Rice University scientists' “recharge-to-recycle” reactor has major implications for the electric vehicle sector. Photo courtesy Jorge Vidal/Rice University.

Engineers at Rice University have developed a cleaner, innovative process to turn end-of-life lithium-ion battery waste into new lithium feedstock.

The findings, recently published in the journal Joule, demonstrate how the team’s new “recharge-to-recycle” reactor recharges the battery’s waste cathode materials to coax out lithium ions into water. The team was then able to form high-purity lithium hydroxide, which was clean enough to feed directly back into battery manufacturing.

The study has major implications for the electric vehicle sector, which significantly contributes to the waste stream from end-of-life battery packs. Additionally, lithium tends to be expensive to mine and refine, and current recycling methods are energy- and chemical-intensive.

“Directly producing high-purity lithium hydroxide shortens the path back into new batteries,” Haotian Wang, associate professor of chemical and biomolecular engineering, co-corresponding author of the study and co-founder of Solidec, said in a news release. “That means fewer processing steps, lower waste and a more resilient supply chain.”

Sibani Lisa Biswal, chair of Rice’s Department of Chemical and Biomolecular Engineering and the William M. McCardell Professor in Chemical Engineering, also served as co-corresponding author on the study.

“We asked a basic question: If charging a battery pulls lithium out of a cathode, why not use that same reaction to recycle?” Biswal added in the release. “By pairing that chemistry with a compact electrochemical reactor, we can separate lithium cleanly and produce the exact salt manufacturers want.”

The new process also showed scalability, according to Rice. The engineers scaled the device to 20 square centimeters, then ran a 1,000-hour stability test and processed 57 grams of industrial black mass supplied by industry partner Houston-based TotalEnergies. The results produced lithium hydroxide that was more than 99 percent pure. It also maintained an average lithium recovery rate of nearly 90 percent over the 1,000-hour test, showing its durability. The process also worked across multiple battery chemistries, including lithium iron phosphate, lithium manganese oxide and nickel-manganese-cobalt variants.

Looking ahead, the team plans to scale the process and consider ways it can sustain high efficiency for greater lithium hydroxide concentrations.

“We’ve made lithium extraction cleaner and simpler,” Biswal added in the release. “Now we see the next bottleneck clearly. Tackle concentration, and you unlock even better sustainability.

Houston-based Solidec has closed an oversubscribed pre-seed round led by New Climate Ventures. Photo courtesy Greentown Labs.

Houston clean-chemicals startup Solidec raises $2M to scale tech

fresh funding

Solidec, a Houston startup that specializes in manufacturing “clean” chemicals, has raised more than $2 million in pre-seed funding.

Houston-based New Climate Ventures led the oversubscribed pre-seed round, with participation from Plug and Play Ventures, Ecosphere Ventures, the Collaborative Fund, Safar Partners, Echo River Capital and Semilla Climate Capital, among other investors.

Solidec’s approach to chemical manufacturing replaces centralized infrastructure with modular on-site production using only air, water and electricity. Solidec’s platform is powered by modular reactors capable of producing widely used chemicals such as hydrogen peroxide, formic acid, acetic acid and ethylene.

“We’ve known the Solidec team for almost two years and have developed a high degree of conviction in the team, their technology, and their go-to-market strategy,” Eric Rubenstein, managing partner at New Climate Ventures, said in a news release. “We’re particularly excited about Solidec’s ability to produce many different widely used chemicals. It gives them critical flexibility to expand and serve a broad customer base.”

Solidec is initially focusing on hydrogen peroxide.

“Traditionally, hydrogen peroxide is produced in centralized, energy-intensive facilities using carbon-intensive inputs, then transported long distances, resulting in a significant carbon footprint,” Ryan DuChanois, co-founder and CEO of Solidec, said in the release. “Solidec’s modular reactor produces clean chemicals like hydrogen peroxide on-site, in fewer steps, and with less energy, slashing emissions, supply-chain risk, and cost.”

Solidec said its technology “is poised to disrupt the multibillion-dollar commodity and chemical industries.” The company has already signed up several customers.

The startup, a Rice University spinout, is a graduate of the Chevron Catalyst Program and a member of Greentown Labs Houston. It was cofounded by DuChanois, Haotian Wang and Yang Xia.

New research from Rice and UH has helped boost the lifespan of CO2RR systems, a newer technology used for carbon capture. Photo via htxenergytransition.org

Rice University and UH labs team up to improve emerging carbon capture technique

new findings

A team of researchers led by professors from two Houston universities has discovered new methods that help stabilize an emerging technique known as carbon dioxide reduction reaction, or CO2RR, that is used for carbon capture and utilization processes.

The team led by Rice University’s Haotian Wang, associate professor in chemical and biomolecular engineering, and Xiaonan Shan, associate professor of electrical and computer engineering at University of Houston, published its findings in a recent edition of the journal Nature Energy.

CO2RR is an emerging carbon capture and utilization technique where electricity and chemical catalysts are used to convert carbon dioxide gas into carbon-containing compounds like alcohols, ethylene, formic acids or carbon monoxide, according to a news release from Rice. The result can be used as fuels, chemicals or as starting materials to produce other compounds.

The technology is used in commercial membrane electrode assembly (MEA) electrolyzers to convert carbon dioxide into valuable compounds, but the technology isn’t perfected. A significant challenge in CO2RR technology has been the accumulation of bicarbonate salt crystals on the backside of the cathode gas diffusion electrode and within the gas flow channels. The salt precipitates block the flow of carbon dioxide gas through the cathode chamber, which reduce the performance and can cause a failure of the electrolyzers.

The goal in the study was to understand why and how bicarbonate salts form during this reaction. The Rice and UH teams worked together using operando Raman spectroscopy, which is a technique that allows researchers to study the structure of materials and any precipitates that adhere to them while the device is functioning.

“By utilizing operando Raman spectroscopy and optical microscopy, we successfully tracked the movement of bicarbonate-containing droplets and identified their migration pattern,” Shan said in the release. “This provided us the information to develop an effective strategy to manage these droplets without interrupting system stability.”

Next, the team worked to prevent the salt crystals from forming. First, they tested lowering the concentration of cations, like sodium or potassium, in the electrolyte to slow down the salt formation. This method proved to be effective.

They also coated the cathode with parylene, a synthetic polymer that repels water, like Teflon, which also notably improved the stability of the electrolyzer and prevented salt accumulation.

“Inspired by the waxy surface of the lotus leaf which causes water droplets to bead up and roll off, carrying off any dirt particles with it and leaving the leaf’s surface clean, we wondered if coating the gas flow channel with a nonstick substance will prevent salt-laden droplets from staying on the surface of the electrodes for too long and, therefore, reduce salt buildup.” Wang said in the release.

According to Wang, these relatively simple discoveries can extend the operational lifespan of CO2RR systems from a few hundred hours to over 1,000 hours.

The findings also have major implications for commercial applications, Shan added.

“This advancement paves the way for longer-lasting and more reliable (CO2RR) systems, making the technology more practical for large-scale chemical manufacturing,” Shan said in the release. “The improvements we developed are crucial for transitioning CO2 electrolysis from laboratory setups to commercial applications for producing sustainable fuels and chemicals.”

Rice professor and Solidec co-founder Haotian Wang's research enables CO2 to be converted into valuable chemicals and fuels. Photo courtesy Welch Foundation.

Houston clean energy pioneer earns prestigious Welch Foundation award

Awards Season

A Rice University professor has earned a prestigious award from the Houston-based Welch Foundation, which supports chemistry research.

The foundation gave its 2025 Norman Hackerman Award in Chemical Research to Haotian Wang for his “exceptionally creative” research involving carbon dioxide electrochemistry. His research enables CO2 to be converted into valuable chemicals and fuels.

The award included $100,000 and a bronze sculpture.

“Dr. Wang’s extensive body of work and rigorous pursuit of efficient electrochemical solutions to practical problems set him apart as a top innovator among early-career researchers,” Catherine Murphy, chairwoman of the foundation’s Scientific Advisory Board, said in a news release.

Wang is an associate professor in the Department of Chemical and Biomolecular Engineering at Rice. The department’s Wang Group develops nanomaterials and electrolyzers for energy and environmental uses, such as energy storage, chemical and fuel generation, green synthesis and water treatment.

Wang also is co-founder of Solidec, a Houston startup that aims to turn his innovations into low-carbon fuels, carbon-negative hydrogen and carbon-neutral peroxide. The startup extracts molecules from water and air, then transforms them into pure chemicals and fuels that are free of carbon emissions.

Solidec has been selected for Chevron Technology Ventures’ catalyst program, a Rice One Small Step grant, a U.S. Department of Energy grant, and the first cohort of the Activate Houston program.

“Dr. Wang’s use of electrochemistry to close the carbon cycle and develop renewable sources of industrial chemicals directly intersects with the Welch Foundation mission of advancing chemistry while improving life,” Fred Brazelton, chairman and director of the Welch Foundation, said in the release.

Ramamoorthy Ramesh, executive vice president for research at Rice University, added: “We are proud to (Dr. Wang) at Rice. He’s using chemical engineering to solve a big problem for humanity, everything that the Welch Foundation stands for.”

Last year, the Hackerman Award went to Baylor College of Medicine's Livia Schiavinato Eberlin, who's known for her groundbreaking work in the application of mass spectrometry technologies, which are changing how physicians treat cancer and analyze tissues. Read more here.

Led by Haotian Wang (left) and Feng-Yang Chen, the Rice University team published a study this month detailing how its reactor system sustainably converts waste into ammonia. Photo by Jeff Fitlow/Rice University

Houston lab develops reactor that sustainably turns waste into ammonia

seeing green

A team of Rice University engineers has developed a reactor design that can decarbonize ammonia production, produce clean water and potentially have applications in further research into other eco-friendly chemical processes.

Led by Rice associate professor Haotian Wang, the team published a study this month in the journal Nature Catalysis that details how the new reactor system sustainably and efficiently converts nitrates (common pollutants found in industrial wastewater and agricultural runoff) into ammonia, according to the university. The research was supported by Rice and the National Science Foundation.

“Our findings suggest a new, greener method of addressing both water pollution and ammonia production, which could influence how industries and communities handle these challenges,” Wang says in a statement. “If we want to decarbonize the grid and reach net-zero goals by 2050, there is an urgent need to develop alternative ways to produce ammonia sustainably.”

Other methods of creating ammonia include the Haber-Bosh process and electrochemical synthesis. The Haber-Bosh process requires large-scale centralized infrastructure and high temperature and pressure conditions. Meanwhile, electrochemical synthesis requires a high concentration of additive chemicals.

According to Rice, the new reactor requires less additive chemicals than the electrochemical synthesis, allowing nitrates to be converted more sustainably. The reactor relies on an innovative porous solid electrolyte as well as recyclable ions and a three-chamber system to improve the reaction’s efficiency.

Additionally, this development provides an effective water decontamination method.

“We conducted experiments where we flowed nitrate-contaminated water through this reactor and measured the amount of ammonia produced and the purity of the treated water,” Feng-Yang Chen, a Rice graduate student who is the lead author on the study, says. “We discovered that our novel reactor system could turn nitrate-contaminated water into pure ammonia and clean water very efficiently, without the need for extra chemicals. In simple terms, you put wastewater in, and you get pure ammonia and purified water out.”

Pedro Alvarez, the George R. Brown Professor of Civil and Environmental Engineering, director of the Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment (NEWT) and the Water Technologies Entrepreneurship and Research (WaTER) Institute at Rice, says the reactor is "very timely and important" for growing cities that must deal with nitrate-contaminated groundwater supplies it.

"Conventional nitrate removal in drinking water treatment involves ion exchange or membrane filtration by reverse osmosis, which generates brines and transfers the nitrate problem from one phase to another,” he continues.

Wang's lab has been making headlines in recent years for innovative processes and technologies focused on the energy transition.

Last year, the lab published a study in Nature detailing a new technology that uses electricity to remove carbon dioxide from air capture to induce a water-and-oxygen-based electrochemical reaction, generating between 10 to 25 liters of high-purity carbon using only the power of a standard lightbulb.

In 2022, Rice reported that Wang’s lab in the George R. Brown School of Engineering had also replaced rare, expensive iridium with ruthenium, a more abundant precious metal, as the positive-electrode catalyst in a reactor that splits water into hydrogen and oxygen.

The lab received a portion of $10.8 million in research grants from the Houston-based Welch Foundation for research focused on converting carbon dioxide into useful chemicals, such as ethanol, last year. And Solidec, founded by Ryan Duchanois and Yang Xia from Wang's Lab, also received a $100,000 award from Rice as part of the One Small Step Grant program.

Wang has also been named among one of the most-cited researchers in the world.
Peng Zhu (left) and Haotian Wang developed a carbon-capture device prototype. Photos courtesy Jeff Fitlow/Rice University

Rice scientists develop simple but game-changing carbon capture device

small scale, big impact

A Rice University lab has developed an efficient, scalable way to capture carbon dioxide — and it just needs to be plugged into a power outlet to work.

The new technology developed in the lab of chemical and biomolecular engineer Haotian Wang, the William Marsh Rice Trustee Chair and an associate professor at Rice, uses electricity to remove carbon dioxide from air capture to induce a water-and-oxygen-based electrochemical reaction. The findings were shared in a study published in Nature last month.

Traditionally, carbon capture requires very energy intensive processes that need high temperatures and for the carbon that's been captured to be regenerated. The process also often requires large-scale infrastructure.

In the Wang lab's method, the small reactor can continuously remove carbon dioxide from a simulated flue gas with nearly 100 percent efficiency, generating between 10 to 25 liters of high-purity carbon using only the power of a standard lightbulb, according to a statement from Rice.

It does not create or consume chemicals, nor does it need to be heated up or pressurized, according to Wang. And it only requires a simple power source.

"The technology can be scaled up to industrial settings—power plants, chemical plants—but the great thing about it is that it allows for small-scale use as well: I can even use it in my office,” Wang says in the statement. “We could, for example, pull carbon dioxide from the atmosphere and continuously inject that concentrated gas into a greenhouse to stimulate plant growth. We’ve heard from space technology companies interested in using the device on space stations to remove the carbon dioxide astronauts exhale.”

Wang and lab member Peng Zhu, a chemical and biomolecular engineering graduate student at Rice and lead author on the study, initially made the discovery when working on an earlier version of the reactor intended for carbon dioxide utilization.

During this process Zhu noticed that gas bubbles flowed out of the reactor’s middle chamber when producing liquid products like acetic acid and formic acid, and that the number of bubbles would increase when more current was applied to the reactor.

This led the scientists to realize that the reactor was creating carbonate ions that were converted into a continuous flow of high-purity carbon dioxide after passing through the reactor's solid-electrolyte layer.

“Scientific discovery often requires this patient, continuous observation and the curiosity to learn what’s really going on, the choice not to neglect those phenomena that don’t necessarily fit in the experimental frame," Wang said in a statement.

A number of players in the Houston area have been making headway in carbon capture space in recent weeks.

Earlier this summer, the U.S. Department of Energy granted more than $45 million in federal funding to four Houston companies to promote the capture, transportation, use, and storage of tons of carbon dioxide emissions.

The Rice Alliance also recently named 15 startups to its Clean Energy Accelerator. A number of the fledgling companies are focused on carbon management and capture.

Video by Brandon Martin/Rice University

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Houston geothermal company raises $97M Series B

fresh funding

Houston-based geothermal energy startup Sage Geosystems has closed its Series B fundraising round and plans to use the money to launch its first commercial next-generation geothermal power generation facility.

Ormat Technologies and Carbon Direct Capital co-led the $97 million round, according to a press release from Sage. Existing investors Exa, Nabors, alfa8, Arch Meredith, Abilene Partners, Cubit Capital and Ignis H2 Energy also participated, as well as new investors SiteGround Capital and The UC Berkeley Foundation’s Climate Solutions Fund.

The new geothermal power generation facility will be located at one of Ormat Technologies' existing power plants. The Nevada-based company has geothermal power projects in the U.S. and numerous other countries around the world. The facility will use Sage’s proprietary pressure geothermal technology, which extracts geothermal heat energy from hot dry rock, an abundant geothermal resource.

“Pressure geothermal is designed to be commercial, scalable and deployable almost anywhere,” Cindy Taff, CEO of Sage Geosystems, said in the news release. “This Series B allows us to prove that at commercial scale, reflecting strong conviction from partners who understand both the urgency of energy demand and the criticality of firm power.”

Sage reports that partnering with the Ormat facility will allow it to market and scale up its pressure geothermal technology at a faster rate.

“This investment builds on the strong foundation we’ve established through our commercial agreement and reinforces Ormat’s commitment to accelerating geothermal development,” Doron Blachar, CEO of Ormat Technologies, added in the release. “Sage’s technical expertise and innovative approach are well aligned with Ormat’s strategy to move faster from concept to commercialization. We’re pleased to take this natural next step in a partnership we believe strongly in.”

In 2024, Sage agreed to deliver up to 150 megawatts of new geothermal baseload power to Meta, the parent company of Facebook. At the time, the companies reported that the project's first phase would aim to be operating in 2027.

The company also raised a $17 million Series A, led by Chesapeake Energy Corp., in 2024.

Houston expert discusses the clean energy founder's paradox

Guest Column

Everyone tells you to move fast and break things. In clean energy, moving fast without structural integrity means breaking the only planet we’ve got. This is the founder's paradox: you are building a company in an industry where the stakes are existential, the timelines are glacial, and the capital requires patience.

The myth of the lone genius in a garage doesn’t really apply here. Clean energy startups aren’t just fighting competitors. They are fighting physics, policy, and decades of existing infrastructure. This isn’t an app. You’re building something physical that has to work in the real world. It has to be cheaper, more reliable, and clearly better than fossil fuels. Being “green” alone isn’t enough. Scale is what matters.

Your biggest risks aren’t competitors. They’re interconnection delays, permitting timelines, supply chain fragility, and whether your first customer is willing to underwrite something that hasn’t been done before.

That reality creates a brutal filter. Successful founders in this space need deep technical knowledge and the ability to execute. You need to understand engineering, navigate regulation, and think in terms of markets and risk. You’re not just selling a product. You’re selling a future where your solution becomes the obvious choice. That means connecting short-term financial returns with long-term system change.

The capital is there, but it’s smarter and more demanding. Investors today have PhDs in electrochemistry and grid dynamics. They’ve been burned by promises of miracle materials that never left the lab. They don't fund visions; they fund pathways to impact that can scale and make financial sense. Your roadmap must show not just a brilliant invention, but a clear, believable plan to drive costs down over time.

Capital in this sector isn’t impressed by ambition alone. It wants evidence that risk is being retired in the right order — even if that means slower growth early.

Here’s the upside. The difficulty of clean energy is also its strength. If you succeed, your advantage isn’t just in software or branding. It’s in hardware, supply chains, approvals, and years of hard work that others can’t easily copy. Your real competitors aren’t other startups. They’re inertia and the existing system. Winning here isn’t zero-sum. When one solution scales, it helps the entire market grow.

So, to the founder in the lab, or running field tests at a remote site: your pace will feel slow. The validation cycles are long. But you are building in the physical world. When you succeed, you don’t have an exit. You have a foundation. You don't just have customers; you have converts. And the product you ship doesn't just generate revenue; it creates a legacy.

If your timelines feel uncomfortable compared to software, that’s because you’re operating inside a system designed to resist change. And let’s not forget you are building actual physical products that interact with a complex world. Times are tough. Don’t give up. We need you.

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Nada Ahmed is the founding partner at Houston-based Energy Tech Nexus.

Houston maritime startup raises $43M to electrify cargo vessels

A Houston-based maritime technology company that is working to reduce emissions in the cargo and shipping industry has raised VC funding and opened a new Houston headquarters.

Fleetzero announced that it closed a $43 million Series A financing round this month led by Obvious Ventures with participation from Maersk Growth, Breakthrough Energy Ventures, 8090 Industries, Y Combinator, Shorewind, Benson Capital and others. The funding will go toward expanding manufacturing of its Leviathan hybrid and electric marine propulsion system, according to a news release.

The technology is optimized for high-energy and zero-emission operation of large vessels. It uses EV technology but is built for maritime environments and can be used on new or existing ships with hybrid or all-electric functions, according to Fleetzero's website. The propulsion system was retrofitted and tested on Fleetzero’s test ship, the Pacific Joule, and has been deployed globally on commercial vessels.

Fleetzero is also developing unmanned cargo vessel technology.

"Fleetzero is making robotic ships a reality today. The team is moving us from dirty, dangerous, and expensive to clean, safe, and cost-effective. It's like watching the future today," Andrew Beebe, managing director at Obvious Ventures, said in the news release. "We backed the team because they are mariners and engineers, know the industry deeply, and are scaling with real ships and customers, not just renderings."

Fleetzero also announced that it has opened a new manufacturing and research and development facility, which will serve as the company's new headquarters. The facility features a marine robotics and autonomy lab, a marine propulsion R&D center and a production line with a capacity of 300 megawatt-hours per year. The company reports that it plans to increase production to three gigawatt-hours per year over the next five years.

"Houston has the people who know how to build and operate big hardware–ships, rigs, refineries and power systems," Mike Carter, co-founder and COO of Fleetzero, added in the release. "We're pairing that industrial DNA with modern batteries, autonomy, and software to bring back shipbuilding to the U.S."