researching for the future

Houston scientists discover breakthrough process for lithium-ion battery recycling

The Rice team's process is up to 10 times more effective than existing lithium-ion battery recycling. Photo by Gustavo Raskosky/Rice University

With the rise of electric vehicles, every ounce of lithium in lithium-ion batteries is precious. A team of scientists from Rice University has figured out a way to retrieve as much as 50 percent of the material in used battery cathodes in as little as 30 seconds.

Researchers at Rice University’s Nanomaterials Laboratory led by Department of Materials Science and NanoEngineering Chair Pulickel Ajayan released the findings a new study published in Advanced Functional Materials. Their work shows that the process overcomes a “bottleneck” in lithium-ion battery recycling technology. The researchers described a “rapid, efficient and environmentally friendly method for selective lithium recovery using microwave radiation and a readily biodegradable solvent,” according to a news release.

Past recycling methods have involved harsh acids, and alternative eco-friendly solvents like deep eutectic solvents (DESs) at times have not been as efficient and economically viable. Current recycling methods recover less than 5 percent of lithium, which is due to contamination and loss during the process.

In order to leach other metals like cobalt or nickel, both the choline chloride and the ethylene glycol have to be involved in the process, according to the researchers at Rice. The researchers submerged the battery waste material in the solvent and blasted it with microwave radiation since they knew that of the two substances only choline chloride is good at absorbing microwaves.

Microwave-assisted heating can achieve similar efficiencies like traditional oil bath heating almost 100 times faster. Using the microwave-based process, Rice found that it took 15 minutes to leach 87 percent of the lithium, which differs from the 12 hours needed to obtain the same recovery rate via oil bath heating.

“This method not only enhances the recovery rate but also minimizes environmental impact, which makes it a promising step toward deploying DES-based recycling systems at scale for selective metal recovery,” Ajayan says in the release.

Due to rise in EV production, the lithium-ion battery global market is expected to grow by over 23 percent in the next eight years, and was previously valued at over $65 billion in 2023.

“We’ve seen a colossal growth in LIB use in recent years, which inevitably raises concerns as to the availability of critical metals like lithium, cobalt and nickel that are used in the cathodes,” the study's co-author, Sohini Bhattacharyya, adds. “It’s therefore really important to recycle spent LIBs to recover these metals.”

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A View From HETI

Fervo Energy has landed a coveted spot on MIT Technology Review's list of global climatetech companies to watch. Photo via fervoenergy.com

Houston-based Fervo Energy has received yet another accolade—MIT Technology Review named the geothermal energy startup to its 2025 list of the 10 global climatetech companies to watch.

Fervo, making its second appearance on the third annual list, harnesses heat from deep below the ground to generate clean geothermal energy, MIT Technology Review noted. Fervo is one of four U.S. companies to land on the list.

Fervo “uses fracking techniques to create geothermal reservoirs capable of delivering enough electricity to power massive data centers and hundreds of thousands of homes,” MIT Technology Review said.

MIT Technology Review said it produces the annual list to draw attention to promising climatetech companies that are working to decarbonize major sectors of the economy.

“Though the political and funding landscape has shifted dramatically in the US since the last time we put out this list,” MIT Technology Review added, “nothing has altered the urgency of the climate dangers the world now faces — we need to rapidly curb greenhouse gas emissions to avoid the most catastrophic impacts of climate change.”

In addition to MIT Technology Review’s companies-to-watch list, Fervo has appeared on similar lists published by Inc.com, Time magazine and Climate Insider.

In an essay accompanying MIT Technology Review’s list, Microsoft billionaire Bill Gates said his Breakthrough Energy Ventures investment group has invested in more than 150 companies, including Fervo and another company on the MIT Technology Review list, Redwood Materials.

In his essay, Gates wrote that ingenuity is the best weapon against climate change.

Yet climate technology innovations “offer more than just a public good,” he said. “They will remake virtually every aspect of the world’s economy in the coming years, transforming energy markets, manufacturing, transportation, and many types of industry and food production. Some of these efforts will require long-term commitments, but it’s important that we act now. And what’s more, it’s already clear where the opportunities lie.”

In a recent blog post highlighting Fervo, Gates predicted geothermal will eventually supply up to 20 percent of the world’s electricity, up from his previous estimate of as much as 5 percent.

Fervo is one of the pioneers in geothermal energy. Gates and other investors have pumped $982 million into Fervo since its founding in 2017. With an estimated valuation of $1.4 billion, Fervo has achieved unicorn status, meaning its valuation as a private company exceeds $1 billion.

Aside from Breakthrough Energy Ventures, oilfield services provider Liberty Energy is a Fervo investor. U.S. Energy Secretary Chris Wright was chairman and CEO of Denver-based Liberty Energy before assuming his federal post.

Axios reported on Oct. 1 that Fervo is raising a $300 million series E round, which would drive up the startup’s valuation. News of the $300 million round comes as the company gears up for a possible IPO, according to Axios.

Fervo co-founder and CEO Tim Latimer told Axios this spring that a potential IPO is likely in 2026 or 2027. Ahead of an IPO, the startup is aiming for a $2 billion to $4 billion valuation, Axios reported.

The first phase of Fervo’s marquee Cape Station geothermal energy plant in Utah is scheduled to go online next year, with the second phase set to open in 2028. Once it’s completed, the plant will be capable of generating 500 megawatts of power. This summer, the startup said it secured $205.6 million in capital to finance construction of the plant.

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