Preparation of sustainable and binder-free electrode materials for high energy asymmetric supercapacitor applications: A cleaner alternative

Abstract

Herein, we demonstrate a pioneering method for repurposing one of the most abundant and noxious weeds (Parthenium hysterophorus or PH) derived ultrahigh surface area carbon as capacitive electrode and design high performance asymmetric supercapacitor with leveraging ternary metal oxides (TMO) (Ni–Co–Mn–O or TMO-1 and Ni–Co–Zn–O or TMO-2) as binder-free pseudocapacitive positive electrodes to improve the performance and efficiency of supercapacitors. Furthermore, the ternary metal oxides (TMO-1 and TMO-2) were synthesized using a one-pot hydrothermal method, followed by annealing. In a three-electrode configuration, both TMO-1 and TMO-2 exhibited remarkable capacitances. At a current density of 0.5 A/g, a total stored charge of 557.23 C/g and 628.22 C/g was obtained for the TMO-1 and TMO-2, respectively. The asymmetric construction using PH-900-K as the negative electrode and TMO-1 or TMO-2 as the positive electrode demonstrated a maximum energy density of 49.29 Wh/kg for the TMO-1//PH-900-K configuration. While the TMO-2//PH-900-K configuration exhibited a maximum energy density of 70.86 Wh/kg.