Sustainable silicon–carbon composite anodes from CO2-derived carbon for enhanced lithium-ion batteries

Lithium-ion batteries (LIBs) are essential for future technologies, and sustainable development demands solutions like carbon capture to address rising CO₂ levels. This study explores a composite anode material composed of recycled carbon (RC) derived from CO₂, nano-silicon (Si), and pitch (P). The RC nanofibers form a stable 3D structure, offering mechanical support and buffering against Si expansion. Incorporating nano-Si enhances electrochemical capacity, while the pitch coating (RC@Si-P) improves structural stability by mitigating volume changes during cycling. The RC@Si-P anode achieves an initial coulombic efficiency of 78.15 %, a 645 mAh/g capacity at 0.1 A/g, significantly higher than graphite and maintains 400 mAh/g after 200 cycles. The results show that pitch encapsulation effectively suppresses Si volume contraction, reducing internal stress and improving cycling durability. This work demonstrates a viable path for upcycling CO₂ into high-performance LIB materials.