Fast kinetics of graphite anodes through interface and bulk engineering: a review
Lithium-ion batteries (LIBs) have long dominated consumer electronics, grid storage, and electric vehicles due to high energy density and cycle life. Graphite remains the most commercialized anode material, owing to its stable layered structure, electrical conductivity, and cost-effectiveness. However, its theoretical specific capacity is limited to 372 mAh/g, and intrinsic Li+ diffusion kinetics are sluggish, impeding high-power and high-energy density systems. This review examines the intercalation and failure mechanisms of graphite anodes, focusing on bulk and surface engineering strategies to enhance fast-charging capability. Key approaches include carbon coating, artificial solid-electrolyte interphase (SEI) layers, and heteroatom doping. Empirical data from recent studies demonstrate that Li3PO4-enriched SEI layers improve Li+ de-solvation, enabling fast charging and low-temperature operation. Black TiO2−x coatings and amorphous Al2O3 layers enhance fast charging by reducing charge-transfer resistance. Pitch crystallinity in carbon coatings affects electrochemical performance, with optimized coatings achieving reversible capacities exceeding 350 mAh/g at 4C. The review synthesizes these advances, highlighting that interface engineering can reduce Li+ diffusion barriers and mitigate graphite exfoliation, while bulk modifications such as sp-carbon interfaces and order@disorder pathways facilitate rapid lithium diffusion. Industrial adoption requires scalable, cost-effective coating methods that maintain cycle life beyond 1000 cycles with minimal capacity fade. The review concludes that synergistic bulk and interface engineering is essential for next-generation graphite anodes, but challenges remain in achieving uniform coatings and preventing SEI degradation under extreme fast-charging conditions.