Optimizing electrochemical performance of sonochemically and hydrothermally synthesized cobalt phosphate for supercapattery devices
By Iqbal, Muhammad Zahir; Khan, Junaid; Siddique, Salma; Afzal, Amir Muhammad; Aftab, Sikandar
Published in International Journal of Hydrogen Energy
2021
Abstract
The supercapattery (hybrid energy storage device) has procured miraculous heed for their significant electrochemical performance, constitute combine features of supercapacitor (prodigious power density) and batteries (substantial energy density), still crave for electrode material with better electrochemical conduct. Here, cobalt phosphate ((Co3(PO4)2) nanostructures were synthesized using sonochemical and hydrothermal approach. The SEM, XRD, and EDX were employed to explore surface morphology, crystal structure, and elemental analysis respectively of as synthesized nanomaterials. The electrochemical performance was evaluated in two and three electrode assembly. The maximum specific capacity of 285 C g-1 at 3 mV/s and 221 C g-1 at 4.1 A g-1 has been obtained by sonochemically synthesized nanomaterial (S1). This electrode material with optimum electrochemical performance was further investigated for supercapattery application. Asymmetric device was fabricated, comprising activated carbon as negative and S1 as positive electrode material. The supercapattery device exhibits a specific capacity of 147.2 C g-1 bearing an outstanding energy density of 34.8 Whkg−1 with a power density of 425.0 W kg-1 at 0.5 A g-1. The device was found to have a remarkable power density of 6800.0 W kg-1 while retaining an energy density of 10.0 Whkg−1 with exceptional capacity preservation of 87.2% after 10,000 consecutive GCD cycles even at 8.0 A g-1. The device performance was further explored in terms of capacitive and diffusion controlled processes and found to have a maximum capacitive contribution of 63.8% at 100 mV s-1. The sonochemical method was found to be the optimal route to synthesize nanomaterials for energy storage applications.