The race to close the EV battery recycling loop

The race to close the EV battery recycling loop thumbnail

IN LATE OCTOBER 2019, a fire broke out at a recycling facility in Scottsdale, Arizona. The blaze consumed a 40,000-square-foot site, and 60-mile-per-hour winds blew a massive smoke plume across a nearby highway, forcing local officials to close the road. The fire was extinguished by firefighters the next day. In the aftermath, the company that operated the site had to suspend collection in nearby cities; the scorched compound had been equipped to handle 85,000 tons of waste a year, and now that junk had nowhere to go except a landfill.

The culprit? A lithium-ion battery, similar to those found in laptops and phones. These cells are generally safe but they can still store volatile energy after they die. This can lead to explosions and fires. A 2021 report from the Environmental Protection Agency found public records of such conflagrations in 28 states between 2013 and 2020, and flagged one facility that had had more than a dozen in a single year. The risk will only grow: The global lithium market can be expected to multiply by a factor of 20 by 2030, according to an estimate from research firm Rystad Energy.

The fact that so many batteries end-up in scrap heaps is a serious problem for the transition to fossil fuels is even more concerning. Although they are an essential component of electric vehicles’, the metals they contain, such as nickel, cobalt, or lithium, are becoming increasingly difficult to find and often only come from a few countries. The next generation of EVs will require the extraction of thousands of tons of lithium, cobalt and other minerals from salt flats around the globe. This is a costly and environmentally destructive process.

” We should recycle everything we can, but in this case of batteries it’s even more important,” says Fengqi You (an engineering professor at Cornell University) who studies the life cycle of elements such as lithium within energy systems. You point out that the domestic EV industry is dependent on lithium that is extracted and refined in other countries around the globe, which means that we have little control over the production of vital materials. If the global supply chain is disrupted, then our access to these precious metals will be affected, putting a halt to efforts to develop green technologies.

Part of Ascend Elements’ battery recycling process
This machine leaches impurities out of shredded batteries, leaving behind lithium, nickel, cobalt, and graphite. Ryan Roddick

The good news is that the dead can rise again. Old batteries, like the one that sparked the fire in Scottsdale, are full of key metals that can be pulled out and pumped back into supply chains. We could dramatically reduce the amount required to supply metal for new cells by establishing the right infrastructure. This would also reduce the risk of literal dumpster fires.

As electric vehicles take off in the US, there are a few startups that are trying to make it happen. Ascend Elements is one of the most advanced and will open a huge battery recycling facility in Georgia this year. It will be able to recover nickel, cobalt and lithium. Other companies are following suit. These companies are working together to scale up before the first EVs are scrapped. Their efforts could close the loop and create a system that is less dependent upon fossil fuels and unnecessary mining.

BRITISH-AMERICAN chemist M. Stanley Whittingham outlined the first conceptual framework for a rechargeable lithium-ion battery in the late 1970s, winning a Nobel for his efforts in 2019. Over the next ten years, his core technology was further developed by entities ranging from NASA to Oxford University. But the concept didn’t go commercial until 1991, when Sony started using the cells to bump up the life of its camcorders. The energy density such batteries can hold has almost tripled since then, and the price of producing them has fallen by more than 97 percent within that same period, from around $7,500 in 1991 to less than $200 in 2018.

All batteries store chemical energy and convert it to electricity. An ordinary cell has two terminals that contain different conductive metals. The anode is the negative side and the cathode the positive side. The electrolyte is a chemical medium that separates these two components. The anode’s electrons are attracted to the positive charge and flow out of the device when you turn it on. The electrons’ movement in the circuit is what creates juice.

This process cannot be reversed with an ordinary battery. The whole thing will die if there are enough electrons left in excess. The lithium-ion battery, however, has a longer life due to its titular element, which is one the lightest and most reactive elements on the periodic table. A bunch of lithium atoms can be found in the cathode in an uncharged state. Plugging your device into a power source causes those reactive lithium atoms to quickly surrender their electrons. They move through the external circuit and then come to rest in the anode. The key advantage is that these leaving electrons leave behind positively charged lithium ions. These ions are then drawn toward the anode by the negative charge of power source through electrolyte. The process reverses when you turn off your device and disconnect it from the power source. The electrolyte is reversible. The lithium ions, which are naturally unstable, move back through the electrolyte and return to the cathode. Meanwhile, the electrons move to combine them, generating electricity. The electrons and ions remain in the cathode while the battery charges again.

Machine extracts minerals from old batteries
Ascend Elements’ machinery recovers graphite from shredded lithium-ion batteries for sale to traditional recyclers. Ryan Roddick

The structure of the metal cathode is crucial to the battery’s durability. It acts as an atomic lasagna made of metals like nickel, cobalt, and thin enough that electrons and lithium ions can get trapped between them. The ions moving back and forth across the battery can cause this lasagna to distort, causing it to swell or crack. Each charge cycle triggers a variety of uncontrolled chemical reactions that slowly degrade the battery. This is similar to how our bodies age. Although you can’t usually see the decay with your naked eye, it will become more difficult for the power cell to move energy over time. An average lithium-ion battery can last a few thousand charges before it begins to wither. The battery will still retain charge even after that, which is why they are so flammable as the molders. )

The rapid growth of the electric vehicle industry has led to a surge in demand and supply for metals, including the lithium. There has been a boom in mining in certain countries, such as Australia, Chile, and China. Worldwide production tripled from 31,000 tons a year in 2010 to 110,000 in 2021. But with the global EV market growing around 20 percent each year, demand is rising much too fast for any producer to keep up. The International Energy Agency predicts annual lithium production could fall short of demand by nearly 2 million tons by 2030. Although there are at least three to four continents that have the potential for mining the metal, nearly all of the factories and refineries are located in China. This creates a classic bottleneck. Research firm Rystad Energy claims that if the metal’s production capacity doesn’t increase, the price could triple by the end the next decade.

A rising demand also leads to higher environmental costs. Companies use tens to billions of gallons per year to extract the metal from the ground, straining resources already scarce in countries like Chile. There have been numerous reports of freshwater depletion and contamination, fish kills, and contamination at lithium mines in Tibet, Argentina, the United States.

All these factors increase the need for recycling. Although lithium-ion batteries were not economically viable enough to recycle, a few organizations tried to keep them out the landfills, including Call2Recycle, Inc. Founded and funded by major battery manufacturers in the 1990s in the hopes of mitigating the environmental risks (and legal liability) posed by their products, the nonprofit has since spun up a collection program that draws refuse from three main sources: repair centers, municipal waste facilities, and a network of 16,000 public-facing drop boxes across the United States. It collected more than 8,000,000 pounds of discarded cell last year.

Scientist checks liquid for metals
Dhiren Mistry, a battery materials engineer at Ascend Elements, tests an aqueous solution containing recovered metals. Ryan Roddick

“When the program started, the dominant battery chemistry was nickel-cadmium,” Eric Frederickson, the program’s managing director of operations, said. He refers to a type cell that is often used in bulky but portable power tools. He says that “lithium ion” is the largest chemistry of batteries we have .”


For a long time, the US’s capacity to recycle lithium was so limited that Call2Recycle had no choice but to ship its scraps overseas. There’s now a new customer, one that promises to transform these scraps into new EV power cells.

ASCEND ELEMENTS’ research and development facility sits in a nondescript office park just outside Worcester, Massachusetts. You’d be able to see that the majority of people within this building spend their time on computers if you were to stand outside. The truth is a bit more complicated. The front office leads into a warehouse, where the company has been perfecting its lithium-ion batteries recycling process and preparing for scaling it up.

Ascend is based on its own interpretation of hydrometallurgy. This involves dissolving the metals in a chemical solution, and then letting them dissolve back into solids. It’s an improvement over the less elegant pyrometallurgy which involves smelting batteries and seperating out superheated components. This can create toxic gases such as dioxins or furans.

After giving me safety glasses, Eric Gratz (Ascend’s cofounder and chief technology officer), shows me how it all works. He yells at me to stop the constant whine from the generator and leads me into a high-ceilinged area dominated by a dozen interconnected machines and tanks. There are three steel vats towering over us, a pair of 10-foot-long contraptions that look like accordions, and a set of several smaller tanks connected by pipes and tubes.

The machinery works together, Gratz claims, like a giant French press coffee machine. Ascend purchases dead batteries from collectors such as Call2Recycle and EV manufacturers. Then, it grinds them up in an ultra-fine-toothed shredder. The Worcester facility receives the residue as a dark powder (or “black mass” in industry parlance) that is used in chemical brews. The goal is to liquefy and remove any impurities, modify the chemical structure, and then condense it back into powder for new manufacturing.

FirstGratz takes me to the trio vats. Behind them is a hopper containing the shredded batteries. Step one is to pipe the black substance into the vats. It will dissolve in a proprietary chemical mix, releasing the atomic structure for the cobalt, nickel, and lithium. This part isn’t difficult. It’s all about turning it back into powder.

Ascend would like to produce material for new batteries–the positive side–since it’s the most difficult to find. As pulverized batteries can contain many different metals, some which aren’t useful, Ascend must first separate any that it doesn’t need. We reach the accordion-like machines by tiptoeing about lab techs, who bustle back and forth. The black-mass slurry is pumped through a series of filter panels, which strain out any non-essential solids. It’s like pushing down the grounds in an old French press. Ascend packages these items and sells them to traditional recyclers.

The next step is to separate and separate the mixture into two key components: lithium and a melange containing nickel, cobalt and manganese. Ascend’s exact process is proprietary. This is part of what differentiates the company from other companies. However, Gratz allows that the company takes advantage of lithium’s unique chemistry. While most metals will dissolve more easily when heated, lithium is less likely to dissolve at higher temperatures. The team can heat the mixture to isolate the important metal. The resulting granules are similar to salt that you would keep in an ordinary shaker.

Then they precipitate the black mass back into powder, another proprietary process, this one taking place in a set of machines that look like older-generation droids from Star Wars–big, boxy trapezoids with little doodads on top. Ascend can adjust the nickel and cobalt concentrations to meet the needs of customers. For example, a battery with more nickel has a shorter shelf-life but can hold more energy. This makes it great for vehicles that have to travel hundreds of kilometers. The final product is identical to the one it came in once the powder has been mixed with the extracted lithium. This can be seen by the Gratz-given jars. The molecular structure of this recycled powder has been rejuvenated and is now ready to store hyperreactive lithiumions.

The process is remarkably efficient: Ascend recovers 98 percent of the most expensive metals, nickel and cobalt. For lithium, Gratz says, that figure is more like 80 percent. The factory’s black powder is ready to roll. The substance is usually sprayed on foil and then rolled or folded into new battery cells by battery manufacturers.

COMPLICATED AS Ascend’s operation in Worcester may seem, it’s just a prototype for a 154,000-square-foot battery recycling plant set to open near Atlanta in the summer of 2022. This operation will be at the heart of the EV boom in the Southeastern US. Volkswagen will soon open an electric vehicle division at Chattanooga’s plant. Ford is also building an assembly plant as well as multiple battery factories in Kentucky and Tennessee. Although Ascend’s facility will not be operational for a few months, manufacturers such as SK Battery America, who help power heavy hitters such as Ford and Volkswagen have already begun to ship pallets of manufacturing scrap. It’s growing by the tons, and is just waiting for the right moment to hit the roads.

When it’s up and running, Ascend’s Georgia plant will be able to turn around 33,000 tons of dead batteries and other waste per year, resulting in enough recycled metal to spark up to 70,000 EVs. Vice president of marketing Roger Lin explained that auto manufacturers can sign a one-way contract to purchase the reconstituted material from dead electric vehicle cells. Or they could make a two-way agreement to get excess scraps from their factories back in a revived state. Ascend could also buy the dead batteries from auto makers and create new material for anyone who requests it.

Mike O’Kronley, CEO of

Ascend, is confident that the old EV batteries that his plant will rely on won’t end-up like so many forgotten cell phone numbers stashed in drawers. He says that one EV battery is equal to a thousand cell phones. He says it’s easier to collect them and transport them to a recycling center than to shredders or junkyards.

Though Ascend may have the head start in lining up customers, it does face strong competition: Li-Cycle, a Canadian recycler building a plant near Rochester, New York, and Redwood Materials, a company founded by Tesla’s former CTO. Both companies are expanding their systems using hydrometallurgical processes similar as Ascend’s.

At the moment, there are not enough EVs that have been retired to provide the required quantity of batteries to meet the demand. “If we recycled every battery in the world, the most recycling can provide is maybe 20 to 30 percent of the demand,” says Ascend CTO Gratz. We will need to continue mining significant amounts cobalt, nickel, and lithium to ensure that there are more EVs on roads.

Ascend is betting that the majority of people will eventually drive EVs and turn in their old ones to make way for new models. “Then,” Gratz states, “we can keep recycling the same nickel, cobalt, and lithium atoms over-and-over

This story originally ran in the Summer 2022 Metal issue of PopSci, as the third in a three-part series about batteries. Read part one and part two or more PopSci stories.

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