Scientists at the University of Leicester have discovered a surprisingly simple way to recycle lithium-ion batteries—using only water and cooking oil to extract valuable metals in just minutes.
The innovative new method removes low-value materials from the crushed remains of discarded lithium-ion batteries, leaving only the purified metals hidden within the mix.
Billions of batteries power our increasingly electric world, from smartphones to electric vehicles. As the U.S. moves toward greater domestic manufacturing, competition for expensive or rare materials has intensified globally. This new recycling method could offer a cheaper and more sustainable alternative to existing practices, helping to ease supply chain pressures.
Professor Andy Abbot and Dr. Jake Yang at the University of Leicester developed the technique under the Faraday Institution’s ReLiB project. Their method capitalizes on the well-known principle that “oil and water don’t mix,” using nano-emulsions formed by the liquids to separate valuable battery-grade metal oxides from crushed battery material.
A New Method for Sustainability
The research builds on previous findings that reveal how ultrasound can create nano-droplets of oil, which can remain stable for weeks. The batteries are first crushed and placed in water, after which the oil nano-droplets, acting like glue, bind hydrophobic graphite particles into an oily mass that floats to the surface. This step effectively removes the carbon from the valuable lithium, nickel, and cobalt oxides in the crushed batteries.
Finally, the oil-graphite mixture can be skimmed off, leaving behind the purified metals for reuse. This approach vastly streamlines current recycling techniques, which typically require burning off the graphite in a furnace before reducing the remaining materials to their precursor state.
The current method requires heavy industrial equipment and has several environmental and economic drawbacks. Burning off the carbon adds significantly to the EV supply chain’s carbon footprint, an issue that is at odds with the goal of making EVs more sustainable.
Additionally, precursor materials recovered through chemical processing are much less valuable and require further refinement than those extracted via the new oil-and-water method.
A Better Starting Point
One of the most significant advantages of the University of Leicester team’s new process is the quality of its end product. Battery-grade crystalline structures are preserved, allowing recovered materials to be directly reused in battery production—eliminating several costly refining steps. In contrast, traditional pyrometallurgical and hydrometallurgical recycling methods introduce additional processing, increasing costs.
“This quick, simple, and inexpensive method could revolutionize how batteries are recycled at scale. We now hope to work with various stakeholders to scale up this technology and create a circular economy for lithium-ion batteries,” Dr. Yang said in a press release.
Continuing Work for Sustainability
The UK government’s innovation agency, Innovate UK, is funding the ReBlend project, a collaboration between the Universities of Leicester and Birmingham, to apply ReLiB’s breakthroughs. The initiative aims to develop a pilot line capable of processing tens of kilograms of black mass per hour, providing a real-world demonstration of environmentally friendly and economically viable short-loop battery recycling.
Battery recycling remains one of the biggest challenges in the EV industry. Manufacturers have struggled to efficiently and sustainably recycle batteries, which limits the technology’s environmental and economic benefits. While there are currently around 40 million EVs worldwide, they are vastly outnumbered by an estimated 10 billion active cell phones, laptops, and tablets. With no regulations requiring recyclability, most of these batteries were not designed with reuse in mind.
“The ReLiB project is one of the Faraday Institution’s flagship projects, developing innovative technology to capture value and retain scarce resources in the circular economy of battery manufacture and recycling,” said Professor Martin Freer, CEO of the Faraday Institution.
“This work offers a promising route for short-loop recycling of lithium-ion batteries at scale,” he added.
The paper, “Using Ultrasonic Oil-water Nano-emulsions to Purify Lithium-ion Battery Black Mass,” appeared on January 31, 2025, in RSC Sustainability.
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.