Investments that make an impact: Battery recycling to fuel greener e-mobility

Northvolt is in some respects Europe’s answer to Tesla’s impressive battery power. It has been building Europe’s first Gigafactory in its native home of Sweden since 2019, with the aim to serve 25 per cent of the European car battery market by 2030. If the pilot recycling facility is successful, a full-scale recycling plant will be built right next to the Gigafactory, which lies on the outskirts of the industrial city of Skellefteå in northern Sweden.

Right now, the recycling of electric car batteries is a complex and technical undertaking. Even before the recycling of the battery itself, Northvolt has to find a safe way to get the battery pack, with all its toxic, flammable chemicals, back to the facility. It’s a process that involves jumping through a number of safety and regulatory hoops. “Whenever a battery pack is being dismantled from the car, it needs to be safely handled,” says Emma Nehrenheim, Northvolt’s chief environmental officer. “It’s very expensive to do this in a safe way, and it is very time demanding.”

Once a battery has been safely delivered to Northvolt’s recycling centre, the process of dismantling and discharging takes place. The problem is that batteries have a tendency to go boom if disassembled incorrectly. There’s lithium, nickel, manganese, graphite and cobalt – all encased in steel, alloy and plastic. A full battery discharge will remove any stored energy and prevent any unwanted thermal runaway events, which could cause the battery to catch fire or explode.

While the dismantling of the battery pack is currently done by hand, Nehrenheim says that Northvolt is in the middle of designing an automated dismantling system. This will not only speed up the process, but also make it safer. The big obstacle for machines to overcome is battery design: no two are the same, forcing recycling facilities to craft different plans for different car batteries.

After the battery has been safely dismantled and the cells and modules retrieved, Northvolt begins to crush those cells in an air-tight vacuum, ensuring that there are no reactive gases like carbon dioxide and oxygen around to contaminate the materials in the cells. The liquid electrolyte is evaporated and condensed, finding use elsewhere in the chemical process.

The crushed material is then sorted based on various properties. Picture a massive sieve collecting the larger materials and separating them from the smaller ones, while a magnet separates magnetic and non-magnetic metals. All of this is then delivered to nearby recycling facilities. “We are dependent on partnerships to recycle,” says Nehrenheim. “Copper is something that we don’t have our own process for. Aluminium is another case where we are working together with partners.”

As soon as all the crushed material has been sorted and separated based on density, magneticity and size, all that remains is a pile of black powder, something that Nehrenheim calls “black mass”. The powder is made up of nickel, manganese, cobalt, lithium hydroxide and graphite – some of the most crucial components in a lithium-ion battery. This powder undergoes something called a hydrometallurgical process, where the black powder is effectively dumped into an acid bath. All those raw materials will be separated from the black powder, leaving behind all the ingredients needed to make a new electric car battery.

Right now the process is relatively slow and complex. But, over time, Northvolt hopes to speed it up and simplify it. Anna Korre, professor of environmental engineering at Imperial College London, says that there are three dominant methods to the recycling of battery cells. Hydrometallurgical is one of them. The other two are pyrometallurgical and direct recycling. Pyrometallurgical recycling is when a battery’s cells are smelted in a furnace at 3,000 degrees Celsius. It’s a violent process in which all the lithium is lost – not an ideal outcome when you’re trying to recycle lithium-ion batteries.

“The hydrometallurgical method performs better in terms of environmental footprint – around a 30 per cent improvement in carbon footprint when recycling is included,” Korre says. In Germany, Duesenfeld uses a hydrometallurgical process to recycle the batteries. In Belgium, Umicore uses a pyrometallurgical process.

Where Northvolt differs, however, is in its use of hydroelectricity to power 100 per cent of its production process, meaning that the company has the potential to bring its greenhouse gas emissions down even further. “We started looking for a site where we could have as high a proportion of renewables as possible to bring down the carbon footprint,” says Nehrenheim. “We have a surplus of hydropower in the Nordics.”

The company will also be sourcing the raw materials needed to produce the batteries directly from the mines, and producing the cathode itself. The refinement will also take place close to the mine. This, Northvolt hopes, will create a shorter and more sustainable supply chain that’s easier to trace and monitor. This differs from other automotive and battery manufacturers who have long, complex global supply chains. Many automotive companies buy their electric car batteries from LG Chem and Panasonic, who in turn purchase the materials to produce the cathode from suppliers like Umicore.

For now, Northvolt isn’t sourcing raw materials from the Democratic Republic of Congo, which is where the large majority of cobalt – a major component in electric car batteries – is mined. In 2016, an Amnesty International report revealed that 35,000 child labourers were working in the country’s cobalt mines. While Northvolt says that it hopes to eventually mine cobalt from the Democratic Republic of Congo, it says it won’t until it can do so in a sustainable and ethical way.

Recycling electric car batteries is already an important issue – but as sales of electric vehicles increase it will become critical. “It’s all about having a good facility for bringing in new packs and EV batteries that enter the market and for evaluating and creating the most cost-efficient way to recycle,” says Nehrenheim. The first block of the Gigafactory recycling plant is expected to be operational in 2022, with the capability to recycle 25,000 tons of battery cells every year.

It might sound like a lot, but that’s only a fraction of the total waste caused by the rise of electric vehicles. In a 2019 paper published in the journal Nature, researchers estimated:

The more than one million electric cars sold worldwide in 2017 could result in 250,000 tons of end-of-life battery packs.

EU law dictates that battery manufacturers are required to take back their spent car batteries once they have come to the end of their life and bans the disposal of car batteries through landfill and incineration.

“The prospect of these ending up in landfill in most countries is remote as there are strong regulations in place to avoid this and the environmental consequences of toxins leaching out into the environment,” says Paul Anderson, co-author of the Nature study and principal investigator for the Faraday Institution’s recycling of lithium-ion batteries project. “We have to recycle them. There's scarcely any other way of making these safe than to actually de-manufacture the batteries.”

Making electric car batteries greener doesn’t just require a lot of clever science – it also costs a lot of money. In July, Northvolt announced that it had raised £2.3 billion in equity and debt to support the development of two lithium-ion Gigafactories and increase research and development into recycling. The company also has investment from BMW, Volkswagen, ABB and Siemens, while the European Investment Bank has also loaned it £315m.

While Europe isn’t a leader in the realm of electric vehicle batteries at the moment, Northvolt is hoping to lead the green battery push. According to BloombergNEF’s lithium-ion battery supply chain rankings for 2020, China is responsible for 80 per cent of the world’s raw material refining, 77 per cent of the world’s cell capacity and 60 per cent of the world’s component manufacturing. “The difficulty with China is that their energy supply currently relies much on coal, which means that its carbon footprint is very high,” says Korre. “The other concern expressed widely is regarding environmental regulations as a whole.”