Toray Industries, Inc. (Tokyo) announced that it has developed technology to scale up a new high-durability, high-selectivity nanofiltration membrane element that can efficiently recover high yields of high-purity lithium when recycling automotive lithium-ion batteries. This advance should significantly increase the recovery of lithium that conventional recycling processes largely discard.
Process for recovering lithium with nanofiltration membrane elements (Source: Toray)
Establishing a closed-loop cycle for lithium by recycling batteries has become a critical technological challenge as more people adopt electrified vehicles and economies decarbonize. The proliferation of nickel- and cobalt-free lithium iron phosphate batteries in recent years has greatly increased demand for recovering lithium. Toray’s new 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%.
Toray harnessed its expertise in organic synthesis and polymer chemistry and nanotechnology to upscale and widen its highly durable and selective nanofiltration membrane elements. It is thus possible to mass-produce modules with elements sized like those in conventional water treatment applications. This practical recycling approach will enable Toray to supply samples to customers, helping accelerate this technology’s commercialization.