The Department of Defense (DOD) has announced that a researcher at The University of Alabama in Huntsville (UAH) has won 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. The work is particularly relevant to power applications for unmanned underwater vehicles (UUVs). Dr. George Nelson in the College of Engineering at UAH, a part of the University of Alabama System, will be leading the three-year study in collaboration with Purdue University as part of the DEPSCoR Research Collaborations program.
“My research group has been working on battery performance and degradation for some time, but when it comes to studying temperature effects we've focused on higher temperature operation, like leaving an EV in the sun on a hot day,” Nelson says. “When I started discussing relevant temperature ranges with my collaborator at Purdue, 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 and advance the current knowledge base.”
The DOD awarded $17.6 million to 27 collaborative academic teams under DEPSCoR, a capacity-building program designed to strengthen the basic research infrastructure at institutions of higher education in underutilized states and territories. The DEPSCoR Research Collaboration competition is open to tenured and tenure-track faculty members in the 37 states and territories eligible to compete for DEPSCoR funds. The program office for the initiative will be the Office of Naval Research.
“Outside of defense applications, these systems could be used for detailed mapping of the ocean floor, inspection of undersea infrastructure – pipelines, cables, oil rigs or offshore wind installations – and searching for wreckage of aircraft,” Nelson explains. “Like rovers for extraterrestrial applications, these UUVs allow us to access places that are inhospitable or inaccessible for humans.”
Distinct battery degradation is expected at elevated and low operating temperatures, the researcher reports. The ultimate goal is to investigate ways to meet the demands to improve the size, weight and power capabilities of these batteries.
“Lithium-ion batteries contain a mixture of materials: millions of particles that store the lithium, materials that help move electric charge through the battery, and a binder that acts like a glue holding these materials together,” Nelson notes. “Changing how these materials are arranged changes how much and how fast energy can be stored or withdrawn from the battery.
“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.”
Nelson will be assisted on the three-year project by Dr. Partha Mukherjee.
“I've known Professor Mukherjee from Purdue for over twelve years,” Nelson says. “He's a collaborator and friend. Our first research project, on tin alloys for lithium-ion batteries, was funded by the National Science Foundation. When I saw the DEPSCoR funding opportunity, the description of the topic on batteries basically said ‘your research.’ Alabama and Indiana were eligible states, and I knew Partha had experience with DOD projects. So, I contacted him right away, and we hit the ground running.”
The Department of Defense's science and technology mission relies on an ecosystem of creative and insightful researchers in every state," says Dr. Bindu Nair, director of the DOD's Basic Research Office, on making the announcement. "DEPSCoR aims to increase the number of academics pursing research in DOD-relevant areas, while enhancing the science and engineering capacity of their institutions into the long term.”
