A facile synthesis of CaMoO4/MXene and its enhanced charge storage performance in an aqueous hybrid supercapacitor

Abstract

In this work, CaMoO4 is prepared by simplest hydrothermal method and comprehensive analysis is conducted on the investigation of crystallographic structure, functional groups, surface morphology and electronic states of the materials. The electrochemical analysis of CaMoO4 nanoparticles is investigated in 2 M KOH and 2 M LiOH electrolytes. The high specific capacities of 126.96 mAh g-1 and 94.11 mAh g-1 are obtained at 1 A g-1 in 2 M KOH and 2 M LiOH electrolytes, respectively. Further, the energy storage capacity of CaMoO4 is enhanced by incorporating the optimum amount of MXene (Ti3C2), resulting in the capacity of CaMoO4/MXene increasing to 161.49 mAh g-1 in 2 M KOH electrolyte. For the practical applications, an aqueous hybrid supercapacitor (HSC) is assembled using CaMoO4/MXene (positive electrode), activated carbon (AC) (negative electrode), cellulose paper (separator) and 2 M KOH (electrolyte). The assembled CaMoO4/MXene//AC device delivers a high energy density of 43.40 W h kg-1 at a power density of 800 W kg-1. To demonstrate its practical applicability, two CaMoO4/MXene//AC devices connected in series successfully powered four red light-emitting diodes (LEDs) connected in parallel. In addition, the devices effectively powered common electronic gadgets such as a kitchen timer, a digital humidity meter, and a toy motor fan.