A team of researchers at Cornell University has developed a new way to restore worn-out lithium-ion batteries, allowing them to recover up to 95% of their original performance.
The breakthrough could make battery recycling much cheaper, reduce environmental pollution, and help ease growing shortages of critical battery materials.
Lithium-ion batteries power everything from smartphones and laptops to electric vehicles. However, the materials needed to make them, such as lithium, nickel, and cobalt, are limited and increasingly difficult to secure.
Countries like the United States depend heavily on imported supplies of these minerals, creating concerns about future availability and supply chain security.
Traditionally, recycling lithium-ion batteries has been an expensive and energy-intensive process.
Most recycling methods involve either melting batteries at very high temperatures or crushing them into a powder before using strong chemicals to extract valuable metals.
While these approaches recover important materials, they require significant energy and additional manufacturing steps to turn the recovered materials back into new batteries.
The Cornell team wanted to find a simpler solution.
Led by chemical engineering professor Vibha Kalra, the researchers developed a technique called Direct Electrode-to-Electrode Regeneration (DEER). Instead of shredding batteries into pieces, the method carefully removes the battery’s electrodes while keeping them intact.
These electrodes are then placed into a special electrochemical solution containing a compound called 1,3-dimethyl-2-imidazolidinone. Over time, the solution removes a thick insulating layer that naturally forms inside batteries as they age.
This layer, known as the solid electrolyte interphase, gradually reduces a battery’s ability to store and deliver energy. By dissolving and removing it, the researchers can restore much of the battery’s lost performance.
According to Kalra, the process essentially repairs the battery rather than breaking it apart and rebuilding it from scratch. After treatment, the restored batteries recovered up to 95% of their original capacity.
The new approach could also dramatically reduce recycling costs. Economic analysis showed that manufacturing recycled battery cells using the DEER method could cost about 56% less than current recycling techniques.
The environmental benefits could be equally important. Compared with conventional recycling methods, the new process would require less water and generate fewer harmful air pollutants.
It also shortens what researchers call the “circularity loop,” meaning valuable battery materials can be returned to use much faster instead of spending years moving through complex recycling and manufacturing processes.
The research team worked with scientists at Argonne National Laboratory’s ReCell Center to evaluate the economic and environmental impacts of the technology.
Currently, the method has been tested on used batteries that still retain about 70% to 80% of their original health, which is common for batteries removed from electric vehicles. The researchers are now working on adapting the technology for large industrial batteries and finding ways to address other forms of battery aging, including the gradual loss of lithium.
If successful on a larger scale, this battery “bath” could help extend battery life, lower recycling costs, and reduce the need for newly mined materials, making the growing battery industry more sustainable for the future.
