Design of Supported–Coated Structure Silicon/Carbon Composites Using Industrial Waste Micrometer-Sized Silicon for an Advanced Lithium-Ion Battery Anode

Silicon (Si) has garnered significant attention as an anode material for an advanced lithium-ion battery (LIB), but it remains challenging to design high-stability Si-based composites with low structural strain and high electrical conductivity. Here, we present a novel Si–carbon anode material (Si/G@TNS-60) derived from recycled wire-cutting polysilicon waste, featuring a unique structure with an internal anchoring load and an external wrapping of flexible two-dimensional (2D) material. The graphite (G) component serves as a conductive anchor carrier, enhancing electronic conductivity and preventing pulverization and electrical contact loss in Si particles. Additionally, the MXene (TNS) protective layer provides mechanical flexibility, isolates Si from direct contact with the electrolyte to reduce side reactions, improves ion and electron diffusion kinetics, and ensures structural stability. Consequently, the Si/G@TNS-60 electrode delivers improved initial coulombic efficiency (ICE, 78.8%), excellent rate performance with a capacity of 485.3 mAh g–1 at 2 C, and sustained durability over 500 cycles at 0.5 C with 83.5% capacity retention. The investigation into the reaction dynamics reveals the hybrid storage mechanism and rapid Li+ diffusion coefficient. Furthermore, ex situ scanning electron microscopy (SEM) demonstrates a minimal volume change and maintains the integrity of the electrode structure. Impressively, the full cell based on the Si/G@TNS-60 anode prelithiated by chemical solution technology and LiNi1/3Co1/3Mn1/3O2 as the cathode shows a raised ICE of 88.5% and maintains excellent cycle stability. This work fundamentally puts forward a facile and effective structural engineering strategy, highlighting the promising application potential of wire-cutting polysilicon waste in advanced LIB technology.