A High-Performance MOF-Based Single Ion Conducting Solid-State Electrolytes for Low-Temperature Lithium Metal Batteries

Single-ionic conducting electrolytes are important for the development of lithium-metal batteries with high energy density and safety. Herein, we propose a new strategy to anchor large anionic group on the skeleton of metal-organic frameworks (MOFs) and achieve preeminent single-ionic conducting electrolytes. Utilizing a postsynthetic modifica-tion (PSM) method, trifluoromethanesulfonyl group is covalently coordinated on amino groups of UiO-66-NH2 framework. Such a single-ionic conducting solid-state electrolyte (SSE) has high ionic conductivity (2.07×10-4 S cm-1 at 25 °C), low activation energy of 0.31 eV, wide electrochemical window run up to 4.52 V, as well as high Li+ trans-ference number of 0.84. Simultaneously, it can effectively inhibit the formation of lithium dendrite. Solid state bat-teries assembled with LiFePO4 as cathode exhibit outstanding rate performance and cyclic stability, especially for low-temperature Li-ion batteries at 0 °C with trace amounts of propylene carbonate (PC) as wetting a...