Synthesis of a crosslinked ether-based polymer for high-performance semi-solid lithium metal batteries integration

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2024-10, Vol.12 (39), p.2743-2752
• Main Authors: Yang, Dezhi, Yang, Yanan, Cui, Yeying, Sun, Yiyang, Zhang, Tao
• Format: Article
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/d4ta04857a

In situ ring-opening polymerization of ether-based monomers has shown promising application in solid-state lithium metal batteries owing to their positive lithium compatibility, mild reaction conditions, and facile preparation. However, typical poly(1,3-dioxolane) (PDOL) based electrolyte still struggles with low ionic conductivity, narrow electrochemical window, and poor thermal stability, which greatly retard its further progress. Herein, we constructed a crosslinked PDOL semi-solid electrolyte initiated by a three-armed crosslinker and high voltage resistant fluorinated solvents, which shows favourable stability toward lithium metal (lithium plating/stripping stably operating for 2700 h at 0.2 mA cm −2 with no significant polarization growth) and a high electrochemical oxidation window of up to 4.6 V. A lithium metal coin cell using this crosslinked semi-solid electrolyte equipped with LFP expresses excellent cycling stability with a capacity retention of 88% for 1000 cycles at 1C. A 50 mA h pouch cell with an NCM811 cathode exhibited favourable working ability. Meanwhile, the crosslinked electrolyte demonstrated better solid-state characteristics and thermal stability compared with a long-chain electrolyte. This work provides a prospective reference for the application of ether-based electrolyte in high safety and high energy density lithium metal batteries. The synergistic effect of the crosslinking molecular design of poly(1,3-dioxolane) and the HOMO-LUMO screening of high voltage resistant fluorinated solvents realizes high-performance lithium metal batteries.