A ZIF67-derived carbon/silicon dioxide (ZIF67-C@SiO₂) composite was synthesized via in situ coating to address volume expansion and capacity fading in lithium-ion batteries (LIBs). The porous, N-doped carbon framework improves lithium-ion diffusion and buffers SiO₂ expansion, delivering a high reversible capacity of 849.7 mAh·g⁻¹ and excellent cycling stability.

Silicon dioxide (SiO₂) is considered a promising anode material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity, low operating potential, and natural abundance. However, its practical application is limited by severe volume expansion and continuous formation of unstable solid electrolyte interphases (SEI), leading to rapid capacity degradation. Herein, a composite material of ZIF67-derived carbon and SiO₂ (ZIF67-C@SiO₂) was fabricated via a simple in situ coating method to address these issues. The porous and nitrogen-doped carbon framework from ZIF67 not only accommodates the volume changes of SiO₂ but also enhances electronic conductivity and lithium-ion diffusion. Electrochemical tests show that ZIF67-C@SiO₂ delivers a high reversible capacity of 849.7 mAh·g⁻¹ with nearly 100% Coulombic efficiency over 100 cycles. In comparison, pure SiO₂ and ZIF67-C exhibit much lower capacities of 98.67 mAh·g⁻¹ and 396.5 mAh·g⁻¹, respectively. Moreover, ZIF67-C@SiO₂ maintains a capacity of 566 mAh·g⁻¹ after 200 cycles at 1 A·g⁻¹ with a Coulombic efficiency of 99.6%. These results highlight the synergistic effect between ZIF67-derived carbon and SiO₂, offering valuable insights into the design of high-performance SiO₂-based anode materials for next-generation LIBs.