Recycling Silicon Cutting Waste from Photovoltaic Industry into High-Performance Anodes for Lithium-Ion Batteries

The photovoltaic (PV) industry annually generates substantial quantities of silicon cutting waste (SCW), posing significant environmental pressure and leading to considerable resource wastage. To address this issue and capitalize on wasted high-purity silicon, a novel, highly dispersed Si-based composite from SCW was developed for use as a high-performance anode in lithium-ion batteries. This study presents a novel approach for the fabrication of a composite material comprising SCW-derived silicon nanoparticles (SiNPs) and carbon nanotubes (CNTs) embedded within a carbon nanofiber (CNFs) network (Si/CNTs@CNFs). SCW was subjected to acid washing, high-temperature pyrolysis, and ball milling to produce nanoscale SiNPs. These SiNPs were then mixed with CNTs to produce Si/CNTs@CNFs via a modified electrospinning process, in which poly(vinylpyrrolidone) (PVP) was used as a stabilizing agent to prevent the agglomeration of SiNPs. This ensured that both SiNPs and CNTs were uniformly dispersed throughout the interconnected CNFs, leading to enhanced electrical conductivity, improved structural stability, and better electrochemical performance for this Si-based anode. The highly dispersed Si/CNTs@CNFs composite material exhibits a reversible capacity of 571.5 mAh g–1 after 200 cycles at a current density of 1 A g–1, showcasing superior electrical performance compared to samples without PVP or without ball milling. This study presents a novel pathway for recycling silicon cutting waste from the solar PV industry, thereby contributing to sustainability and the advancement of renewable energy resources.