Cable-type secondary battery

1. A cable-type secondary battery, comprising:

an inner electrode supporter; and

a sheet-form laminate of inner electrode-separation layer-outer electrode, helically wound on an outer surface of the inner electrode supporter,

wherein the laminate of inner electrode-separation layer-outer electrode is formed by carrying out compression for the integration of an inner electrode, a separation layer for preventing a short circuit, and an outer electrode, the inner electrode comprises an inner current collector and an inner electrode active material layer formed on a surface of the inner current collector, and the outer electrode comprises an outer current collector and an outer electrode active material layer formed on a surface of the outer current collector, wherein a peel strength between the inner electrode and the separation layer or between the separation layer and the outer electrode is 15 to 300 N/m.

2. The cable-type secondary battery according to claim 1 , further comprising a polymer film formed on another surface of the inner current collector or the outer current collector.

3. The cable-type secondary battery according to claim 2 , wherein the polymer film is made of any one selected from the group consisting of polyolefin, polyester, polyimide, polyamide and a mixture thereof.

4. The cable-type secondary battery according to claim 1 , wherein the outer current collector is in the form of a mesh.

5. The cable-type secondary battery according to claim 1 , wherein the inner electrode further comprises a polymer supporting layer formed on the surface of the inner electrode active material layer.

6. The cable-type secondary battery according to claim 5 , wherein the polymer supporting layer is a porous layer having a pore size of 0.01 to 10 μm and a porosity of 5 to 95%.

7. The cable-type secondary battery according to claim 5 , wherein the polymer supporting layer comprises a linear polymer with polarity, an oxide-based linear polymer or a mixture thereof.

8. The cable-type secondary battery according to claim 7 , wherein the linear polymer with polarity is selected from the group consisting of polyacrylonitrile, polyvinyl chloride, polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polyethylene imine, polymethyl methacrylate, polybutyl acrylate, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyarylate, poly-p-phenylene terephthalamide and a mixture thereof.

9. The cable-type secondary battery according to claim 7 , wherein the oxide-based linear polymer is selected from the group consisting of polyethylene oxide, polypropylene oxide, polyoxymethylene, polydimethylsiloxane and a mixture thereof.

10. The cable-type secondary battery according to claim 1 , wherein the separation layer has an area that is larger in size than those of the inner current collector and the outer current collector.

11. The cable-type secondary battery according to claim 1 , wherein at least one of the inner current collector and the outer current collector further comprises a primer coating layer consisting of a conductive material and a binder.

12. The cable-type secondary battery according to claim 11 , wherein the conductive material comprises any one selected from the group consisting of carbon black, acetylene black, ketjen black, carbon fiber, carbon nanotube, graphene and a mixture thereof.

13. The cable-type secondary battery according to claim 11 , wherein the binder is selected from the group consisting of polyvinylidene fluoride (PVDF), polyvinylidene fluoride-co-hexafluoro propylene, polyvinylidene fluoride-co-trichloroethylene, polybutyl acrylate, polymethyl methacrylate, polyacrylonitrile, polyvinylpyrrolidone, polyvinylacetate, polyethylene-co-vinyl acetate, polyethylene oxide, polyarylate, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinylalcohol, cyanoethylcellulose, cyanoethylsucrose, pullulan, carboxyl methyl cellulose, styrene-butadiene rubber, acrylonitrile-styrene-butadiene copolymer, polyimide and a mixture thereof.

14. The cable-type secondary battery according to claim 1 , wherein the inner current collector or the outer current collector being in the form of a wound sheet has a plurality of recesses on at least one surface thereof.

15. The cable-type secondary battery according to claim 14 , wherein the plurality of recesses are continuously patterned or intermittently patterned.

16. The cable-type secondary battery according to claim 15 , wherein the continuously patterned recesses are spaced apart from each other in a longitudinal direction.

17. The cable-type secondary battery according to claim 15 , wherein the intermittently patterned recesses are formed with a plurality of holes.

18. The cable-type secondary battery according to claim 17 , wherein the plurality of holes have a circular or polygonal shape.

19. The cable-type secondary battery according to claim 1 , wherein the inner current collector is made of stainless steel, aluminum, nickel, titanium, sintered carbon, or copper; stainless steel treated with carbon, nickel, titanium or silver on the surface thereof; an aluminum-cadmium alloy; a non-conductive polymer treated with a conductive material on the surface thereof; or a conductive polymer.

20. The cable-type secondary battery according to claim 19 , wherein the conductive material is selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfurnitride, indium tin oxide (ITO), silver, palladium, nickel and a mixture thereof.

21. The cable-type secondary battery according to claim 19 , wherein the conductive polymer is selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfurnitride and a mixture thereof.

22. The cable-type secondary battery according to claim 1 , wherein the outer current collector is made of stainless steel, aluminum, nickel, titanium, sintered carbon, or copper; stainless steel treated with carbon, nickel, titanium or silver on the surface thereof; an aluminum-cadmium alloy; a non-conductive polymer treated with a conductive material on the surface thereof; a conductive polymer; a metal paste comprising metal powders of Ni, Al, Au, Ag, Pd/Ag, Cr, Ta, Cu, Ba or ITO; or a carbon paste comprising carbon powders of graphite, carbon black or carbon nanotube.

23. The cable-type secondary battery according to claim 22 , wherein the conductive material is selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfurnitride, indium tin oxide (ITO), silver, palladium, nickel and a mixture thereof.

24. The cable-type secondary battery according to claim 22 , wherein the conductive polymer is selected from the group consisting of polyacetylene, polyaniline, polypyrrole, polythiophene, polysulfurnitride and a mixture thereof.

25. A cable-type secondary battery, comprising:

an inner electrode supporter; and

a sheet-form laminate of inner electrode-separation layer-outer electrode, helically wound on an outer surface of the inner electrode supporter,

wherein the laminate of inner electrode-separation layer-outer electrode is formed by carrying out compression for the integration of an inner electrode, a separation layer for preventing a short circuit, and an outer electrode, the inner electrode being an anode or a cathode, and the outer electrode being a cathode or an anode corresponding to the inner electrode, wherein a peel strength between the inner electrode and the separation layer or between the separation layer and the outer electrode is 15 to 300 N/m.

26. The cable-type secondary battery according to claim 25 , wherein when the inner electrode is an anode and the outer electrode is a cathode, an inner electrode active material of the inner electrode comprises an active material selected from the group consisting of natural graphite, artificial graphite, or carbonaceous material; lithium-titanium complex oxide (LTO), and metals (Me) including Si, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe; alloys of the metals; an oxide (MeOx) of the metals; a complex of the metals and carbon; and a mixture thereof, and

an outer electrode active material of the outer electrode comprises an active material selected from the group consisting of LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiFePO 4 , LiNiMnCoO 2 , LiNi 1-x-y-z Co x M1 y M2 z O 2 (wherein M1 and M2 are each independently selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo, and x, y and z are each independently an atomic fraction of oxide-forming elements, in which 0≦x<0.5, 0≦y<0.5, 0≦z<0.5, and x+y+z≦1), and a mixture thereof.

27. The cable-type secondary battery according to claim 25 , wherein when the inner electrode is a cathode and the outer electrode is an anode, an inner electrode active material of the inner electrode comprises an active material selected from the group consisting of LiCoO 2 , LiNiO 2 , LiMn 2 O 4 , LiCoPO 4 , LiFePO 4 , LiNiMnCoO 2 , LiNi 1-x-y-z Co x M1 y M2 z O 2 (wherein M1 and M2 are each independently selected from the group consisting of Al, Ni, Co, Fe, Mn, V, Cr, Ti, W, Ta, Mg and Mo, and x, y and z are each independently an atomic fraction of oxide-forming elements, in which 0≦x<0.5, 0≦y<0.5, 0≦z<0.5, and x+y+z≦1), and a mixture thereof, and

an outer electrode active material of the outer electrode comprises an active material selected from the group consisting of natural graphite, artificial graphite, or carbonaceous material; lithium-titanium complex oxide (LTO), and metals (Me) including Si, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe; alloys of the metals; an oxide (MeOx) of the metals; a complex of the metals and carbon; and a mixture thereof.