Life cycle assessment of lithium-ion battery recycling using pyrometallurgical technologies

Among existing and emerging technologies to recycle spent lithium-ion batteries (LIBs) from electric vehicles, pyrometallurgical processes are commercially used. However, very little is known about their environmental and energy impacts. In this study, three pyrometallurgical technologies are analyzed and compared in terms of global warming potential (GWP) and cumulative energy demand (CED), namely: an emerging direct current (DC) plasma smelting technology (Sc-1), the same DC plasma technology but with an additional pre-treatment stage (Sc-2), and a more commercially mature ultrahigh temperature (UHT) furnace (Sc-3). The net impacts for the recovered metals are calculated using both open-loop and closed-loop recycling options. Results reveal that shifting from the UHT furnace technology (Sc-3) to the DC plasma technology could reduce the GWP of the recycling process by up to a factor of 5 (when employing pre-treatment, as is the case with Sc-2). Results also vary across factors, for example, different metal recovery rates, carbon/energy intensity of the electricity grid (in Sc-1 and Sc-2), rates of aluminum recovery (in Sc-2), and sources of coke (in Sc-3). However, the sensitivity analysis showed that these factors do not change the best option which was determined before (as Sc-2) except in a few cases for CED. Overall, the research methodology and application presented by this life cycle assessment informs future energy and environmental impact assessment studies that want to assess existing recycling processes of LIB or other emerging technologies.

Automated summary

This study analyzed and compared three pyrometallurgical technologies for recycling spent lithium-ion batteries in terms of global warming potential and cumulative energy demand. Results show that shifting to DC plasma technology could significantly reduce the environmental impacts. Factors such as metal recovery rates and energy intensity of the electricity grid affect the results, but the best option remains the same.