What Happens To Used EV Batteries (And Can They Be Recycled)

Electric vehicles have the same expected lifespan as combustion-engine vehicles, at around 15 years. However, their batteries don't last nearly as long. Typical warranties for electric vehicle (EV) batteries are 8 to 10 years, meaning the average EV will need a complete battery replacement at least once in its working life. That raises the question: What happens to those massive batteries once they reach their expiration date?

The good news is that much of an EV battery can be recycled. The bad news is that many parts in an EV battery can't be recycled. Lithium, for example, is notoriously difficult to process for reuse, and estimates for its rate of recycling vary wildly. Because of such challenges in recycling, it's not uncommon for an entire EV battery to get tossed in the trash. However, some experts predict that game-changing breakthroughs for the EV industry in the coming years will improve the efficiency and lifespans of new EV batteries, which would mean less e-waste. Development of novel battery technologies may also produce more sustainable and environmentally friendly designs.

Even though the future of EV battery recycling is optimistic, the fate of any one EV battery today depends on many factors. Currently, the industry's reliance on lithium and other non-recyclable materials means no EV battery in operation today will ever be 100% recycled. Thus, if you want to know what will happen to your EV's half-ton battery, you'll have to break down its parts to see what gets recycled.

When an EV battery gets recycled, only some of the parts are extracted, while the rest get thrown away. The reason is twofold. For one, some materials like graphite are too cheap for recycling to make economic sense. Other materials are hard to recycle. Lithium recycling, for example, has a risk of releasing toxic chemicals and even exploding, with a small margin for error.

The most precious metals in EV batteries are always the first to get extracted. These are typically found in the battery's cathode. The cathode is the part of a battery that acts as a positive terminal and can contain valuable elements like nickel, cobalt, and manganese. Such metals are present in small quantities, but their high value makes extracting them worth the hassle. And a hassle it is. Cathodes are composed of numerous metal alloys, so separating the different elements and refining them into pure ingots requires intense chemical processes. The two most common such extraction processes are pyrometallurgy and hydrometallurgy.

As the name suggests, pyrometallurgy ignites the battery at a high temperature, which burns away non-valuables like plastic and liquifies the metal. Further heat may then be applied to extract the precious metals. Hydrometallurgy involves soaking the materials in acid. Such processes result in toxic byproducts, so recycling isn't always as environmentally friendly as you might think.

Other recyclable metals, like copper and aluminum, can be found in the battery's shielding, harnesses, and wires. They're easier to obtain, since they can be removed during the disassembly. Finally, once all the recyclables have been extracted, the stuff left over, including plastic, cheap-to-replace metals, and other byproducts, get thrown away. Some scientists predict a future in which 100% of batteries will be able to get recycled, but we're not there yet. Only time will tell.

The idea that all EV batteries end up in landfills is one of six common myths surrounding EVs, but many still do nonetheless. Used EV batteries may also get repurposed for things like solar panels, wind turbines, and backup power units. One example of EV batteries being repurposed can be found in Amsterdam's Johan Cruijff Arena. It's the biggest commercial energy storage facility to use EV batteries in Europe, with a storage capacity of 3 megawatts. That massive capacity is thanks to nearly 150 new and used Nissan Leaf batteries. The batteries are charged during the day by the stadium's solar panels. More impressive, the stadium offers EV charging stations in the parking lot, bringing the "reuse" concept full circle.

Reuse depends on the remaining capacity of the used battery. An EV battery reaches its end-of-life state once it can store only around 75% of its original capacity, at which point it may be reused as storage for homes, facilities, and the aforementioned football stadiums. Repurposed EV batteries can provide as much as 10 more years of service. 

But once a battery is totally dead, there are only two options: recycle or toss. For totally spent batteries, many countries have set goals to increase the rate of recycling. The EU has pledged to recycle 70% of dead lithium batteries by the year 2030, while the U.S. government has implemented several policies to incentivize an increase in battery recycling. The current rates of recycling aren't nearly as lofty. A commonly cited number for EV battery recycling rates is only 5% worldwide. However, skeptics have questioned the validity of the "5% myth," arguing recycling rates are probably higher. Either way, the recycling rate is almost certainly far from the EU's target of 70%.

While the low rates of EV battery recycling are concerning, even the recycling process itself can be environmentally problematic. Recycling batteries often threatens the health of the nearby ecosystem and the health of the workers at the facility. Thus, whether recycled, reused, or outright tossed, every EV battery eventually leads to toxic byproducts entering the environment. The pyrometallurgical process emits massive amounts of greenhouse gasses as the plastic components and other non-recyclable materials are combusted into smoke. The acid baths used in hydrometallurgy also produce a significant quantity of waste, leaving behind toxic liquids and solids that can't be reused or recycled.

When lithium batteries and their byproducts are disposed of in landfills, they're not just dangerous for the local ecology. They can also cause dangerous fires that emit toxic smoke, ignite surrounding waste, and threaten worker safety. For example, nearly half of all waste fires in the U.K. are caused from lithium batteries mixed in with the rest of the trash. Firefighters risk their personal safety for weeks or even months trying to get the blaze under control. All the while, the tons of water used to fight the fire seep toxins from the dump site into the water supply as plumes of greenhouse gasses billow into the sky.

Even if a lithium battery doesn't burst into flame, it still has the power to pollute. Over time, the cells leach toxins into the surrounding area. Heavy metals like arsenic, cadmium, chromium, nickel, and lead can all be found in EV batteries, and they're all linked to multiple forms of cancer. When a battery burns, those metals enter the air; when it doesn't, they can enter the soil and the water table. 

Although the current state of EV battery recycling and its environmental impact might seem grim, there's good news for the future. For one, new battery technologies are on the horizon, with some proposed alternatives replacing non-recyclable parts with safer, more abundant materials like sodium, glass, and even water. (With a water-based battery, you could forget about those trash fires caused by lithium-based batteries.)

Other potential breakthroughs in battery tech could make batteries last longer. By increasing the lifespan of a battery, such innovations would reduce the rate at which batteries get trashed. One example is called "pulse current charging," which essentially provides an intermittent cool-down period while charging up a battery. Pulse current charging is employed in various applications today, but scientists predict that it could be optimized to increase a battery's lifespan by decades.

Even if new battery technologies don't swoop in to save the day, there's still a good chance that recycling techniques will increase in scale and efficiency. One reason so few batteries get recycled is because there currently aren't enough facilities to process them. But thanks to governmental and economic pressures, the EV recycling industry is growing as private EV manufacturers are assuming the responsibility of recycling. Volkswagen recently broke ground on a pilot recycling facility and Tesla has partnerships to make sure their used batteries don't head directly to landfills.

Many governments are incentivizing the expansion of EV battery recycling plants. In the United States, subsidies exist for companies that use recycled materials for their EV batteries, as long as the recycling took place on U.S. soil. And in 2023, the U.S. Department of Energy provided $200 million in funding towards research into reducing the cost of EV battery recycling. Hopefully such examples are just the tip of the iceberg.