Secondary battery of excellent productivity and safety

1. A secondary battery, comprising:

a jelly-roll having a cathode/separator/anode structure mounted in a cylindrical battery case;

a plate-shaped insulator mounted on a top of the jelly-roll, the plate-shaped insulator comprising a multi-layer structure having a woven fabric or a knit fabric made of fibers,

wherein each layer has a woven fabric or a knit fabric made of fibers,

wherein the plate-shaped insulator has fine pores having a nonuniform diameter in a longitudinal direction, and

wherein a distance between fine pores is in the range of 10 μm to 100 μm and the distance is uniform.

2. The secondary battery according to claim 1 , wherein the fibers comprise synthetic fibers, natural fibers, or synthetic fibers and natural fibers.

3. The secondary battery according to claim 1 , wherein an electrolyte permeates the fine pores formed in the woven fabric or knit fabric and foreign matter having a size of 100 μm or higher does not permeate the fine pores.

4. The secondary battery according to claim 3 , wherein the fine pores have a size of 1 μm to 100 μm.

5. The secondary battery according to claim 1 , wherein the insulator has a thickness of 0.1 mm to 0.5 mm.

6. The secondary battery according to claim 1 , wherein the battery is a lithium secondary battery.

7. The secondary battery according to claim 1 , wherein the battery comprises an opening perforated in the insulator, to provide gas discharge and pass-through of electrode terminals.

8. A device comprising the secondary battery according to claim 1 as a power source.

9. The device according to claim 8 , wherein the device is selected from a cellular phone, a portable computer, a light electronic vehicle (LEV), an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle and a power-storing device.