More than a fifth of the cars sold worldwide last year were electric. As the market for electric vehicles slowly and steadily picks up, so does the urgency for powering these vehicles sustainably. Today’s EVs run on lithium-ion batteries. The critical metals that go into those batteries as well as the fate of the batteries once they are spent carry an environmental burden.
Recycling batteries is a way to address both those concerns. And in a new study published in the journal Energy Storage Materials, researchers report a way to recycle lithium-ion batteries that is more efficient and eco-friendly than known technologies.
The new technique recovers over 92% of three critical metals used in battery electrodes—nickel, manganese, and cobalt—and converts them into high-performance electrode materials. The process uses about 9% less energy and reduces carbon emissions by almost 14% compared with traditional recycling.
Batteries contain two electrodes: a positively charged cathode and a negatively charged anode. In lithium-ion batteries, the cathode is typically a mix of lithium, nickel, manganese and cobalt (NMC), although researchers have been trying to find cheaper, more readily available substitutes.
Mining cobalt, nickel, and lithium has been linked with impacts on the environment and local communities. There is also a push to mine these metals from the deep ocean, which carries unforeseen risks. And today, most discarded batteries end up in landfills.
Recycling batteries would reduce dependence on mining for new metals as well as the amount of waste generated. Today’s recycling processes involve pulverizing them and then either heating the powder at high temperatures or dissolving it in harsh chemicals.
Yan Wang at Worcester Polytechnic Institute and colleagues came up with a new process that combines the best of traditional methods and newer direct recycling technology. They employ this method on two older types of battery cathodes: one based on NMC with a low nickel content, and another based on lithium and manganese.
The researchers cut and shred the mixed cathode materials and dissolve them in a solution containing sulfuric acid and hydrogen peroxide. This gives nickel sulfate, which the researchers modify to increase nickel content. The end result is a nickel-rich NMC cathode compound that has 83% nickel.
Testing shows that batteries made with these recycled materials have similar performance as those made from newly mined materials. The devices retain 88% of their capacity after 500 charge cycles and more than 85% capacity after 900 cycles in commercial-scale pouch cells.
Source: Jiahui Hou et al. Upcycling Mixed Spent Ni-Lean Cathodes into Ni-Rich Polycrystalline Cathodes. Energy Storage Materials, 2025
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