August 2018

The crucial part of battery engineering is interface engineering, especially when it comes to lithium metal anodes. An ideal interface prevents the electrolyte from reacting with lithium without impairing the battery performance. One possibility for the formation of optimized interfaces is the application of a protective layer between the electrolyte and the lithium anode.A suitable method to deposit such layers is ion beam sputtering. The controlled sputtering rate leads to very thin but uniform layers. In combination with an additional plasma source (cf. schematic) an oxidation or nitridation of the protection layer is possible. This method enables the application of a multitude of materials. Already a 1 nm - 5 nm thick interlayer is able to significantly slow down the increase of the total resistance Rt of the battery (cf. comparative measurement on the right part of the picture). (Picture submitted by Matthias Geiß).