Free-Standing Carbon Materials for Lithium Metal Batteries

Lithium metal, with its high theoretical capacity and low redox potential, is the most promising next-generation high-energy-density battery anode material. However, the formation of uneven surface layers and dead lithium, significant volume changes in the electrode, and dendrite growth lead to rapid capacity degradation, low cycling stability, and safety issues, limiting the commercialization of lithium metal batteries (LMBs). As a strategy to improve the stability of LMBs, introducinga three-dimensional (3D) structure with a large surface area can accommodate lithium (Li) inside the structure and homogenize local current density. Also, as a current collector and host material, free-standing carbon materials, with the advantages of lightness, low cost, electrochemical and mechanical stability, and excellent electronic conductivity, can effectively enhance energy density and cycle performance. In this review, we first discuss the chemical properties of carbon, and then summarize recent research progress related to the 3D structuring and chemical modification of carbon materials as a Li metal host. Finally, we present perspectives on future research for the practical application of free-standing carbon materials for LMBs.