Fig. 1

Schematic diagram of the operating principle and charging progress of LIBs"

Fig. 2

Fast-charging graphite facing with the main challenge: (a) Li plating on the graphite anode at 100% DOD at 1 C[27]; (b) Voltage curves of graphite electrodes charged at the 2 C rate with or without local heating of the graphite electrode in coin cells[28]; (c) Li plating occurs on the surface of the high temperature area of the centrally heated graphite anode after fast charging[28]; (d) Li+ diffusion modes in graphite; (e) The concentration polarization diagram of the graphite electrode; (f) Photos of Li+ concentration distribution during the lithiating process of the graphite anode[35]"

Fig. 3

Structure design of fast-charging graphite anode: (a) Schematic diagram of preparation of acid-treated graphite and KOH etched graphite, with the increase of the spacing between the KOH etched graphite layers, the surface pores are generated to promote Li+ diffusion and improve its fast charging performance[39]; (b) Voltage curves of GFms composite electrode under different discharge current densities, when the current is increased from 0.2 C to 30 C, the capacity retention rate is as high as 92%[40]; (c) A magnetic field is applied to make the graphite particles perpendicular to the collector and schematic diagram of the Li+ diffusion path, the structure shortens the Li+ diffusion distance and increases the Li+ diffusion rate[46]"

Table 1

Comparison of structure designing strategies and electrochemical properties of graphite anode materials"

Fig. 4

Chemical modification of graphite anode improves its charge-discharge performance: (a) Preparation process of SEAG, the electrode can achieve fast Li+ diffusion[56]; (b) Schematic diagram of synthesis of raw graphite and PTFE modified graphite, F doping is conducive to the fast Li+ diffusion in graphite[52]; (c) Rate performance of LNO and graphite half cells at 68—1360 mA/g, the LNO half cell rate performance has been significantly improved[58]"

Table 2

Comparison of chemical modification strategies and electrochemical properties of graphite anode materials"

Fig. 5

Fast-charging graphite anode surface coating: (a) Microstructure diagram of hard carbon coated graphite[63]; (b) TiO2-x @graphite core-shell structure,the TiO2-x coating helps to reduce the interface resistance between the electrode and the electrolyte[66]; (c) Rate performance of graphite coated with Al2O3 of different thickness at different current densities,graphite with 1% Al2O3 has a reversible capacity of about 337.1 mAh/gat the current density of 100 mA/g[67]; and (d) MoO x -MoP x / graphite anode material preparation process, both MoO x and nanoscale MoP x can effectively inhibit Li plating during fast charging[68]"

Table 3

Comparison of surface coating strategies and electrochemical properties of graphite anode materials"