ИСТИНА

Currently, the rapid development of modern technologies requires a continuous increase in performance of energy accumulation and storage systems. That’s because creation of a new generation of batteries with high specific energy and power is highly demanded. Metallic lithium is one of the most promising anode materials for lithium-based rechargeable batteries, including promising lithium-sulfur, lithium-air and other systems [1-3]. The main reason that prevents the successful introduction of lithium-metal batteries into operation is associated with the formation of non-uniform lithium deposits during the charging process. In this work, we examine lithium plating in "solvent - in - salt" (SIS) electrolytes with typical salt concentration of up to 5 M [4]. We performed cyclic voltammetry using Ni disk as the working electrode. Metallic lithium was employed as a counter electrode, Ag+/Ag electrode was used as a reference. Cyclic voltammetry of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) solution in prorylene carbonate reveals the expansion of electrochemical stability window range with increasing electrolyte concentration, as well as the shift of the lithium redox potential in positive direction. Results of galvanostatic cycling of symmetrical lithium cells allow us to assume that increased electrolyte concentration (more than 4 moles of salt per 1 l of solvent) leads to more uniform lithium plating at the current density of 0.1 mA/cm2. Although we found that the number of cycles until cell death is noticeably increased for highly concentrated electrolytes, further detailed studies of the morphology of resulting lithium precipitates is required.