基于阳离子缺位钙钛矿氧化物的固体氧化物燃料电池复合阴极材料研究

发布时间：2024-12-11 22:31

　　固体氧化物燃料电池(solid oxide fuel cell,SOFC)是将化学能直接转化成电能的高效绿色能源技术。将SOFC工作温度由1000℃高温降低至500-750℃中温范围是目前该领域的重要研究方向。工作温度的降低有利于减小SOFC的制备和运行成本,提高结构稳定性以及延迟使用寿命,但是同时也能够导致阴极、电解质、阳极和其他元件的性能下降。特别是,由于阴极氧还原反应(oxygen reduction reaction,ORR)活化能大,导致阴极极化阻抗随温度降低显著增大,从而限制了中温SOFC的输出功率。钴基钙钛矿结构氧化物是重要的中温SOFC阴极候选材料。它们具有高电子-离子混合电导率和ORR催化活性,但是也往往具有大的热膨胀系数(thermal expansion coefficient,TEC),与常用电解质材料 Gd0.1Ce0.9O1.95(GDC)、Sm0.2Ce0.8O1.9(SDC)和La0.9Sr0.1Ga0.8Mg0.2O2.85(LSGM)等的TEC值不匹配,容易导致在高温烧结或运行过程中SOFC结构的开裂,进而引起SOFC性能的恶化。而且,该类材料在相对较...

【文章页数】：132 页

【学位级别】：博士

【文章目录】：
Abstract
摘要
Table of Major Symbols
1 Introduction
    1.1 Fuel Cells
    1.2 Solid Oxide Fuel Cell
        1.2.1 The Principal and Operation
        1.2.2 Efficiency
    1.3 Components of SOFC
        1.3.1 Anode
        1.3.2 Electrolyte
        1.3.3 Cathode
    1.4 SOFC Cell Designs
    1.5 Mixed Ionic Electronic Conductor and Its Oxygen Reduction Mechanism
        1.5.1 ABO₃ Perovskite
        1.5.2 Layered Perovskites LnBaCo₂O6-δ

    1.6 Motivation and Objective of this Thesis
2 Experimental Methods
    2.1 Synthesis of Cathode and Electrolyte Powders
        2.1.1 Sol-Gel Method for Synthesis of Cathode Powder
        2.1.2 Solution Combustion Process for Synthesis of Electrolyte
    2.2 Fabrication of Electrolyte Pellet
    2.3 Fabrication of Cathode Layers
    2.4 Characterization Techniques
        2.4.1 X-Rays Diffraction (XRD)
        2.4.2 Thermal Expansion Coefficient (TEC)
        2.4.3 Scanning Electron Microscopy (SEM)
        2.4.4 AC Impedance Spectroscopy
3 Composite cathodes of (LaBa)_0.45CoO_3-δ-SDC
    3.1 Introduction
    3.2 Experimental Details
        3.2.1 Powder Synthesis and Cell Fabrication
        3.2.2 Characterizations
    3.3 Results and Discussion
        3.3.1 Phase Structures
        3.3.2 Thermal Expansion Behavior
        3.3.3 Electrical Conductivities
        3.3.4 Microstructure of the Cathodes
        3.3.5 Electrochemical Performance
        3.3.6 Single Cell Performance
    3.4 Summary
4 Performance Comparison Between PrBa_0.92Co₂O_6-δ-SDC Composite CathodesSynthesized with Different Methods
    4.1 Introduction
    4.2 Experimental Details
        4.2.1 Sample Preparation
        4.2.2 Characterizations
    4.3 Results and Discussion
        4.3.1 Phases and Microstructures of the Cathodes
        4.3.2 Electrochemical Performance
        4.3.3 Single Cell Performance
    4.4 Summary
5 Effects of SDC Content on Performance of Composite Cathode Materials ofPrBao.92Co₂O_6-δ-SDC
    5.1 Introduction
    5.2 Experimental Details
        5.2.1 Powder Synthesis
        5.2.2 Characterizations
    5.3 Results and Discussion
        5.3.1 Phase Structures of the Composites
        5.3.2 Thermal Expansion Behavior
        5.3.3 Electrical Conductivities
        5.3.4 Microstructures of the Cathodes
        5.3.5 Electrochemical Performance of the Cathodes
        5.3.6 Reaction Mechanism of the Cathodes
    5.4 Summary
6 Composite Cathodes of Pr_0.95BaCo₂O_6-δ-SDC
    6.1 Introduction
    6.2 Experimental Details
        6.2.1 Sample Preparation and Characterizations
    6.3 Results and Discussion
        6.3.1 Phase Structure
        6.3.2 Thermal Expansion Behavior
        6.3.3 Microstructures of the Cathodes
        6.3.4 Electrical Conductivities
        6.3.5 Electrochemical Performance of the Cathodes
        6.3.6 Single Cell Performance
    6.4 Summary
7 Conclusions and Outlook
    7.1 Conclusions
    7.2 总结
    7.3 Outlook
    7.4 Innovative Points
    7.5 创新点
References
Research Projects and Publications during PhD Period
Acknowledgement
Curriculum Vitae



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