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

A new study from Rice’s Kinder Institute reports Houston has been "losing ground" since the oil crash. Photo via Unsplash

A new study from Rice’s Kinder Institute shows that Houston is still feeling the economic effects of the 2014-2016 oil crash, more than a decade later.

Though Houston, nicknamed the Energy Capital of the World, has continued to grow over the time period, the city has still fallen behind other comparable metropolitan areas in earnings and job creation, according to the research. The report is one part of a three-part series that will take a look at regional economic mobility and suggest ideas to expand opportunity.

“When you look at what’s happened in other locations, we’re losing ground,” Flávio Cunha, director of the Center for Economic Mobility at Rice’s Kinder Institute for Urban Research, said in a release. “Our economy is growing, but it’s no longer growing at the rate it used to.”

Global oil prices fell 70 percent between 2014 and 2016, the report said, marking one of the three largest declines since World War II and the longest-lasting downturn since 1986. The report excluded pandemic-related gaps, and it mentions 2017’s Hurricane Harvey as a possible indicator that economic growth stalled after the 2014-2016 oil price crash recovery.

To understand the long-term impact of the crash, researchers compared Houston’s economic performance with 54 metropolitan areas like San Antonio, Pittsburgh and others with less dependence on the energy industry.

Some of the key findings in the report included:

  • Job creation: In 2019, Houston had approximately 240,000 fewer private-sector jobs than similar cities. Employment was 15 percent lower in goods-producing industries and 4 percent lower in the services industries than the control group.
  • Income shifts: Income per resident was 13 percent lower compared to the peer group. Workers who remained employed earned 10 percent less between 2015 and 2019 than in other metros. The 13 percent drop in income equates to roughly $76 billion a year in forgone income, or $10,700 per resident per year in 2025 dollars. The decline was a trend across every age group, education level and sex.
  • Population changes: The rate of people moving to Houston slowed, rather than a surge of people leaving.
  • Hiring changes: Hiring fell sharply for young workers ages 19-24.

Cunha says the most surprising finding was that these trends persisted a decade later. According to the report, by 2024, Houston’s wages and income per resident remained about a fifth and a sixth below those in peer cities, and jobs per resident had continued to lose ground.

“What really surprises me is not that there was this change. It’s that this change has been long-lasting,” he added. “We followed it up to 2024, and we still don’t detect that the economy has recovered from that one shock.”

Read the full report here.

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