Solid-state electrolytes could offer a solution, and pairing them with a high-voltage cathode and a lithium metal anode leads to increased energy density.
The path to now
“We should really be reusing polymers for something else instead of discarding them into the ocean,” says Chen, speaking of the packaging industry and consumer plastics. “Unfortunately,” she says, “it’s cheaper to make new ones instead of recycling.”
“I’ve always wanted to do more fundamental research, which you cannot do in the commercial sector,” Chen says. In 2017, she went back to her national laboratory roots. “I wanted to work in an institution where R&D is the focus.”
“The challenge with current EVs is to further increase driving range, and that means higher energy density,” says Chen. “This requires revolutionary design of the battery chemistry.”
To address this, Chen is researching solid polymer electrolytes.
The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy and Office of Science fund Chen’s work. Her research often relies on the Spallation Neutron Source and the Center for Nanophase Materials Sciences, Office of Science user facilities at ORNL.
Chen has built her career around understanding the structures, properties, and behaviors of polymers. Before joining ORNL’s Materials Science and Technology Division in 2017, Chen was a senior chemist at Dow Chemical. There, she focused on developing polymer dielectric films with increased thermal conductivity and mechanical flexibility for semiconductor applications.
Chen’s work advances sustainable chemistry through recycling and upcycling—think of shoes made of water bottles. She hopes research like hers will help public and private sectors consider and address end-of-life issues in polymer design.
Chen has welcomed the environment change and enjoys the benefits of working at a national lab.
Although she was working in her field, Chen realized her passion was research and development, which is not necessarily a priority in industry.
Chen is a staff researcher with the Fast and Cooperative Ion Transport in Polymer-Based Materials, or FaCT, one of 16 newly funded DOE Energy Frontier Research Centers that partner mainly with universities and national labs around the country working to solve pressing scientific challenges at the forefront of fundamental energy science research. FaCT researchers aim to build a model of ion transport in polymers that will inform the future design of energy storage and conversion materials, such as battery electrolytes.
Chen’s research at ORNL focuses on developing 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 readily with liquid electrolytes in current lithium-ion batteries, leading to fire safety concerns.
To improve the sustainability of EV batteries, manufacturers are interested in recycling spent batteries to recapture materials like lithium, cobalt, and nickel. Chen thinks that polymers deserve the same recycling consideration.
She also appreciates the multidisciplinary collaboration. “University work is very siloed,” says Chen. “My favorite thing about the lab is that I can access an expert in any field if I have a problem or question. They are all right here.”
The future of plastics
“The No. 1 difference is that here the science output is the most important thing,” says Chen. Putting her passion into publishing research performed at ORNL earned Chen an American Chemical Society Young Investigator Award in 2022.
