Recent Developments in Design and Fabrication of Graphene-Based Interdigital Micro-Supercapacitors for Miniaturized Energy Storage Devices
The rapid development of miniaturized electronic devices requires state-of-the-art small-form-factor energy storage units for power supply. Micro-supercapacitors (MSCs), as microscale supercapacitors, have great potential to replace microbatteries or electrolytic capacitors due to their high power density and long cycling stability. The planar design of interdigital microelectrodes not only shortens the ionic diffusion distance but also enables the direct integration of the device on-chip or on a flexible substrate for various applications. Graphene, with a unique 2-D nanostructure, has been extensively studied as a supercapacitor material with superior charge storage capability. Recently, the progress in thin-film fabrication technologies has facilitated the development of graphene-based MSCs, which results in device miniaturization and improved areal capacitance. This paper reviews the recent advances on the design of graphene-based MSCs and discusses the technical trend regarding large-scale fabrication and stretchable/wearable energy storage devices.