Fabrication of Elastic Cyclodextrin-Based Triblock Polymer Electrolytes for All-Solid-State Lithium Metal Batteries

Lithium metal batteries with liquid electrolytes usually suffer from the growth of lithium dendrites and safety issues such as leaking and volatilization. Solid polymer electrolytes (SPEs) can relieve these problems due to their chemical and electrochemistry stability. However, PEO-based SPEs are still too brittle to endure bending, stretching, and shearing. Herein, highly elastic cyclodextrin-based triblock polymer electrolytes (CDTPEs) were fabricated via the ring-opening polymerization and initiator-free thiol–ene reaction. The rubbery PTMC segment endows the CDTPEs excellent elasticity to suffer from bending, stretching, and complicated conditions. This CDTPE integrates an excellent elongation (580%) and favorable ionic conductivity (1.5 × 10–3 S cm–1 at 100 °C). More importantly, the stable lithium stripping/plating process for over 2200 h was achieved due to the uniform lithium electrodeposition. The cyclodextrin component is verified to be beneficial for the uniform lithium electrodeposition. The LiFePO4/CDTPE/Li cells exhibit stable cycling performance and reversible specific discharge capacity. Our work may provide a method for stabilizing lithium metal batteries.