Solvent-Free Encapsulation of Nano Si in Carbon Enables Stable Lithium Storage

Silicon is a promising candidate anode material for high-energy lithium-ion batteries (LIBs) due to its high theoretical capacity. However, its practical utilization is limited by its low intrinsic electrical conductivity and significant volume expansion during lithiation. To address these challenges, substantial efforts have been dedicated to developing silicon/carbon composites. Herein, we report a solvent-free approach for encapsulating nano Si in nitrogen-doped carbon (Si@NC). The nitrogen-doped carbon coating significantly improves the electrical conductivity and effectively accommodates the volume fluctuation of nano Si. The resulting Si@NC composite manifests an impressive reversible capacity of 915 mAh g –1 with decent cyclability. This scalable, cost-effective, and environment-benign synthesis, which is solvent-free and flammable gas-free, offers a viable approach for the construction of high-performance silicon/carbon anodes.