The volumetric expansion of silicon anodes in lithium-ion batteries leads to a shortened cycling life and rapid capacity decay.Consequently,it is imperative to enhance the cyclic stability of silicon anode materials.In this study,we employed a molten salt-assisted magnesiothermic reduction method and successfully devised a silicon nanomaterial reinforced with silicon carbide(SF-Si)by utilizing silica fume containing elemental carbon,which is an industrial solid waste.The resulting SF-Si sample not only retained the SiC present in the silica fume but also converted the elemental carbon into SiC,achieving a SiC content of 16.4％(mass fraction).Comparative analysis with silicon material prepared from heat-treated silica fume without elemental carbon removal(H-SF-Si)revealed that SF-Si exhibited superior cyclic and rate performance.It attained a high specific capacity of 2 584.76 mAh·g-1 in the first cycle,maintained an 83％capacity retention after 100 cycles,and even at a high current density of 5 A·g-1,the average capacity remained at 877.28 mAh·g-1.These enhancements were primarily attributed to the higher SiC content.The study underscores the potential application of silica fume in the domain of silicon anodes for lithium-ion batteries,with its carbon element playing a constructive role in the preparation of silicon-based nanomaterials.
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