New Imaging Technique Finds Formation of Aluminum Alloys to Blame for Next-Gen Battery Failures

New Imaging Technique Finds Formation of Aluminum Alloys to Blame for Next-Gen Battery Failures

03/03/2015 04:52 PM EST

(Top) A cross-section scanning electron microscope image of a representative Al anode all-solid-state thin-film battery before cycling. (Bottom) Top down scanning electron microscope images showing the how the aluminum anode surface evolves during the first cycling step. By increasing the charging current, the density of clusters also increases (red shows the effect of 10 nanoamps after 50 minutes, green is 20 nanoamps at 17 minutes, and blue is 30 nanoamps at 3 minutes), indicating that the aluminum–lithium alloy formation is a kinetically driven process. Credit: NIST View hi-resolution image

Researchers working at the National Institute of Standards and Technology (NIST), the University of Maryland, and Sandia National Laboratories, have for the first time imaged the inner workings of experimental solid-state batteries as they charged and discharged while making detailed measurements of their electrochemical health. Their work has helped explain why the batteries rapidly lose performance and suggests a way for improving them.
The results appear in theJournal of Materials Chemistry A.*
While most batteries on the market today have liquid electrolytes, solid-state batteries have, as the name implies, a solid one. Not needing a liquid makes these batteries amenable to high throughput manufacturing techniques and opens the door to making them smaller, thinner and even flexible.
In fact, the entire battery assembly can be little more than a few micrometers thick.
In commercially available lithium-ion batteries used in cell phones, for example, the anode (the side of the battery where electrons flow out to a circuit) is usually made of carbon. But in these new solid-state batteries, scientists have been experimenting with other materials, including aluminum because it’s so light, an important consideration for mobile devices.
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