Constructing lithiophilic coating layer on the natural graphite for high-rate lithium-ion batteries

Graphite is expected to remain an essential anode material in commercial lithium-ion batteries (LIBs) for the foreseeable future, attributed to its outstanding energy density , cycling durability, and cost-effectiveness. However, the inertness of graphite surface to Li + and its limited ion diffusion channels restrict the rate capability of graphite anodes. Herein, we grew ZIF-8 in situ on the surface of graphite, followed by carbonization to construct a lithiophilic coating of Zn/N-doped amorphous carbon with an expanded interlayer spacing. The lithiophilic sites provided by Zn/N-doping facilitate uniform Li + intercalation, eliminating the inertness of graphite. Defects caused by edge N-doping provide diffusion channels for Li + between carbon layers, promoting fast Li + transport. Additionally, the uniform lithiophilic coating ensures the stability of the graphite interface. The Zn/N-doped amorphous carbon-coated graphite (ZNCG-800) showed excellent rate capability, with a specific capacity of 116 mAh g -1 at 5C. A high discharge specific capacity of 257.7 mAh g -1 was consistently maintained by ZNCG-800 after 500 cycles at a high current density of 1.0 A g -1 (2.7C), which is three times higher than that of graphite. Post-cycling analyses using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), and Raman spectroscopy demonstrated that the lithophilic coating not only facilitates the formation of inorganic component-rich SEI but also effectively inhibits the destruction of graphite structure. This work provides an effective strategy for enhancing the rate capability of anodes in alkali metal-ion batteries (AMIBs) through the application of ion-affinitive surface coatings .