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Passion for renewable energy leads to battery research

Meet Simon Hafner, College of Engineering and Applied Science Outstanding Graduate for Research

Simon Hafner in battery lab

Simon Hafner conducts research in the Electrochemical Energy Laboratory. 

During his time at Boulder, mechanical engineering BS/MS student and Boettcher Scholar Simon Hafner said his job as a researcher was to take apart complex systems, breaking them into easy-to-analyze problems.

This year, he was selected as Outstanding Graduate for Research in the College of Engineering and Applied Science based on his five years of battery research as an undergraduate and graduate student. Already, he has published seven papers and is listed on three patents.

Participation in the Energy Club in 2014 introduced him to Professor Se-Hee Lee. Given his interest in Lee’s research, he soon became involved as an undergraduate researcher for the Electrochemical Energy Laboratory. When he first began, he learned everything from how to build simple and complex battery cells to habits like note-taking, cleanliness, assembly and tear-down.

“From the start, I was attracted to research opportunities in renewable energy,” Hafner said. “I soon learned that much of renewable energy boils down to materials science.”

The goal of Hafner’s research was to increase the energy density and lifetime of batteries, so they could be replaced less often for a lower price. He also rebuilt lithium ion batteries into solid-state batteries to increase safety, stability and shelf life.

“The top three places batteries are used include mobile phones, transportation and grid storage,” Hafner said. “Because they’re used so broadly, it’s important we make them affordable, safe and long-lasting.”

To increase energy density, Hafner researched three potential solutions: pseudocapacitors, a material halfway between a battery, which stores energy in a chemical form, and a capacitor, which stores energy in an electric field; silicon anode batteries which can hold 10 times as much lithium as conventional batteries; surface coatings which make batteries more stable.

Hafner said he is thankful to his team, especially in challenging moments. “Watching all of these very great researchers succeed but also overcome failures has helped me to keep going,” Hafner said. 

Hafner said he has also learned many things from Lee including how putting one’s work in context yields success, that it’s worth the extra care to get high-quality, repeatable results and to never be afraid of innovation.

“When I came to Professor Lee with new ideas, he only encouraged me,” Hafner said.

In addition to research at Boulder, Hafner interned at SiILion, NREL and Science Discovery. He also studied abroad in South Korea, completing Korean language courses and participating in a short battery experiment while there. Looking ahead, Hafner hopes to begin a career working in energy and technology.