Molten salt assisted synthesis of Si/C nanocomposite derived from palygorskite and sodium alginate for electrochemical lithium storage.

This article focuses on the development of a silicon/carbon (Si/C) nanocomposite anode material for lithium-ion batteries (LIBs) using a facile and eco-friendly molten salt assisted precarbonization–reduction method. The composite is synthesized from palygorskite (PAL), a natural Si-containing nanorod mineral, and sodium alginate (SA), a biomass-derived carbon source, where SA plays a dual role in uniformly embedding PAL nanoparticles in the carbon matrix and generating molten sodium chloride (NaCl) to suppress unwanted silicon carbide (SiC) formation. The resulting PAL-Si/C composite exhibits a high reversible specific capacity of 1362.7 mA h g⁻¹, an initial Coulombic efficiency of 70.3% at 200 mA g⁻¹, and excellent long-term cycling stability, attributed to the carbon matrix accommodating Si volume changes and enhancing conductivity. This study demonstrates that the molten salt assisted method using PAL and SA provides a promising, scalable approach for producing high-performance Si/C anode materials for next-generation LIBs.