TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Method: The anode is prepared by coating a composition for electrodes containing an anode active material on a sheet-shaped current collecting member made of aluminum or an aluminum alloy, followed by drying and compressing. The cathode is prepared by coating a composition for electrodes containing a cathode active material on a sheet-shaped current collecting member made of copper or a copper alloy, followed by drying and compressing. Preferred Property: An average particle size of the anode active material is 0.1-50 mum.    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The silicon polymer includes, as the repeating unit, a structure of formula (R1)Si(R2)(X) (1).R1, R2 = optionally substituted alkyl, alkoxy, aryl or aryloxy group;X = O, N, alkylene group, phenylene group, Si, metal atom and/or atomic group.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The metal ion salt (1-300 mass%) is trifluoro-methanesulfonic acid lithium (LiCF3SO3), hexafluorophosphonic acid lithium (LiPF6), Li perchlorate (ClO4), Li iodide, tetrafluoroboric acid lithium (LiBF4), LiCF3CO2 (sic), LiSCN (sic), trifluoro-methane sulfonic acid imide lithium, sodium iodide, NaCF3SO3, NaClO4, NaBF4, Na hexafluoroarsenate (AsF6), potassium (CF3SO3), KSCN, KPF6, KClO4 or KAsF6.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The inorganic fine particles (0.1-100 mass%) are silica (silicon oxide), aluminum oxide, zinc oxide, magnesium oxide or titanium oxide. The anode active material is an oxide of a Li-containing transition metal. The oxide of a Li-containing transition metal is LigCoO2, LigNiO2, LigMnO2, LigCojNi1-jO2 or LihMn2O4. The cathode active material is a carbon material from petroleum pitch, natural graphite, artificial graphite, a sintered product of a polyacrylonitrile resin, a sintered product of a furfuryl alcohol resin or carbon fibers. It is an amorphous oxide of a semi-metal element or a chalcogenide.g = 0.02-1.2;j = 0.1-0.9;h = 0-2Preferred Property: A primary average particle size of the inorganic fine particles is not more than 500 nm. EXAMPLE - A mixture of a silicon polymer (A-1, 10 g) and N-lithium-bis-(trifluoromethane)sulfonimide (4 g) was dissolved in acetonitrile (5 ml), to which was added Aerosil 50 (1 g). Then, acetonitrile was distilled off under reduced pressure to obtain an electrolytic composition (E-1). Electrolytic composition (E-1, 10 g) was mixed with compound (d, 5 g). The liquid was cast on Teflon (RTM; polytetrafluoroethylene). The cast liquid was heated at 100degreesC for 4 hours in an argon gas atmosphere to obtain a solid electrolyte thin film (SPE-1). The solid electrolyte thin film (SPE-1) had ion conductivity of 1.1x10-4 S/cm and Li ion transport number of 8.