Recycling Electric Car Batteries: An Overview

What happens to those big batteries when they reach their end of life?

Mehanic doing service on electric car battery
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There were some 11 million electric vehicles on the world's roads in 2020, but by the end of the decade, that number could be 145 million. By 2040, it could be 530 million. When those vehicles reach their end of life, there will be approximately 200,000 metric tons of lithium-ion batteries that need to be disposed of, recycled, or reused. How that will be done in an economical and sustainable manner is still to be determined.

The EV battery recycling industry is still in its infancy, since most EVs have been on the road fewer than five years, and their batteries may last two to three times longer than that. Much is still to be done in terms of research, standardization, and development. Without robust recycling, the world faces a highly toxic problem on its hands. With it, the environmental benefits of electric vehicles increase even more.

The Need for EV Battery Recycling

Lithium-ion batteries are the key component in an electric vehicle—its most expensive component and the one that requires a supply chain of raw materials that can have human-rights and environmental costs. While electric vehicles emit no greenhouse gases during operation, the manufacturing process can contribute up to a quarter of the total global warming emissions in the life cycle of the vehicle. Most of the emissions come from the production of electricity to store in the battery, and the specific level of emissions from battery manufacturing is still uncertain.

Keeping lithium-ion batteries out of landfills is essential because of their toxicity and flammability. Recycling and reusing EV batteries can play a large role in reducing the need for lithium, cobalt, and nickel, and thus reduce the human and environmental costs of battery manufacturing and disposal.

Challenges to Recycling

One of the obstacles in the way of large-scale EV battery recycling is the numerous chemistries of the batteries, which vary from model to model. While lithium-ion batteries have been in commercial use since 1991, the technology is still changing rapidly, with ongoing research into new chemistries and technologies that may be more energy-dense, cost-effective, safe, conducive to human rights, and environmentally sustainable. Lithium-ion technology is a mature one, but what EV batteries will look like in 2030 is an open question.

Another challenge is the many form factors that the batteries come in. Unlike ordinary alkaline or nickel-cadmium battery cells used in the home or the lead-acid batteries used in gasoline vehicles, EV batteries do not come in uniform sizes and shapes. Rather, individual battery cells are arranged in modules that are themselves organized in a pack, with all parts connected by sophisticated circuitry and for safety reasons tightly sealed with nearly unbreakable glues. Aggregating battery cells this way is necessary for the power and energy densities that EVs require.

With so many different form factors, disassembling and recycling each one can take hours, raising the cost of the materials to the point where it's currently cheaper for manufacturers to buy new materials than recycled ones. The problem is both one of process and of scale.

Reuse Before Recycle

Batteries lose roughly 2.3% of their energy capacity annually, meaning a new 64kWh battery might have 48.4kWh (76%) of its original storage capacity after 12 years. Cars remain on the road in the United States for an average of 11.6 years, so a battery with 48kWh of capacity is still a useful product with a second life, even if the rest of the car is scrapped.

Energy storage, itself a booming industry, can repurpose these batteries after the EV itself has reached the end of its life. They can be used as energy storage devices in residences, in microgrids to provide power to communities and schools, as utility-scale storage to provide reliability and resilience to the electricity grid, or even to power robots. Reuse can double the useful lifetime of the batteries, at which point, they can be recycled.

The EV Battery Recycling Process

At present, given the challenges, recycling is performed one battery pack at a time. The packs must first have their glues broken apart to access the individual cells. Then the cells can either be burned or dissolved in a pool of acid, producing either a lump of charred materials or a slurry of potentially toxic ones. Burning requires immense amounts of energy while using solvents poses health risks. Other, less harmful or energy-intensive methods, such as using water, are still in the research and development stage. Currently, simple manual disassembly yields a higher rate (80%) of materials recovery than either fire or solvents.

Recyclers seek mainly to extract the more marketable cobalt and nickel in batteries, as lithium and graphite are too readily available at lower prices for them to be worth recovering. As new chemistries emerge, especially those that seek to reduce the use of cobalt, one main source of recyclers' income may be lost. Another source of income in the recycling process can be recycling a battery's anode and cathode intact, rather than breaking them down into their component materials.

Policies for EV Battery Recycling

Electric vehicles still only representing about 1% of the vehicles on the world's roads. Government policies can help shape this nascent industry by creating a closed loop between manufacturing and recycling. Ample legislation covering the manufacturing, use, and recycling of lithium-ion batteries already exists, mostly due to safety concerns. These can be expanded in the following areas to make EV batteries part of a circular economy.

Labeling

As with other products, labeling is key to efficient recycling. Most EV battery packs contain no information about the chemistry of the anode, cathode, or electrolyte, meaning recyclers are left in the dark about their contents and need to disassemble batteries individually. Like the resin ID code (the number inside the triangle) on plastics, content labels on batteries will allow them to be mechanically sorted and processed, lowering costs and improving recycling rates. The U.S.-based Society of Automotive Engineers, which established standards for battery charging infrastructure, has recommended labeling of the batteries themselves.

Design Standards

For many products, end-of-life considerations fall upon the consumer, not the manufacturer. Incorporating design standards into the manufacturing process may be difficult in a nascent and disruptive industry like electric vehicles, but it has been a successful part of recycling efforts in mature markets like aluminum, glass, car catalysts, and lead-acid batteries. Design standards will eventually emerge by government regulation or from within the industry itself.

Co-Location

Being the heaviest part of an electric vehicle, batteries are expensive to ship, so producing them close to automotive manufacturing centers and ultimately to customers is another consideration. Co-locating battery recycling industries with EV manufacturing can greatly reduce the cost of EVs and reduce their life-cycle greenhouse gas emissions. Here, government support rather than regulations can incentivize co-location.

J.B. Straubel, a co-founder of Tesla and a key contributor to its battery development, founded Redwood Materials to recycle EV battery materials and send them back into Tesla's battery supply chain. Being based in the United States, Redwood Materials shortens Tesla's otherwise long supply chains.

Closing the Loop

The recycling of lead-acid batteries should give EV battery manufacturers, recyclers, and policymakers a model to emulate. Over 98% of the materials by mass in lead-acid batteries are currently recycled, in large part because they are made of a standard mixture of materials enclosed in a single case. With improvements in technologies and better coordination of the entire life cycle of lithium-ion batteries, the Union of Concerned Scientists predicts that the United States can reduce its reliance on demand for mined resources from foreign sources by 30% to 40% by 2030. Closing the loop between EV battery manufacturing and recycling will make electric vehicles an even more sustainable alternative to gasoline-powered cars.

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