Researchers used new X-ray techniques to map transformations that occur within the conductive silver matrix found inside lithium-based batteries. These observations could potentially open the door for improvements to the modern battery.
The matrix inside a lithium-battery has the ability to bring conductivity to surrounding material, but researchers have been unsure about exactly how this phenomenon occurs, Stony Brook University reported.
To gain insight into the structures researchers mapped out the changing atomic architecture and its link to the battery's rate of discharge. The observations revealed a slow discharge rate early in the battery's life creates the most conductive network. These findings could lead to new design approaches
"Armed with this insight into battery cathode discharge processes, we can target new materials designed to address critical battery issues associated with power and efficiency," said study coauthor Esther Takeuchi, a SUNY Distinguished Professor in the Department of Materials Science and Engineering at Stony Brook University and Chief Scientist in Brookhaven Lab's Basic Energy Sciences Directorate.
The researchers used bright X-ray beams to probe to probe lithium batteries with silver vanadium diphosphate (Ag2VP2O8) electrodes. The cathode material, nicknamed SVOP, is extremely stable, high voltage, and has a central matrix that was the key to the researchers' work.
"To visualize the cathode processes within the battery and watch the silver network take shape, we needed a very precise system with high-intensity x-rays capable of penetrating a steel battery casing," said study coauthor and Stony Brook University Research Associate Professor Amy Marschilok. "So we turned to NSLS."
The intense X-ray beams were found to have the ability to pass through the sample. Each set of detected beam angles showed the changing chemistry of the battery's matrix as a function of discharge.
"This kind of analysis and interpretation requires considerable time and expertise, but the results can be stunning," said Brookhaven Lab postdoctoral researcher and study coauthor Kevin Kirshenbaum
