Gentle it up: Battery particles inform the true story of a battery’s cost
by Jared Pike for Purdue Information
West Lafayette, IN (SPX) Oct 30, 2025
Lithium-ion batteries energy our telephones, automobiles, and even properties; guaranteeing their secure and environment friendly conduct has change into extremely necessary. Utilizing a easy optical method, Purdue College researchers have noticed a battery’s particular person particles lighting up as they cost – enabling a extra full image of the battery’s general well being and efficiency.
“Lithium-ion batteries – in reality, all batteries – perform due to tens of millions of chemical interactions taking place on the particle stage,” mentioned Kejie Zhao, professor of mechanical engineering. “Characterizing them turns into a mechanical and electrochemical drawback.”
In Zhao’s lab, they use many instruments to bridge this hole between mechanics and electrochemistry to create higher batteries. One in every of these instruments is an easy RGB digital camera.
“It is solely been just lately found that particular person particles in a battery’s electrode truly seem brighter as they cost,” Zhao mentioned. “Our breakthrough is that we take a look at a whole bunch of particles at a time, and may use their brightness ranges to find out how evenly the cost is distributed by the electrode.”
This analysis has been revealed in Proceedings of the Nationwide Academy of Sciences.
The experiment started with a lithium-ion coin cell battery in a glove field crammed with inert gasoline (lithium is risky when uncovered to the open air). Zhao’s workforce centered a easy optical microscope onto a bunch of 100 to 1,000 particular person particles. They slowly charged the battery and recorded time-lapse video of the identical group of particles over a number of hours. By analyzing the brightness stage of those particular person particles, they might reconstruct a particularly exact spatial mannequin of how evenly the battery is charged.
“The superb half about this course of is that you do not want high-powered instruments – only a easy optical microscope and digital camera,” Zhao mentioned. “It would not even have to be in focus; the brightness ranges persistently ship correct knowledge both approach.”
With picture processing and knowledge evaluation, the workforce extracted precious knowledge in regards to the building and operation of those batteries. “Proper now, the one method to high quality management for a battery’s particles is to look at them within the manufacturing facility,” Zhao mentioned. “However by observing optically how they cost over time, we get a extra correct image. We have established that there’s a direct mathematical correlation between the optical brightness of particles and the general state of cost of the battery.”
And that is necessary, as a result of a battery’s charging and discharging conduct depends on its heterogeneity, or how evenly distributed particles are all through the electrode. If cost is concentrated in a single place, the battery is extra more likely to degrade, fail, and even burn catastrophically. “Even on the particle stage, clusters of cost can result in native defects, which may result in degraded efficiency and finally thermal runaway,” Zhao mentioned.
Whereas Zhao’s experiments centered particularly on lithium nickel manganese cobalt oxides (NMC), he mentioned that this optical course of has been confirmed to work for a lot of electrode supplies – lithium cobalt oxide, graphite, and others – due to the change {of electrical} conductivity upon charging and discharging. In different phrases, this characterization course of can be utilized for any kind of battery formulation sooner or later.
“Batteries have at all times been tough to diagnose,” he mentioned. “Seeing them behave like this, in an energetic charging or discharging state, affords a lot extra info than analyzing them in a static state. We have confirmed the theoretical basis, and now we are able to use optical microscopes with confidence to research in the present day’s batteries and set up the science for future battery applied sciences.”
Analysis Report:On the Scale of Heterogeneity in Composite Electrodes of Batteries
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