High-performance gel electrolyte for enhanced interface compatibility and lithium metal stability in high-voltage lithium battery

All-solid-state lithium batteries are still plagued by poor interface issue and difficult to achieve commercialization within a short time. Quasi-solid electrolyte has become an important development strategy to compromise liquid battery and all-solid-state battery. Herein, a high-performance gel electrolyte for enhanced interface compatibility and lithium metal stability in high-voltage lithium battery was provided via in-situ polymerization of 1, 3-dioxolane (DOL) and 1, 2-dimethoxyethane (DME) under initiation of LiPF6. By adjusting the DOL/DME ratio, the electrochemical behavior of the gel electrolyte was optimized. The gel electrolyte with DOL/DME ratio of 1:1 has a high ionic conductivity of 3.3 × 10−4 S cm−1 and a Li+ migration number of 0.68. Based on this gel electrolyte, the interface compatibility and lithium metal stability in high-voltage lithium battery were greatly enhanced, the Li-Li symmetric cell can be stably cycled over 700 h with no obvious polarization at a current density of 0.1 mA cm−2, the capacity retention rate of the high-voltage NCM622/Li battery reaches above 80 % after 150 cycles at 0.5 C and 25 ℃. This work provides a practical idea for the development of high-performance polymer electrolytes and facilitates their application in Li-metal batteries. [Display omitted] •High performance DOL/DME composite gel electrolyte was prepared.•The influence of DOL/DME ratio on the performance of lithium battery was explored.•The gel electrolyte favors interfacial compatibility and lithium metal stability.