Perspective on 3D-designed micro-supercapacitors

As an energy storage device to operate miniaturized electronics, micro-supercapacitors (MSCs) have been developed for the past decades. One of main drawback in realization of MSCs is limited areal capacitance due to low material loading per unit area on the substrate. Three dimensional (3D) electrodes with high aspect ratio could be a promising strategy to overcome this, resulting in unprecedented MSC performance. In this review, after discussing cutting-edge approaches of electrode designs, we summarize the recent achievement of 2D to 3D electrodes in MSCs. Also, as a novel fabrication technology, manufacturing of the 3D electrodes by 3D printing is discussed. Finally, we propose a perspective on the development of 3D printed micro-supercapacitors. This includes discussion of key parameters for MSC performance and forward-looking approach of 3D architectured electrodes to achieve higher electrochemical performance of MSCs. (c) 2020 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).