Newswise – For those who dream of driving their electric vehicle long distances to see the world’s largest ball of twine, Chelsea Chen is committed to making it happen.
Chen, a polymer physicist at the Department of Energy’s Oak Ridge National Laboratory, studies ion transport in solid electrolytes, which could help electric vehicle battery charges last longer.
“The challenge with current electric vehicles is to further increase the range, and that means higher energy density,” Chen said. “This requires a revolutionary design of battery chemistry.”
To address this problem, Chen is researching solid polymer electrolytes.
“Solid electrolytes are the key to higher energy density. Polymers meet both the cathode and the anode in the EV Batteries. Understanding and optimizing the structure and properties at the interface is key to improving the performance of solid-state batteries.”
Just the facts’
Chen is a research associate at the Fast and cooperative ion transport in polymer-based materialsor FaCT, Center, one of 16 newly funded DOEs Energy Frontier Research Centers These work primarily with universities and national laboratories across the country, working to solve pressing scientific challenges at the forefront of fundamental research in the energy sciences. FaCT researchers want to develop a model of ion transport in polymers that will influence the future design of energy storage and conversion materials such as battery electrolytes.
Chen’s research at ORNL focuses on the development of solid-state batteries and understanding ion transport in polymer-ceramic composite electrolytes and at electrolyte/electrode interfaces.
Popular high energy density designs use a lithium metal anode. However, lithium reacts easily with liquid electrolytes in current lithium-ion batteries, raising fire safety concerns.
Solid-state electrolytes could offer a solution, the combination of which with a high-voltage cathode and a lithium metal anode leads to increased energy density.
The path to now
Chen was born in northeast China. Her favorite subject in high school was chemistry. “I have always been interested in titration experiments, seeing how one material reacts with another,” she said.
As a student at Shanghai Jiao Tong University in China, Chen was surrounded by polymer experts. “They have a large polymer program housed in their chemistry department,” Chen said. “I worked with so many professors who specialized in polymers.”
Chen received her PhD in macromolecular science and engineering from the University of Michigan with a dissertation on controlling the spatial distribution of nanoparticles within a thin polymer host film. She completed postdoctoral studies at the University of California, Berkeley, and Lawrence Berkeley National Laboratory, where she studied the structure of polymers using electron microscopy and small-angle X-ray scattering.
Chen has built her career on understanding the structures, properties and behaviors of polymers. Before joining ORNL’s Materials Science and Technology Department in 2017, Chen was a senior chemist at Dow Chemical. There she focused on the development of dielectric polymer films with increased thermal conductivity and mechanical flexibility for semiconductor applications.
Although she was active in her field, Chen realized that her passion was research and development, which is not necessarily a priority in the industry.
“I always wanted to do more basic research, which is not possible in the commercial sector,” Chen added. In 2017, she returned to her national laboratory roots. “I wanted to work in an institution where research and development is the focus.”
Chen has embraced environmental change and enjoys the benefits of working in a national laboratory.
“The biggest difference is that scientific output is the most important thing here,” Chen said. Because she channeled her passion into publishing research conducted at ORNL, Chen was awarded the American Chemical Society Young Investigator Award in 2022.
She also values multidisciplinary collaboration. “University work is very isolated,” Chen said. “What I like about the laboratory is that if I have any problems or questions, I can rely on an expert in any subject area. They’re all fine here.”
The future of plastics
As Chen collects her data, she’s also interested in what’s happening with polymer products in general, not just electrolytes for electric vehicle batteries.
“We should really reuse polymers for something else instead of throwing them into the sea,” Chen said, speaking of the packaging industry and consumer plastics. “Unfortunately,” she said, “it’s cheaper to make new ones instead of recycling.”
To improve the sustainability of electric vehicle batteries, manufacturers are interested in recycling used batteries to recover materials such as lithium, cobalt and nickel. Chen believes polymers deserve the same recycling consideration.
Chen’s work advances sustainable chemistry through recycling and upcycling—think shoes made from water bottles. She hopes research like hers will help the public and private sectors consider and address end-of-life issues in polymer design.
The DOE Office of Energy Efficiency and Renewable Energy and the DOE Office of Science are funding Chen’s work. Her research frequently relies on the spallation neutron source and user facilities of the Center for Nanophase Materials Sciences, DOE Office of Science at ORNL.
UT-Battelle manages ORNL for the DOE’s Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit energy.gov/science. — Christy White