<i>In situ</i> hybrid crosslinked poly-DOL quasi-solid-state electrolytes for stable high-voltage lithium metal batteries

The development of poly(dioxolane) quasi-solid-state electrolytes (PDEs) <i>via in situ</i> polymerization has emerged as a promising strategy for the advancement of high-performance lithium-metal batteries. However, the practical application of linear PDEs in high-voltage lithium metal batteries is currently limited by their electrolyte and electrolyte/electrode interface instability and poor thermal stability. Herein, we present a novel <i>in situ</i> hybrid crosslinked PDOL quasi-solid-state electrolyte (HCPDE), which involves a 3D crosslinked polymer network and a unique high-voltage-resistance electrolyte within the framework. Benefiting from the synergistic effect of the crosslinked network structure and high-voltage-resistance electrolyte, the HCPDE exhibits significantly enhanced oxidative stability while maintaining high ion-conducting properties. The HCPDE exhibits an ionic conductivity of 1.95 × 10^-4 S cm^-1 at 30 °C, a Li⁺ transference number of 0.74, and an extended electrochemical stability window of over 4.7 V. Furthermore, the designed HCPDE stabilises the electrolyte/electrode interphase. Exceptional cyclability is demonstrated in both the Li∥Li symmetric cell, with over 1800 hours of operation, and the Li∥LiNi_0.83Co_0.12Mn_0.05O₂ (NCM83) cell, which achieves a capacity retention of 91.7% after 200 cycles at 0.5C. The corresponding pouch cell also performs impressively, maintaining 85.7% capacity retention over 150 cycles. This study provides new insights into the development of ether-based quasi-solid-state lithium metal batteries.