TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The anode is made of a carbon material.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: In (S1), the first polymer and the second polymer are random copolymers including a component unit having formula of -(CH2CH(CH2-O-(CH2CH2-O)n- R1)-O)- (I) and a component unit having formula of -(CH2CH(R2)-O)- (II). In (S2), the polymers have a low glass transition point, are not cross-linked and have the lowest cross-linking density in parts nearest to the cathode side and the anode side. In (S2), the polymers are random copolymers including a component unit having formula (I) and a component unit having formula (II).R1=1-12C alkyl, 2-8C alkenyl, 3-8C cycloalkyl, 6-14C aryl, 7-12C aralkyl and 7-12C tetrahydropyranyl;n=1 - 12;R2=H, alkyl, alkenyl, cycloalkyl, aryl or allyl. EXAMPLE - A cathode was formed as follows: Lithium composite oxide of LiCoO2 (91 pbw) as a cathode active material, graphite (6 pbw) as a conductive agent and polyvinylidene fluoride (3 pbw) as a binding agent were mixed together to obtain a cathode composite mixture. The cathode composite mixture was dissolved in 1-methyl-2-pyrrolidone as a solvent to obtain slurry type cathode application solution. The obtained cathode application solution was applied to a rectangular aluminum foil as a cathode current collector to have the application density of 1.41 mg/cm2. The cathode application solution was dried at 110degreesC, and compression-molded by a roll press machine to form the cathode having a cathode active material layer laminated on the cathode current collector. Then, the aluminum foil was cut into a rectangular form to manufacture a cathode lead. The cathode lead was attached to the cathode current collector under pressure. Anode was formed as follows: Graphite (90 pbw) having an average particle diameter of 3 microns as an anode active material and polyvinylidene fluoride (PVdF) (10 pbw) as a binding agent were mixed together to obtain an anode composite mixture. The anode composite mixture was dissolved in 1-methyl-2-pyrrolidone as a solvent to obtain slurry type anode application solution. The anode application solution was applied to a rectangular copper foil as an anode current collector to have the application density of 0.6 mg/cm2. The anode application solution was dried at 110degreesC, and compression-molded by a roll press machine to form the anode having an anode active material layer laminated on the anode current collector. Then, the nickel foil was cut into a rectangular form to manufacture an anode lead. The anode cathode lead was attached to the anode current collector under pressure. A first polymer layer forming a solid electrolyte was formed on the cathode and the anode as follows: A solid type random copolymer whose principal structure included a component unit of -(CH2CH(CH2-O-(CH2CH2-O)2-CH3)-O)- (Ia) (25 mol.%) and a component unit of -(CH2CH2-O)- (Ib) (75 mol.%) whose average molecular weight was one thousand thousands and whose glass transition point measured by a differential scanning calorimeter was -60degreesC was prepared. Lithium tetrafluoroborate (LiBF4) was weighed so that it was assumed that the number of mols of electrolyte salt was (A) and the total number of mols of ethylene oxide unit was (B), as the mixing ratio of the electrolyte salt to the random copolymer, the value (A)/(B) was 0.06. Solution obtained by dissolving the random copolymer and the weighed lithium tetrafluoroborate (LiBF4) into acetonitrile as a solvent was uniformly applied on the cathode active material layer by a casting method. After that, the solution was dried in vacuum to remove acetonitrile as the solvent to form the first polymer layer having the thickness of 10 microns on the cathode. In the same manner, the first polymer layer was formed on the anode. Then, a second polymer layer disposed between the first polymer layers was formed as follows: A solid type random copolymer whose principal structure included the component unit of (Ia) (20.6 mol.%), the component unit of (Ib) (77.5 mol.%) and a component unit of -(CH2CH(CH2-O-CH2CH=CH2)-O)- (Ic) (1.9 mol.%) and whose average molecular weight was one thousand thousands was prepared. Lithium tetrafluoroborate (LiBF4) was weighed. The mixing ratio (A)/(B) was 0.06. A photosensitizer was dissolved into solution obtained by dissolving the random copolymer and the weighed lithium tetrafluoroborate (LiBF4) into acetonitrile as the solvent to prepare the solution. The prepared solution was uniformly applied on a smooth Teflon plate. After that, the solution was dried in vacuum to remove acetonitrile. The dried solution was irradiated with ultraviolet rays, radically polymerized and solidified to form the second polymer layer having the thickness of 50 microns. Then battery element was formed as follows: The first polymer layers respectively formed on the cathode and the anode were opposed to the second polymer layer and pressed to form the battery element. In the battery element, the cathode lead and the anode lead were drawn out and the battery element was sealed under reduced pressure and accommodated in an outer package film. Thus, the lithium-ion secondary battery was formed.