Li-metal anode with ultrahigh capacity (3,860 mAh/g) and lowest redox potential (−3.04 V versus standard hydrogen electrode) holds the key in advancing the next-generation high-energy-density batteries. The intrinsic defects of hyper-reactivity, dendritic growth, large volume change, and poor wettability on substrate, however, impede its practical applications. Recently, Li-metal-based composite (LMC), made by compositing metallic Li with various functional materials, has been proposed as an alternative to Li-metal anode, exhibiting unique physicochemical properties and excellent performances. To this end, we summarize recent advances in the synthesis, structure, properties, and electrochemical performance of LMC in terms of different functional materials. A special focus has been placed on the wetting behavior of Li metal with different carbons and the fascinating compositing reactions for LMC. We conclude with a discussion on the prospects and essential research directions for exploiting LMC from the fundamental research and practical application point of view. It is expected that this review will encourage Li-metal batteries to step forward to real applications.
