A mixed solvent for an electrolyte for a lithium secondary battery and lithium secondary battery comprising the same

The present disclosure relates to mixed solvent for a lithium secondary battery electrolyte capable of improving safety and reliability of the lithium secondary battery and a lithium secondary battery comprising the electrolyte. The mixed solvent for a lithium secondary battery electrolyte of the present invention comprises at least one non-aqueous organic solvent, a further solvent comprising an ester, a fluoroalkylether and a phosphazene.