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 fluorinated alkyl groups (R—O—R′) and a second ether solvent. The first ether solvent may be 5-ethoxy-1,1,2,2,3,3,4,4-octafluoropentane, 1,1,2,2,3,3,4,4-octafluoro-5-methoxypentane, or a mixture thereof, while the second ether solvent can be selected from dimethoxyethane, diethyl ether, and similar ethers. The lithium salt includes compounds like LiTFSI, LiFSI, or LiPF6. The first ether solvent comprises 30-90 vol % of the electrolyte, with lithium salt concentration ranging from 0.1 M to 3.0 M. This electrolyte composition enhances battery stability, making it suitable for lithium and lithium metal secondary batteries.