ELECTROLYTE COMPOSITION FOR LITHIUM SECONDARY BATTERY AND LITHIUM SECONDARY BATTERY CONTAINING THE SAME

An electrolyte composition for lithium secondary batteries includes a lithium salt and an organic solvent. The organic solvent includes a first ether solvent with a structure represented by R—O—R′, where R is a fluorine-substituted C1-2 alkyl and R′ is an unsubstituted C1-3 alkyl and may also include a second ether solvent. The first ether solvent may include methyl 1,1,2,2-tetrafluoroethyl ether, ethyl 1,1,2,2-tetrafluoroethyl ether, or a combination thereof, in a concentration of about 30 to 90 vol % of the total electrolyte composition. The lithium salt may include one or more compounds from a specific group and be present at a molarity of approximately 0.1 M to 3.0 M. This electrolyte composition is also compatible with lithium metal secondary batteries containing lithium metal anodes, offering improved performance and stability.