Chapter 1 Introduction and Literature Background 1.1 Energy demands and challenges 1.2 Electrochemical Energy Storage Systems 1.2.1 Electrochemical Capacitors (ECs) 1.2.2 Lithium-ion Battery 1.2.3 Electrochemical Capacitor vs. Battery 1.3 Introduction to Graphene 1.3.1 Various Approaches Leading to Graphene Oxide/Graphene 1.3.2 Graphene for Soft Energy Storage Devices References Chapter 2 Electrochemical Exfoliation Synthesis of Graphene 2.1 Introduction 2.2 Experiment and Characterization 2.2.1 Material synthesis 2.2.2 Material Characterization 2.3 Results and Discussions 2.3.1 The Synthesis of Graphene Flakes 2.3.2 The Mechanism for Electrochemical Exfoliation 2.3.3 Electrochemical Performance of Resulted Graphene Flakes 2.4 Conclusion References Chapter 3 High-Performance Graphene Foam/Fe3O4 Hybrid Electrode for Lithium Ion Battery 3.1 Introduction 3.2 Experiment and Characterization 3.2.1 Materials Synthesis 3.2.2 Material Characterization 3.3 Results and Discussions 3.3.1 The Synthesis of GF/Fe3O4 Hybrid Films 3.3.2 Electrochemical Performance of GF/Fe3O4 3.3.3 Underlying mechanism for the enhanced electrochemical performance 3.4 Conclusion References Chapter 4 Graphene Foam (GF)/Carbon Nanotubes (CNTs) Hybrid Film-based High-Performance Flexible Asymmetric Supercapacitors 4.1 Introduction 4.2 Experiment 4.2.1 Material Synthesis and Device Fabrication 4.2.2 Material Characterization 4.3 Results and Discussions 4.3.1 Fabrication of GF/CNTs Hybrid Films 4.3.2 Fabrication of GF/CNTs/MnO2 and GF/CNTs/Ppy Hybrid Films 4.3.3 Electrochemical Performance of GF/CNTs/MnO2 and GF/CNTs/Ppy Hybrid Electrodes 4.3.4 Electrochemical Performance of GF/CNTs/MnO2 // GF/CNTs/Ppy ASCs 4.3.5 Underlying Mechanism for Enhanced Electrochemical Performance 4.4 Conclusion References Chapter 5 Graphene Foam/Carbon Nanotubes Hybrid Film based Flexible Alkaline Rechargeable Ni/Fe Battery 5.1 Introduction 5.2 Experiment 5.2.1 Materials Synthesis 5.2.2 Materials Characterization 5.3 Results and Discussions 5.3.1 The Synthesis of GF/CNTs/Ni(OH)2 and GF/CNTs/Fe2O3 5.3.2 Electrochemical Performance of GF/CNTs/Ni(OH)2 and GF/CNTs/Fe2O3 5.3.3 Electrochemical Performance of f-Ni/Fe Battery 5.3.4 Underlying Mechanism for Enhanced Electrochemical Performance 5.4 Conclusion References Chapter 6 Conclusions, Comments and Future Work 6.1 Conclusions 6.2 Comments and Future Work References
Dr. Jilei Liu is currently working as a research Fellow at Nanyang Technological University (NTU). He received his B.Sc in Material Physics from Hunan University (Changsha, China, 2008), M. Sc from Shanghai Institute of Ceramics, Chinese Academy of Sciences (Shanghai, China, 2011)and Ph.D. degree from Nanyang Technological University (NTU, Singapore, 2015). Dr. Liu’s research interests include synthesis and characterization of carbon allotropes (graphene, CNTs, and graphene/CNTs hybrids), and their applications in electrochemical energy storage devices (i.e. supercapacitors, Li+/Na+/K+ ion batteries, aqueous alkaline batteries, etc).
This thesis focuses on the synthesis and characterization of various carbon allotropes (e.g., graphene oxide/graphene, graphene foam (GF), GF/carbon nanotube (CNT) hybrids) and their composites for electrochemical energy storage applications. The coverage ranges from materials synthesis to electrochemical analysis, to state-of-the-art electrochemical energy storage devices, and demonstrates how electrochemical characterization techniques can be integrated and applied in the active materials selection and nanostructure design process. Readers will also discover the latest findings on graphene-based electrochemical energy storage devices including asymmetric supercapacitors, lithium ion batteries and flexible Ni/Fe batteries.
Given the unique experimental procedures and methods, the systematic electrochemical analysis, and the creative flexible energy storage device design presented, the thesis offers a valuable reference guide for researchers and newcomers to the field of carbon-based electrochemical energy storage.