Reversing lithium dendrites via trigger-type carbonized ZIF-8 gradient for stable lithium metal anodes

Although metallic lithium is one of the most potential anode candidates for next-generation batteries, its applications are still restricted by several problems, especially the formation of lithium dendrites. However, insufficient emphasis has been placed on dealing with the incipient lithium dendrites. Herein, a three-dimensional insulating glass-fiber skeleton with gradient-distributed trigger-type carbonized ZIF-8 (GF-cZIF8) was developed. In this structure, plentiful conductive cZIF-8 on the collector/skeleton interface guided uniform lithium nucleation, while highly conductive and lithophilic cZIF-8 on the skeleton passivated and reversed lithium dendrites to a stable part of lithium anode when trigged by lithium dendrites. In addition, insulating glass fibers improved the homogeneity of Li ions. As a consequence, the GF-cZIF8/Cu collector exhibited a high and stable coulombic efficiency of 98 % after 280 cycles, and the GF-cZIF8-Li anode exhibited a low voltage hysteresis of 17 mV and a long cycling life up to 1100 h. A three-dimensional insulating glass-fiber skeleton with gradient-distributed trigger-type carbonized ZIF-8 (GF-cZIF8) is developed. Such unique features not only guide uniform lithium nucleation and deposition through plentiful conductive cZIF-8 on the collector/skeleton interface, but also passivate and reverse lithium dendrites during cycling processes. Therefore, resulted anodes exhibit enhanced electrochemical performances including a long cycle life and a stable Coulombic efficiency. [Display omitted] •A three-dimensional with gradient-distributed trigger-type carbonized ZIF-8 (GF-cZIF8) was developed.•Plentiful conductive cZIF-8 guides uniform lithium nucleation.•Highly conductive/lithophilic cZIF-8 gradient passivated and reversed lithium dendrites.•Insulating glass fibers improve the homogeneity of Li ion flux.