Electrolyte for lithium secondary battery and lithium secondary battery including the same
An electrolyte for a lithium secondary battery according to embodiments of the present invention includes an organic solvent, a lithium salt, and an additive including a cyclic ether-sulfate-based compound. Thereby, cycle characteristics and high-temperature stability of the lithium secondary battery may be improved.
1. An electrolyte for a lithium secondary battery comprising:
an organic solvent;
a lithium salt; and
an additive including a cyclic ether-sulfate-based compound,
wherein the cyclic ether-sulfate-based compound includes an ether group and a sulfate group which form a single ring structure.
2. The electrolyte for a lithium secondary battery according to claim 1 , wherein the cyclic ether-sulfate-based compound includes a cyclic sulfate-based compound containing an ether group in a ring.
3. The electrolyte for a lithium secondary battery according to claim 1 , wherein the cyclic ether-sulfate-based compound is represented by Formula 1 below:
in Formula 1, R 1 and R 2 are each independently an alkanediyl group having 1 to 4 carbon atoms, and n is an integer of 1 to 8.
4. The electrolyte for a lithium secondary battery according to claim 1 , wherein the cyclic ether-sulfate-based compound includes an ethyleneoxy group.
5. The electrolyte for a lithium secondary battery according to claim 1 , wherein the cyclic ether-sulfate-based compound includes three or more ether groups.
6. The electrolyte for a lithium secondary battery according to claim 1 , wherein the cyclic ether-sulfate-based compound is included in an amount of 0.1 to 15% by weight based on a total weight of the electrolyte.
7. The electrolyte for a lithium secondary battery according to claim 1 , wherein the additive further includes a cyclic sulfonate-based compound.
8. The electrolyte for a lithium secondary battery according to claim 1 , wherein the organic solvent includes at least one of ethylene carbonate (EC), ethyl methyl carbonate (EMC), dimethyl carbonate (DMC), or diethyl carbonate (DEC).
9. A lithium secondary battery comprising:
a cathode;
an anode;
a separator interposed between the cathode and the anode; and
the electrolyte for a lithium secondary battery according to claim 1 .