A group of researchers from Michigan Technological University, with the assistance from Lei Pan, an assistant professor of chemical engineering, are using mining techniques that are more than a century old to recycle lithium-ion batteries at low cost.
These techniques were used to separate metal from ore, thus Pan had a suspicion that they will work for recycling batteries today. He suggested that his students pursue that line of inquiry.
The research involved plenty of late hours and dead ends, most of the time when things worked out, it was kind of an accident. The group was trying all kinds of solvents to liberate chemicals and later found out that plain water worked the best.
They used tried and true mining industry techniques to separate everything in the lithium-ion batteries: the casing, metal foils, the anode and cathode, and the lithium-metal-oxide (the most valuable component). These materials and components can be used to produce new lithium-ion batteries, that are as good as the produced ones from new parts. The biggest advantage of these processes is that they are inexpensive and energy efficient. Additionally, these materials are even cheaper than new ones.
They used standard gravity separations to separate copper from aluminum, and froth flotation to recover critical materials, including graphite, lithium, and cobalt. These methods are the cheapest ones and they do not require new infrastructure to be built since it already exists.
The researchers presented their results at the People, Prosperity, and the Planet competition last April in Washington, DC. There, their work was noticed by EPA’s representatives, and they were amazed by how simple the method is, and how nobody had discovered it before.
The research is already published in the journal Sustainable Materials and Technologies.
This is a crucial discovery for the development of the EV market since materials for batteries are expensive and becoming very difficult to be obtained. This will make recycling a more attractive solution to this problem.