Sustainable regeneration of cathode active materials from spent lithium-ion batteries by repurposing waste coffee powder†

To develop sustainable recycling methods for spent lithium-ion batteries (LIBs), the use of renewable materials and minimizing energy consumption are essential. Here, we propose a biomass-based, energy-intensive reduction method to recover Li and Co from spent LIBs. Waste coffee powder was used as a biomass to provide carbon and reducing gas during the reduction process. During selective thermal transformation, the carbon and reducing gas derived from waste coffee powder converted the cathode material of LIBs LiCoO₂ into Li₂CO₃ and Co/CoO, recovering 89.23% of Li and 93.27% of Co. Compared to the conventional carbothermic reduction process, this transformation occurred at a lower temperature (600 °C) due to the synergetic effect of reducing gas and carbon. Moreover, LiCoO₂ was regenerated from the recovered Li₂CO₃ and Co/CoO, demonstrating excellent electrochemical performances in terms of charge–discharge capacity, cyclic performance, rate performance, EIS, and CV curve analysis. An EverBatt-based environmental and economic analysis shows that this reduction method reduces greenhouse gas (GHS) emissions and energy consumption, making it economically viable. Overall, this research offers an eco-friendly and energy-efficient method to recycle spent LIBs using waste biomass. Additionally, this study will contribute to achieving several Sustainable Development Goals (SDGs).