Application of Silicon-Carbon Composite Anode Materials in Lithium-Ion Batteries

Lithium-ion batteries (LIBs) have become indispensable energy storage devices in modern society, powering a wide range of applications from portable electronics to electric vehicles and large-scale grid storage. Graphite, the most widely used commercial anode material, possesses a theoretical specific capacity of 372 mAh/g; however, its practical capacity has been gradually declining, limiting further improvements in energy density. Silicon, as a promising alternative anode material, offers a remarkably high theoretical specific capacity of approximately 3579 mAh/g for silicon-lithium alloys. Nevertheless, silicon suffers from severe volume changes of about 300% during the lithiation process, which leads to electrode pulverization, continuous formation and rupture of solid electrolyte interphase (SEI) layers, and ultimately rapid capacity fading. To address these challenges, incorporating silicon into a carbon matrix has emerged as a widely adopted strategy. The carbon framework serves to enhance mechanical integrity, maintain continuous electrical conductivity, and stabilize the electrode-electrolyte interface. This review systematically introduces three primary categories of silicon-carbon (Si-C) composite anode materials: silicon-graphite composites, silicon-carbon nanotube (CNT) composites, and silicon-graphene composites. For each category, the preparation methods, structural characteristics, electrochemical performance, and existing limitations are comprehensively discussed. Furthermore, emerging strategies involving hierarchical carbon architecture design, electrolyte additive engineering, and advanced binder development are explored. Finally, prospective directions for the large-scale implementation of Si-C composite anodes toward achieving high-energy-density lithium-ion batteries are proposed.