LIQUID ELECTROLYTE COMPRISING ORGANIC CARBONATES AND CYCLIC SULFOXIDES FOR APPLICATIONS IN LITHIUM SECONDARY BATTERIES

摘要

The invention relates to novel liquid electrolytes for applications in rechargeable lithium ion batteries, lithium metal batteries and lithium-sulfur batteries. Electrolyte mixtures comprising organic nonlinear carbonates as solvent and cyclic sulfoxides as cosolvent in combination with at least one lithium salt show elevated conductivities and reduced viscosities compared to electrolytes based exclusively on propylene carbonate. Moreover, they are soluble within a wide temperature window and show good conductivities and excellent stabilities even at low temperatures. The solvents permit high solubility and dissociation of various lithium salts, are inexpensive to produce and simultaneously safe to the human organism. When the electrolytes of the invention are used in batteries having a carbon-based electrode as anode and a transition metal electrode as cathode, effective, electrically insulating protective layers having good Li⁺ ion conductivity are formed on both electrodes, and these enable stable cycling with high and reversible discharge capacities.