Vesicle-shaped ZIF-8 shell shielded in 3D carbon cloth for uniform nucleation and growth towards long-life lithium metal anode

摘要

Lithium metal has aroused extensive research interests as the anode for next-generation rechargeable batteries.However,the well-known dendritic Li growth and consequent safety issues still impair the long-term cycling performance.Herein,a hybrid structure composed of 3 D carbon cloth and vesicleshaped hollow ZIF-8 modification shell(HZS@CC)was prepared as a smart host for guiding uniform Li deposition.The long-range interconnected 3 D carbon fiber network enables the reduced local current density with homogeneous electrons distribution.Synergistically,abundant surface polar groups and the ultrastructure on ZIF-8 particles effectively guide a well-distributed Li-ions flow to promote the uniform Li nucleation and growth.As a result,stable Li plating/stripping for 2000 h with a low overpotential(≈15 mV)at 1 mA cm^(-2) were achieved in symmetric cells.Coupling with LiFePO_(4) cathode,the full cell delivered long life over 1200 cycles at 6 C.This research demonstrated that a homogenization guiding of Li-ions is of great importance to better make use of the structural advantage of 3 D hosts and achieve improved electrochemical performance.