Method of preparing gel polymer electrolyte secondary battery and gel polymer electrolyte secondary battery

1. A method of preparing a gel polymer electrolyte secondary battery including a cathode, an anode, a separator and a gel polymer electrolyte in a battery case, the method comprising:

(S1) coating a polymerization initiator on a surface of a cathode and/or anode, the surface needed to be contacted with a gel polymer electrolyte;

(S2) putting an electrode assembly including the cathode, the anode, the non-woven fabric separator into the battery case; and

(S3) forming a gel polymer electrolyte by introducing a gel polymer electrolyte composition including an electrolyte solvent, an electrolyte salt and a polymer electrolyte monomer into the battery case and polymerizing the monomer,

wherein the electrode has no polymerization initiators, and wherein the electrode is produced by coating, pressing and drying a slurry for the cathode and/or anode, said slurry consisting of an electrode active material, binder, conductive material and solvent.

2. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the polymerization initiator is at least one selected from the group consisting of benzoyl peroxide, acetyl peroxide, dilauryl peroxide, di-tert-butyl peroxide, t-butyl-peroxy-2-ethylhexanoate, cumyl hydroperoxide, t-amyl-(2-ethylhexyl)monoperoxy carbonate, hydrogen peroxide, 2,2′-azobis(2-cyanobutane), 2,2′-azobis(methylbutyronitrile), AIBN and AMVN.

3. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the polymer electrolyte monomer is a monomer having a polymerizable functional group selected from the group consisting of a vinyl group, an epoxy group, an allyl group and a (meth)acryl group.

4. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the electrolyte solvent is at least one selected from the group consisting of cyclic carbonate, linear carbonate, lactone, ether, ester, sulfoxide, acetonitrile, lactam, ketone and halogen derivatives thereof.

5. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the electrolyte salt is a combination of (i) a positive ion selected from the group consisting of Li + , Na + and K + , and (ii) a negative ion selected from the group consisting of PF 6 − , BF 4 − , Cl − , Br − , I − , ClO 4 − , AsF 6 − , CH 3 CO 2 − , CF 3 SO 3 − , N(CF 3 SO 2 ) 2 − and C(CF 2 SO 2 ) 3 − .

6. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the monomer is included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of a mixture of the electrolyte solvent and the electrolyte salt.

7. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 ,

wherein the polymerization initiator is included in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of a mixture of the electrolyte solvent and the electrolyte salt.

8. The method of preparing a gel polymer electrolyte secondary battery according to claim 1 , further comprising

performing thermal treatment or light radiation in the polymerization of the monomer.

9. A gel polymer electrolyte secondary battery prepared according to claim 1 .