Shedding Light on Battery Degradation

Winter 2024

A graphic showing multiple flashlights with a yellow background.

Batteries are ubiquitous in our daily lives, powering everything from flashlights and smartphones to computers and electric cars. Yet they often stop working at inopportune moments, and little is known about why they gradually lose their ability to store and deliver energy over time, a process known as degradation.

Yayuan Liu, assistant professor in the Department of Chemical and Biomolecular Engineering, is working to shed light—literally—on why this process happens.

“The higher the voltages the greater the energy batteries can carry, but at that high voltage the battery is really sensitive and prone to degradations,” Liu says. “Today people really don’t know what the degradation pathway is at high voltages, because a lot of the chemical processes taking place inside the battery as it degrades are very transient in nature. They have lifetimes of [just] seconds to minutes, so that makes it very difficult to look at the root cause.”

Liu is taking the concept of fluorescence microscopy—which uses a higher intensity light source than traditional microscopy and is usually applied to biological fields—and adapting it to the study of electrochemical systems.

She notes that despite electrochemical batteries being inorganic and artificially produced, there are striking similarities between the cells in batteries and those in the human body.

“In our body, there is also a generation of transient species like free radicals or heterogeneities, which people study day to day in biology using fluorescence microscopy. I’ve always been fascinated by the correlations between life science and material science,” she says.

Supported by a $600,000, four-year Young Investigator Award from the Arnold and Mabel Beckman Foundation, she hopes to demonstrate the capability of this new imaging tool for electrochemistry research. She believes fluorescence microscopy is ideal for studying electrochemical systems because it can detect a single molecule emitting visible light and is non-disruptive. “You can observe everything going on in situ, while the battery is operating and without damaging it,” she says.

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