Advances and perspectives of CVD-fabricated nano-scale Si-C anodes

The commercialization of nanoscale Si and SiOₓ anodes faces challenges like substantial volume expansion, extensive interfacial side reactions, and low initial Coulombic efficiency. Recently, Si-C anodes produced through chemical vapor deposition (CVD) by co-pyrolyzing silane and hydrocarbon gases on carbon scaffolds have attracted considerable attention from both academia and industry. The porous structure of carbon matrix facilitates the in-situ growth of Si particles, enhancing electrical conductivity and mechanical strength. This innovative design endows Si-C anodes with high initial Coulombic efficiency, large reversible capacity, minimal volume expansion, and stable cycling performance. However, comprehensive research on these CVD-derived anodes is still lacking, particularly regarding the structural-property-performance relationships. This review aims to highlight recent developments by examining the fabrication processes that influence electrochemical performance. Special attention is paid to various carbon materials, including Super P carbon, graphene, carbon nanotubes, and porous carbons with diverse pore size distributions and volumes. Factors affecting Si deposition, such as deposition model, precursor selection, temperature, atmosphere, and kinetics, are also discussed. Additionally, the review summarizes the use of carbon films on Si particles, considering aspects like layer thickness, hydrocarbon gas sources and temperatures. Finally, effective strategies are proposed to promote the industrial adoption of Si-C anodes.