Enhancing the Performance of Cobalt‐based Oxide Electrode Material for Asymmetric Supercapacitor Devices

Abstract

AbstractSupercapattery is an energy storage device which shows high power and energy densities compared to supercapacitors and batteries. A simple and cost‐effective sol‐gel method was used to synthesize the aluminium‐doped cobalt oxide (Al‐Co3O4). The structural, morphological and composition analyses were investigated using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and X‐ray photoelectron spectroscopy (XPS). Further, Brunauer‐Emmett‐Teller (BET) calculations were performed, which showed an enhancement in surface area. The specific capacity of the Al‐doped sample was increased up to 708 C/g compared to the reference sample (Co3O4=420 C/g). A supercapattery device was designed by using the activated carbon as a negative electrode and the Al‐Co3O4 as the positive electrode in two electrode assemblies. The estimated value of the specific capacity of Al‐Co3O4 was 189 C/g. Furthermore, the obtained energy and power density values were 42 Wh/kg and 2080 W/kg, respectively. To investigate the stability, this device was subjected to 5000 charging/discharging cycles that maintained 90 % of its initial capacity. Our findings provide a foundation for improving the performance of energy storage devices.