Electrolyte for lithium secondary battery, and lithium secondary battery comprising electrolyte
The present invention relates to an electrolyte for a lithium secondary battery, and a lithium secondary battery comprising the electrolyte, the electrolyte comprising a non-aqueous organic solvent; lithium salt; and an additive comprising a compound which contains a difluorophosphite (—OPF 2 ) group which is expressed by a particular chemical formula.
1. An electrolyte for a lithium secondary battery, comprising
a non-aqueous organic solvent;
a lithium salt; and
an additive comprising a compound represented by Chemical Formula 1:
wherein, in Chemical Formula 1, A is a substituted or unsubstituted aliphatic chain or (—C 2 H 4 —O—C 2 H 4 —)n and n is an integer ranging from 1 to 10.
2. The electrolyte for a lithium secondary battery of claim 1 , wherein in Chemical Formula 1, A is C2 to C20 hydrocarbon chain or (—C 2 H 4 —O—C 2 H 4 -)n and n is an integer ranging from 1 to 5.
3. The electrolyte for a lithium secondary battery of claim 1 , wherein the compound represented by Chemical Formula 1 is a compound represented by Chemical Formula 1-1:
4. The electrolyte for a lithium secondary battery of claim 1 , wherein an amount of the additive is 0.1 wt % to 10 wt % based on a total amount of the electrolyte for a lithium secondary battery.
5. The electrolyte for a lithium secondary battery of claim 1 , wherein an amount of the additive is 0.1 wt % to 5 wt % based on a total amount of the electrolyte for a lithium secondary battery.
6. The electrolyte for a lithium secondary battery of claim 1 , wherein the additive further comprises an additionally additive selected from fluoroethylene carbonate, vinylethylene carbonate, succinonitrile, hexane tricyanide, lithiumtetrafluoroborate, and propanesultone.
7. The electrolyte for a lithium secondary battery of claim 6 , wherein an amount of the additional additive is 0.1 wt % to 20 wt % based on a total amount of the electrolyte for a lithium secondary battery.
8. A lithium secondary battery, comprising
a positive electrode including a positive active material;
a negative electrode including a negative active material; and
the electrolyte of claim 1 .
9. The lithium secondary battery of claim 8 , wherein the positive active material comprises cobalt.
10. The lithium secondary battery of claim 8 , wherein the positive active material comprises a lithium metal oxide represented by Chemical Formula 4:
Li p (Ni x Co y Me z )O 2 [Chemical Formula 4]
wherein, in Chemical Formula 4, 0.9≤p≤1.1, 0.5≤x≤0.98, 0≤y 0.3, 0<z≤0.3, x+y+z 1, and
Me is at least one of Al, Mn, Mg, Ti, and Zr.
11. A method of manufacturing the lithium secondary battery of claim 8 , the method comprising:
coating a positive active material layer on a first current collector to prepare the positive electrode;
coating a negative active material layer on a second current collector to prepare the negative electrode;
mixing the non-aqueous organic solvent, the lithium salt, and the additive comprising the compound represented by Chemical Formula 1 to prepare the electrolyte; and
adding the electrolyte to the positive electrode and the negative electrode.
12. A lithium secondary battery additive comprising:
a compound represented by Chemical Formula 1:
wherein, in Chemical Formula 1, A is a substituted or unsubstituted aliphatic chain or (—C 2 H 4 —O—C 2 H 4 -)n and n is an integer from 1 to 10, and
wherein the compound is configured for a lithium secondary battery.
13. The additive of claim 12 , wherein the lithium secondary battery additive consists of the compound represented by Chemical Formula 1.
14. A method of manufacturing the lithium secondary battery additive of claim 12 , the method comprising:
providing the compound represented by Chemical Formula 1,
wherein the additive is configured for the lithium secondary battery.