As the demand for batteries is on the upswing, manufacturers are pressed to find ready sources of raw materials to meet the high demand. New methods of extracting metals from spent batteries show promise as a means of recycling precious metals such as cobalt and nickel.

In the past, spent batteries were not often recycled. Doing so was a messy process that was time-consuming, cumbersome and often not worth the effort.

Researchers at Rice University have developed a process known as flash Joule heating, which involves subjecting battery waste to extremely high temperatures for a brief time. With this technique, what used to take close to 24 hours can now be accomplished in 20 minutes.

This process, published in the December 2023 issue of the scientific journal “Science Advances,” has proven effective in liberating valuable metals, such as nickel and cobalt, from the complex structure of spent batteries. There is potential to streamline metal recovery from discarded batteries, addressing challenges associated with resource scarcity and environmental sustainability. The extracted metals can be repurposed to produce new batteries, contributing to a closed-loop and circular approach to materials in the battery industry.

“Battery recycling is a very big deal, especially now,” said James Tour, professor of materials science and nano-engineering at Rice. “Batteries in electric vehicles last about 10 years, and many of those are coming due now, because it’s been about 10 years that we’ve been using them.”

The flash Joule heating method offers a more efficient and sustainable solution. By rapidly heating the battery waste, the researchers observed that the metals could be easily separated, allowing for a more straightforward and cost-effective recovery process. This technique simplifies the metal recovery process and aligns with the broader goals of creating a more sustainable and environmentally friendly approach to battery recycling.

“Currently, 95% of batteries are not recycled because we don’t have the capacity to recycle them, even as waste from electronics is increasing at an annual rate of 9%,” Tour said, whose lab previously developed a process for recycling battery anodes. “A lot of current battery recycling processes involve the use of very strong acids, and these tend to be messy, cumbersome processes. What we found is that if you ‘flash’ the black mass, then you can easily separate out the critical metals using only low-concentration hydrochloric acid. You could say the flash liberates the metals, so they dissolve easier. We’re still using acid, but much less. That’s why the economics is so much better.”