Unlocking Reversible Silicon Redox for High‐Performing Chlorine Batteries

• Published in: Angewandte Chemie International Edition 2023-09, Vol.62 (37), p.e202306789-n/a
• Main Authors: Yuan, Bin, Wu, Liang, Geng, Shitao, Xu, Qiuchen, Zhao, Xiaoju, Wang, Yan, Liao, Meng, Ye, Lei, Qu, Zongtao, Zhang, Xiao, Wang, Shuo, Ouyang, Zhaofeng, Tang, Shanshan, Peng, Huisheng, Sun, Hao
• Format: Article
• Language: English
• Subjects: Anodes; Chemistry; Chlorine; Chlorine Battery; Dichloroethane; Dilution; Electrochemical analysis; Electrochemistry; Electrode materials; Electrolytes; Energy storage; Interface Engineering; Low Cost; Metals; Polyacrylonitrile; Rechargeable batteries; Silicon; Silicon Anode Chemistry
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202306789

Chlorine (Cl)‐based batteries such as Li/Cl2 batteries are recognized as promising candidates for energy storage with low cost and high performance. However, the current use of Li metal anodes in Cl‐based batteries has raised serious concerns regarding safety, cost, and production complexity. More importantly, the well‐documented parasitic reactions between Li metal and Cl‐based electrolytes require a large excess of Li metal, which inevitably sacrifices the electrochemical performance of the full cell. Therefore, it is crucial but challenging to establish new anode chemistry, particularly with electrochemical reversibility, for Cl‐based batteries. Here we show, for the first time, reversible Si redox in Cl‐based batteries through efficient electrolyte dilution and anode/electrolyte interface passivation using 1,2‐dichloroethane and cyclized polyacrylonitrile as key mediators. Our Si anode chemistry enables significantly increased cycling stability and shelf lives compared with conventional Li metal anodes. It also avoids the use of a large excess of anode materials, thus enabling the first rechargeable Cl2 full battery with remarkable energy and power densities of 809 Wh kg−1 and 4,277 W kg−1, respectively. The Si anode chemistry affords fast kinetics with remarkable rate capability and low‐temperature electrochemical performance, indicating its great potential in practical applications. Reversible Si redox has been unlocked in Cl‐based batteries through rational electrolyte dilution and anode passivation, which demonstrates excellent electrochemical performance and high practicability. It enables us to revisit the overlooked Cl‐based batteries and to harness them for sustainable and high‐performance energy storage.