External field regulation of Li deposition in lithium metal batteries

Lithium (Li) metal is considered as the "Holy Grail" among various anodes due to its high theoretical specific capacity and low electrochemical potential. However, the Li anode undergoes uncontrollable dendrite growth and infinite volume expansion during cycling, seriously impeding the commercialization of high-energy-density Li metal batteries (LMBs). Considering the Li deposition is a dynamic electrochemical process, the external filed regulation has become a hotspot strategy to promote the cycling performance and safety application of Li mental anodes (LMA). Herein, we focus on the external fields involved during Li deposition, systematically summarizing the current progress of external field regulation for LMA. The mechanisms and limitations in regulating Li deposition are amply discussed. New perspectives and future research directions are also provided. With various external field being investigated and applied in Li metal anode system, it is expected that the dynamic regulation strategy can deliver great opportunities and promote the practical application of next-generation high-energy-density LMBs and other metal batteries.