TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Device: The MEESC can be in a form of a microbattery or a double-layer capacitor (DLC).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The substrate material is made of a single crystal or amorphous material. The substrate material can be glass, alumina, semiconductor materials, preferably silicon, for use in microelectronics and ceramic materials. The through cavities of the substrate are formed by Inductive Couple Plasma etching. The through cavities have an aspect ratio of 0.03-0.4 and a cylindrical geometry. The diameter of the cavities is 15-150 microns. The solid electrolyte can be LixPOyNzwhere:x is greater than 2 but less than 3;2y = 3z; andz is greater than 0.18 but less than 0.43.The solid electrolyte can also be LiS-SiS2 glasses doped with up to 5% LiSO4 or 30% LiI, or lithium carbonate (Li2CO3) doped with up to 10% (% atomic weight relative to Li) of calcium, magnesium, barium, strontium, aluminum, or boron. The anode layer can be an alkali metal (M), alkali metal alloy or in the charged state consisting of lithiated forms of carbon or graphite. The cathode layer can be LiCoO2, LiNiO2, LiMn2O4, copper (II) sulfide (CuS), copper (I) sulfide (Cu2S), titanium sulfide (TiS2), vanadium pentoxide (V2O5), V3O8, or lithiated forms of these vanadium oxides and metal sulfides. The two electrodes can be made of carbon powder having a surface are higher than 100 m2/g.    TECHNOLOGY FOCUS - POLYMERS - Preferred Materials: The solid electrolyte can also be a polymer electrolyte based on poly(ethylene oxide) and CF3SO3Li, (CF3SO2)2NLi, LiI or ammonium and ammonium quaternary salts, or their mixtures. The polymer electrolyte comprises 2-15% (v/v) high surface area of inorganic, nanosize particles of ceramic powder which consists of aluminum trioxide (Al2O3), silicon dioxide (SiO2), magnesium oxide (MgO), titanium oxide (TiO2) or their mixtures. EXAMPLE - A microbattery consisting of four thin films: a carbon anode, Al doped Li2CO3 solid electrolyte, LiCoO2 cathode and carbon current collector was fabricated in the discharged state on a perforated 400 micron thick silicon wafer which contains 60 micron in diameter through holes. A thin carbon film was deposited through chemical vapor deposition (CVD) at 850degreesC by passing a methane (10%)-argon (90%) gas mixture for three minutes over the wafer. A second layer of thin aluminum doped Li2CO3 solid electrolyte was deposited at 475degreesC on the first one by CVD. A third thin layer of LiCoO2 cathode was deposited at 500degreesC on the second one. A fourth thin carbon current collector layer was deposited at 800degreesC on the third one. The cell was cycled at 0.01 mA and at room temperature between 2.5 and 4.1 V for more than 10 stable cycles.