With the number of electric vehicles (EVs) in the United States projected to skyrocket to 26.4 million by 2030, the need is great for not only producing, but improving, the safety and efficiency of the batteries that power them, as well as cell phones, autonomous unmanned vehicles and smart electronics. Researchers at The University of Alabama in Huntsville (UAH), a part of the University of Alabama System, are doing their part to ensure Alabama is leading the way to power this coming revolution.
Central Alabama boasts the largest continuous vein of graphite in the entire country, and the state is set to open the nation's first graphite processing site in Coosa County, a 42,000-acre site that will process coated spherical graphite, the mineral that makes up roughly 50 percent of a lithium-ion battery. Set to open in late 2024, the plant will turn out 7,500 metric tons of graphite in its first year, ramping up to 40,000 tons by 2028. And when the batteries that use these raw materials come to the end of their lifespan, many will go to a recycling plant in Tuscaloosa, a facility capable of processing up to 10,000 tons of lithium-ion batteries per year.
With the “cradle” and “grave” aspects of the battery life-cycle covered to the south, UAH is fast helping to transform North Alabama into a national hub focusing on the heart of the battery technology timeline: making lithium-ion batteries safer and more efficient for users, both on land and sea. University research initiatives recently garnered nearly $1.5 million in federal funding to bolster the vital middle prong of this burgeoning domestic industry.
Turning down the heat
News of sudden battery failures impacting EVs and airplanes, as well as smart electronics and utility-scale energy storage, drove Dr. Guangsheng Zhang to research a phenomenon called “thermal runaway,” a condition where the lithium-ion cell enters an uncontrollable self-heating state, causing smoke, fire or even explosions. The researcher won a National Science Foundation Faculty Early Career Development (CAREER) Program award totaling $598,181 to support his research, a five-year project slated to run through April 2028.
“I was shocked by news that lithium-ion batteries may suddenly fail energetically, all without warning,” Zhang says. “What is most concerning is that, in some cases, the batteries caught fire when the devices or vehicles were not in use. Investigations have attributed many of those fires to thermal runaway caused by internal short circuit (ISC).”
Zhang focused his postdoctoral work on in situ studies of fuel cells to develop diagnostic methods to trigger and characterize ISC, a critical failure mechanism of lithium-ion cells. “There are still many unknowns,” he notes. “What is the threshold of ISC causing thermal runaway? How does ISC form and slowly evolve to that threshold, in some cases after years of normal operation? How can ISC be prevented from reaching the threshold?”
Answering these questions is the goal of the current project. The researcher believes the insights gained will inspire engineers in battery-powered industries to derive innovative solutions to prevent thermal runaway. The project will also spark educational and outreach activities, such as seminars on energy storage, new courses on batteries and mentoring undergraduate research with hands-on workshops.
Building smart systems to battle “range anxiety”
Another way to improve the function of lithium-ion batteries is by improving the onboard electronic battery management systems (BMS) that work to detect abnormal behavior. Dr. Avimanyu Sahoo, an expert in intelligent control systems, is collaborating with Sandia National Laboratories to develop control methods that emulate characteristics of human intelligence, such as adaptation and learning, to enhance the safety, efficiency and longevity of lithium-ion battery packs. Sahoo, who will act as principle investigator for the project, was awarded a National Science Foundation Established Program to Stimulate Competitive Research (EPSCoR) Fellowship totaling $279,105 to advance these goals.
“Given my background in intelligent control, I recognized the potential to improve battery management systems by incorporating advanced algorithms, enhancing the accuracy of operational decisions, ensuring the safety of the battery pack, the vehicle and its users,” the researcher explains.
Intelligent systems can gather, analyze and respond to data they collect, making them especially applicable to improving BMS behavior. Developing a “smart” BMS capable of monitoring the smallest part of a battery pack in real time and learning abnormal behavior for future prediction could prove the key to addressing battery concerns.
“Our project is centered on crafting an AI-driven model aimed at achieving a more precise monitoring of individual cells within a battery pack,” Sahoo notes. “Imagine having a highly intuitive system within electric vehicles that can keep a constant and detailed check on each battery cell's health and performance. This system would not only foresee potential internal issues and regulate temperature to prevent overheating, but also ensure each cell operates optimally.”
The ultimate goal is to create a more reliable and efficient battery, charting a new frontier in energy management, as well as minimizing the risk of pack overheating, while addressing “range anxiety” drivers might experience due to long distances between charging stations.
Taking temps in the deep blue sea
Not to be outdone by advances on land, a UAH researcher is working on a battery initiative for the Office of Naval Research. Dr. George Nelson earned a Defense Established Program to Stimulate Competitive Research (DEPSCoR) award for $600,000 to study how high-energy density lithium-ion batteries degrade over a range of temperatures, particularly relevant to unmanned underwater vehicles (UUVs), essential for work in environments that are inhospitable or inaccessible for humans, like mapping the ocean floor, inspecting undersea infrastructure — pipelines, cables, oil rigs or offshore wind installations — or searching for aircraft wreckage. The researcher is leading the three-year study in collaboration with Purdue University as part of the DEPSCoR Research Collaborations program.
“When it comes to studying temperature effects on batteries, we've focused on higher temperature operation, like leaving an EV in the sun on a hot day,” Nelson says. “When I started discussing temperature ranges with my collaborator, Dr. Partha Mukherjee, the topic of operation at colder ocean temperatures, like those seen in UUVs, surfaced. We were not aware of studies that involved high-capacity materials at low temperatures, so it seemed natural to pursue that area.”
Lithium-ion batteries contain a mixture of materials: the millions of particles that store the lithium, as well as substances that help move the electric charge through the battery and a binder that acts like a “glue” holding all these materials together.
“Changing how these materials are arranged changes how much and how fast energy can be stored or withdrawn from the battery,” Nelson says. “Materials like silicon or tin can hold a lot of lithium, but that also means the particles swell and shrink a lot — by 300% or more — when the battery is charged and discharged. This makes the battery fall apart inside and fail prematurely. Ultimately, we want to understand how the materials inside the battery should be mixed to help them operate longer under demanding environmental conditions.”
All in all, UAH minds working on projects like these are making a significant difference in helping America transition to its electric future.
