Electrolyte for lithium secondary battery and lithium secondary battery including same
The present invention relates to an electrolyte for a lithium secondary battery and a lithium secondary battery including the same, the electrolyte including a lithium salt, an additive containing a compound represented by Formula 1, and an organic solvent.
1. An electrolyte for a lithium secondary battery, comprising:
a lithium salt;
an additive containing a compound represented by Formula 1 below; and
an organic solvent:
wherein, in Formula 1,
R is hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m is an integer of 0 to 2, and
wherein A is a substituted or unsubstituted hetero ring having 4 to 6 carbon atoms and containing a hetero element selected from the group consisting of nitrogen, oxygen, and sulfur.
2. The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Formula 1 is a compound represented by Formula 1-1 below:
wherein in Formula 1-1, R 1 and R 2 are each independently selected from the group consisting of hydrogen and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and
wherein A is a substituted or unsubstituted hetero ring having 4 to 6 carbon atoms and containing at least one hetero element selected from the group consisting of nitrogen, oxygen, and sulfur.
3. The electrolyte for a lithium secondary battery of claim 1 , wherein the at least one hetero element of A comprises nitrogen.
4. The electrolyte for a lithium secondary battery of claim 3 , wherein the at least one hetero element of A further comprises oxygen.
5. The electrolyte for a lithium secondary battery of claim 3 , wherein the nitrogen is located at a site in A which connects to the remaining portion of the compound represented by Formula 1.
6. The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Formula 1 is one or more selected from the group consisting of a compound represented by Formula 1-2 below and a compound represented by Formula 1-3 below:
wherein, in Formula 1-2, R 3 and R 4 are each independently selected from the group consisting of hydrogen and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms,
wherein, in Formula 1-3, R 5 and R 6 are each independently selected from the group consisting of hydrogen and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.
7. The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Formula 1 is a compound represented by Formula 1-4 below:
wherein, in Formula 1-4, R 7 and R 8 are each independently selected from the group consisting of hydrogen and a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.
8. The electrolyte for a lithium secondary battery of claim 1 , wherein the additive is included in an amount of 0.1 parts by weight to 3 parts by weight based on 100 parts by weight of the electrolyte for a lithium secondary battery.
9. The electrolyte for a lithium secondary battery of claim 1 , wherein the lithium salt comprises one or more selected from the group consisting of LiPF 6 and LiBF 4 .
10. A lithium secondary battery, comprising:
a positive electrode;
a negative electrode;
a separator; and
the electrolyte of claim 1 .