Abstract

Transition metal phosphates are gaining attention as an environmentally sustainable and high-theoretical capacity material for electrochemical energy storage devices. This study investigates the impact of adding functionalized graphene Oxide (GO) on the electrochemical sites of cobalt-phosphate (Co₃(PO₄)₂/GO composite) because of its high surface area and electrical conductivity to open up new possibilities for enhancing the performance of energy storage devices. Herein, nanoflakes like cobalt phosphate and composites with graphene oxide were synthesized using a hydrothermal approach. The crystallinity, morphological effect, and chemical compositional analysis were analyzed via XRD, SEM, and EDS. Then, the electrochemical performance is measured in two different setups, i.e., 2-electrode and 3-electrode cell assembly. In the 3-electrodes setup, the cobalt phosphate/GO composite revealed a high specific capacity of 660?C/g, corresponding to 5?mV/s compared to the individual. In the device performance, cobalt phosphate/GO is utilized as +ev electrode, whereas -ev electrode consists of activated carbon in supercapattery. In their results, the assembled devices produced a specific capacity of 458?C/g with remarkable energy and power density of 82.69?Wh/kg and 433.33?W/kg corresponding to a current density of 0.7?A/g, respectively, with good capacitive retention of 94.77% after 6?K cycles. Moreover, the theoretical calculation measure from Dunn's model reveals a capacitive contribution increased from 35.51% to 71.12% with an increase in scan rates. The study offers a new avenue for advanced energy storage applications.