A team at MIT has developed a self-assembling battery electrolyte that could transform how electric vehicle batteries are recycled.
Published in Nature Chemistry, the study introduces a solid-state electrolyte that disassembles in minutes when exposed to a simple organic solvent – offering a cleaner, more scalable alternative to conventional recycling methods.
“So far in the battery industry, we’ve focused on high-performing materials and designs, and only later tried to figure out how to recycle batteries made with complex structures and hard-to-recycle materials,” said first author Yukio Cho PhD ’23. “Our approach is to start with easily recyclable materials and figure out how to make them battery-compatible. Designing batteries for recyclability from the beginning is a new approach.”
The material is built from aramid amphiphiles (AAs), which mimic Kevlar’s strength and self-assemble into nanoribbons in water. These ribbons incorporate polyethylene glycol (PEG) to conduct lithium ions and form a mechanically stable, ion-conducting structure.
“The material is composed of two parts,” Cho explained. “The first part is this flexible chain that gives us a nest, or host, for lithium ions to jump around. The second part is this strong organic material component that is used in the Kevlar, which is a bulletproof material. Those make the whole structure stable.”
When immersed in solvent, the electrolyte dissolves like cotton candy, allowing the battery to fall apart for easier recycling. While performance was limited by polarisation effects, the team sees potential for integrating the material into future battery designs.
“If we can start to recycle lithium-ion batteries from battery waste at scale, it’ll have the same effect as opening lithium mines in the US,” Cho added.
The research was supported by the National Science Foundation and the U.S. Department of Energy.
Image: A depiction of batteries made with MIT researchers’ new electrolyte material, which is made from a class of molecules that self-assemble in water, named aramid amphiphiles (AAs), whose chemical structures and stability mimic Kevlar. Credit: Courtesy of the researchers, edited by MIT News.
