TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The electrodes alternate between positive and negative electrodes. Each of the positive and negative electrodes is separated from adjacent electrodes by porous separators (6) having a thickness of 1-2.5 mm. The capacitor has ultracapacitor or supercapacitor capacitance.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The capacitor electrode comprises a high surface area material selected from ruthenium oxide, silver oxide, cobalt oxide, conducting polymers, or preferably activated carbon. The activated carbon material has a surface area of 1000-2500 m2/g. The capacitor electrode further comprises carbon black. The negative electrode additive is present in an amount that increases the potential window of the capacitor negative electrode to at least -1.2V. The capacitor positive electrode additive is present in an amount that increases the potential window of the capacitor positive electrode to at least +1.2V. The electrolyte is sulfuric acid. The positive electrode comprises lead dioxide, nickel oxide, silver oxide, manganese oxide, lithium polymer materials, mixed lithium oxides including lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides and lithium vanadium oxides, or lithium conductive polymer cathode materials. The negative electrode comprises lead, zinc, cadmium, metal hydroxides, lithium in metal or alloy form with other metals such as aluminum, or lithium ion intercalation materials. Preferred Compositions: The capacitor electrode comprises a coating comprising 5-20% carbon black, 40-80% activated carbon, 0-10% carbon fibers, and 5-25% binder. The negative electrode additive comprises, in sulfate or hydroxide form, 1-40 weight % lead, 1-20 weight % zinc, 0-5 weight % cadmium, or 0-5 weight % silver. The positive electrode additive comprises, in oxide, sulfate or hydroxide form, 0-30 weight % lead, 0-2 weight % iron, and 0.05-1 weight % antimony.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The capacitor electrode comprises a high surface area material selected from ruthenium oxide, silver oxide, cobalt oxide, conducting polymers, or preferably activated carbon. The activated carbon material has a surface area of 1000-2500 m2/g. The capacitor electrode further comprises carbon black. The negative electrode additive is present in an amount that increases the potential window of the capacitor negative electrode to at least -1.2V. The capacitor positive electrode additive is present in an amount that increases the potential window of the capacitor positive electrode to at least +1.2V. The electrolyte is sulfuric acid. The positive electrode comprises lead dioxide, nickel oxide, silver oxide, manganese oxide, lithium polymer materials, mixed lithium oxides including lithium nickel oxides, lithium cobalt oxides, lithium manganese oxides and lithium vanadium oxides, or lithium conductive polymer cathode materials. The negative electrode comprises lead, zinc, cadmium, metal hydroxides, lithium in metal or alloy form with other metals such as aluminum, or lithium ion intercalation materials. Preferred Compositions: The capacitor electrode comprises a coating comprising 5-20% carbon black, 40-80% activated carbon, 0-10% carbon fibers, and 5-25% binder. The negative electrode additive comprises, in sulfate or hydroxide form, 1-40 weight % lead, 1-20 weight % zinc, 0-5 weight % cadmium, or 0-5 weight % silver. The positive electrode additive comprises, in oxide, sulfate or hydroxide form, 0-30 weight % lead, 0-2 weight % iron, and 0.05-1 weight % antimony.