Foreword ix
Preface xi

1 Introduction for Anode-Free Batteries 1
Jiawei Wang and Hua Wang

1.1 Development of Rechargeable Batteries 1
1.1.1 Brief History of Traditional Rechargeable Batteries 1
1.1.2 Development of Metal Batteries 2
1.1.3 The Rise of Anode-Free Batteries (AFBs) 4
1.2 Fundamentals of AFBs 6
1.2.1 The Conceptualization of AFBs 6
1.2.2 The Configuration of AFBs 6
1.2.2.1 Cathode Materials 7
1.2.2.2 Electrolytes 7
1.2.2.3 Current Collectors (for Negative Electrode) 8
1.2.2.4 Separators 8
1.2.3 The Working Principle of AFBs 8
1.3 The Issues and Strategies of AFBs 10
1.3.1 Critical Issues for AFBs 10
1.3.1.1 Metal Dendrite 11
1.3.1.2 Dead Metal 11
1.3.1.3 Unstable SEI 11
1.3.2 Strategies for AFBs 12
1.3.2.1 Current Collector Engineering 12
1.3.2.2 Electrolyte Modulation 13
1.3.2.3 Metal-Ion-Supply Agents 15
1.4 Progress in Upscaling of AFBs 15
1.4.1 Challenges in Upscaling from Coin Cells to Pouch Cells 15
1.4.2 Progress in Pouch-Type AFBs 17
1.4.3 Industrialization of AFBs 19

2 Anode-Free Lithium Batteries 29
Qiaonan Zhu and Hua Wang

2.1 Introduction 29
2.2 Fundamentals of Anode-Free Lithium Batteries (AFLBs) 32
2.2.1 Energy Storage Mechanisms of AFLBs 32
2.2.2 Challenges of AFLBs 32
2.2.3 Development History of AFLBs 33
2.3 Performance Optimization Strategies and Research Progress 35
2.3.1 Current Collector Design 35
2.3.1.1 Introduction 35
2.3.1.2 Lithiophilic Design 35
2.3.1.3 3D Structure Design 43
2.3.1.4 Artificial SEI 44
2.3.1.5 Multifunctional Layer 45
2.3.2 Liquid Electrolyte Engineering 46
2.3.2.1 Introduction 46
2.3.2.2 Liquid Electrolyte 47
2.3.3 Solid-State Electrolyte Engineering 61
2.3.3.1 Solid-Electrolyte Electrolyte Characteristics 63
2.3.3.2 Polymer Electrolyte 65
2.3.3.3 Inorganic Solid-State Electrolyte 69
2.3.4 Other Optimization Method 73
2.3.4.1 Li Supply 73
2.3.4.2 Pressure Control 76
2.3.4.3 Charging Protocol 77
2.3.4.4 Advanced Characterization Methods for AFLBs 80
2.4 Summary and Perspectives 84

3 Anode-Free Sodium Batteries 93
Jiangchun Chen and Hua Wang

3.1 Introduction 93
3.2 Fundamentals of AFSBs 94
3.2.1 Energy Storage Mechanism of AFSBs 94
3.2.2 Development History of AFSBs 94
3.2.3 Challenges of AFSBs 97
3.2.3.1 Limited Sodium Inventory 98
3.2.3.2 Severe Volume Changes 98
3.2.3.3 Sodium Dendrite Growth 98
3.2.3.4 Unstable SEI 99
3.3 Performance Optimization Strategies and Research Progress 100
3.3.1 Current Collector Design 100
3.3.1.1 Surface Modification and Functionalization 101
3.3.1.2 Structure Design of Current Collector 114
3.3.2 Electrolyte Engineering 120Contents vii
3.3.2.1 Solvents 121
3.3.2.2 Salts 124
3.3.2.3 Additives 126
3.3.3 Separator Modifications 129
3.3.4 Sodium Compensation Reagents 131
3.3.5 Cathode Material Optimization 133
3.3.6 Anode-Free Solid-State Sodium Batteries 134
3.3.6.1 Solid Electrolyte Materials 137
3.3.6.2 Current Collectors 140
3.4 Summary and Perspectives 142

4 Anode-Free Zinc Batteries 155
Yanmei Li, Jingwen Jiang, and Hua Wang

4.1 Introduction 155
4.2 Fundamentals of AFZBs 158
4.2.1 Working Mechanism of AFZBs 158
4.2.2 Challenges of AFZBs 159
4.2.2.1 Zn Dendrite 160
4.2.2.2 Side Reactions 161
4.3 Optimization Strategies 161
4.3.1 Current Collector Design 161
4.3.2 Surface Coating 162
4.3.3 Alloying Engineering 167
4.3.4 3D Structure 170
4.4 Electrolyte Engineering 174
4.4.1 Functional Additives 175
4.4.2 Cosolvent Electrolyte 178
4.4.3 Nonaqueous Electrolyte 182
4.5 Conclusion and Outlook 186

5 Other Anode-Free Battery Systems 193
Hao Lan and Hua Wang

5.1 Anode-Free Potassium Metal Batteries 193
5.2 Anode-Free Aluminum Metal Batteries 198
5.3 Anode-Free Magnesium Metal Battery 202
5.4 Anode-Free Tin Metal Battery 204
References 206

6 Perspectives for Anode-Free Rechargeable Batteries 209
Dandan Yu and Hua Wang

6.1 The Status of AFBs 210
6.2 Outlooks of AFBs 218
6.2.1 From Coin-Cell Proofs to Pouch-Cell Validation 218viii Contents
6.2.2 In Situ and Operando Characterization 219
6.2.3 Development of High-Capacity and Metal-Rich Cathode 219
6.2.4 Safety Considerations 220
6.2.5 Scalable Manufacturing and Commercial Viability of Anode-Free Batteries 221
6.3 Conclusions 222

Index 225