Flash upcycling of waste glass fibre-reinforced plastics to silicon carbide

The increasing use of fibre-reinforced plastics (FRPs) has triggered an urgent need for proper end-of-life management strategies. Currently, most adopted methods are landfilling, incineration and solvolysis, which lead to undesirable environmental contamination and waste of resources. To address this issue, we develop a solvent-free and energy-efficient flash upcycling method enabling ultrafast conversion of the mixture of different FRPs to SiC, a widely used reinforcement and semiconducting material, with high yields (>90%). By tuning operation conditions, SiC with two different phases, 3C-SiC and 6H-SiC, can be selectively synthesized with high phase purity (90–99%). The obtained SiC powders can be used as the anode material for lithium-ion batteries. The 3C-SiC anode exhibits superior reversible capacity and rate performance at 0.2 C over the 6H-SiC anode (741 mAh g−1 vs 626 mAh g−1), while both show good cycling stability. Life cycle assessment reveals that the flash upcycling method developed here greatly reduces the energy demand, greenhouse gas emissions and water consumption over other available FRP disposal methods. Overall, this work provides a viable method for sustainable management of end-of-life FRPs, contributing to clean production and circular economy.