Generation of Si@C/SiC@C core–shell nanoparticles by laser irradiation of silicon grinding waste

Abstract

AbstractIn recent years, the demand for lithium‐ion batteries has increased because of the global focus on carbon neutrality. Silicon/carbon (Si/C) composite nanoparticles have potential for application as high‐performance anode materials in lithium‐ion batteries, which can enable the widespread use of lithium‐ion batteries or lithium‐ion capacitors and contribute toward decarbonized society. In this study, Si@C/SiC@C core–shell nanoparticles with sizes in the range of 10–40 nm were produced by pulsed laser irradiation (wavelength = 1070 nm; pulse width = 10 ms) of a mixture of graphite powder and waste Si powder discharged from the grinding process of Si wafers. High‐speed camera observations of the laser‐induced plume were conducted to elucidate the nanoparticle generation mechanism, and it was determined that Si/SiC nanoparticles were formed within the laser‐induced plume in the early stage of laser irradiation. Si and C demonstrated different plume propagation patterns and plume decay times, and the time difference enabled the coating of the generated Si/SiC nanoparticles with a thin layer of graphene, forming core–shell hybrid structures. The electron diffraction results revealed that the generated nanoparticles were mainly composed of 3C‐SiC@C core shells, which is a novel nanomaterial with promising applications as anode materials for future lithium‐ion batteries.