbreviations | |
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Subscripts | |
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Greek | |
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Advanced High Resolution Characterization Techniques for Degradation Studies in Fuel Cells | |
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Introduction | |
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Optical Visualization | |
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Flow Channels | |
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Gas Diffusion Media | |
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Catalyst Layers | |
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Neutron Imaging | |
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Magnetic Resonance Imaging | |
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Electron Spectroscopy and Microscopy | |
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X-ray Photoelectron Spectroscopy (XPS) | |
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Electron Microscopy - SEM and TEM | |
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X-ray Techniques | |
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X-ray Diffraction | |
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X-ray Fluorescence Spectrometry | |
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X-ray Absorption Technique | |
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Thermal Mapping | |
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Summary and Outlook | |
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Computational Modeling Aspects of PEFC Durability | |
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Introduction | |
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Significant Literature | |
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Macroscopic Models of Chemical Membrane Degradation | |
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Microscopic Models of Membrane Degradation | |
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Macroscopic Models of Mechanical Membrane Degradation | |
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Macroscopic Models for Mechanical Degradation of Catalyst Layer and Interface | |
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Models of Contamination | |
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Macroscopic Models of Carbon Corrosion | |
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Microscopic Models on Platinum Dissolution | |
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Macroscopic Models of Catalyst Degradation | |
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Our Recent Approaches toward Macroscopic Models of Catalyst Degradation | |
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Sirnplified Model | |
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Integrated Model | |
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Results and Discussion | |
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Summary and Future Challenges | |
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Acknowledgments | |
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Nomenclature | |
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Greek | |
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Index | |