Surface Modification of Lithium Metal as an Anode in Lithium Metal-Based Batteries

The growing demand for high-energy-density storage systems, driven by the rapid expansion of electric vehicles (EVs) and portable electronics, has recognized lithium metal anode (LMA) as a promising candidate in next-generation rechargeable batteries. LMA offers an ultrahigh theoretical specific capacity and the lowest electrochemical potential among known anode materials, which makes it a compelling alternative to conventional graphite. However, LMA exhibits critical challenges, including unstable solid electrolyte interphase (SEI) formation, dendrite growth, low Coulombic efficiency, and volume fluctuations, which lead to poor cycle stability, reduced energy efficiency, and safety risks such as internal short circuits. To address these challenges, surface modifications have displayed promising potential in stabilizing lithium metal. These techniques aim to create a more stable and uniform interface between lithium and electrolyte, reduce dendrite formation, and enhance the overall electrochemical property. Herein, we reviewed the current lithium metal surface modification strategies, including the discussion of chemical, physical, and hybrid modification approaches in both liquid and solid-state electrolyte systems. It was found that the optimal design of interfacial chemistry helps to suppress parasitic reactions, regulate Li-ion flux, and improve mechanical stability during battery cycling. A better understanding of these advancements provides significant knowledge in constructing a safe, reliable, and higher-performance lithium metal-based battery.