A world wide crew of scientists, which includes nanoengineers from the University of California San Diego, has learned By utilizing computer simulations and X-ray experiments, the researchers were able to “see” in detail why lithium ions move at a slow pace within a solid electrolyte, particularly at the interface between the electrolyte and electrode. The research showed that increased vibrations at the interface hinder the movement of lithium ions more than in other parts of the material. These discoveries, published on April 27th in the journal Nature Materials, could result in the development of novel approaches to improve ionic conductivity in solid-state batteries.
Solid-state batteries, which contain electrolytes made of solid materials, hold the promise of being safer, as well as longer lasting and more efficient, than traditional lithium-ion batteries with flammable liquid electrolytes.
But a major issue with these batteries is that the movement of lithium ions is more restricted, particularly where the electrolyte makes contact with the electrode.
“Our ability to make better solid-state batteries is hindered by the fact that we do not know what exactly is happening at the interface between these two solids,” said study co-senior author Tod Pascal, a professor of nanoengineering and chemical engineering and member of the Sustainable Power and Energy Center at the UC San Diego Jacobs School of Engineering. “This work provides a new microscope for looking at these sorts of interfaces. By seeing what the lithium ions are doing and understanding how they move through the battery, we can start engineering ways to get them back and forth more efficiently.”
For this study, Pascal teamed up with his longtime collaborator, Michael Zuerch, a professor of chemistry at UC Berkeley, to develop a technique to directly probe lithium ions at the interface. Over the past three years, the two groups have worked on developing an entirely new spectroscopic approach for probing buried, functional interfaces, such as those present in batteries. Pascal’s lab led the theoretical work, while Zuerch’s lab led the experimental work.
The new technique that they developed combines two established approaches. The first is X-ray adsorption spectroscopy, which involves hitting a material with X-ray beams to identify …
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