A Chemically Bonded Ultraconformal Layer between the Elastic Solid Electrolyte and Lithium Anode for High‐performance Lithium Metal Batteries

• Published in: Angewandte Chemie International Edition 2023-07, Vol.62 (28), p.e202304339-n/a
• Main Authors: Yang, Na, Cui, Yujie, Su, Hang, Peng, Jiaying, Shi, Yongzheng, Niu, Jin, Wang, Feng
• Format: Article
• Language: English
• Subjects: Anodes; Batteries; Chemical bonds; Chemically Bonded Ultraconformal Layer; Critical current density; Electrochemistry; Electrolytes; Electrolytic cells; Fluorination; Ion transport; Ions; Lithium; Lithium batteries; Lithium Metal Battery; Molten salt electrolytes; Resilient Interface; Side reactions; Solid electrolytes; Solid-State Electrolyte; Vapor-Phase Fluorination
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202304339

Although high ionic conductivities have been achieved in most solid‐state electrolytes used in lithium metal batteries (LMBs), rapid and stable lithium‐ion transport between solid‐state electrolytes and lithium anodes remains a great challenge due to the high interfacial impedances and infinite volume changes of metallic lithium. In this work, a chemical vapor‐phase fluorination approach is developed to establish a lithiophilic surface on rubber‐derived electrolytes, which results in the formation of a resilient, ultrathin, and mechanically integral LiF‐rich layer after electrochemical cycling. The resulting ultraconformal layer chemically connects the electrolyte and lithium anode and maintains dynamic contact during operation, thus facilitating rapid and stable lithium‐ion transport across interfaces, as well as promoting uniform lithium deposition and inhibiting side reactions between electrolyte components and metallic lithium. LMBs containing the novel electrolyte have an ultralong cycling life of 2500 h and deliver a high critical current density of 1.1 mA cm−2 in lithium symmetric cells as well as showing good stability over 300 cycles in a full cell. In this work, we report a vapor‐phase fluorination approach to build a lithiophilic surface on elastic rubber‐derived electrolytes, which results in a ultraconformal, chemically bonded, mechanically integral LiF‐rich layer after electrochemical operation. Lithium metal batteries containing the novel electrolyte have an ultralong cycling life of 2500 h and deliver a high critical current density of 1.1 mA cm−2 in lithium symmetric cells as well as showing good stability over 300 cycles in a full cell.