Electrolyte for lithium secondary battery and lithium secondary battery including the same
An electrolyte for a lithium secondary battery includes a lithium salt, an organic solvent, and a compound represented by Chemical Formula 1. The compound forms a solid electrolyte interphase on a surface of an anode. A lithium secondary battery including the electrolyte and having improved high-temperature storage properties can be provided.
1 . An electrolyte for a lithium secondary battery, comprising:
a lithium salt;
an organic solvent; and
a compound represented by Chemical Formula 1:
wherein, in Chemical Formula 1, R 1 to R 3 are each independently a substituted or unsubstituted C 1 -C 6 alkyl group, or a substituted or unsubstituted C 1 -C 6 alkoxy group,
L 1 is a substituted or unsubstituted C 2 -C 6 alkylene group, or a substituted or unsubstituted C 2 -C 6 alkenylene group, and
L 2 is a substituted or unsubstituted C 3 -C 5 alkylene group, or a substituted or unsubstituted C 3 -C 5 alkenylene group.
2 . The electrolyte for a lithium secondary battery of claim 1 , wherein R 1 to R 3 are each a substituted or unsubstituted C 1 -C 3 alkoxy group, L 1 is a substituted or unsubstituted C 2 -C 6 alkylene group, and L 2 is a substituted or unsubstituted C 3 -C 4 alkylene group.
3 . The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Chemical Formula 1 includes a compound represented by Chemical Formula 2:
4 . The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Chemical Formula 1 is included in an amount ranging from 0.1 wt % to 5 wt % based on a total weight of the electrolyte.
5 . The electrolyte for a lithium secondary battery of claim 1 , further comprising an auxiliary additive that includes at least one selected from the group consisting of a fluorine-containing cyclic carbonate-based compound, a fluorine-containing phosphate-based compound, a sultone-based compound, a cyclic sulfate-based compound and a fluorine-containing phosphine-based compound.
6 . The electrolyte for a lithium secondary battery of claim 5 , wherein the auxiliary additive is included in an amount ranging from 1 wt % to 10 wt % based on a total weight of the electrolyte.
7 . The electrolyte for a lithium secondary battery of claim 5 , wherein a weight ratio of the auxiliary additive relative to the compound represented by Chemical Formula 1 in the electrolyte is in a range from 0.5 to 10.
8 . The electrolyte for a lithium secondary battery according to claim 1 , wherein the organic solvent comprises a linear carbonate-based solvent and a cyclic carbonate-based solvent.
9 . A lithium secondary battery, comprising:
an electrode assembly comprising a cathode and an anode facing the cathode; and
the electrolyte for a lithium secondary battery according to claim 1 impregnating the electrode assembly.
10 . The lithium secondary battery of claim 9 , wherein the cathode comprises a cathode current collector and a cathode active material layer formed on the cathode current collector, and
the cathode active material layer comprises a lithium metal oxide containing nickel.
11 . The lithium secondary battery of claim 9 , wherein the anode comprises an anode current collector and an anode active material layer formed on the anode current collector, and
the anode active material layer comprises a silicon-based active material.
12 . The lithium secondary battery of claim 10 , wherein the lithium metal oxide contains at least 80 mol % of nickel among all elements excluding lithium and oxygen.
13 . The lithium secondary battery of claim 11 , wherein a content of silicon atoms based on a total weight of the anode active material layer is in a range from 1 wt % to 20 wt %.