This advance should significantly increase the recovery of lithium that conventional recycling processes largely discard.
Establishing a closed-loop cycle for lithium by recycling batteries has become a critical technological challenge as more people adopt electrified vehicles and economies decarbonise.
Process for recovering lithium with nanofiltration membrane elements
The proliferation of nickel- and cobalt-free lithium iron phosphate batteries in recent years has greatly increased demand for recovering lithium.
Toray’s technology would enable efficient and high-quality lithium recovery from diverse lithium-ion battery variants, including nickel-cobalt and lithium iron phosphate types. It also makes it possible to extract cobalt and nickel, which are also vital for lithium-ion batteries.
To date, Toray’s nanofiltration membranes have recovered lithium from salt lakes. Doing that with used lithium-ion batteries requires filtering highly acidic sulfuric acid leachate that extracts metals from those batteries. Conventional membranes are insufficiently acid-resistant.
Toray addressed this challenge by developing a highly durable and selective nanofiltration membrane with much better acid resistance.
The membrane filters sulfuric acid leachate from black mass produced when heat-treating end-of-life lithium-ion batteries.
The company proposed and demonstrated what it positions as the world’s first technology for selectively separating and recovering lithium with membranes. Multiple laboratory-scale demonstrations confirmed lithium recovery rates exceeding 95%.
See also: Viewpoint: Reliability and predictability will revolutionise Li-ion battery technology
