Direct Laser Writing of Graphene Made from Chemical Vapor Deposition for Flexible, Integratable Micro‐Supercapacitors with Ultrahigh Power Output

Abstract

High-performance yet flexible micro-supercapacitors (MSCs) hold great promise as miniaturized power sources for increasing demand of integrated electronic devices. Herein, this study demonstrates a scalable fabrication of multilayered graphene-based MSCs (MG-MSCs), by direct laser writing (DLW) of stacked graphene films made from industry-scale chemical vapor deposition (CVD). Combining the dry transfer of multilayered CVD graphene films, DLW allows a highly efficient fabrication of large-areal MSCs with exceptional flexibility, diverse planar geometry, and capability of customer-designed integration. The MG-MSCs exhibit simultaneously ultrahigh energy density of 23 mWh cm and power density of 1860 W cm in an ionogel electrolyte. Notably, such MG-MSCs demonstrate an outstanding flexible alternating current line-filtering performance in poly(vinyl alcohol) (PVA)/H SO hydrogel electrolyte, indicated by a phase angle of -76.2° at 120 Hz and a resistance-capacitance constant of 0.54 ms, due to the efficient ion transport coupled with the excellent electric conductance of the planar MG microelectrodes. MG-polyaniline (MG-PANI) hybrid MSCs fabricated by DLW of MG-PANI hybrid films show an optimized capacitance of 3.8 mF cm in PVA/H SO hydrogel electrolyte; an integrated device comprising MG-MSCs line filtering, MG-PANI MSCs, and pressure/gas sensors is demonstrated.

Automated Scalpel Patterning of Solution Processed Thin Films for Fabrication of Transparent MXene Microsupercapacitors

“…Preparation of Polyvinyl Alcohol (PVA)/H 3 PO 4 Gel Electrolyte : 1 g PVA (Alfa Aesar, 98%) was dissolved in 10 mL DI H 2 O at 80 °C for 4 h after which a transparent gel is formed. 1 g (0.6 mL) of concentrated phosphoric acid (Alfa Aesar) was added to 10 wt% PVA gel and stirred for 30 min to obtain PVA/H 3 PO 4 gel electrolyte …”

“…It is even more challenging to fabricate coplanar microsupercapacitors out of such thin films . Generally, fabrication of microsupercapacitors often employs state‐of‐the‐art microfabrication techniques, which involve the use of masks and a number of processing steps including coating photoresist and solvent treatments . All these factors not only increase the cost but also affect the optoelectronic properties of thin films.…”

Electrochromic Effect in Titanium Carbide MXene Thin Films Produced by Dip‐Coating

“…[50] In situ UV-vis-NIR, XRD, and Raman Spectroscopy Experiments: For in situ electrochemical measurements with UV-vis-NIR spectroscopy, XRD, and Raman spectroscopy, the systems were precycled 5 times by cyclic voltammetry at 20 mV s −1 to determine the potential window of the device. [50] In situ UV-vis-NIR, XRD, and Raman Spectroscopy Experiments: For in situ electrochemical measurements with UV-vis-NIR spectroscopy, XRD, and Raman spectroscopy, the systems were precycled 5 times by cyclic voltammetry at 20 mV s −1 to determine the potential window of the device.…”

On‐Chip Microsupercapacitors: From Material to Fabrication

“…Combining dry transfer and laser direct writing, Zhu et al engraved the CVD‐grown graphene using ultraviolet laser under ambient conditions to produce on‐chip MSCs with a high energy density. The resultant high performance was attributed to the larger interlayer distance of the laser‐machined graphene structure than thermally or chemically reduced rGO materials . The 2D material MoS 2 , electrospinning nanofibers, and MXenes were also patterned by laser ablation as active mass layers .…”