Polysiloxane-based compound for electrolyte of lithium secondary battery, organic electrolyte solution including the polysiloxane-based compound, and lithium battery using the solution

1. An additive for an electrolyte of a lithium secondary battery, the additive comprising a polysiloxane-based compound represented by Formula 1 below:

wherein:

R1 and R2 are each independently selected from the group consisting of hydrogen; a halogen group; an oxirane group; an oxetane group; a cyclohexene oxide group; a thiol group; a hydroxyl group; an amino group; —COOH; —C 6 H 4 —OH; —C(═CH 2 )CH 3 ; a C1-C20 alkyl group substituted with hydrogen, a halogen group, an oxirane group, an oxetane group, a cyclohexene oxide group, a thiol group, a hydroxyl group, an amino group, —COOH, —C 6 H 4 —OH, or —C(═CH 2 )CH 3 ; and a C6-C20 aryl group substituted with hydrogen, a halogen group, an oxirane group, an oxetane group, a cyclohexene oxide group, a thiol group, a hydroxyl group, an amino group, —COOH, —C 6 H 4 —OH, or —C(═CH 2 )CH 3 ,

at least one of R1 and R2 is selected from the group consisting of an oxirane group, an oxetane group, and a cyclohexene oxide group;

R3 is a C1-C5 alkyl group;

A1 and A2 are each independently a C2-C8 alkylene oxide repeating unit;

l and p are real numbers in the range of 1 to 50;

m and o are integers in the range of 1 to 10; and

n is an integer in the range of 1 and 30.

2. The additive of claim 1 , wherein the polysiloxane-based compound is represented by Formula 2 below:

wherein l, n, p, R1 and R2 are as defined in claim 1 .

3. The additive of claim 1 , wherein R1 and R2 are each independently selected from the following functional groups:

4. The additive of claim 1 , wherein the polysiloxane-based compound is represented by any one of Formulae 4 to 7 below:

wherein n is in the range of 1 to 30, and l and p are each independently in the range of 1 to 10.

5. An organic electrolyte solution comprising:

a lithium salt;

an organic solvent; and

an additive comprising the polysiloxane-based compound of claim 1 .

6. The organic electrolyte solution of claim 5 , wherein the amount of the polysiloxane compound is 0.1 to 5 wt %, based on the total weight of the organic electrolyte solution.

7. The organic electrolyte solution of claim 5 , wherein the lithium salt comprises a fluorine atom that is covalently bonded to a carbon atom.

8. The organic electrolyte solution of claim 5 , wherein the concentration of the lithium salt in the organic electrolyte solution is 0.01 to 2.0 M.

9. The organic electrolyte solution of claim 5 , wherein the organic solvent comprises at least one of a high dielectric constant solvent and a low boiling point solvent.

10. The organic electrolyte solution of claim 9 , wherein the high dielectric constant solvent comprises at least one selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, 1-fluoroethylene carbonate, and gamma butyrolactone.

11. The organic electrolyte solution of claim 9 , wherein the low boiling point solvent comprises at least one selected from the group consisting of a dimethyl carbonate, an ethymethyl carbonate, a diethyl carbonate, a dipropyl carbonate, a dimethoxyethane, a diethoxyethane, and a fatty acid ester derivative.

12. A lithium battery comprising:

a cathode;

an anode; and

the organic electrolyte solution according to claim 5 .

13. The lithium battery of claim 12 , wherein the anode comprises an anode active material comprising graphite particles and silicon microparticles.

14. An organic electrolyte solution comprising:

a lithium salt;

an organic solvent; and

an additive comprising the polysiloxane-based compound of claim 2 .

15. An organic electrolyte solution comprising:

a lithium salt;

an organic solvent; and

an additive comprising the polysiloxane-based compound of claim 3 .

16. An organic electrolyte solution comprising:

a lithium salt;

an organic solvent; and

an additive comprising the polysiloxane-based compound of claim 4 .