Discovery could lead to longer-lasting EV batteries
Michael Toney and team tested lithium-ion battery coin cells for capacity loss over time. (Photo: Jesse Petersen)
Batteries lose capacity over time, but the cause isn’t fully understood. Now a team led by CU Boulder engineer Michael Toney has uncovered a key mechanism behind battery degradation.
Published in Science, the study reveals that hydrogen molecules from the battery’s electrolyte migrate to the cathode during charging, taking spots normally occupied by lithium ions. This weakens the electric current, decreases capacity, and causes mechanical stress that can crack the cathode.
“Now that we understand what’s causing batteries to degrade, the battery chemistry community can design better batteries,” said Toney, a professor in the Department of Chemical and Biological Engineering.
The discovery could help electric vehicles run farther and last longer, while advancing energy storage systems needed to accelerate the transition to clean energy and reduce greenhouse gas emissions.
Principal investigators
Michael Toney; Gang Wan
Funding
U.S. Department of Energy; U.S. National Science Foundation (NSF); Taiwan’s Ministry of Science and Technology of Taiwan and Ministry of Education
Collaboration + support
Argonne National Laboratory; Army Research Laboratory; Stanford University
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Discovery could lead to longer-lasting EV batteries, hasten energy transition