Effect of Ar-N 2 Ratio on Morphology and Electrochemical Properties of Lithium Electrodes Manufactured by Magnetron Sputtering

This article discusses the possibility of regulating the morphology of lithium electrodes manufactured by magnetron sputtering from a liquid-phase target on stainless steel substrates by a composition of argon-nitrogen gas mixture. Lithium electrodes produced by magnetron sputtering in an impurities-free argon gas, have a polycrystalline structure. The sizes of lithium crystals depend on the thickness of fabricated electrodes and vary from units to tens of microns. An increase in the content of nitrogen in a mixture with argon leads to a decrease in the size of lithium crystals and, in the limiting case, to the formation of a microcrystalline structure of lithium electrodes. The effect of nitrogen on the morphology of lithium electrodes is explained by the formation of lithium nitride on the surface of growing lithium crystals, which disrupts the regularity of condensing lithium layers and hinders the growth of crystals. Lithium electrodes fabricated by magnetron sputtering of lithium in argon-nitrogen mixtures have better electrochemical properties compared to electrodes produced in pure argon. Li deposits as bcc crystal by magnetron sputtering in Ar sputter gas. Effect of ratio of Ar-N 2 in sputter gas on deposited Li crystals was studied. Increase N 2 in Ar-N 2 sputter gas leads to decrease in size of deposited Li crystals. Li 3 N forms on surface of deposited Li by magnetron sputtering in Ar-N 2 . Li 3 N on surface of Li increases cycling duration of metal lithium electrodes.