There may soon be a better way to handle post-consumer products that contain lithium-ion batteries. Researchers and scientists at the US Idaho National Laboratory (INL) are working on a solution to make the recycling of such batteries easier and more efficient.
The global lithium-ion battery market is expected to double in size in the next five years, reaching US$ 71 billion (EUR 60 billion) by 2025. Market analysts at Statista point out that demand worldwide for e-mobility alone is likely to increase from 142 gigawatt hours (GWh) recorded in 2018 to 2 333 GWh hours in 2030. It means there is much work to be done in terms of recycling with only about 5% of the world’s Li-ion batteries being properly recycled.
Electricity powers leaching
A positive development is that INL has devised a ‘proof-of-principle’ approach to battery recycling that works at room temperature and without relying on aggressive chemicals.
The innovation, INL researcher Tedd Lister explains, consists of the electrochemical-assisted leaching of active materials from Li-ion batteries. This method recovers valuable metals from the mixed shredded Li-ion batteries. ‘Instead of heat, the energy comes from electricity which powers the reactions that leach the cobalt, lithium, manganese, and other materials out of the batteries,’ Lister says.
Turning to electrons to act as a ‘green reagent’ allows the use and regeneration of Fe2+ in low concentrations instead of hydrogen peroxide as a reducing agent.
96% sorting efficiency
The INL team conducted tests on shredded Li-ion batteries, supplied by Retriev Technologies in Ohio. The chemicals used for metals separation was supplied by Solvay, based in Brussels.
After refining the electrochemical process, Lister and his crew managed to hit 96% sorting efficiency for extracted cobalt, lithium, manganese and nickel all of which exit the process in a single output stream. This was achieved at pulp densities up to 240 grams per litre. Meanwhile, copper can be recovered individually as it deposits on the cathode, which significantly simplifies the downstream separation process.
Preliminary cost analyses demonstrate approximately 80% reduction in energy and chemical costs compared to traditional hydrometallurgical routes. Another benefit is that this novel battery recycling approach could make use of any excess energy produced by utility-sized electricity plants.
Future plans include developing an electrochemical procedure for the leaching process to separate the output into cobalt, lithium, manganese and nickel streams. The R&D crew is also exploring reuse for another critical material, graphite, as it remains an interesting yet untapped recycling opportunity.
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