Candadian researchers from University of Calgary report novel ceramic ALD coated solid electrolyte for safe Li-batteries (LINK): Existing lithium-ion batteries like those used in the Tesla Motors cars, Chevrolet Volt, Nissan Leaf and other electric and plug-in hybrid vehicles, as well as in portable electronics, use membranes of organic polymer compounds and lithium salts as the electrolyte.
This is an illustration of a Li-rich garnet structure based all-solid-state-Li battery. While other research groups in the world have used garnet to build lithium batteries, “We showed we can use the lithium metal very efficiently, with the lowest interface-charge transfer resistance between the lithium electrode and the garnet electrolyte,” Thangadurai says. (Figure from www.ucalgary.ca)
The electrolyte in a battery separates the two electrodes (the positive cathode and the negative anode), and conducts the lithium ions between the electrodes during charging and discharging cycles. Currently used organic polymer-based electrolytes are flammable, so fire is a safety issue.
Instead of organic polymers for their battery, Wachsman and co-principal investigators Thangadurai and Liangbing Hu (at the UMD), along with other UMD scientists, used a solid ceramic electrolyte, which doesn’t burn.
The research team also used, for the first time, a technique called atomic layer deposition to place a thin film of aluminum oxide on top of a garnet structure coating the ceramic electrolyte.