Kentucky’s bourbon industry produces vast quantities of waste grain that is costly to transport and process. Researchers have now found a way to turn that by-product into high-performance energy-storage materials with potential applications in electric vehicles and large-scale grid storage.

More than 95 percent of all bourbon whiskey is made in Kentucky. For each barrel of bourbon, the industry also produces between six and 10 times as much “stillage”—a slurry of spent grain and water. This is normally sold to farmers as a livestock feed or soil additive, but it needs to be dried out first to reduce the weight and make it easier to process.

This is a major burden on distilleries, says Josiel Barrios Cossio, a graduate student in the University of Kentucky’s chemistry department. It either requires a lot of time and space to dry the stillage out via evaporation, or an expensive heating process. He and his colleagues have demonstrated that they can instead directly convert the wet stillage into useful carbon materials that can be used to make electrodes for batteries and supercapacitors.

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In research presented at the spring meeting of the American Chemical Society in Atlanta today, Barrios Cossio showed that the carbon materials could be used to create supercapacitors that match or exceed the energy density of commercial devices, and hybrid lithium-ion supercapacitors that can store up to 25 times as much energy as conventional designs. While the work is just a proof-of-concept, Barrios Cossio says, it could ultimately allow distilleries to turn a waste stream into a source of profit.

“And it’s a win-win scenario, because we can potentially have a more renewable and abundant biomass source, or feedstock, to produce these materials that are every day more in demand from the car industry and renewable energy applications,” he says.

Innovative Energy-Storage Solutions

Barrios Cossio first conceived of the idea while taking part in a research traineeship run by the U.S. National Science Foundation aimed at finding solutions to problems related to water, energy, and food systems. After visiting several distilleries and seeing the scale of the waste produced, as well as the challenges these businesses face in disposing of it, he began thinking of ways to put the stillage to more productive use.

He discovered a group at the Friedrich Schiller University Jena, in Jena, Germany, that had developed a process for converting waste grain from beer breweries into electrode materials for energy-storage devices. Barrios Cossio then spent a summer internship at the lab to learn about their techniques.

After returning to the United States, Barrios Cossio contacted several distilleries to source some stillage to experiment with and soon got a response from the Wilderness Trail Distillery in Danville, Kentucky. “I asked them, ‘Can I take a gallon of stillage?’” he says. “They replied to me some days later saying, ‘Yeah, you are welcome to take it. I would prefer that you take 10,000 gallons and get rid of the stillage from that day.’”

University of Kentucky researchers developed supercapacitor electrodes using bourbon distillery waste that can store more energy per kilogram than commercial devices.Josiel Barrios Cossio

To turn the stillage into useful materials, the researchers relied on a process called hydrothermal carbonization. This involves heating the wet slurry at high pressure to create a fine black carbon powder called hydrochar. One benefit of the process, says Barrios Cossio, is that the high water content of the stillage helps generate the pressure required to power the conversion.

The resulting hydrochar was then used to create two different high-value carbon materials. In one experiment, the team combined the hydrochar with potassium hydroxide and heated the mixture to around 800 °C, creating a material called activated carbon. This material is extremely porous, which means it can have a surface area higher than 1,000 square meters per gram, says Barrios Cossio. That makes it ideal for creating high-capacity supercapacitors, which store energy as charged ions on the surface of the electrode material.

The team showed that a coin-sized double-layer capacitor built using their hydrochar-derived electrodes could store up to 48 watt hours per kilogram—on par with commercially available supercapacitors.

The team also showed that they could create “hard carbon” by heating their hydrochar in a furnace at 200 °C. This material has a similar structure to graphite, which is made up of orderly stacks of single-atom-thick graphene sheets. Unlike graphite, however, in hard carbon the sheets are arranged more haphazardly. This leads to many small pores and defects, which are ideal for storing alkali metal ions, such as lithium and sodium, commonly used in batteries.

Barrios Cossio used their hydrochar-derived hard carbon to create a batterylike electrode infused with lithium ions, and then combined this with an electrode made of activated carbon to produce a hybrid supercapacitor. The device represents a balance between the high-energy capacity of batteries and the fast discharging speeds of capacitors, which Barrios Cossio says could be particularly useful for applications like electric vehicles and grid stabilization.

At present, the devices are just a proof-of-concept. Barrios Cossio admits that scaling up the process to industrial levels will require considerable refinement. The team is also currently conducting a techno-economic analysis to assess whether the approach is commercially viable. But project supervisor Marcelo Guzman, a professor of chemistry at the University of Kentucky, says it could be a promising and sustainable way to meet the growing demand for energy storage.

“Kentucky is a state that has been investing since 2019 heavily in trying to develop an industry for batteries for cars,” he says. “There has been billions of dollars going into that sector, so there is going to be a big need for material supply. We think we came on board with that problem at the right time, in the right place, and we could have materials that could be really interesting to the battery industry.”

Canada-based Northern Graphite and Saudi industrial group Obeikan Investment have signed a financing agreement to jointly develop and operate a large-scale battery anode material (BAM) facility in Saudi Arabia through a joint venture company.

The $200-million BAM facility will have an initial annual production capacity of 25,000 tonnes. Construction of the facility is expected to start in 2026 and first-phase production is expected to begin in 2028. The facility will be scalable over time to meet growing global demand for graphite anode materials sourced outside of China.

The facility will be located in Yanbu, a strategically positioned industrial and logistics hub on the Red Sea that has direct access to European, North American and Middle Eastern markets.

Obeikan will hold a 51% stake in the joint venture company and Northern Graphite will hold 49%.

Obeikan will lead the organizing of local debt funding required to finance construction, development and commissioning of the plant. The partners will provide the remaining funding as equity in proportion to their ownership interests and through commercial banks.

Northern and Obeikan are in negotiations with battery manufacturers to secure long-term offtake agreements for the initial 25,000 tonnes per year of production. The joint venture will also enter into a long-term offtake agreement to purchase up to 50,000 tonnes of graphite concentrate annually from Northern’s Okanjande project in Namibia. That agreement will accelerate the restart and potential expansion of the graphite mine, which has been in a care and maintenance status since 2018.

“We are partnering with a well-financed and experienced industrial player, gaining scale, financing strength, and access to one of the world’s most strategically important industrial hubs, while accelerating the restart of our Okanjande mine in Namibia and advancing our broader mine-to-market strategy,” said Hugues Jacquemin, Chief Executive Officer of Northern Graphite.

Source: Northern Graphite

Toshiba has carved out a significant share of the lithium-ion battery market in industrial, automotive, and energy sectors—despite championing a more expensive anode material with lower energy density. The Japanese company is using lithium titanium oxide (LTO) anodes as it competes with standard lithium-ion batteries to gain a foothold in price-sensitive markets including low-power vehicles, boats, and industrial equipment, where lead-acid batteries still dominate.

First introduced in 2008, Toshiba’s SCiB batteries are now available as single cells, modules, and packs that can be configured in series or parallel to match voltage and capacity needs. For example, the Type 3 module can be linked in series to deliver over 1,000 volts and roughly 40 kilowatt hours. As energy storage systems in industry, for example, SCiB batteries are used to reduce grid-frequency changes in substations, and as battery storage for renewable energy systems; while in transportation, it can be found powering electric ferries and battery-powered locomotives.

In October, Toshiba launched its SCiB 24-volt battery pack designed to replace standard industrial lead-acid batteries in Japan’s cost-conscious mobility market, and which can be adapted to similar form factors used overseas.

Advantages of LTO Anodes

Toshiba’s SCiB 24-volt battery pack can be deployed as a standalone unit or configured in series and parallel.Toshiba

Though LTO carries a premium price tag, “it provides a long life of over 20,000 cycles, greater safety, rapid recharging, and it can operate as low as -30 °C,” says Shigeru Shimakawa, a technical fellow in Toshiba’s battery systems engineering department. These are key advantages for competing in the 24-volt lead-acid replacement market, he says, because lead-acid batteries are heavy and bulky, charge slowly, and have short life cycles—though low cost explains their continued popularity.

Yasushi Midorikawa, a senior manager of battery sales and marketing at Toshiba, explains how LTO’s advantages compare with those of competing graphite-based lithium-ion batteries. Any lithium-ion battery charges and discharges energy by moving lithium ions from the anode to the cathode and back again. The difference is that graphite anodes store the ions between tight carbon layers, which slows their movement. LTO, by comparison, has a three-dimensional tunnel structure that provides more space for ions to move freely and safely at high speeds, which allows it to charge faster.

That said, graphite operates at a lower potential relative to lithium than LTO, giving it the advantage of a higher cell voltage and energy density. “A higher potential reduces the energy density of a cell,” says Neeraj Sharma, a professor of chemistry focusing on battery materials at the University of New South Wales Sydney, in Australia. “For example, when comparing graphite and LTO with the same cathode, the graphite cell will have a higher energy density. Generally speaking, this means you need more LTO-cathode cells to get the equivalent energy density of a graphite cell.”

But during fast charging or at low temperatures, lithium can be deposited on the graphite anode, a condition known as lithium plating. Over time, this plating leads to the growth of dendrites, tiny needles of metallic lithium that can damage the anode, reducing its ability to hold and release ions efficiently, which shortens the battery’s cycle life compared to LTO.

“Lithium-ion plating is a key failure mechanism for graphite-based lithium-ion batteries,” says Sharma. “And it is often associated with battery fires, risks, and safety.”

Toshiba is trialing swappable 24-volt battery packs with LTO anodes for electric motorbikes in Bangkok.Toshiba

Battery-Swapping Innovations

Toshiba is testing its 24-volt battery pack in Bangkok as a replacement for lead-acid batteries used in electric motorcycle taxis. Last year, the company teamed up with Naturenix, a Tokyo-based battery technology startup specializing in designing fast-charging lithium-ion battery pack systems for small electric vehicles. Together, the companies conducted a proof-of-concept (PoC) service test that allowed drivers of electric motorcycle taxis to swap battery packs at a charging station.

“From the resulting test data, we estimate a battery life of over 10 years is possible even in Bangkok’s hot climate,” says Haruchika Ishii, a business development fellow in Toshiba’s battery division. “And if specialized maintenance is used, this could be extended to about 18 years.” He adds that from December to March 2026, a new phase of testing will begin with a paid service supporting 100 motorcycles using five charging stations.

Yet even with these promising results, Toshiba faces a well-entrenched rival. Honda Motor Company has already established a battery-swapping business in Asia and elsewhere. As early as 2019, Honda began testing its lithium-ion Mobile Power Packs in motorbikes and scooters in the Philippines, Indonesia, and Japan. In 2022, commercial operations commenced in Japan and then in Bengaluru, India, and Honda has since broadened the business to Delhi and Mumbai, as well as Thailand and Europe.

But Toshiba says its approach to the battery-swapping business is different. “SCiB’s long life and fast charging—80 percent of capacity in six minutes—changes the economics of electrification, making a subscription model possible for battery as a service,” says Ishii. Typical lithium-ion batteries degrade relatively quickly, making a subscription model less practical, he says. “Also, swapping a SCiB battery is optional—not essential, because charging time is so quick,” he adds. “So fewer charging stations will be needed.”

Toshiba is also eyeing small boats. In October, Yamaha Motor began testing the technology in an electric sightseeing boat servicing the port of Yokohama, Japan. The vessel previously used lead-acid batteries powering twin electric propulsion systems produced by Yamaha, but the batteries had to be exchanged for fresh ones after every trip. Now, each propulsion system is powered by a SCiB 24-volt battery pack configured in a set of two in series and six in parallel, delivering 5.76 kilowatt-hours for a combined total of 48 volts and 11.52 kWh. As of this writing, the companies said it was too soon to provide test results.

For certain use cases, Sharma says SCiB looks to be a good, safe competitor to lower-cost lithium-ion batteries when it comes to replacing lead-acid ones. “Key advantages compared to lead-acid batteries is its higher energy density, so you can have the same energy density with a smaller footprint, and it can perform for a longer number of cycles,” he says. “As for graphite-based lithium-ion batteries, SCiB is safer and so more suited for certain applications.”