Improving Lithium Ionic Conductivity through Lattice Vitrification Effect for MOFs-Based Solid-State Electrolytes

Abstract

Metal–organic frameworks (MOFs) have been corroborated as promising solid-state electrolyte (SSE) materials due to their structural diversity and porosity, while the crystalline feature of conventional MOFs severely impedes ion migration due to their abundant grain boundaries. The lattice vitrification strategy is an efficient way to eliminate crystal boundary resistance and facilitate ion conduction with a homogeneous ion flux. Herein, ZIF-76 glass (agZIF-76) is reported as SSEs for lithium-ion batteries. agZIF-76 can achieve a remarkable ion conductivity of 1.3 × 10–3 S cm–1 and a high Li+ transference number of 0.77 at 25 °C, higher than those of crystalline ZIF-76-based SSEs (7.6 × 10–4 and 0.65), as well as suppressing Li dendrites. Impressively, Li metal batteries pair with LiFePO4 (LFP) cathode and agZIF-76 present an initial capacity of 102.7 mAh g–1 with a decay rate of 0.035% per cycle at 1C. Hence, vitrification of MOFs will be a potential way for exploiting advanced SSEs.