The rapid development of miniaturized portable electronic devices, such as micro-electromechanical systems, microrobots and implantable medical devices, has stimulated intense demand for micro-scale power sources.
Although miniaturized micro-batteries that store energy by redox reactions provide the most frequently used micro-power source for current portable electronics on chip, their limited lifetime (hundreds or thousands of cycles) and low power densityA figure of merit usually expressed in Joules per cubic inch for capacitorsA figure of merit usually expressed in Joules per cubic inch for capacitorsA figure of merit usually expressed in Joules per cubic inch for capacitors rule out applications that require high power over a short timeframe.
Micro-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. (MSCs) with a short ion diffusion distance are newly emerging miniaturized high-power microelectrochemical energy-storage devices that can deliver high power densityA figure of merit usually expressed in Joules per cubic inch for capacitorsA figure of merit usually expressed in Joules per cubic inch for capacitorsA figure of merit usually expressed in Joules per cubic inch for capacitors, fast 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.. and discharge, and a superior cycling lifetime (millions of cycles). MSCs possess great potential for flexible and on-chip portable and self-powered operation.
GrapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. has been demonstrated to be a very promising candidate for constructing high-performance and flexible MSCs due to its unique structural features and physical properties, e.g., large surface area, high intrinsic areal 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. and gravimetric 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.. GrapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice.-based MSCs can fully utilize the planar geometry and advantageous features of grapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. for on-chip energy storage. Planar MSCs that allow electrolyte ions to rapidly interact with all grapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. layers in the horizontal direction are superior to conventional sandwich-like stackedMultiple capacitor elements stacked in multi-unit arrangement to provide bulk capacitance and lower ESR.Multiple capacitor elements stackedMultiple capacitor elements stacked in multi-unit arrangement to provide bulk capacitance and lower ESR. in multi-unit arrangement to provide bulk capacitance and lower ESR. devices.
