A lithium secondary battery comprising: a positive electrode comprising a positive active material represented by Formula 1; a negative electrode; and an electrolyte disposed between the positive electrode and the negative electrode, the electrolyte comprising a lithium salt, a nonaqueous solvent, and a cyclic compound represented by Formula 2, wherein an amount of the cyclic compound is from 0.1 percent by weight to less than 2 percent by weight based on a total weight of the electrolyte, wherein the electrolyte further comprises vinylene carbonate, and wherein the vinylene carbonate, is contained in an amount of less than 2 percent by volume, based on a total volume of the electrolyte, Formula 1 Li x Ni y M 1-y O 2 wherein, in Formulae 1 and 2, 0.9 ≤ x ≤ 1.2, 0.7 ≤ y ≤ 0.95, M comprises Al, Mg, Mn, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Bi, or a combination thereof, and R 1 and R 2 are each independently a substituted or unsubstituted methylene group or a substituted or unsubstituted ethylene group, wherein a substituent of the substituted methylene or ethylene group comprises a halogen, a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, a tert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, a vinyl group, a propenyl group, a butenyl group, or a combination thereof; wherein the nonaqueous solvent comprises a linear carbonate and a cyclic carbonate mixed at a volume ratio of 1:1 to 9:1; wherein the nonaqueous solvent comprises fluoro-ethylene carbonate in an amount of 0.5 volume percent to 7 volume percent, based on a total volume of the nonaqueous solvent; wherein the lithium secondary battery is not a lithium secondary battery as disclosed in any of Examples 10, 11 and 14 to 20 of EP 3 291 352 A2. a positive electrode comprising a positive active material represented by Formula 1; a negative electrode; and an electrolyte disposed between the positive electrode and the negative electrode, the electrolyte comprising a lithium salt, a nonaqueous solvent, and a cyclic compound represented by Formula 2, wherein an amount of the cyclic compound is from 0.1 percent by weight to less than 2 percent by weight based on a total weight of the electrolyte, wherein the electrolyte further comprises vinylene carbonate, and wherein the vinylene carbonate, is contained in an amount of less than 2 percent by volume, based on a total volume of the electrolyte, Formula 1 Li x Ni y M 1-y O 2 wherein, in Formulae 1 and 2, 0.9 ≤ x ≤ 1.2, 0.7 ≤ y ≤ 0.95, M comprises Al, Mg, Mn, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Bi, or a combination thereof, and R 1 and R 2 are each independently a substituted or unsubstituted methylene group or a substituted or unsubstituted ethylene group, wherein a substituent of the substituted methylene or ethylene group comprises a halogen, a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, a tert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, a vinyl group, a propenyl group, a butenyl group, or a combination thereof; wherein the nonaqueous solvent comprises a linear carbonate and a cyclic carbonate mixed at a volume ratio of 1:1 to 9:1; wherein the nonaqueous solvent comprises fluoro-ethylene carbonate in an amount of 0.5 volume percent to 7 volume percent, based on a total volume of the nonaqueous solvent; wherein the lithium secondary battery is not a lithium secondary battery as disclosed in any of Examples 10, 11 and 14 to 20 of EP 3 291 352 A2. M comprises Al, Mg, Mn, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, Bi, or a combination thereof, and R 1 and R 2 are each independently a substituted or unsubstituted methylene group or a substituted or unsubstituted ethylene group, wherein a substituent of the substituted methylene or ethylene group comprises a halogen, a methyl group, an ethyl group, a propyl group, an iso-propyl group, a butyl group, a tert-butyl group, a trifluoromethyl group, a tetrafluoroethyl group, a vinyl group, a propenyl group, a butenyl group, or a combination thereof; wherein the nonaqueous solvent comprises a linear carbonate and a cyclic carbonate mixed at a volume ratio of 1:1 to 9:1; wherein the nonaqueous solvent comprises fluoro-ethylene carbonate in an amount of 0.5 volume percent to 7 volume percent, based on a total volume of the nonaqueous solvent; wherein the lithium secondary battery is not a lithium secondary battery as disclosed in any of Examples 10, 11 and 14 to 20 of EP 3 291 352 A2.