All-solid-state flexible asymmetric micro supercapacitors based on cobalt hydroxide and reduced graphene oxide electrodes

Abstract

In-plane micro supercapacitors (micro-SC) have attracted interest due to their high areal and volumetric capacitance that is dependent upon their electrode structure. This study proposes simply-fabricated micro-SCs based on cobalt hydroxide and electrochemically-reduced graphene oxide (erGO). The Au electron collector was prepared via photolithography, and Co(OH)(2) and erGO were deposited on the Au surface via electrodeposition. Using facile two-step fabrication method and cost-effective materials, the prepared micro-SCs exhibit good electrochemical performance in PVA-KOH-KI solid electrolyte. The in-plane interdigitated electrode maximizes the areal capacitance by increasing the facing area between the anode and cathode. The micro-SC presents good power density (100.38 mu W cm(-2)) and a wide potential window due to the electric double-layer properties of erGO and pseudocapacitive performance of Co(OH)(2). These fabricated micro-SCs are flexible and can be used in various wearable and small-scale energy storage devices.