TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The compound is in the form of associated superstructure obtained by repeating the unit cell.Preferred Components: The A, B, and/or C comprises a metal doped with further metal.Preferred Compositions: The electrode comprises at least30 wt.% compound.    TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The substrate is a matrix, and the compound or mixture of compound is held inside the matrix, forming a cohesive unit. It has a release property, and the layer which comprises the compound with high conductivity for electrons, after it has been applied, is removed from the substrate and subjected to an optional heat treatment. The electrode is carbon electrode, ruthenium (II) oxide electrode, or hydrated ruthenium (II) oxide electrode. Preferred Definitions:    A = La, Sm, Sr or Nd (preferably La, Sm or Nd);    B = La, Sm, Sr or Nd (preferably Sr);    C = Co, Mn or Fe (preferably Co);    x = 4;    y = 0;    epsilon = 0.    EXAMPLE - A layer of suspension comprising the inventive compounds, solvent, and dispersing agents, surfactant and wetting agent was applied to a metal foil or plastic film. The layer applied with the suspension was dried, and the solvent and auxiliaries were removed. If appropriate, the layer was heat treated, calcined, or sintered after the drying. The substrate bearing the layer had thickness of approximately 2-1000 microns and porosity of approximately 5-40%. The substrate was used in supercapacitor or battery. The obtained internal resistance of the supercapacitor was measured with the aid of impedance spectroscopy. The charging and discharging cycles were carried out, cyclic voltammograms were recorded, and carried out again at current densities of at most100 mA/g SmSrCoO4-delta (inventive compound) and between cell voltages of 0-1.8 V.    Results showed that potential curve of electrode during charging and discharging with current 0.1 A/g led to effective capacitance for the inventive compound of approximately 30 F/g (shown at the figure).