Generation of high-aspect-ratio 3C-SiC nanowires and evaluation of their potential as battery materials

• Laser processing was used to synthesize silicon carbide nanowires from waste silicon. • Plume confined by two plates enhanced nanowire aspect ratio and yield • High plume density and temperature sustained nanowire growth. • Silicon carbide nanowires outperformed graphite and silicon in battery performance. Waste Silicon (Si) powder generated during semiconductor manufacturing has attracted attention as a potential anode material for lithium-ion batteries. This study proposes a novel method to fabricate high-aspect-ratio cubic silicon carbide (3C-SiC) nanowires using a mixture of waste Si and graphite powders through laser processing. The mixture is placed between two plates to sandwich the laser-induced plume. This confinement promotes nanowire growth, increases the aspect ratio, shortens the lithium-ion diffusion length, and enables the fabrication of flexible electrodes. High-speed camera observations confirmed that the sandwiched plume was compressed and remained in air for nearly 10 s. Consequently, nanowires approximately 100–1200 nm in length and 15–60 nm in diameter (aspect ratio greater than 25) were generated. Electron diffraction and XRD analyses revealed that the nanostructures mainly comprised 3C-SiC. Battery performance evaluation tests of the generated nanowires showed that after 10 charge–discharge cycles at a current density of 50 mA/g, the SiC nanowires exhibited a specific capacity of 455 mAh/g, significantly higher than that of Si nanoparticles (291 mAh/g) and comparable to that of C-coated SiC nanoparticles (477 mAh/g). The SiC nanowires outperformed both Si nanoparticles and graphite anodes, demonstrating the potential of the proposed method in next-generation lithium-ion battery (LIB) anode fabrication.