Simple and Versatile Fabrication of 3D Micro-Supercapacitors Using Pneumatic Printing Combined with Intense Pulsed White Light

Abstract

Recently, rapid developments of compact mobile and wearable electronics and micro-medical devices are accelerating an increasing demand for miniaturized energy storages such as micro-supercapacitors. Graphene, a representative two-dimensional carbon material, has attracted enormous interest due to its excellent electrical, mechanical, physical and chemical properties. In particular, many efforts have been made to fabricate graphene-based micro-supercapacitors due to its large specific surface area and superior electrical conductivity. However, many of the attempted fabrication processes have drawbacks, such as complicated multiple-step procedures to create micron-sized interdigitated electrodes and usage of harmful or toxic chemicals during the etching process. In addition, high-temperature treatment is demanded to obtain high-quality graphene materials which is suitable for high-performance graphene-based micro-supercapacitors. Therefore, simple, cost effective and energy efficient strategies are still required for the fabrication of graphene-based micro-supercapacitors. Here, we report a simple, agile and facile method for the fabrication of three-dimensionally printed micro-supercapacitors with high-aspect-ratio electrode micro-arrays using a pneumatic printing technique in conjunction with an intense pulsed white light (IPWL) technology. By using this combined method, micron-sized electrode patterns can be easily printed on diverse substrates, and graphene- or metal oxide-based three dimensional micro-patterns can be fabricated within milliseconds by irradiating the IPWL on graphene oxide or metal oxide precursor patterns, which is exceptionally faster and easier than other graphene reduction and metal oxide formation methods. The as-prepared micro-patterns are further utilized as micro-supercapacitor electrodes, and their electrochemical properties and supercapacitive performance are investigated by means of cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy.