The capacitors of electronic circuits function something like batteries – storing electrical chargeThe amount of electricity present upon the capacitor's plates. Also, the act of forcing of electrons onto the capacitor's plates. See CoulombA coulomb is the unit of electric charge. It is named after Charles-Augustin de Coulomb.1 coulomb is the amount of electric charge transported by a current of 1 ampere in 1 second. It can also be defined in terms of capacitance and voltage, where one coulomb is defined as one farad of capacitance times one volt of electric potential difference.. that can be quickly dumped to power devices like camera flashes. So-called “supercapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries.” take the energy-storing abilities of capacitors a step further, storing a far greater chargeThe amount of electricity present upon the capacitor's plates. Also, the act of forcing of electrons onto the capacitor's plates. See CoulombA coulomb is the unit of electric charge. It is named after Charles-Augustin de Coulomb.1 coulomb is the amount of electric charge transported by a current of 1 ampere in 1 second. It can also be defined in terms of capacitance and voltage, where one coulomb is defined as one farad of capacitance times one volt of electric potential difference.. in a much smaller package.

The photograph shows clearly the large grains closely packed together and separated by well-defined grain boundaries. The densityA figure of merit usually expressed in Joules per cubic inch for capacitors of the CCTO ceramic is 94 percent of the maximum theoretical densityA figure of merit usually expressed in Joules per cubic inch for capacitors, indicating the superior nature of the samples. Credit: R. K. Pandey/Texas State University

In a paper published in the journal AIP Advances researchers describe the possibility of fabricating a new class of high heat-tolerant electronics that would employ supercapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries. made from a material called calcium-copper-titanate, or CCTO, which the researchers have identified for the first time as a practical energy-storage material.

Devices using CCTO supercapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries. could compete with similar devices currently in use and could operate at much higher temperatures than standard silicon circuits, “more like the temperature in an engine,” says William Stapleton, an assistant professor of electrical engineering at Texas State University (TSU) in San Marcos, Texas. CCTO had been identified as a promising supercapacitor material before, but its development for practical applications faced unexpected hurdles.

The lead author Raghvendra Pandey, Ingram Professor of electrical engineering at Texas State University, San Marcos, TX along with Stapleton and other collaborators, showed that in CCTO two properties of fundamental importance for the efficiency of a capacitor device are tightly linked. The first property, called permittivityPreferred term for dielectric constant., is the physical property of the capacitor material that allows it to store energy– with higher permittivityPreferred term for dielectric constant. values representing a better capacitor.

The second property, called loss tangent “has to do with how efficiently energy can be moved into and out of the capacitor, that is, how much is lost in the process to inefficiency,” Stapleton said.

“When the loss tangent is high,” explain Pandey, “the capacitor is ‘leaky’ and it cannot hold a stored chargeThe amount of electricity present upon the capacitor's plates. Also, the act of forcing of electrons onto the capacitor's plates. See CoulombA coulomb is the unit of electric charge. It is named after Charles-Augustin de Coulomb.1 coulomb is the amount of electric charge transported by a current of 1 ampere in 1 second. It can also be defined in terms of capacitance and voltage, where one coulomb is defined as one farad of capacitance times one volt of electric potential difference.. for more than a few seconds.”

Researchers found that permittivityPreferred term for dielectric constant. and loss tangent increased or decreased in tandem in CCTO. Efforts to simultaneously retain the high permittivityPreferred term for dielectric constant. while minimizing the loss tangent might not succeed unless a new approach is taken for processing the material. While the work could help explain why researchers have had trouble producing ideal CCTO material in the past, Pandey and his research team have demonstrated that CCTO supercapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries. should be capable of achieving high permittivityPreferred term for dielectric constant. while maintaining low loss tangent, which would make them suitable for storing energy at the desired levels for many industrial applications.

“Efficient, high-speed, high-densityA figure of merit usually expressed in Joules per cubic inch for capacitors energy storage is important to many fields, and supercapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries. offer this,” Stapleton said. “Fields such as ‘green’ energy and electric vehicles could benefit immediately from the use of these materials.”