Recent Progress in Micro‐Supercapacitor Design, Integration, and Functionalization

Abstract

Owing to the advantages of high power density, fast charge/discharge rates, as well as long lifetime, micro‐supercapacitors have drawn much attention for their potential application in miniaturized electronics. Great progress has been made in recent years. On the one hand, many efforts have been devoted to the design and fabrication of high‐performance miniaturized supercapacitors. On the other hand, integration of micro‐supercapacitors with multiple functional materials and devices has emerged with the development of portable and wearable microelectronics. This review first discusses the recent progress of fabrication methods and strategies in the micro‐supercapacitor field. The recent reports on integration of micro‐supercapacitors with smart functions, for instance, self‐charging, self‐protection, electrochromism, self‐healing, sensing, stretchability, as well as photo‐switchimg, are summarized. The perspectives on micro‐fabrication strategies and integrated multifunctionalities of smart micro‐supercapacitors are provided at the end.

Direct Graphene‐Carbon Nanotube Composite Ink Writing All‐Solid‐State Flexible Microsupercapacitors with High Areal Energy Density

“…Because the electrode materials play the crucial role in determining the areal energy density of MSCs, numerous efforts have been devoted to develop the high‐performance electrode materials, such as graphene, [ 10–12 ] carbon nanotube (CNT), [ 9,13 ] activated carbon, [ 9,14 ] transition metal oxide/hydroxide, [ 2,9,15–20 ] and conductive polymer. [ 9,21–23 ] Among these materials, graphene has attracted great attention, thanks to its high surface‐to‐volume ratio, promising theoretical capacitance, and good intrinsic electrical and mechanical properties.…”

Advances on three‐dimensional electrodes for micro‐supercapacitors: A mini‐review

“…Particularly, the in‐plane electrodes configuration not only eliminates the separator and thus significantly reducing the size of MSC unit, but also narrows interspace between positive and negative electrodes to shorten the ionic diffusion distance . Moreover, its intriguing features of straightforward integratability, outstanding mechanical flexibility, good scalability, and ingenious deployments as well as precise tunability of electrodes pattern enable it to gain much popularity recently …”

“…9,10 Moreover, its intriguing features of straightforward integratability, [11][12][13][14] outstanding mechanical flexibility, [14][15][16][17][18] good scalability, [19][20][21][22] and ingenious deployments 23 as well as precise tunability of electrodes pattern enable it to gain much popularity recently. [24][25][26][27] Alternative to gravimetric normalization of performance, [28][29][30] the large areal/volumetric capacities are long-term scientific pursuits for MSCs, although high volumetric energy and power densities are readily achieved for the in-plane MSCs with thin films at present, 31-33 they still suffer from severely low areal energy density compared with the sandwich counterparts. 5,6 Additionally, in contrast to MBs, there is a considerable gap in energy storage capability for MSCs whatever their configurations are to fail to meet the growing demand for energy consumption of electronic components.…”

Hierarchical Ordered Dual‐Mesoporous Polypyrrole/Graphene Nanosheets as Bi‐Functional Active Materials for High‐Performance Planar Integrated System of Micro‐Supercapacitor and Gas Sensor

“…[ 1–3 ] As one competitive miniaturized energy storage unit, micro‐supercapacitors (MSCs) constructed on a planar substrate exhibit significant advantages such as separator‐free architecture, high power density, fast charge/discharge rate, outstanding cycling stability, and favorable safety. [ 4,5 ] They can be directly integrated with energy harvesters (e.g., solar cell and nanogenerator) and energy consumption units (e.g., digital display and sensor) to realize a self‐powered standalone system. [ 6–9 ] In particular, for body‐attachable and portable detection of gas pollutants (e.g., NH 3 , one of the most common gases in industry, agriculture, and our daily life), [ 10–12 ] the MSC‐gas sensor integrated system represents a more and more important core technique of swiftly and reversibly monitoring surrounding gas in real‐time to control industrial processes, reduce environmental pollution, and manage physical health.…”