Rapid thermal shock engineering of silicon/carbon hybrid anodes for high-capacity Li-ion batteries

The development of high-capacity anode materials remains pivotal for advancing lithium-ion battery technologies. While silicon offers a much higher theoretical capacity than graphite (3579 vs. 372 mAh g⁻¹), its severe volume expansion (>300 %) during cycling induces rapid electrode degradation. Many improvement measures often have disadvantages such as high preparation cost and rapid performance degradation. To overcome this limitation, cost-effective silicon-carbon (Si/C) composites have been extensively explored as next-generation anode materials. Herein, we report a rapid thermal shock strategy (<10 s) to fabricate structurally optimized silicon-carbon (Si/C) composites that resolve this critical challenge. The Si/C-1000 anode, synthesized at 1000 °C, achieves uniform dispersion of silicon nanoparticles (9.85 wt%, <50 nm) within a stress-buffering graphitic matrix through controlled vaporization-redeposition mechanisms. This architecture synergistically enhances interfacial stability and charge transfer kinetics, demonstrating exceptional electrochemical performance: 586/636 mAh g⁻¹ initial charge/discharge capacities at 0.1 C, 92 % initial Coulombic efficiency (ICE), outperforming most state-of-the-art Si/C systems. This work establishes a commercially viable pathway to harness silicon’s ultrahigh capacity through precision nanoscale engineering, addressing both fundamental and practical barriers in high-energy battery development.