The Complete Guide to EV Battery Recycling Techniques

Electric cars have been hailed as the future of personal transportation, but one glaring issue stands in the way — a lack of EV battery recycling capabilities. Engineers must find a solution to the ever-growing pile of EV waste. Otherwise, the complex batteries powering today’s commutes will fill tomorrow’s landfills, leaching toxins into the soil and requiring automakers to keep mining metals. What can be done? 

Ultrasonic Waves

Researchers working on the Faraday Institution’s ReLib project have developed a method to use ultrasonic waves for EV battery recycling. The technique allows them to recycle a battery’s anode and cathode without relying on shredding. 

Researchers have used the technique to separate anode powder — usually graphite based — from the battery’s copper backing sheet. The method is also useful for retrieving the cobalt, manganese and nickel cathode powder glued onto an aluminum sheet during manufacturing. 

Separating these components using ultrasonic waves would incur 60% cost savings compared to buying new materials if adopted at scale. The technology could also process 100 times more items in the same amount of time as hydrometallurgy, which uses water and sulphuric acid to extract metals. 

Hydrometallurgy

This EV battery recycling technique involves using an aqueous solution during processing. One form of metallurgy — leaching — entails soaking lithium-ion batteries in strong acids so the metals dissolve. This method helps recover a large amount of materials. 

However, leaching also usually requires recycling technicians to remove plastic casings and drain the batteries before processing them, making the process expensive and time-consuming. The complexity of hydrometallurgy is one of the reasons it’s often cheaper to mine new battery metals rather than recycle them. People recycle less than 5% of lithium-ion batteries compared to a whopping 99% of lead batteries, according to some estimates.

However, one company that uses hydrometallurgy could make it easier to recycle used EV cells. Li-Cycle, purportedly the largest lithium-ion battery recycler in North America, uses leaching to refine batteries and recover over 95% of all their raw materials. 

First, Li-Cycle places batteries in a vat that shreds and discharges them. They then enter a chemical bath that frees up the metals hidden inside. 

The plastic battery separator disintegrates into flakes. The current collectors become copper and aluminum foil, while the anode’s graphite becomes concentrated carbon. The method also individually retrieves lithium, cobalt and nickel from the cathode.

The U.S. Department of Energy granted Li-Cycle a $375 million loan in February 2023. This will allow Li-Cycle to build a factory in New York to process 200,000 batteries a year, significantly eliminating the strain from used cells ending up in the garbage. Although leaching is time-consuming, scaling up the overall number of recycling facilities is one way to make it viable. 

Pyrometallurgy

Pyrometallurgy is the most common method of deactivating lithium batteries. This technique involves burning batteries to destroy their plastic casings and other unwanted materials, and what’s left is a fraction of the original metals. Usually, only nickel or cobalt from the cathode and copper from the current collectors are recoverable, while most of the lithium and aluminum are lost. 

Although the process is straightforward, it carries a heavy environmental price tag. Smelting — a common pyrometallurgy technique — employs a fossil-fuel-powered furnace which, in turn, releases even more emissions into the atmosphere during use. 

Smelting operations already exist to process mined ore, so repurposing them for EV battery recycling is convenient. The few lithium-ion cells people recycle usually end up in a smelting furnace. 

Now, a Nevada-based company called Redwood Materials wants to change the nature of lithium battery recycling. It aims to create a closed-loop supply chain by retrieving, reprocessing and reusing metals from spent batteries. 

The organization combines leaching and pyrometallurgy to recover up to 98% of a battery’s nickel, cobalt, aluminum, graphite and copper and repurpose them into new battery materials. It can also retrieve over 80% of the lithium from an EV battery. 

Technicians heat the batteries in converters that separate the metals. Redwood harnesses residual energy — like the organics in the electrolytes — to power the converters from the batteries themselves rather than fossil fuels. 

The result is a leftover metal alloy when the process is complete. Technicians then filter the material using a hydrometallurgical technique to retrieve its components.

Redwood’s process fully breaks down batteries into their basic parts, including cobalt sulfate, nickel sulfate and lithium carbonate. These materials are ready for reintroduction into the battery production process. 

Demand for EV batteries is surging, and Redwood is poised to be a key player in the recycling industry if its method catches on. Combining hydro- and pyrometallurgy has proven highly effective — and using residual battery energy simultaneously reduces emissions and lowers costs. The company has already processed roughly 500,000 pounds of materials in its Nevada factory.

Direct Recycling

As the name implies, direct recycling recovers and reuses battery components directly without destroying their chemical structure. It requires less processing and keeps a battery cathode’s crystalline nanostructure intact. Less processing means a dramatically lower cost of material reuse. 

The problem is that few manufacturers design batteries with recycling in mind. Rather, they emphasize efficiency, durability and low production costs. This business model means many lithium batteries contain glue and very small parts. There is also no standard for battery design across the board, so creating a universal process to pick batteries apart is challenging. 

Still, engineers are working on it. The U.S. Department of Energy’s Argonne National Laboratory leads the ReCell Center, which aims to improve EV battery recycling. Among its goals is to create economically viable direct recycling processes. 

Researchers have already developed and tested a few techniques in the lab that successfully recovered materials from lithium batteries. Real-world trials will be the next step in determining if the methods work — and whether they’re affordable — on a larger scale. 

Simplifying EV Battery Recycling

The growing EV movement will profoundly benefit human health and reduce climate change, but it cannot come at the expense of the environment. Automakers must start designing with EV battery recycling in mind to promote a circular economy. Additionally, engineers need to create new techniques and equipment to process spent batteries. 

They need to hurry — because for every lithium battery manufacturers produce, another grain of sand falls in the hourglass and the landfill gets a little bit deeper