Waste to Wealth:\nS,N-Codoped Si/C Anode Derived from\nWaste Tire Oil Exhibits Superior Performance in Lithium-Ion Batteries

Integrating silicon (Si) nanoparticles with carbonous\nmaterials\nhas been regarded as an effective strategy to suppress the serious\nvolume expansion and poor electrical conductivity of the Si anode\nin lithium-ion batteries (LIBs). Herein, the Si/C composite coated\nwith a S,N-codoped graphene layer (Si@SNG) has been prepared via a\nfacile and easily scale-up strategy that combines the vertical fluidized-bed-derived\nchemical vapor deposition in which the lightweight waste tire pyrolysis\noil with high S content and pyridine is utilized as carbon source\nand dopants. The introduction of S,N-codoped graphene layer and graphite\nmatrix can effectively increase Li<sup>+</sup> storage room and conductivity,\nwhile buffering the volume expansion of pure Si. As result, the Si@SNG\nanode delivers a high initial Coulombic efficiency (ICE) of 86.91%,\nlarge specific capacity of 2446 mAh g<sup>–1</sup> at 0.3 A\ng<sup>–1</sup> and 90.3% capacity retention rate for 600 cycles\nwithin 0.01–1 V. In addition, the Si@SNG@G-P composite containing\nSi@SNG (10 wt %) and graphite matrix (90 wt %) has been\nprepared by ball milling and liquid-phase coating. As the anode, Si@SNG@G-P\nexhibits a high specific capacity of 695 mAh g<sup>–1</sup> at 0.05 A g<sup>–1</sup> coupled with 94.6% capacity retention\nrate for 500 cycles within 0.01–2 V. Moreover, the full cell\nassembled by Si@SNG@G-P anode and LiFePO<sub>4</sub> cathode shows\na high specific capacity of 157.7 and 128 mAh g<sup>–1</sup> at 0.2 and 4 C, 93.1% capacity retention for 200 cycles along with\na high energy density of 257.3 Wh kg<sup>–1</sup>. Therefore,\nthis work offers a low-cost and high-efficiency preparation strategy\nfor obtaining Si-based materials with outstanding electrochemical\nperformance in LIBs.