Gel polymer electrolyte composition, gel polymer electrolyte and electrochemical device comprising the same

1. A gel polymer electrolyte composition, comprising:

i) a compound acting as a monomer for forming gel polymer by polymerization and having at least two double bonds at an end thereof;

ii) an electrolyte solvent containing carbonate and linear saturated ester;

iii) an electrolyte salt; and

iv) a polymerization initiator,

wherein the compound having at least two double bonds at an end is represented by the following Chemical FIG. 1:

where A is alkylene of C 1 -C 12 or haloalkylene of C 1 -C 12 ; a is an integer of 0-30; B is H or methyl group; b is an integer of 2-6; X is

where E 1 to E 4 are respectively hydrogen, alkyl group of C 1 -C 12 , haloalkyl group of C 1 -C 12 , or hydroxyalkyl group of C 1 -C 12 independently, and m is an integer of 0-30.

2. The gel polymer electrolyte composition according to claim 1 ,

wherein the compound having at least two double bonds at an end is any one or a combination of at least two selected from the group consisting of tetraethylene glycol diacrylate, poly ethylene glycol diacrylate having a molecular weight of 50-20,000, 1,4-butanediol diacrylate, 1,6-hexandiol diacrylate, trimethylolpropane triacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, and dipentaerythritol hexaacrylate.

3. The gel polymer electrolyte composition according to claim 1 ,

wherein the compound having at least two double bonds at an end is included in the content of 0.5 to 10 parts by weight, based on 100 parts by weight of the gel polymer electrolyte composition.

4. The gel polymer electrolyte composition according to claim 1 ,

wherein the carbonate is any one or a combination of at least two selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), fluoroethylene carbonate (FEC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC) and methyl propyl carbonate (MPC).

5. The gel polymer electrolyte composition according to claim 1 ,

wherein the linear saturated ester is any one or a combination of at least two selected from the group consisting of methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, butyl propionate, and methyl pivalate.

6. The gel polymer electrolyte composition according to claim 1 ,

wherein the linear saturated ester is included in the content of 10 to 90 parts by weight, based on 100 parts by weight of the carbonate.

7. A gel polymer electrolyte formed by polymerizing the gel polymer electrolyte composition defined in claim 1 .

8. The gel polymer electrolyte according to claim 7 ,

wherein the gel polymer electrolyte is formed by means of in-situ polymerization of the gel polymer electrolyte composition inside an electrochemical device.

9. The gel polymer electrolyte according to claim 7 ,

wherein the gel polymer electrolyte is formed by polymerizing the gel polymer electrolyte composition under an inert condition.

10. An electrochemical device, comprising a cathode, an anode, and the gel polymer electrolyte defined in claim 7 .

11. The electrochemical device according to claim 10 ,

wherein the electrochemical device is a lithium secondary battery.