Facile Hydrothermal Synthesis and Electrochemical Properties of CaMoO₄ Nanoparticles for Aqueous Asymmetric Supercapacitors

Calcium molybdate (CaMoO₄) nanoparticles were prepared by a facile, adoptable, and cost-effective hydrothermal method. The synthesized nanoparticles were investigated by various material analysis techniques. The prepared nanomaterials were subjected as an electrode material for supercapacitors to check their electrochemical properties. The supercapacitive properties of CaMoO₄ electrode material were obtained using the cyclic voltammetry, galvanostatic charging/discharging, and electrochemical impedance spectroscopy measurements. The specific capacity of the electrode material was found to be 118.25 mAh g^-1 at 2 A g^-1. At the high current density of 20 A g^-1, the specific capacity of 50 mAh g^-1 was obtained. To test the practical application of the electrode material, aqueous asymmetric supercapacitors (ASCs) were fabricated using CaMoO₄ and activated carbon (AC) as positive and negative electrodes, respectively. The fabricated CaMoO₄//AC device showed the specific capacity and energy density of 25.77 mAh g^-1 and 18.68 W h kg^-1, respectively at 0.5 A g^-1. Twelve light-emitted diodes and a motor fan were powered using series-connected two ASC devices.