Recycling the Lithium-Ion Batteries from Electric Vehicles

By Abigail Lindner

Between 2019 and 2020, the sale of electric vehicles (EVs) rose 40%, to a record 3 million [9]. Estimates place over 10 million EVs on the road in 2020, and the International Energy Agency predicts that that number will be between 145 million and 230 million by 2030 [8]. The past five or so years have witnessed incredible growth in the EV market, bolstered by industry and government investments and scientific support. 

Compared to conventional, fossil fuel vehicles, EVs are associated with reductions in greenhouse gas (GHG) emissions and improvements in urban air quality. These environmental benefits, however, are dampened by the environmental waste problems that are expected to hit in ten to fifteen years with a “battery bomb” of used-up lithium-ion batteries (LIBs) [3].

The vast majority of EVs run on LIBs because lithium is lightweight, energy-dense, and durable for repeated recharging [11]. The average battery pack, based on conservative 2017 estimates, weighs over half a ton, about 250 kilograms or 550 pounds, and has a volume of half a cubic meter, approximately equivalent to thirty-five cubic feet. Sans interventions, the resultant battery pack waste when the batteries in all of the EVs sold in 2017 die would amount to 250,000 tons and over seventeen million cubic feet [6]. 

There is an obvious need to develop waste management efforts for EV batteries now.

Reasons to Recycle LIBs

In the waste management hierarchy, reuse is preferred over recycling. The most well-known reuse opportunity for LIB reuse is stationary energy storage. As EV production and sale is anticipated to grow by the millions each year, though, second-use avenues will be quickly exhausted. Moreover, even the batteries that filter through one or two rounds of reuse will eventually need to be recycled.

The advantages of recycling LIBs are primarily based on the costs, economic and otherwise, of mining virgin materials. Recycling is expected to reduce demand for primary materials and reduce or eliminate the environmental and social costs of new mining.

Consider an NMC532 lithium-ion battery. For metals, its composition requires 8 kilograms (about 18 pounds) of lithium, 35 kilograms (about 77 pounds) of nickel, 20 kilograms (about 44 pounds) of manganese, and 14 kilograms (about 31 pounds) cobalt [2]. In addition, EVs require a substantial amount of copper - at least nine times as much as traditional vehicles with internal combustion engines [7].

Some of these metals are mined and processed in the United States; the country is, for instance, one of the leading producers of copper. However, the majority of other metals, including cobalt and lithium, come from international sources. Chief among these is cobalt, the most rare and expensive metal in LIBs [1]. About two-thirds of the global supply of cobalt is mined in the Democratic Republic of the Congo, a country mired by human rights abuse [2]. Moreover, most LIB production happens in the East Asian countries of China, Japan, and South Korea [2]. 

Researchers at Earthworks, an environmental nonprofit focused on mineral and energy development and sustainable solutions, studied the potential for recycling to reduce demand for new mining. They calculated the recycling could significantly contribute to a decrease in total demand for primary metals in 2040. Specifically, recycling could reduce demand for lithium by 25%, cobalt by 35%, and copper by 55% [4].

As EV use increases with improving technology and accessibility, the importance of the metals for LIBs will rise, and sellers in the United States would be hamstrung if the main providers of those metals, many overseas, reduced or cut production. Recovering these valuable metals via recycling would create a more stable supply chain that can withstand vulnerable links and supply risks [6]. This secondary source of metals could insulate the EV industry from shockwaves caused by conflict within the countries mining the primary materials or producing the lithium-ion batteries; or from tension between the United States and these countries. In the case of cobalt in the Democratic Republic of the Congo, lessening dependence on virgin metals will also make the EV supply chain more ethical.

Beyond the supply chain advantages of LIB recycling, there are environmental and social benefits. On the environmental side, mining is among the most polluting industries, affecting both air and water [10]. For lithium, there are two main natural sources of the metal: mineral ore and mineral-rich brine. The former is energy-intensive and the latter is water-intensive [2]. U.S.-based mining efforts in Nevada, for instance, cross into land used by American Indian tribe members and ranchers. The lithium extraction operations may consume billions of gallons of groundwater that humans and cattle living on the land need [11].

It takes tons of either - mineral ore and mineral-rich brine - for a single ton of lithium. Specifically, if mining mineral ore, 250 tons are needed to produce one ton of lithium; if using mineral-rich brine, 750 tons are needed [6]. In contrast, twenty-eight tons of used, recycled lithium-ion batteries could theoretically produce one ton of lithium. That amounts to millions of tons of conserved ore, brine, and water. 

Barriers to Recycling

Despite the numerous advantages to recycling lithium-ion batteries, there are legitimate economic and technological barriers.

On the economic front, while the EV industry has grown significantly in the past two decades, it still lacks a strong economic driver to recycle used LIBs [4]. To take full advantage of the materials-saving potential of recycling, a coordinated policy framework for collection, transportation, design, and quality assurance and liability is needed, but this amount of industry reorganization has not been enacted at a large scale because, except for cobalt, it is often easier to construct virgin batteries from new materials than to reuse old ones [1, 7]. 

The price discrepancy exists because, through the 20th century, mining innovations have made the process of extracting metals from the earth less expensive and because the process of extracting metals from spent LIBs remains relatively expensive.

On the technological front, there are difficulties in transporting, storing, manually testing, and dismantling LIBs. Unlike the toaster-oven-sized lead-acid batteries used in conventional vehicles, lithium-ion batteries are sizable, thick plates that often span the length and width of a car. Given their size and weight, transportation costs are high, accounting for about 40% of the total recycling cost [1]. Then, when they are transported, LIBs present risks in storage because their materials, including metals and organic chemicals, used in them are highly reactive, with risk of fires, and toxic [1, 6]. Storing tons of LIBs in anticipation of improved extraction technologies is not a safe, long-term option.

These same dangers in storage arise in testing and dismantling. Dana Thompson of the University of Leicester, a PhD researcher focused on LIB recycling, warns, “Cut too deep into a Tesla cell, or in the wrong place, and it can short-circuit, combust, and release toxic fumes” [7]. Careful disassembly requires skilled auto-technicians with high-voltage training and insulated tools, who are scarce [1, 6]. Moreover, the wide differences in construction and the constant evolution of cathode chemistry make it near impossible to establish a standard framework for this work [2, 7].

Current Battery Recycling Efforts

EV batteries are typically composed of a main pack that contains several modules. The modules have numerous smaller cells, inside which “lithium atoms move through an electrolyte between a graphite anode and a cathode sheet composed of a metal oxide” [10]. The cathode contains the valuable metals that make electric vehicles possible.

The three main LIB recycling methods are pyrometallurgy, hydrometallurgy, and direct recycling. In pyrometallurgy, battery cells are mechanically separated, then burned into a charred black mass from which the metals can be extracted. In hydrometallurgy, the batteries are dunked into pools of acid to make a “metal-laden soup” [10]. Both metallurgical techniques destroy the cathode. In direct recycling, the cathode is kept intact. Of the three, pyrometallurgy and hydrometallurgy are most technologically accessible as of writing [6]. (A concise comparison of these methods is available from Harper et al. (2019) in Figure 6.)

Much technological investment is being funneled into discovering better recycling strategies. U.S.-based organizations aimed at improving EV battery recycling include the ReCell Center at the Argonne National Laboratory, launched and funded by the U.S. Department of Energy; and advanced battery pack manufacturer Spiers New Technologies in Oklahoma.

In Massachusetts, Ascend Elements is making strides in LIB recycling. Founded in 2015 under the name Battery Resources and currently based in Westborough, Ascend takes spent LIBs and upcycles them into a value-added product using their patented Hydro-to-Cathode technology [5]. This technology was developed by Worcester Polytechnic Institute professor Dr. Yan Wang, WPI Metal Processing Institute founder Diran Apelian, and former post-doc student Eric Gratz. The company claims that their process recovers “almost 100% of the metals and produces no toxic waste” [5].

In addition to improving recycling technologies, companies must also improve battery technologies. It will be important that EV manufacturers design batteries with recycling in mind now [10]. Helpful changes include development of a manufacturer labeling system so that dismantlers know what type of battery they’re dealing with and, thus, what method will be safest and most effective in breaking the metals down; and removal of the glues and wires that hold LIBs together and complicate or make near-impossible disassembly today.

It remains expensive to recycle - or, in Ascend’s case, upcycle - LIBs, but materials scientists and chemical engineers expect that, as EV use increases, economies of scale will kick in to drive down recycling costs and make recycling more attractive [1, 2].

Conclusion

Work remains to be done for the responsible reuse and recycling of batteries. To reduce fossil fuel dependence, it is not enough to simply replace fossil fuel-run vehicles with electric vehicles. In addition to the energy demands of EV construction, the fossil fuel dependence of many electric grids, and other pre-production- and production-relevant points, processes are needed to recycle the millions of lithium-ion batteries that will eventually die in the millions of new EVs expected to be on the road each year.

Recycled LIBs have the potential to provide a majority of the metals for new batteries, reducing or eliminating new mining and the accompanying environmental and social harms. Materials scientists and engineers around the world are developing and streamlining recycling processes; governments and private companies and individuals, recognizing the potential and positive trajectory of electric vehicles, are investing millions into these endeavors. There is hope that the technology necessary to make EVs cleaner, at least on the end-of-life battery side, will become more technologically and financially accessible.

Works Cited

1. Barber, G. & Marshall, A. (2021, November 2). Cars are going electric. What happens to the used batteries? Wired. Retrieved 2022, June 5, from https://www.wired.com/story/cars-going-electric-what-happens-used-batteries/.
2. Castelvecchi, D. (2021). Electric cars and batteries: how will the world produce enough? Nature, 596, 226-229. https://doi.org/10.1038/d41586-021-02222-1.
3. Cooley, B. (2022, May 21). Why electric car battery recycling matters as much as the cars themselves. CNET. Retrieved 2022, June 5, from https://www.cnet.com/roadshow/news/why-electric-car-battery-recycling-matters-as-much-as-the-cars-themselves/.
4. Dominish, E., Florin, N. & Wakefield-Rann, R. (2021). Reducing new mining for electric vehicle battery metals: responsible sourcing through demand reduction strategies and recycling. Report prepared for Earthworks by the Institute for Sustainable Futures, University of Technology Sydney. Retrieved 2022, June 5, from https://earthworks.org/publications/recycle-dont-mine/.
5. Gellerman, B. (2022, January 25). Mass. startup transforms old electric car batteries into better-than-new ones. WBUR. Retrieved 2022, June 5, from https://www.wbur.org/news/2022/01/25/lithium-ion-battery-recycling-electric-vehicles.
6. Harper, G., Somerville, R., Kendrick, E., Driscoll, L., Slater, P., Stolkin, R., Walton, A., Christensen, P., Heidrich, O., Lambert, S., Abbott, A., Ryder, K., Gaines, L. & Anderson, P. (2019). Recycling lithium-ion batteries from electric vehicles. Nature, 575, 75-86. https://doi.org/10.1038/s41586-019-1682-5.
7. IDTechEx. (2017, June). The electric vehicle market and copper demand. International Copper Association. https://copperalliance.org/wp-content/uploads/2017/06/2017.06-E-Mobility-Factsheet-1.pdf.
8. International Energy Agency. (2021, April). Global outlook 2021: Technology report - April 2021. https://www.iea.org/reports/global-ev-outlook-2021.
9. International Energy Agency. (2021, November). Electrical vehicles: Tracking report - November 2021. https://www.iea.org/reports/electric-vehicles.
10. Morse, I. (2021, May 20). A dead battery dilemma. Science. Retrieved 2022, June 5, from  https://www.science.org/content/article/millions-electric-cars-are-coming-what-happens-all-dead-batteries.
11. Penn, I. & Lipton, E. (2021, May 6). The lithium gold rush: Inside the race to power electric vehicles. The New York Times. Retrieved 2022, June 5, from https://www.nytimes.com/2021/05/06/business/lithium-mining-race.html.