Surface Decoration of TiC Nanocrystals onto the Graphite Anode Enables Fast-Charging Lithium-Ion Batteries

To significantly reduce the charging time of commercial lithium-ion batteries (LIBs), it is essential to control the surface properties of graphite anodes because the charging process involves sluggish interfacial kinetics between graphite and the electrolyte. For the effective surface modification of graphite, herein we demonstrate the surface decoration with titanium carbide (TiC) nanocrystals onto graphite particles via a simple wet-coating process. The high electrical conductivity, low Li⁺ adsorption energy, and small surface diffusion barrier of the TiC nanocrystals facilitate fast Li⁺ adsorption and migration in the graphite surface by reducing the overpotential upon the charging process. The feasibility of the TiC nanocrystal-decorated graphite (TiC@AG) anode is thoroughly examined with an in-depth understanding of the interfacial reaction mechanism. Furthermore, the full-cell with a commercial cathode (LiNi_0.8Co_0.1Mn_0.1O₂) and TiC@AG anode demonstrates an impressive capacity retention (94.5%) after 300 cycles under fast-charging condition (3 C-charging and 1 C-discharging) without any sign of Li plating. The charging time of the TiC@AG full-cell was estimated at 16.2 min (80% of state of charge), which is substantially shorter than that of the artificial graphite full-cell. Our findings offer practical insights into the design principles of advanced graphite anodes, contributing to the realization of fast-charging LIBs.