Ionic Liquid-Impregnated ZIF-8/Polypropylene Solid-like Electrolyte for Dendrite-free Lithium-Metal Batteries

Metal-organic framework (MOF)-based solid-like electrolytes have attracted more prospective due to the combined merits of solid-state electrolytes and liquid electrolytes. However, most MOF-based solid-like electrolytes using organic liquid electrolytes cannot fundamentally solve the safety issues of lithium-metal batteries, and the ionic conductivity and mechanical strength of the electrolytes should be further enhanced. Herein, the ionic liquid-impregnated polypropylene (PP) porous membrane with integrally distributed ZIF-8 nanoparticles is designed. The solid-like electrolyte possesses an increased ionic conductivity of 2.09 × 10^-4 S cm^-1 at 25 °C, lithium-ion transference number (0.45), mechanical strength, electrochemical window, and excellent nanowetted interfaces. Furthermore, the Li symmetrical cell shows excellent Li plating/stripping properties for 550 h at 0.1 mA cm^-2 and 0.1 mA h cm^-2. The LiFePO₄/Li full battery with the solid-like electrolyte demonstrates an excellent rate capability and cycling stability with the initial discharge capacity of 157.9 mA h g^-1 and a capacity retention ratio of 91.23% after 450 cycles at 0.2 C. The work offers a new avenue toward MOF-based solid-like electrolytes for high-safety lithium-metal batteries.