Facile synthesis of carbon-coated silicon nanocomposite with tremella-like porous structure for superior lithium-ion storage.

This article focuses on the development of a facile synthesis strategy combining gel coating, high-temperature carbonization, and molten salt-assisted magnesiothermic reduction (MSA-MR) to prepare a unique tremella-like silicon/carbon (Si/C) composite with an internal void structure (IV-Si/C) for use as a high-performance anode material in lithium-ion batteries (LIBs). Using tetraethyl orthosilicate (TEOS) and sodium alginate (SA) as raw materials, the study demonstrates that α-L-guluronic blocks in SA facilitate uniform dispersion of nanosized silicon particles in the carbon matrix, while NaCl generated during synthesis enhances SiO2 crystallization, inhibits silicon carbide (SiC) formation, and improves carbon reduction during MSA-MR. The resulting IV-Si/C nanocomposite exhibits a high reversible specific capacity of 1899.6 mAh g⁻¹, an initial Coulombic efficiency of 75.96%, superior rate capability, and long-term cycling stability, attributed to its unique porous structure and uniform carbon coating. These findings suggest potential for scalable production of functional Si/C nanomaterials with improved electrochemical performance for next-generation LIB applications.