TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Salt: The lithium salt is LiBF4, LiPF6, CnF2n-1CO2Li (n=1-4), CnF2n-1SO3Li (n=1-4), (FSO2)2NLi, (CF3SO2)2NLi, (C2F5SO2)2NLi, (CF3SO2)3CLi, (CF3-SO2-N-COCF3)Li or (R-SO2-N-SO2CF3)Li (where R is alkyl or aryl group).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The monomer composition contains fused-salt monomer and copolymerizable polyfunctional monomer. The fused-salt monomer is 1-vinyl-3-alkyl imidazolium ion, 4-vinyl-1-alkyl pyridinium cation, 1-alkyl-3-allyl imidazolium ion and 3 other specific compounds which are claimed. The quaternary ammonium cation is quaternary diaryl-dialkyl ammonium. The anion is selected from bis((trifluoromethyl)sulfonyl) amide anion, 2,2-trifluoro-N-(trifluoromethyl sulfonyl) acetamide anion, bis((pentafluoroethyl) sulfonyl) amide anion, bis((fluoro)sulfonyl) amide anion and tetra-fluoro borate anion. Vacuum heat-pressing is performed at 90degreesC and at 21 kg/cm2.    TECHNOLOGY FOCUS - POLYMERS - Preferred Compound: The polyvinylidene fluoride is a polyvinylidene fluoride containing carbon-carbon-carbon double bond. The polyvinylidene fluoride is a composite polyelectrolyte composition containing a polymer and polymer blend of fused-salt monomer. EXAMPLE - 1-methyl imidazole (in g) (37) was dissolved in 200 ml of 1,1-trichloroethane. A solution containing p-chloro methyl styrene (68.7) dissolved in 1,1,1-trichloro ethane (100 ml) was added by continuous stirring. The obtained product was washed and dried to obtain 1-methyl-3-(4-vinyl benzyl) imidazolium chloride. On the other hand, potassium bis((trifluoro methyl) sulfonyl) amide (31.9) was dissolved in water (100 ml) at 70degreesC. The obtained solution was added to 1-methyl-3-(4-vinyl benzyl) imidazolium chloride, and stirred at 50degreesC. Double decomposition reaction was performed for 4 hours. The obtained product was washed and dried, to obtain 1-methyl-3-(4-vinyl benzyl) imidazolium bis((trifluoromethyl) sulfonyl) amide at a yield of 85%. The obtained compound (8.4) was blended with polyvinylidene fluoride modified polymer (10) and a solution containing benzoyl peroxide (0.17) in dimethyl acetoamide (80). Lithium bis((trifluoromethyl) sulfonyl) amide (4) was added, to obtain an electrolyte precursor liquid. The obtained liquid was coated on a polyester film, dried and polymerized, to obtain a transparent film of thickness 25 microns, ionic conductivity 2.1x10-3 S/cm and peel strength 11 MPa. Vacuum press-heating was performed, to obtain a polyelectrolyte film of ionic conductivity about 24% and peel strength 21 kg/cm2 at 90degreesC.