Preface -- 1 Introduction 1 Qingguang Pan and Yongbing Tang -- 1.1 Introduction -- 1.2 New Energy Storage Devices -- 1.3 Conclusion -- References -- 2 Mechanisms and Promising Cathode Catalysts for Metal-Air Batteries 27 Tao Zhang and Zhiqian Hou -- 2.1 Introduction -- 2.2 Overview of Metal-Air Batteries -- 2.3 Summary and Outlook -- References -- 3 Rechargeable Lithium-Sulfur Batteries 55 Girum Girma Bizuneh, Fang Li, Abdullah N. Alodhayb, and Jianmin -- 3.1 Background -- 3.2 Components and Mechanism of Lithium-Sulfur Batteries -- 3.3 The Existing Challenges of Li-S battery -- 3.4 Sulfur Cathode -- 3.5 Lithium Anode -- 3.6 Aprotic Electrolytes for Li-S Batteries -- 3.7 Separators and Functional Interlayers -- 3.8 Conclusion and Perspective -- References -- 4 Metal-CO 2 Batteries: Mechanisms and Advanced Materials 91 Chang Guo, Keyu Xie, and Xiao Han -- 4.1 Introduction -- 4.2 The Electrochemistry Mechanism of Metal-CO2 Battery -- 4.3 The Cathode Materials of Metal-CO2 Battery -- 4.4 The Electrolyte of Metal-CO2 Battery -- 4.5 Summary and Outlook -- References -- 5 Multivalent-Ion Batteries: Magnesium and Beyond 121 Qirong Liu and Yongbing Tang -- 5.1 Electrolyte Chemistry of Multivalent-Ion Batteries -- 5.2 Intercalation Chemistry of Multivalent-Ion Batteries -- 5.3 Interfacial Chemistry of Multivalent-Ion Batteries -- 5.4 Concluding Remarks -- References -- 6 Dual-Ion Batteries: Materials and Mechanisms 143 Luojiang Zhang and Yongbing Tang -- 6.1 Introduction -- 6.2 Cathode Materials -- 6.3 Anode Materials -- 6.4 Electrolytes -- 6.5 Conclusion and Prospects -- References -- 7 M-N-C Catalysts for Fuel Cells 171 Xiao Zhao -- 7.1 Introduction -- 7.2 Synthesis and Characterizations of M-N-C Catalysts -- 7.3 Fe-N-C-Based Catalysts -- 7.4 Non-Fe Metal Centers -- 7.5 Dual- and Multimetallic SACs -- 7.6 Durability of M-N-C Catalysts -- 7.7 Perspective -- References -- 8 Developments and Prospects of Aqueous Batteries 203 Shuo Yang, Shengmei Chen, and Chunyi Zhi -- 8.1 Introduction -- 8.2 Aqueous Batteries Based on Monovalent Metal Ions -- 8.3 Aqueous Batteries Based on Multivalent Metal Ions -- 8.4 Aqueous Batteries Based on Nonmetallic Ions -- 8.5 Challenges and Solutions of Aqueous Batteries -- 8.6 Conclusions and Future Perspectives -- References -- 9 Progress and Perspectives of Flow Batteries: Material Design and Engineering 231 Mengqi Zhang, Changkun Zhang, Xianfeng Li, and Guihua Yu -- 9.1 Introduction -- 9.2 Research Progress on the Electrolyte -- 9.3 Research Progress on the Membrane -- 9.4 Electrodes and Bipolar Plates -- 9.5 Other Novel FBs -- 9.6 FB Systems and Applications -- 9.7 Conclusions and Remaining Challenges -- References -- 10 Hybrid Capacitor 263 Lin Liu, Tianyi Wang, Hong Gao, Chengyin Wang, and Guoxiu Wang -- 10.1 Introduction -- 10.2 The Formation, Energy Storage Mechanism, and Performance Evaluation of Hybrid Capacitor -- 10.3 Recent Advances in Hybrid Capacitors -- 10.4 Conclusion -- References -- 11 Flexible Energy Storage Devices 299 Chuan Xie and Zijian Zheng -- 11.1 Introduction of FLBs -- 11.2 Materials and Structures for Achieving High-Performance FLBs -- 11.3 Challenges and Perspectives -- References -- Index.