Abstract: A multilayered high performance capacitor formed of two or more conductors with a dielectric layer and one or more a dielectric-conductor interface layer sandwiched in between the conductors. The capacitor may be fabricated using many thin layers, at the nano level, providing a nanocapacitor. The capacitor may employ an interleaved structured where numerous conductor layers are interleaved with other conductor layers. The dielectric layers may be multilayered or a single layer and may consist of materials with high dielectric constants ranging from 800 to over 1 million, including materials in the perovskite-oxide family. The capacitor can be shaped, sized and the appropriate materials selected to obtain breakdown voltages within the range of 0.1 to over 11 MV/cm and to obtain specific energies and energy densities equivalent to or exceeding the power characteristics of known capacitors, fuel cells, and batteries.

Abstract: Several embodiments for determining the state of charge of a cell or battery are disclosed. In accordance with one method of this invention, an A.C. voltage is applied to a cell or battery through a shunt. The phase angle between the A.C. voltage across the battery terminals and the A.C. current through the battery (measured as a shunt voltage) is continuously monitored. This phase angle is converted to an analog voltage which represents the A.C. component that is phase shifted by the impedance of the battery. The impedance and thus the phase angle changes with the state of charge of the battery. The analog voltage can be coupled to a meter that provides a phase angle reading or a state of charge reading. Further, the analog voltage can be used to control charge and discharge circuitry. In accordance with a second method, the state of charge of a battery is determined by taking phase angle readings based on input and output A.C. voltages.