Al₂O₃-Catalyzed Graphitization Constructing Flake-Arrayed Graphite With Abundant Li⁺ Diffusion Pathways for Fast-Charging LIBs

The increasing demand for high-performance lithium-ion batteries accelerates the development of advanced anodes that combine high energy density and fast-charging capabilities. This work presents a novel Al₂O₃-assisted non-transition-metal catalytic strategy to synthesize high-performance artificial graphite from petroleum coke. Notably, this strategy achieves an exceptional graphitization degree of 92.3% at a relatively low temperature of 2600°C, significantly reducing energy consumption. During graphitization, Al₂O₃ initially transforms into the intermediate carbide Al₄C₃, then decomposes at elevated temperatures to catalyze the rearrangement of liberated active carbon atoms into highly ordered graphitic microcrystals. This process induces the formation of a unique flake-arrayed structure with abundant pathways for Li⁺ intercalation and diffusion, significantly enhancing the electrochemical performance. Consequently, the prepared graphite (PAG-2600) delivers a reversible capacity of 353.3 mAh g⁻¹ at 0.1 C. At a high rate of 3 C, it retains 252.0 mAh g⁻¹ (72.1% retention) and demonstrates superior cycling stability, preserving 86.6% capacity after 500 cycles. Furthermore, the LiFePO₄//PAG-2600 full cell achieves a remarkable energy density of 209.3 Wh kg⁻¹ at a power density of 1793.7 W kg⁻¹, demonstrating practical fast-charging potential. This study highlights catalytic graphitization as an energy-efficient strategy to enhance the high-rate performance of graphite anodes for next-generation lithium-ion batteries.