Elaboration of a microstructured inkjet-printed carbon electrochemical capacitor

Abstract

Carbon-based micro-supercapacitors dedicated to energy storage in self-powered modules were fabricated with inkjet printing technology on silicon substrate. An ink was first prepared by mixing an activated carbon powder with a PTFE polymer binder in ethylene glycol stabilized with a surfactant then deposited by inkjet on patterned gold current collectors with the substrate heated at 140 • C in order to assure a good homogeneity. Electrochemical micro-capacitors with electrodes in an interdigital configuration were fabricated, and characterized using electrochemical techniques in 1 M Et 4 NBF 4 propylene carbonate electrolyte. These micro-devices show an excellent capacitive behavior over a wide potential range of 2.5 V for a cell capacitance of 2.1 mF cm −2. The newly developed technology will allow the integration of the storage device as close as possible to the MEMS-based energy harvesting device, minimizing power losses through connections.

Scalable fabrication of high-power graphene micro-supercapacitors for flexible and on-chip energy storage

“…This corresponds to an areal capacitance that varies only slightly from 2.32 mF cm À 2 at 16.8 mA cm À 3 to 1.35 mF cm À 2 at 1.84 Â 10 4 mA cm À 3 . This is superior to the values reported in the literature for EDLC micro-supercapacitors, with typical capacitance values of 0.4-2 mF cm À 2 collected at much lower charge/discharge rates 2,4,25 .…”

“…Among the most desirable properties of a microsupercapacitor, high-power density, high-rate capability and especially high-frequency response are crucial for future applications 2,3 . From a materials perspective, carbon is earth abundant and inexpensive; hence, many nanostructured carbon-based materials have been studied for use in electric double-layer (EDL) micro-supercapacitors, including activated carbons 4 , carbon nanotubes 5 , carbide-derived carbons 1,6 and onion-like carbon 2 . In addition, transition metal oxides such as ruthenium oxide 7 and manganese oxide 8 , and conducting polymers such as polypyrrole 9 and polyaniline 10 have been used as materials for pseudo-capacitive micro-supercapacitors.…”

Improved conductivity and capacitance of interdigital carbon microelectrodes through integration with carbon nanotubes for micro-supercapacitors

“…4(b)). Moreover, the specific capacitance is higher than that of several reported micro-supercapacitors containing carbonbased microelectrodes including photoresist-derived carbon [14,37], carbide-derived carbon [38], inkjetprinted carbon [39], vertically aligned CNTs [40,41], graphene films [42], graphene/CNT [43], and reduced graphene oxide/Fe 2 O 3 [44]. In addition, the chargedischarge curves at a current density of 0.1 mA·cm -2 confirm the significant improvement in electrochemical performance (Fig.…”

Ultrafast charge and discharge biscrolled yarn supercapacitors for textiles and microdevices

“…Important recent advances in the micro-supercapacitor field have exploited novel active materials, such as carbon nanotubes (CNTs) 2 , reduced graphene oxide 3 , activated carbon 4 , conducting polymers 5,6 and metal oxides 7 . Many methods for fabricating miniature energy storage devices, such as rolling thin films into nanotubes 8,9 and micro-patterning [4][5][6][10][11][12] require micro-electromechanical system technology, which is expensive and difficult to upscale. Also, maintaining high energy and power densities under conditions where micro-supercapacitors are subjected to various bending and stretching deformations remains a challenge.…”