We are in 2035 and electric cars are invading the roads. Petrol & diesel cars will soon be a thing of the past, with the European Union banning their sale or order to speed up switch to cleaner mobility & mitigate climate change. This is because electric vehicles do not emit carbon dioxide while driving, but their rechargeable batteries causing environmental & social concerns. They contain rare & expensive metals. And once the batteries expire, they are difficult to recycle.
Normal lithium-ion batteries are made up of many individual cells and weigh hundreds of pounds. The battery pack used in the Nissan Leaf contains 192 pocket cells, that of the Tesla Model S contains 7,104 cylindrical cells, all grouped into modules that are screwed, welded & glued together to be controlled as a single unit. As batteries begin to pile-up, automakers, battery makers and researchers are trying to prevent them from ending up in landfills.
Recyclers are primarily interested in extracting precious metals & minerals from cells. Getting these materials is complex & dangerous: after removing the steel casing, the battery pack must be carefully un-bundled into the cells, to avoid puncturing any dangerous materials. The electrolyte, a liquid whose role is to move lithium ions between the cathode and the anode, can ignite or even explode when heated. It is only after the pack has been disassembled that recyclers can safely extract the conductive lithium, nickel, copper & cobalt.
Used in the cathode, cobalt is the most sought after material used in batteries. In its raw form, the rare bluish-gray metal comes primarily from the Democratic Republic of the Congo, where miners work in hazardous conditions. The world’s leading electric car makers are already moving away from cobalt, deterred by human rights abuses, supply chain shortages & fluctuating prices.
This raises the question of whether recyclers will still find it useful to dismantle new types of batteries lacking most valuable ingredients. “When you move to more durable materials & inexpensive materials, the incentive to recycle and recover them diminishes,” said Jenny Baker, an energy storage expert at Swansea University. She likens this to a consumer electronics of dilemma: It’s often cheaper to buy a new cell phone than to repair or recycle it.
Recycling was not a big deal when electric vehicles were still rare. There were 11 million electric cars & buses on the world’s roads at the end of 2020, and according to the International Energy Agency (IEA), there could be 145 million by 2030. Both 2 and 3 wheels are not even included in this figure.
As sales of electric vehicles continue to grow, so will the volume of spent batteries. Based on the million cars sold in 2017, researchers at the UK’s Faraday Institution, a research institute focused on battery technology, have estimated that around 250,000 tonnes of unprocessed batteries will reach the end of their live in 15-20 years.
This equates to half a million cubic meters of spent batteries, enough to fill 200 Olympic zise swimming pools, although some of those batteries either retire early when cars crash, or are reused in other industries & recycled later.
The global capacity to recover raw materials from used batteries is estimated at 830,000,000 tonnes per year, according to London-based consultancy Circular Energy Storage. “A large part of this is in China and not available for other markets, the import of waste batteries being prohibited in China,” said the Managing Director Hans Eric Melin. Chinese companies occupy more than 2/3 of the lithium-ion battery supply chain. But the ban can be resolved by going through recyclers in Southeast Asia, Melin says.
Europe is slowly catching up, both in terms of battery production & recycling, with automakers leading the charge in re-claim valuable materials. The IEA predicts that recycling could meet up to 12% of the electric vehicle industry’s demand for lithium, nickel, copper & cobalt by 2040.
The Volkswagen group, which includes Audi, Porsche and other brands, recycles up to 3,600 batteries per year during a pilot phase at its new plant in Salzgitter, in northern Germany. Mineral processors are also showing interest in entering the market: Australian mining company Neometals has partnered with German company SMS Group to build an industrial-scale battery crushing plant, also based in Germany – a choice of appropriate location, given that the country is the largest automaker in Europe.
“Our sense of urgency to start recycling is much higher than many realize,” says Bo Normark, industrial strategy manager at EIT InnoEnergy, an EU-funded sustainable innovation accelerator. Lithium-ion batteries have a lifespan of over ten years, so it will take some time for them to build up. But much earlier, “in fact, today”, says Normark, it will be necessary to recycle the waste resulting from battery production. These releases include scrap and other waste generated during the manufacturing process or batteries that fail quality tests.
But before battery recycling can be scaled up, the industry must rethink its approach. Today’s recycling methods are crude & designed to extract only high-value materials from cells. University of Birmingham researcher Gavin Harper uses the Snakes and Ladders board game analogy to explain how lithium-ion batteries are currently produced & recycled. A player starts with the raw materials at the bottom of the board, moves up the board to produce a battery, and aims to end up at the top of the board with a completely recycled battery. Snakes, which make a player slide across different squares on the board, are of different lengths & correspond to different recycling methods.
In a first step, recyclers typically grind the cathode and anode materials of used batteries into a dusty mixture, the so-called black mass. In the board game analogy, this would be the first slide-down on a snake, says Harper. The black mass can then be processed in 1 of 2 ways to extract its valuable components. One method, called pyrometallurgy, involves smelting the black mass in a furnace powered by fossil fuels. It is a relatively inexpensive method but a lot of lithium, aluminum, graphite & manganese are lost in the process.
Another method, hydrometallurgy, extracts metals from the dark mass by dissolving them in acids and other solvents. This method, Harper says, would fit a shorter snake in the board game because more material can bere-covered: you fall-back, but not as many squares as using pyrometallurgy. The process, however, consumes a lot of energy & produces toxic gases and sewage.
“The Holy Grail for Recycling is this idea of direct recycling, which takes us a little long along the board,” says Harper. In Simple terms: the cathode is separated from the battery cell, regenerated in a chemical process and then positioned back in a cell. “This is definitely something that has been proven possible and that can work. There is a furious push for research techniques,” says Harper, referring to the ReCell Center, an American research collaboration focused on battery recycling. and funded by the Department of the United States. Similar efforts are underway in Britain & Europe.
While some research institutes, companies & startups are trying to find the best way to recycle lithium-ion batteries, others are working on cheaper and more durable types of batteries. Chinese manufacturers CATL and BYD already produce cheaper, less toxic and cobalt-free lithium iron phosphate batteries. They are also banking sodium-ion batteries, which use abundant sodium instead of the relatively rare lithium, to become the next generation of electric vehicle batteries.
Baker says we should stop thinking of recycling as a process of extracting precious metals from a battery. “Value isn’t just the elements, it’s the combination of those elements, the way they were designed and put together,” says Baker. In other words, to properly recycle batteries, we might just need to completely rethink batteries from ground-up.
Achieving net zero emissions by 2050 will require innovative solutions on a global scale.