A non-aqueous electrolyte for a lithium secondary battery comprising an ionizable lithium salt and an organic solvent, the non-aqueous electrolyte comprising: (a) 1 to 10 parts by weight of a compound having a vinylene group or vinyl group per 100 parts by weight of the non-aqueous electrolyte; and (b) 10 to 300 parts by weight of a dinitrile compound having an ether bond represented by the following chemical formula 1, per 100 parts by weight of the compound having the vinylene group or vinyl group: where R 1 to R 3 are each independently C 1 -C 5 alkylene or alkenylene, and m is an integer of 1 to 5, wherein the compound having the vinylene group or vinyl group is any one of a vinylene carbonate-based compound, an acrylate-based compound having a vinyl group, a sulfonate-based compound having a vinyl group, and an ethylene carbonate-based compound having a vinyl group, or mixtures thereof, wherein the dinitrile compound having an ether bond is any one of 3.5-dioxa-heptanedinitrile, 1,4-bis(cyanoethoxy)butane, bis(2-cyanoethyl)-monoformal, bis(2-cyanoethyl)-diformal, bis(2-cyanoethyl)-triformal, ethyleneglycol bis(2-cyanoethyl)ether, diethyleneglycol bis(2-cyanoethyl)ether, triethyleneglycol bis(2-cyanoethyl)ether, tetraethyleneglycol bis(2-cyanoethyl)ether, 3,6,9,12,15,18-hexaoxacicosane dinitrile, 1,3-bis(2-cyanoethoxy)propane, 1,4-bis(2-cyanoethoxy)butane, 1,5-bis(2-cyanoethoxy)pentane, and ethyleneglycol bis(4-cyanobutyl)ether, or mixtures thereof, wherein the non-aqueous electrolyte further comprises cyclic carbonate substituted with halogen represented by the following Chemical Formula 3: where X and Y are each independently hydrogen, chlorine, or fluorine, and both X and Y are not hydrogen, wherein the content of a mixture of the cyclic carbonate substituted with halogen and the compound having the vinylene group or vinyl group is 1 to 10 parts by weight per 100 parts by weight of the non-aqueous electrolyte.. (a) 1 to 10 parts by weight of a compound having a vinylene group or vinyl group per 100 parts by weight of the non-aqueous electrolyte; and (b) 10 to 300 parts by weight of a dinitrile compound having an ether bond represented by the following chemical formula 1, per 100 parts by weight of the compound having the vinylene group or vinyl group: where R 1 to R 3 are each independently C 1 -C 5 alkylene or alkenylene, and m is an integer of 1 to 5, wherein the compound having the vinylene group or vinyl group is any one of a vinylene carbonate-based compound, an acrylate-based compound having a vinyl group, a sulfonate-based compound having a vinyl group, and an ethylene carbonate-based compound having a vinyl group, or mixtures thereof, wherein the dinitrile compound having an ether bond is any one of 3.5-dioxa-heptanedinitrile, 1,4-bis(cyanoethoxy)butane, bis(2-cyanoethyl)-monoformal, bis(2-cyanoethyl)-diformal, bis(2-cyanoethyl)-triformal, ethyleneglycol bis(2-cyanoethyl)ether, diethyleneglycol bis(2-cyanoethyl)ether, triethyleneglycol bis(2-cyanoethyl)ether, tetraethyleneglycol bis(2-cyanoethyl)ether, 3,6,9,12,15,18-hexaoxacicosane dinitrile, 1,3-bis(2-cyanoethoxy)propane, 1,4-bis(2-cyanoethoxy)butane, 1,5-bis(2-cyanoethoxy)pentane, and ethyleneglycol bis(4-cyanobutyl)ether, or mixtures thereof, wherein the non-aqueous electrolyte further comprises cyclic carbonate substituted with halogen represented by the following Chemical Formula 3: where X and Y are each independently hydrogen, chlorine, or fluorine, and both X and Y are not hydrogen, wherein the content of a mixture of the cyclic carbonate substituted with halogen and the compound having the vinylene group or vinyl group is 1 to 10 parts by weight per 100 parts by weight of the non-aqueous electrolyte.. where R 1 to R 3 are each independently C 1 -C 5 alkylene or alkenylene, and m is an integer of 1 to 5, wherein the compound having the vinylene group or vinyl group is any one of a vinylene carbonate-based compound, an acrylate-based compound having a vinyl group, a sulfonate-based compound having a vinyl group, and an ethylene carbonate-based compound having a vinyl group, or mixtures thereof, wherein the dinitrile compound having an ether bond is any one of 3.5-dioxa-heptanedinitrile, 1,4-bis(cyanoethoxy)butane, bis(2-cyanoethyl)-monoformal, bis(2-cyanoethyl)-diformal, bis(2-cyanoethyl)-triformal, ethyleneglycol bis(2-cyanoethyl)ether, diethyleneglycol bis(2-cyanoethyl)ether, triethyleneglycol bis(2-cyanoethyl)ether, tetraethyleneglycol bis(2-cyanoethyl)ether, 3,6,9,12,15,18-hexaoxacicosane dinitrile, 1,3-bis(2-cyanoethoxy)propane, 1,4-bis(2-cyanoethoxy)butane, 1,5-bis(2-cyanoethoxy)pentane, and ethyleneglycol bis(4-cyanobutyl)ether, or mixtures thereof, wherein the non-aqueous electrolyte further comprises cyclic carbonate substituted with halogen represented by the following Chemical Formula 3: where X and Y are each independently hydrogen, chlorine, or fluorine, and both X and Y are not hydrogen, wherein the content of a mixture of the cyclic carbonate substituted with halogen and the compound having the vinylene group or vinyl group is 1 to 10 parts by weight per 100 parts by weight of the non-aqueous electrolyte.. where X and Y are each independently hydrogen, chlorine, or fluorine, and both X and Y are not hydrogen, wherein the content of a mixture of the cyclic carbonate substituted with halogen and the compound having the vinylene group or vinyl group is 1 to 10 parts by weight per 100 parts by weight of the non-aqueous electrolyte..