Environmental hotspots and greenhouse gas reduction potential for different lithium-ion battery recovery strategies

The ever-growing demand for lithium-ion batteries (LIBs) and the shortage of metal minerals have led to urgent needs in battery recycling. Current recycling technologies cannot keep up with the exaltation of the LIB market and meet UN Sustainable Development Goals (SDGs). A holistic assessment of environmental tradeoffs is critical for recycling technological innovation. We divided traditional hydrometallurgy and pyrometallurgy recycling into three generalized phases and identified stepwise environmental “hotspots” among different LIB recycling techniques using life cycle assessment (LCA). Greenhouse gas (GHG) emission and cumulative energy demand (CED) vary among recycling approaches from 67 to 286 kg carbon dioxide equivalent (CO2eq) and 1164–4349 MJ, respectively, for reproducing 1 kg LCO cathode from recovered cobalt. Comparatively, a direct “cathode-healing” process emits 21–154 kg CO2eq and utilizes 267–2251 MJ to regenerate 1 kg LCO. When substituting the stepwise recycling with the direct approach, 127 of 162 modeled scenarios show GHG reduction. Up to 36.5 million metric tons of CO2eq may be reduced if 100% stepwise recycling is replaced by the green direct approach by 2025. Our study provides insights into optimizing LIB recovery technologies to minimize environmental impacts and offer quantitative evidence for sustainable management and technological innovation for spent LIB recovery.