Miniaturized supercapacitors: key materials and structures towards autonomous and sustainable devices and systems

Abstract

Supercapacitors (SCs) are playing a key role for the development of self-powered and self-sustaining integrated systems for different fields ranging from remote sensing, robotics and medical devices. SC miniaturization and integration into more complex systems that include energy harvesters and functional devices are valuable strategies that address system autonomy. Here, we discuss about novel SC fabrication and integration approaches. Specifically, we report about the results of interdisciplinary activities on the development of thin, flexible SCs by an additive technology based on Supersonic Cluster Beam Deposition (SCBD) to be implemented into supercapacitive electrolyte gated transistors and supercapacitive microbial fuel cells. Such systems integrate at materials level the specific functions of devices, like electric switch or energy harvesting with the reversible energy storage capability. These studies might open new frontiers for the development and application of new multifunction-energy storage elements.

Co-generation of hydrogen and power/current pulses from supercapacitive MFCs using novel HER iron-based catalysts

“…3b) ohmic drop that contributed roughly 95% to ΔV ohmic . These results are in agreement with previously presented data [56], [57], [58]. Moreover, the capacitance of the cell (C cell ) can be extrapolated (Eq.…”

“…Consequently, the utilization of SC-MFC follows the direction of enhancing power output of a MFC system. Those performances were similar to the one previously presented in SC-MFCs working with similar electrolyte and same electrode materials [56], [57], [58]. Power pulses obtained are much higher than continuous power produced in a single chamber MFC [56], [57], [58].…”

“…3a and b, respectively. Those specific values of t pulse and i pulse were adopted in order to compare to previous reported data on similar operating conditions [56], [57], [58], [64]. The behaviors of the four separate cells were very similar and comparable to each other indicating reproducibility of the materials utilized and the process.…”

“…Although commercial external supercapacitors are suitable for certain applications, some issues remain because of the long recharge time required for devices or sensors [48], [49], [50], [51], [52], [53], [54], [55]. Recently, Santoro et al shown that the integration of the MFC electrodes as an internal supercapacitor in a supercapacitive microbial fuel cell (SC-MFC) [56], [57], [58] is a new approach to increase the current pulses and it could be used to simplify the combined system MFC-MEC system for energy neutral H 2 production.…”

“…The internal EDLC is then fully recharged and conditions, previous the discharge pulse, are re-established. In those conditions, the MFC electrodes work as a self-powered, self-recharged supercapacitor that is able to generate pulsed current/power [56], [57], [58]. It has been shown that intermittent load implementation enhances the output of a microbial fuel cell [59], [60] and SC-MFC operation follows this direction and operating strategy.…”