Rational Design of Porous Carbon Hosts for Silicon/Carbon Anodes in Lithium-Ion Batteries: Controlled Synthesis, Silicon Incorporation, Carbon Coating, and Electrochemical Applications

Silicon/carbon (Si/C) composites combine the high theoretical specific capacity of silicon with the electronic conductivity, structural stability, and volume-buffering capability of carbon, making them promising anode candidates for next-generation high-energy-density lithium-ion batteries. However, the substantial volume variation of silicon during repeated charge/discharge processes continuously perturbs the electrode/electrolyte interface, and the resulting interfacial instability remains a major barrier to practical application. Porous carbon host design and Si/C interface regulation have become key routes for improving structural robustness and electrochemical performance. Most existing reviews focus on the failure mechanisms of silicon-based anodes or the structural classification of Si/C composites, whereas the structural regulation role of porous carbon hosts has not been systematically summarized. This review places porous carbon hosts at the center of analysis and summarizes the main preparation strategies, including the hard-templating method, soft-templating method, combined hard- and soft-templating method, template-free synthesis, and etching strategies, with emphasis on their pore-forming mechanisms, structural regulation features, and industrialization potential. Building on this host-centered framework, silicon incorporation and carbon coating strategies are further discussed in terms of their effects on silicon distribution, Si/C interfacial stability, electronic transport, and volume-expansion accommodation. This review further evaluates recent advances in Si/C anodes for lithium-ion batteries from the perspectives of initial Coulombic efficiency, cycling stability, and practical electrode performance. Finally, key challenges related to scalable preparation, structural consistency, electrode-processing compatibility, and industrial adaptation are identified, and future directions for porous-carbon-host-based Si/C anodes are proposed.