Now, researchers at the Department of Energy’s SLAC National Accelerator Laboratory and colleagues from Purdue University, Virginia Tech, and the European Synchrotron Radiation Facility have discovered that the factors behind battery decay actually change over time. Early on, decay seems to be driven by the properties of individual electrode particles, but after several dozen charging cycles, it’s how those particles are put together that matters more.
“The fundamental building blocks are these particles that make up the battery electrode, but when you zoom out, these particles interact with each other,” said SLAC scientist Yijin Liu, a researcher at the lab’s Stanford Synchrotron Radiation Lightsource and a senior author on the new paper. Therefore, “if you want to build a better battery, you need to look at how to put the particles together.”
A battery’s life
In the end, they identified more than 2,000 individual particles, for which they calculated not only individual particle features such as size, shape and surface roughness but also more global traits, such as how often particles came into direct contact with each other and how varied the particles’ shapes were.
Next, they looked at how each of those properties contributed to particles’ breakdown, and a striking pattern emerged. After 10 charging cycles, the biggest factors were individual particles’ properties, including how spherical the particles were and the ratio of particle volume to surface area. After 50 cycles, however, pair and group attributes — such as how far apart two particles were, how varied their shapes were and whether more elongated, football-shaped particles were oriented similarly — drove particle breakdown.
“It’s no longer just the particle itself. It’s particle-particle interactions” that matter, Liu said. That’s important, he said, because it means manufacturers could develop techniques to control such properties. For example, they might be able to use magnetic or electric fields to align elongated particles with each other, which the new results suggest would result in longer battery life.
And, co-senior author and Virginia Tech chemist Feng Lin said, the results could be applied beyond the particulars of the present research. “This study really sheds light on how we can design and manufacture battery electrodes to obtain long cycle life for batteries,” Lin said. “We are excited to implement the understanding to next-generation, low-cost, fast charging batteries.”
The research was funded by the DOE Laboratory Directed Research and Development program at SLAC and by the National Science Foundation. SSRL is a DOE Office of Science user facility.
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Materials provided by DOE/SLAC National Accelerator Laboratory. Original written by Nathan Collins. Note: Content may be edited for style and length.
Post time: Jun-06-2022