TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The pregel composition contains at least one substance such as compound having a reactive double bond, at least one linear or branched polymeric compound and at least one isocyanate compound, capable of reacting to form polymeric gel electrolyte. EXAMPLE - (In weight parts) Dehydrated ethylene oxide/propylene oxide random copolymer (870), 4,4'-diphenylmethane diisocyanate (107.4) and methyl ethyl ketone (100) were mixed in a reactor to yield polyurethane prepolymer with isocyanate end groups. The reactor was cooled and benzoquinone (0.3), dibutyltin laurate (5), hydroxyethyl acrylate (16.3) and 1,4-butanediol (6.3) were added and reacted at 50 degreesC. Methyl ethyl ketone was removed to yield unsaturated polyethylene compound. The weight average molecular weight distribution of the compound was found to be 17300 and 6200 as determined by gel permeation chromatography. Unsaturated polyurethane compound (60), methoxy polyethylene glycol monomethacrylate (30) and ethyl methyl carbonate (9) as entrainer were charged to a reactor. The moisture content of the mixture was 14560 ppm. The system was evacuated and an azeotropic dehydration was carried out to yield pregel composition. The moisture level of the pregel composition was measured by Karl Fischer titration and was found to be 40. An electrolyte solution was prepared by dissolving 1.43 mol/kg of lithium hexafluoro phosphate in a 1:1 volumetric mixture of ethylene carbonate and diethyl carbonate as non-aqueous solvent. Pregel composition (10) was added to electrolyte solution (90) followed by addition of azobisisobutyronitrile (0.5) to yield polymer electrolyte solution. The electrolyte solution was introduced into a cell assembly containing positive and negative electrodes and the laminate was sealed and heated to produce the secondary battery. The secondary battery was subjected to a 200-cycle charge/discharge test. The cycle deterioration was calculated as a ratio of capacitance in the 200th charge-discharge cycle to the capacitance in the first cycle, and was found to be 90%.