Abstract: Succinonitrile has shown significant promise for application in polymer electrolytes for solid-state lithium metal batteries due to its high ionic conductivity at low-temperature. However, the use of Succinonitrile is limited due to its corrosion of Li metal. Herein, we report a solid polymer electrolyte with high ionic conductivity (2.17 × 10^−3 S cm^−1, 35 °C) enhanced by Ti₃C₂T_x. Corrosion of the Li anode is prevented due to the Succinonitrile molecules being efficiently anchored by Ti₃C₂T_x. Meanwhile, the coordination environment of Li⁺ is weakened due to the introduction of competitive coordination induction effects into the polymer electrolyte, resulting in efficient Li⁺ conduction. Furthermore, the mechanical properties of the electrolyte are enhanced by modulating the ratio of Ti₃C₂T_x to suppress the growth of Li dendrites. Therefore, Li||Li symmetric batteries deliver stable cycling up to 8000 h at 28 °C. LiFePO₄||Li full batteries exhibit excellent cycling stability of 151.7 mAh g^−1 with a capacity retention of 99.3 % after 300 cycles. This work not only presents a new idea to suppress the corrosion of the Li anode by Succinonitrile but also provides a simple, feasible, and scalable strategy for high-performance Li metal batteries.

Key words: Solid electrolyte, MXene, Ionic conductivity, Low-temperature, Lithium metal battery