How recycling EV batteries is easier with silicones?

The electric vehicle (EV) battery recycling industry is evolving rapidly, driven by the increasing demand for EVs and the growing need for sustainable practices. Despite advancements in technology, batteries cannot be charged and discharged indefinitely. Eventually, they reach the end of their useful lives, and the next step is recycling or disposal. Battery recycling aims to minimise environmental impact and conserve non-renewable resources becoming an important part of the supply chain for critical minerals.

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How are batteries recycled?

While specific recycling processes and technologies may vary, after being discharged, collected batteries are disassembled, either manually or by using automated processes, to separate the various components, such as cells, modules, casings and wiring. These disassembled components then undergo mechanical processing, which may involve shredding, crushing, or other size reduction techniques to separate out valuable materials, such as metals and minerals.

The processed materials are then subjected to either hydrometallurgical or pyrometallurgical processing, using chemical reactions or high temperature smelting to recover metals. Once extracted and purified, materials such as cobalt, lithium, nickel and copper can be reused in the production of new batteries or other applications, contributing to a more circular economy.

The battery recycling market

The Asia-Pacific region, particularly China, currently dominates the lithium-ion battery recycling market, with companies like Brunp and GEM leading the way. According to research collated by GlobalData, China has made significant investments, including a $5 billion battery recycling facility announced by CATL in Hubei, supported by government initiatives aimed at bolstering the recycling sector.

In the European Union, battery recycling has gained momentum with the introduction of updated regulations and recycling targets, including a goal of recovering 50% of lithium from recycled batteries by 2027 and 80% by 2031. Major players in the region are ramping up their recycling capabilities, with joint venture partners Northvolt and Hydro expecting to process 70,000 tons of battery packs by 2025 rising to 300,000 tons by 2030, for example. Additionally, in July 2023, the EU issued Regulation 2023/1542, setting standards for the carbon footprint and recycled content of new batteries.

Globally, the market for EV battery recycling is projected to grow significantly, with McKinsey forecasting revenues to reach $95 billion by 2040, up from just over $2 billion in 2022. This growth is essential not only for environmental sustainability but also for reducing reliance on raw material imports, particularly in Europe, where the recovery of materials from end-of-life batteries could supply up to a quarter of the continent’s EV needs by 2030.

However, despite this progress and the increasing demands, challenges remain, including outdated regulations that do not account for the latest battery chemistries and the need for more effective recycling technologies.

Challenges in recycling

John Albaugh is Market Development Manager for Electric Vehicles at Elkem Silicones, one of the world’s largest silicone manufacturers. Elkem supplies battery materials and silicone solutions for battery packs to the automotive industry.

Albaugh explains that the use of polyurethanes in battery packs can be a major obstacle when it comes to recycling. “Mechanically speaking, they’re adhesives,” Albaugh says. “You’re not going to be able to separate them, as their adhesive strengths are so high that, even with sand blasting, you can’t separate them effectively.” This means that the waste has to be mechanically shredded and then burned before the ore can be reclaimed.

When it comes to recycling, it is the rare earth ores inside the batteries that are valuable. “If you use adhesives, then harvesting those battery packs is going to be much more difficult,” says Albaugh.

Even after disassembly, polyurethane foams can be more challenging to recycle than other materials. Isocyanates, found in many products including polyurethane foams, paints, coatings and glues, include compounds classified as potential human carcinogens. “This toxicity means that there are special disposal guidelines,” notes Albaugh.

Making recycling easier with silicones

Silicones, however, are non-toxic, inert and have a proven track record of safety, having been used by Elkem for over 70 years. Silicone can replace polyurethane in EV batteries due to its high thermal stability and fire-retardant properties, as well as being highly adaptable to evolving battery chemistries, while its non-adhesive bonding makes it much simpler to remove from parts and battery cells, facilitating easier recycling.

Albaugh also explains that new, modular battery designs can help facilitate the mechanical separation of materials, making it easier to recycle or repurpose battery components. For instance, spent battery modules can be reused in other applications, such as energy storage systems, extending the overall lifecycle of the battery materials and reducing waste. Additionally, as Elkem’s silicones offer robust fire protection within the battery modules, this increases their value for reuse without the need for rework or upgrades.

“We are also working with recyclers on second-life potential uses for the spent silicone after it’s been separated from the batteries,” says Albaugh. In 2021, the company launched a project to investigate chemical recycling of silicone waste at its Lyon plant. Following the validation of the company’s eco-friendly depolymerisation process, this initiative is now being performed at pilot scale.    

As EV adoption continues to grow, it is certain that the industry will need to address the challenges of recycling and reusing these valuable battery resources, establishing a value chain and market for used battery packs that will incentivise and focus the industry on the recyclability and reusability of battery designs.

Elkem is actively contributing to improving the sustainability and circularity of battery technologies. This aligns with the industry’s growing emphasis on responsible end-of-life management of these critical energy storage components.

For more information on developing battery technologies and recycling, download the free paper below.