Correlation between Electrolyte Concentration and Lithium Morphology during Lithium Bis(fluorosulfonyl)amide–Tetraglyme Electrolyte Deposition–Dissolution Reactions

Electrodeposition and chemical dissolution reactions of Li are strongly affected by the electrolyte concentration at the electrode surface. In this study, we investigated the processes involved in the formation of Li deposits at various electrolyte concentrations and different numbers of deposition–dissolution cycles. Growth of the deposits during the cycles was assessed using a digital microscope. The thickness of the fibrous layer was strongly dependent on the electrolyte solute–solvent molar ratio. The thickness of the fibrous layer increased as the number of cycles increased when the electrolyte solute–solvent molar ratio was low but decreased when the molar ratio was high. Temporal changes in the electrolyte concentration and in the diffusion layers near the electrode were identified using a laser interference microscope. The results led us to conclude that there are three fibrous Li deposit growth models that occur at different solvent–solute molar ratios.