TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The active material layer includes an active material and a conductive agent; and the fluorine resin exists between the active material and the conductive agent and on surface of the active material and the conductive agent. The fluorine resin includes vinylidenefluoride-hexafluoropropylene copolymer and/or polyvinylidenefluoride. Preferred Method: The fluorine resin film or fluorine resin is prepared by coating the electrode with a composition containing 0.5-7, preferably 1-3 pbw fluorine resin and 93-99.5 pbw organic solvent, and drying the resultant coating. Polymerization is performed by heating at 60-130degrees C or radiation by e-beam, gamma -beam, or UV-ray. Preferred Composition: The polymer electrolyte composition includes 2-7 pbw crosslinking monomer and 93-98 pbw electrolytic solution, based on 100 pbw of the composition. It further includes a second crosslinking monomer (5-20 pbw) capable of crosslinking with the crosslinking monomer, and polymerization initiator (1-5 pbw), based on 100 pbw of the crosslinking monomer. EXAMPLE - Kynar 2801(RTM: vinylidenefluoride-hexafluoropropylene (VdF-HFP) copolymer mixed in a weight ratio of 88:12) (1 g) was dissolved in 99 g tetrahydrofuran (THF) to prepare a fluorine resin film composition. Lithium cobalt oxide (LiCoO2) (94 g), Super-P(RTM: Not defined) (3 g), and polyvinylidenefluoride (PVDF) (3 g) were dissolved in N-methyl-2-pyrrolidone (80 g) to prepare a cathode active material slurry. The cathode active material slurry was coated on an aluminum foil having a width of 4.9 cm and a thickness of 147 mu m, followed by drying at 80degrees C, forming a VdF-HFP copolymer film having a thickness of 7 mu m on a cathode. Separately, 90 g mezophase carbon fiber and 10 g PVDF were dissolved in 80 g N-methyl-2-pyrrolidone to prepare anode active material slurry. The anode active material slurry was coated on a copper foil having a width of 5.1 cm and a thickness of 178 mu m, followed by drying at 90degrees C, forming a VdF-HFP copolymer film having a thickness of 7 mu m on an anode. A Celgard(RTM: porous VdF-HFP film having a porosity of 30-50%) was interposed between the cathode and anode and wound to form an electrode assembly. The electrode assembly was put into a battery case, decompressed and then a polymer electrolyte composition was injected into the battery case under a decompressed condition. The polymer electrolyte composition was prepared by mixing 50 g electrolytic solution containing 1.3 M lithium phosphorus hexafluoride (LiPF6) and ethylene carbonate:dimethyl carbonate:propylene carbonate in a weight ratio of 3:5:2, 7.5 g polyethylene glycol dimethacrylate, and 0.5 g azoisobutyronitrile. The resultant product was cured at 70degrees C for approximately 15 seconds, completing a lithium secondary battery exhibiting a swelling thickness of 7.15 mm, discharge capacity of 310 mAh, and impedance (evaluated by determining resistance values before and after charging/discharging) of 0.6 Omega . The battery exhibited no thermal runaway and an exothermic reaction slightly occurred after approximately 1200 minutes.