NONAQUEOUS ELECTROLYTE AND ELECTROCHEMICAL DEVICE INCLUDING THE SAME

The present disclosure relates to a nonaqueous electrolyte having improved stability. The nonaqueous electrolyte includes: a first solvent including a heterocyclic compound having at least one double bond or not, and containing at least one of oxygen and sulfur atoms; a second solvent including at least one of an ether-based compound, an ester-based compound, an amide-based compound and a carbonate-based compound; and a first lithium salt, wherein the first lithium salt includes lithium bis(nonafluorobutanesulfonyl)imide, and the lithium bis(nonafluorobutanesulfonyl)imide is present in an amount of 2-5 wt% based on 100 wt% of the total weight of the nonaqueous electrolyte.