Densified Laser-Induced Graphene for Flexible Microsupercapacitors

Abstract

Microsupercapacitors have attracted significant attention due to several of their advantageous characteristics such as lightweight, small volume, and planar structure that is favorable for high mechanical flexibility. Among the various micro supercapacitor forms, those with laser-induced graphene (LIG) electrodes are promising as flexible energy storage devices. While LIG microelectrodes can be fabricated simply by direct laser writing, the capacitance and energy density of these devices are limited because of the relatively low density of LIG, which leads to low surface areas. These limitations could be overcome by densifying the LIG. Here, we report the use of densified laser-induced graphene (d-LIG) to fabricate flexible micro supercapacitors. Interdigitated d-LIG electrodes were prepared by duplicate laser pyrolysis of a polyimide sheet by using a CO2 laser. A PVA-H2SO4 gel-type electrolyte was then applied to the d-LIG electrode surface to assemble a d-LIG micro supercapacitor. This d-LIG micro supercapacitor exhibited substantially increased capacitance and energy density versus conventional low-density LIG micro supercapacitors. While the d-LIG electrode exhibited a substantial change in resistance when subjected to bending at a radius of 3 mm, the change in the capacitance of the d-LIG micro supercapacitor was negligible at the same bending radius due to reinforcement by the infiltrated poly(vinyl alcohol) (PVA) electrolyte, demonstrating the potential application of d-LIG micro supercapacitors in wearable electronics.

High-Performance Washable PM2.5 Filter Fabricated with Laser-Induced Graphene

“…When the laser power was above 5.2 W, the sample structure collapsed and could not be used as a filter. The result reveals that the electrical resistances of the dLIG samples were lower than those of the corresponding sLIG samples in all the cases, consistent with the findings of previous studies [ 28 , 32 ] because of the increased density of the dLIG, increasing conduction paths within a given volume. For all types of LIG filters, the resistance decreased as the laser power increased.…”

Laser-Induced Graphene Based Flexible Electronic Devices

“…Meanwhile, the conductivity, electrochemical performance [24,27,35,36], biocompatibility [37,38], and hydrophobicity [39][40][41] of LIG also have been systematically studied. A variety of LIG devices have been developed, including sensors [14][15][16][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], supercapacitors [17,[43][44][45][46][47][48][49][50][51][52][53][54][55], nanogenerators [54][55][56][57][58]…”

“…Meanwhile, the conductivity, electrochemical performance [ 24 , 27 , 35 , 36 ], biocompatibility [ 37 , 38 ], and hydrophobicity [ 39 , 40 , 41 ] of LIG also have been systematically studied. A variety of LIG devices have been developed, including sensors [ 14 , 15 , 16 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], supercapacitors [ 17 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ], nanogenerators [ 54 , 55 , 56 , 57 , 58 , 59 , 60 , …”

Flexible Quantum Dot Light‐Emitting Device for Emerging Multifunctional and Smart Applications

“…Carbon-based material electrodes have good electrical and mechanical properties, such as graphene materials have been studied in various fields, including various sensors, [206,207] supercapacitors, [208,209] etc. However, QLEDs based on graphene electrodes have inferior performance compared to QLEDs based on ITO electrodes, meaning that graphene as electrodes in flexible QLEDs is still a huge challenge.…”