Upcycling of silicon scrap collected from photovoltaic cell manufacturing process for lithium-ion batteries via transferred arc thermal plasma

As the supply of photovoltaic industry products increases rapidly, measures to solve the upcoming related waste problem are urgently required. In particular, the fabrication process of Si wafers leads to significant Si scrap residue, and approximately 40% of crystalline Si ingots are wasted as Si scrap. Here, a feasibility study was conducted to investigate the recycling of Si scrap waste collected during the solar panel manufacturing process using the transferred arc thermal plasma. Si-NP with a particle size of 100 nm or less applicable as an anode material for lithium-ion batteries (LIBs) was successfully upcycled by the transferable arc thermal plasma method, and the developed LIB showed excellent electrochemical performance. Si-NPs electrodes show a discharge capacity of 2920 mAh g−1 at 0.1 A g−1, and 2167 mAh g−1 at 0.4 A g−1. In addition, silicon-graphite (Si-G) composites were also prepared to improve the electrochemical properties of LIBs. Furthermore, the possible pros and cons of the method proposed in this study were discussed including economic evaluation. These results show that the transferred arc thermal plasma is a simple, eco-friendly, and cost-effective method of upcycling Si-NPs anode material from Si scrap waste for high-performance LIBs.