Eco‐Efficiency Analysis of a Lithium‐Ion Battery Waste Hierarchy Inspired by Circular Economy

Abstract

Summary: A circular economy (CE)‐inspired waste management hierarchy was proposed for end‐of‐life (EOL) lithium‐ion batteries (LIBs) from electric vehicles (EVs). Life cycle eco‐efficiency metrics were then applied to evaluate potential environmental and economic trade‐offs that may result from managing 1,000 end‐of‐life EV battery packs in the United States according to this CE hierarchy. Results indicate that if technology and markets support reuse of LIBs in used EVs, the net benefit would be 200,000 megajoules of recouped cumulative energy demand, which is equivalent to avoiding the production of 11 new EV battery packs (18 kilowatt‐hours each). However, these benefits are magnified almost tenfold when retired EV LIBs are cascaded in a second use for stationary energy storage, thereby replacing the need to produce and use less‐efficient lead‐acid batteries. Reuse and cascaded use can also provide EV owners and the utility sector with cost savings, although the magnitude of future economic benefits is uncertain, given that future prices of battery systems are still unknown. In spite of these benefits, waste policies do not currently emphasize CE strategies like reuse and cascaded use for batteries. Though loop‐closing LIB recycling provides valuable metal recovery, it can prove nonprofitable if high recycling costs persist. Although much attention has been placed on landfill disposal bans for batteries, results actually indicate that direct and cascaded reuse, followed by recycling, can together reduce eco‐toxicity burdens to a much greater degree than landfill bans alone. Findings underscore the importance of life cycle and eco‐efficiency analysis to understand at what point in a CE hierarchy the greatest environmental benefits are accrued and identify policies and mechanisms to increase feasibility of the proposed system.