EV battery recycling: how Mercedes is giving EV batteries a second life

We’ve all suffered the annoyance of the slow demise of a mobile phone battery, when it seems like you’re spending more time charging it up every day than using it. The same thing will eventually happen to the much larger batteries in your electric vehicle (EV).

Car makers deem an EV battery to be at the end of its useful life when it drops to 70% of its original capacity; at this point, the range of the car it’s powering is too far reduced. This point might be reached after 200,000 miles and between 10 and 20 years’ of use. However, rather than being simply thrown away, batteries can be recycled, and this is something many car makers are gearing up for.

While several car manufacturers have started to plan battery recycling plants, or are busy exploring partnerships with other organisations that already do this type of work, Mercedes-Benz has plunged headfirst into the issue by constructing its own facility to recycle lithium-ion batteries.

In October 2024, it opened a 6800 square metre site in Kuppenheim, southern Germany, that can reclaim up to 96% of the precious metals found in every EV battery module. Initially, the facility is running at a restricted capacity, but when it’s fully operational in two to three years’ time, it will be able to recycle 2500 tonnes of battery materials every year.

This makes Mercedes the first European car maker to undertake all the steps involved in battery recycling, from shredding (to separate plastic, aluminium, copper and iron) to extracting the rare earth minerals, which include cobalt, nickel and lithium. The facility is on the site of a former car body assembly factory and was built in just 18 months at a cost of nearly €50 million.

Currently, up to 99% of the materials used in Mercedes’ combustion-engined cars can be recycled, and the new plant will help the brand improve the level of sustainability of its EVs. That’s partly because the carbon impact of recycling batteries to produce new ones in Germany is far less than if the metals were imported from abroad.

Mercedes board member Jörg Burzer says: “This [facility] turns today’s batteries into tomorrow’s sustainable mine for raw materials. It’s an important step towards raw material independence .” However, it won’t eliminate the need for new raw materials to be mined for EV batteries altogether. “I think we will always need 20%, 30% or 40% [of materials sourced using mining],” adds Burzer.

The metals recovered will be used in the production of 50,000 new EV battery modules a year – enough to make around 5000 new EV battery packs. There are a number of battery modules in each vehicle’s EV battery pack; that of the Mercedes EQC, for example, contains six.

While the number of recycled battery packs is low compared with the number of new EVs being sold each year, the factory has been designed to be scalable so it can increase its capacity as demand grows.

At first, though, the plant will focus on recycling the batteries used in prototype EVs and for battery testing. Currently, there’s a limited supply of end-of-life lithium-ion batteries; Mercedes’ first mass-produced electric car, the EQC, was launched in 2018, and the expected lifespan of its battery modules is eight to 10 years. However, Mercedes says the first bank of recycled battery modules will be seen in a production car soon.

While the facility is currently geared up for processing lithium-ion batteries, the technology used at Kuppenheim can be adapted to recycle lithium iron phosphate and nickel manganese cobalt batteries, as well as the solid-state batteries that are expected to appear over the coming years.

Kuppenheim might not be a one-off; Mercedes is planning to build recycling plants in other regions if there’s enough demand. And while the company isn’t currently planning on recycling batteries from other EV brands, it isn’t ruling this out in the future.

How Mercedes recycles EV batteries

The Kuppenheim plant combines mechanical and hydrometallurgic processes on a scale – the brand says – never seen before in a single plant in Europe. Many existing battery recycling facilities employ pyrometallurgical processes that use fire and heat to reclaim precious metals, but hydrometallurgic (liquid chemical) technology promises substantial efficiency advantages. It uses less energy (the process uses 100% green electricity, supplied by solar panels on the roof of the plant), and it produces less material waste, enabling a greater proportion of metals to be recovered.

In total, it takes two days to completely process a battery module. The recycling process is made up of two stages. First, there’s the mechanical separation of the plastic, copper, aluminium and iron. This involves a grinder breaking the battery apart, with gravity-based and magnetic systems used to sieve the components into separate containers.

During this part of the process, the ‘black mass’, which contains the precious metals, is syphoned off and sent to the next recycling area. Here, the hydrometallurgical process uses a liquid solution in 100 separate tanks to filter out the cobalt, copper, lithium, manganese and nickel components, one precious metal at a time, with the graphite also being recovered.

The iron and aluminium previously recovered are then fed through the same hydrometallurgical process to separate all remaining traces of precious metals. 

How other brands are getting behind EV battery recycling 

The Volkswagen Group UK has been working with Ecobat Solutions UK for a number of years; the latter company recycles the high-voltage batteries from VW EVs.

Ecobat collects end-of-life lithium-ion batteries from dealerships, distribution centres and vehicle dismantling sites, using vehicles that meet the safety requirements to transport hazardous materials.

The EV batteries are taken to the firm’s UK plant in the West Midlands, where they’re broken up and the various components are separated out for recycling or reuse in non-EV applications. The black mass of the battery is sent to a specialist refining company, which extracts the precious metals so they can be returned to the battery production process.

More recently (in April 2024), Nissan started working with Ecobat, investigating how the company could help with reusing end-of-life EV batteries. Ecobat grades decommissioned batteries, assessing their suitability for use in battery energy storage systems or mobile power charging systems, and recycles the rest.

Ecobat is one of a growing number of independent companies setting up EV recycling facilities. One such company in the UK, Recyclus Group, opened its first plant in September 2023. It extracts the precious metals from battery modules and says it will process up to 8300 tonnes of batteries each year. Other recyclers, including Veolia, Umicore and Cawleys, are also planning large-scale operations in the UK and overseas.

BMW currently uses external partners to recycle its EV batteries, but in November 2024 it announced that it’s building its own plant in Bavaria. Construction of the £8.3 million site will begin in the second half of 2025.

Read more: The best electric cars

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