EVs might get a lot cleaner, thanks to recyclable solid-state batteries from MIT

A team of MIT researchers has developed a new, self-assembling electrolyte for batteries that could help tackle the looming electronic waste problem posed by the electric vehicle boom. The team created a novel kind of solid-state electrolyte that quickly breaks apart when submerged in an “organic solvent.” This allows for easy recycling of valuable components.

This finding — published in the journal Nature Chemistry — could usher in a new era in battery design. The electrolyte is made from molecules similar to Kevlar in chemical structure. When exposed to water, these molecules automatically assemble themselves, forming millions of strong, ion-conducting nanoribbons that can be hot-pressed into a solid material. This solid electrolyte is then used as a connecting layer to hold a battery's positive and negative electrodes together.

At the end of the battery’s life, the entire cell can simply be submerged in an organic solvent. The electrolyte dissolves in minutes — a process the first author compared to cotton candy dissolving in water — causing the battery to fall apart, enabling the easy recycling of the battery's components.

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. 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. — Yukio Cho, the first author of the paper.

The team successfully built a working solid-state battery using the new electrolyte they made, though its performance was subpar compared to “gold-standard commercial batteries.” The researchers say it could spur the development of a circular economy for batteries, reducing the need for constant mining of new material.