Research Trends and Future Perspectives on Zn-Ion Batteries Using Ga-Based Liquid Metal Coatings on Zn Anodes

Zn-ion batteries (ZIBs) are considered promising alternatives to conventional Li-ion secondary batteries due to their high safety, environmental friendliness, and cost-effectiveness. Despite these advantages, uneven metal plating and stripping, dendrite formation, and passivation and corrosion owing to the hydrogen evolution reaction (HER) have hindered the practical implementation of ZIBs. A promising route for overcoming these problems involves coating the Zn anode with eutectic gallium indium (EGaIn)-based liquid metal (LM) with a strong Zn affinity and growth direction tenability. Despite considerable research on EGaIn-coated Zn anodes for ZIBs, this topic has not been comprehensively reviewed. Hence, this Review introduces the application of LMs to ZIBs and particularly discusses the mitigation of stability issues using LM and the fundamental processes related to Zn anodes. We summarize the progress in this field and suggest promising future research directions to advance ZIBs.