Feng Li, PhD, is Professor in the Institute of Metal Research at the Chinese Academy of Sciences, China. He has published over 200 peer-reviewed articles. His research focuses on novel carbon-based materials for energy applications.Lei Wen, PhD, is Associate Professor in the Institute of Metal Research at the Chinese Academy of Sciences, China. He earned his doctorate from Northeastern University in China. His research focuses on electrochemical energy storage devices.Hui-ming Cheng, PhD, is Professor in the Institute of Metal Research at Chinese Academy of Sciences, China. His research focuses on low-dimensional materials for energy applications.

• Preface xiiiAbbreviations xv1 Introduction 11.1 Energy Conversion and Storage: A Global Challenge 11.2 Development History of Electrochemical Energy Storage 31.3 Classification of Electrochemical Energy Storage 41.4 LIBs and ECs: An Appropriate Electrochemical Energy Storage 61.5 Summary and Outlook 10References 102 Materials and Fabrication 152.1 Mechanisms and Advantages of LIBs 152.1.1 Principles 152.1.2 Advantages and Disadvantages 162.2 Mechanisms and Advantages of ECs 182.2.1 Categories 182.2.2 EDLCs 182.2.3 Pseudocapacitor 202.2.4 Hybrid Capacitors 212.3 Roadmap of Conventional Materials for LIBs 222.4 Typical Positive Materials for LIBs 232.4.1 LiCoO2 Materials 232.4.2 LiNiO2 and Its Derivatives 252.4.3 LiMn2O4 Material 262.4.4 LiFePO4 Material 272.4.5 Lithium–Manganese-rich Materials 282.4.6 Commercial Status of Main Positive Materials 282.5 Typical Negative Materials for LIBs 292.5.1 Graphite 292.5.2 Soft and Hard Carbon 312.6 New Materials for LIBs 332.6.1 Nanocarbon Materials 332.6.2 Alloy-Based Materials 352.6.3 Metal Lithium Negative 392.7 Materials for Conventional ECs 392.7.1 Porous Carbon Materials 402.7.2 Transition Metal Oxides 412.7.3 Conducting Polymers 422.8 Electrolytes and Separators 422.8.1 Electrolytes 422.8.2 Separators 452.9 Evaluation Methods 462.9.1 Evaluation Criteria for LIBs 462.9.2 Theoretical Gravimetric and Volumetric Energy Density 462.9.3 Practical Energy and Power Density of LIBs 472.9.4 Cycle Life 482.9.5 Safety 482.9.6 Evaluation Methods for ECs 492.10 Production Processes for the Fabrication 502.10.1 Design 502.10.2 Mixing, Coating, Calendering, and Winding 512.10.3 Electrolyte Injecting and Formation 512.11 Perspectives 51References 533 Flexible Cells: Theory and Characterizations 673.1 Limitations of the Conventional Cells 673.1.1 Mechanical Properties of Conventional Materials 673.1.2 Limitations of Conventional Architectures 683.1.3 Limitations of Electrolytes 693.2 Mechanical Process for Bendable Cells 693.2.1 Effect of Thickness 703.2.2 Effect of Flexible Substrates and Neutral Plane 713.3 Mechanics of Stretchable Cells 723.3.1 Wavy Architectures by Small Deformation Buckling Process 723.3.2 Wavy Architectures by Large Deformation Buckling Process 743.3.3 Island Bridge Architectures 753.4 Static Electrochemical Performance of Flexible Cells 763.5 Dynamic Performance of Flexible Cells 773.5.1 Bending Characterization 783.5.2 Stretching Characterization 783.5.3 Conformability Test 793.5.4 Stress Simulation by Finite Element Analysis 793.5.5 Dynamic Electrochemical Performance During Bending 833.5.6 Dynamic Electrochemical Performance During Stretching 853.6 Summary and Perspectives 90References 904 Flexible Cells: Materials and Fabrication Technologies 954.1 Construction Principles of Flexible Cells 954.2 Substrate Materials for Flexible Cells 954.2.1 Polymer Substrates 964.2.2 Paper Substrate 974.2.3 Textile Substrate 984.3 Active Materials for Flexible Cells 984.3.1 CNTs 984.3.2 Graphene 994.3.3 Low-Dimensional Materials 994.4 Electrolytes for Flexible LIBs 1014.4.1 Inorganic Solid-state Electrolytes for Flexible LIBs 1024.4.2 Solid-state Polymer Electrolytes for Flexible LIBs 1044.5 Electrolytes for Flexible ECs 1044.6 Nonconductive Substrates-Based Flexible Cells 1074.6.1 Paper-Based Flexible Cells 1084.6.2 Textiles-Based Flexible Cells 1124.6.3 Polymer Substrates-Based Flexible Cells 1174.7 CNT and Graphene-Based Flexible Cells 1214.7.1 Free-standing Graphene and CNTs Films for SCs 1214.7.2 Free-standing Graphene and CNT Films for LIBs 1224.7.3 Flexible CNTs/Graphene Composite Films for the Cells 1254.8 Construction of Stretchable Cells by Novel Architectures 1274.8.1 Stretchable Cells Based onWavy Architecture 1274.8.2 Stretchable Cells Based on Island-Bridge Architecture 1294.9 Conclusion and Perspectives 1304.9.1 Mechanical Performance Improvement 1314.9.2 Innovative Architecture for Stretchable Cells 1324.9.3 Electrolytes Development 1324.9.4 Packaging and Tabs 1324.9.5 Integrated Flexible Devices 133References 1335 Architectures Design for Cells with High Energy Density 1475.1 Strategies for High Energy Density Cells 1475.2 Gravimetric and Volumetric Energy Density of Electrodes 1495.3 Classification of Thick Electrodes: Bulk and Foam Electrodes 1515.4 Design and Fabrication of Bulk Electrodes 1535.4.1 Advantages of Bulk Electrodes 1535.4.2 Low Tortuosity: The Key for Bulk Electrodes 1555.5 Characterization and Numerical Simulation of Tortuosity 1575.5.1 Characterization of Tortuosity by X-ray Tomography 1575.5.2 Numerical Simulation of Tortuosity on Rates by Commercial Software 1585.6 Fabrication Methods for Bulk Electrodes 1595.7 Thick Electrodes with Random Pore Structure 1605.7.1 Pressure-less High-temperature Sintering Process 1605.7.2 Cold Sintering Process 1615.7.3 Spark Plasma Sintering Technology 1625.7.4 Brief Summary for Sintering Technologies 1655.8 Thick Electrodes with Directional Pore Distribution 1655.8.1 Iterative Extrusion Method 1655.8.2 Magnetic-Induced Alignment Method 1685.8.3 CarbonizedWood Template Method 1685.8.4 Ice Templates Method 1725.8.5 3D-Printing for Thick Electrodes 1735.8.6 Brief Summary for Bulk Electrodes 1755.9 Carbon-Based Foam Electrodes with High Gravimetric Energy Density 1785.9.1 Graphene Foam 1795.9.2 CNTs Foam 1815.9.3 CNT/Graphene Foam 1815.10 Carbon-Based Thick Electrodes 1825.10.1 Low Electronic Conductive Material/Carbon Foam 1825.10.2 Large Volume Variation Materials/Carbon Foam 1865.10.3 Compact Graphene Electrodes 1885.10.4 Summary for Carbon Foam Electrodes 1895.11 Thick Electrodes Based on the Conductive Polymer Gels 1915.12 Summary and Perspectives 193References 1956 Miniaturized Cells 2056.1 Introduction 2056.1.1 Definition of the Miniaturized Cells and Their Applications 2056.1.2 Classification of Miniaturized Cells 2066.1.3 Development Trends of the Miniaturized Cells 2076.2 Evaluation Methods for the Miniaturized Cells 2096.2.1 Evaluation Methods for Electric Double-layer m-ECs 2106.2.2 Evaluation methods for m-LIBs and m-ECs 2116.3 Architectures of Various Miniaturized Cells 2126.4 Materials for the Miniaturized Cells 2136.4.1 Electrode Materials 2136.4.2 Electrolytes for the Miniaturized Cells 2146.5 Fabrication Technologies for Miniaturized Cells 2156.5.1 Fabrication of Miniaturized Cells with 2D Parallel Plate Configuration 2166.6 Fabrication Technologies for 2D Interdigitated Cells 2206.7 Printing Technologies for 2D Interdigitated Cells 2226.7.1 Advantages of Printing Technologies 2226.7.2 Classification of Printing Techniques 2226.7.3 Screen Printing for Miniaturized Cells 2246.7.4 Inkjet Printing 2286.8 Electrochemical Deposition Method for 2D Interdigitated Cells 2286.9 Laser Scribing for 2D Interdigitated Cells 2316.10 In Situ Electrode Conversion for 2D Interdigitated Cells 2346.11 Fabrication Technologies for 3D In-plane Miniaturized Cells 2366.11.1 3D Printing for 3D Interdigitated Configuration Cells 2366.11.2 3D Interdigitated Configuration by Electrodeposition 2396.12 Fabrication of Miniaturized Cells with 3D Stacked Configuration 2406.12.1 3D Stacked Configuration by Template Deposition 2416.12.2 3D Stacked Configuration by Microchannel-Plated Deposition Methods 2456.13 Integrated Systems 2476.14 Summary and Perspectives 249References 2507 Smart Cells 2637.1 Definition of Smart Materials and Cells 2637.1.1 Definition of Smart Cells 2637.1.2 Definition of Smart Materials 2637.2 Type of Smart Materials 2647.2.1 Self-healing Materials 2647.2.2 Shape-memory Alloys 2657.2.3 Thermal-responding PTC Thermistors 2667.2.4 Electrochromic Materials 2677.3 Construction of Smart Cells 2687.3.1 Self-healing Silicon Anodes 2687.3.2 Aqueous Self-healing Electrodes 2717.3.3 Liquid-alloy Self-healing Electrode Materials 2737.3.4 Thermal-responding Layer 2747.3.5 Thermal-responding Electrodes Based on the PTC Effect 2767.3.6 Ionic Blocking Effect-Based Thermal-responding Electrodes 2787.4 Application of Shape-memory Materials in LIBs and ECs 2807.4.1 Self-adapting Cells 2807.4.2 Shape-memory Alloy-Based Thermal Regulator 2817.5 Self-heating and Self-monitoring Designs 2827.5.1 Self-heating 2837.5.2 Self-monitoring 2857.6 Integrated Electrochromic Architectures for Energy Storage 2867.6.1 Integration Possibilities 2867.6.2 Integrated Electrochromic ECs 2877.6.3 Integrated Electrochromic LIBs 2897.7 Summary and Perspectives 291References 292Index 301