TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Condition: The inorganic oxide particles are covalently bonded to the polymer or other inorganic oxide particles through urethane groups, urea groups and/or thiocarbamate groups.Preferred Component: The inorganic oxide particles have hydroxyl groups. It comprises alumina; and nanoparticles, where at least50% has a smallest dimension less than 50 nm.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The crosslinked solid ionically conductive polymer is prepared from a polymer of formula A-(alkylene oxide)n-A, and a molar excess of a compound of formula Z-R-T. The solid ionically conductive polymer comprises a poly(alkylene oxide) polymer or a poly(alkylene imine) polymer having urethane groups, urea groups and/or thiocarbamate.A, T, R, Z = as defined above.Preferred Composition: The polymer electrolyte composition further comprises a liquid electrolyte comprising a liquid at 20degreesC and the salt to provide a gel electrolyte composition that is nonswellable. Preferred Condition: The solid polymer electrolyte composition has a swell ratio of less than 2, an interfacial resistance of 10-100 ohmsasteriskcm2, ands a crystalline melting point of less than 60degreesC, a crystallization temperature of less than 40degreesC, and a glass transition temperature of -30 to -40degreesC. The gel electrolyte composition has an ionic conductivity of at least1x10-4 S/cm at 20degreesC. EXAMPLE - Alumina powder was dried at 110degreesC under vacuum for 24 hours. A solid ethylene oxide-propylene oxide-ethylene oxide block copolymer (EOPOEO polymer) was dried at 45degreesC under vacuum for 48 hours and polyethylene oxide having a molecular weight of 600000 (PEO600K) was dried at 50degreesC under vacuum for 48 hours. A solution of solid EOPOEO polymer (104.90 g), PEO600K (5.52 g), lithium bis(trifluorosulfon)imide salt (19.45 g), antioxidant (0.55 g), acetonitrile (104.30 g), and toluene (26.09 g) was made by dissolving the solids in a glass jar. To this was added alumina (13.95 g), acetonitrile (5.10 g) and toluene (1.28 g) and the mixture was blended for 15 minutes at 1500 revolutions per minute. Triisocyanate solution (18.59 g) was added to the mixture prior to coating, and dibutyltin dilaurate solution (0.23 g) was added to the mixture just before coating. An 18-micron smooth thin film was made.