Battery scientists often work in academic isolation at universities, out of sight and mind of battery users. They sometimes work remotely too, far way from each other and each contributing their piece to a scientific puzzle. Today we report how one such contributor discovered hidden pathways in lithium batteries, through which ions travel between electrodes.
Background to The Discovery of Hidden Pathways
The core project studied which electrolyte structures provided the best ‘lithium hopping pathways’, through solid-state battery electrolytes. In the end, the team selected a lithium tantalum oxychloride electrolyte material as the best prospect.
Confirming this decision required detailed study and analysis of lithium ions, as they travel through solid electrolytes charging and discharging batteries. Ions are atoms or groups of atoms, and hence the sub-microscopic building blocks of physical life.
The Ion Pathways in Lithium Tantalum Oxychloride
Illinois Tech Research Professor of Chemistry, James Kaduk, was responsible for identifying the hidden pathways in lithium batteries, with specific reference to the lithium tantalum oxychloride electrolyte.
This challenge required detailed understanding of how the ions moved through the material. “My contribution is small but ends up being useful,” Kaduk later recalled. “What really gets me excited is finding out where the atoms are.”
His task was by no means straightforward. The lithium ions were sub-microscopically small, and surrounded by dense tantalum in the subject electrolyte. X-rays did not help. And so Kaduk searched for gaps in the tantalum that could provide pathways for lithium ions.
His indirect approach paid off. It revealed gaps within the crystal structure of lithium tantalum oxychloride, that were close enough to each other for ions to ‘hop through’. Those hidden pathways in the subject lithium batteries helped explain how they conducted ions efficiently, even at low temperatures.
More Information
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Sodium Ions Beat Lithium Charging Rate
Preview Image: Professor of Chemistry James Kaduk
