Economic and environmental feasibility assessment of emerging biometallurgical recycling methods for spent electric-vehicle batteries

Efficient recycling of valuable metals from spent electric vehicle (EV) batteries is critical for improving the stability of the raw material supply and achieving sustainable development. Currently, the predominant methods for recycling spent EV batteries include pyrometallurgical and hydrometallurgical recycling, but neither is efficient in saving energy and mitigating pollution. Emerging biometallurgical recycling methods provide a promising alternative to conventional techniques by eliminating the need for additional toxic chemicals, thus reducing operational costs and pollution emissions. Despite their potential advantages for metal recovery from spent EV batteries, they have not been widely adopted in the industry due to uncertain economic and environmental feasibility. Thus, this study presents a comprehensive feasibility assessment of biometallurgical recycling methods for spent EV batteries based on economic benefits and environmental impacts. The economic benefits are analyzed using an integrated system dynamics (SD) and cost-benefit analysis (CBA) approach to address system complexity and the time delay impact. Moreover, the life cycle assessment (LCA) model estimates 12 environmental impact categories using the ReCiPe characterization method. From the economic perspective, biometallurgical methods are more economically feasible than hydrometallurgy and pyrometallurgy, with 16 % and 27 % greater profits, respectively. Sensitivity analysis indicates that profitability is prominently influenced by the market price volatility of recovered metals, especially cobalt, and battery type variability. Furthermore, higher operating efficiencies and additional cost reductions can be achieved through economies of scale, thereby enhancing recycling profitability. From the environmental perspective, biometallurgical recycling of spent EV batteries is more environmentally sustainable than conventional methods due to reduced chemical reagents and energy consumption. For instance, biometallurgical recycling has a global warming potential (GWP) of 6.26 kg CO2 eq./kg, which can effectively reduce emissions by 6.4 and 9.5 kg CO2 eq./kg compared to conventional methods, respectively. Overall, this work will help governments and businesses select the most sustainable recycling method, thereby promoting sustainable development of the battery industry.