English Abstract
Abstract:
We report hydrothermal synthesis of Lanthanum tungstate (La2(WO4)3) as an electrode materials for supercapacitor applications. The electrochemical properties of the nanoparticles were investigated using cyclic voltammetry galvanostatic charge–discharge (GCD) and electrochemical impedance spectroscopy in 2.0 M KOH solution as an aqueous electrolyte. The highest specific capacitance of 920.1 F/g was achieved at a scan rate of 5.0 mV/s. A discharging time of 370.43 s was also recorded. La2(WO4)3 shows excellent electrochemical performance with power density of 1876.9 Wkg−1 and energy density of 19.5 Whkg1. La2(WO4)3 is employed as a positive and graphite as a negative electrode in a two-electrode system. The outstanding energy density of 77.7 Wh/kg and power density of 562.7 W/kg was achieved at a current density of 1.0 A/g while a high power density of 4028.8 W/kg is attained with energy density of 39.79 Wh/kg at a current density of 7.0 A/g. The device shows the outstanding capacity retention of 83.8% after 2000 GCD cycles. Additionally, the charge storage mechanism is analyzed for the asymmetric supercapacitor using Dunn’s model. The capacitive and diffusive behavior of whole nanomaterials was examined in detail; also the exponent law is utilized to ascertain the asymmetric nature of the fabricated material, determined through b values. This favorable behavior of La2(WO4)3 suggest potential candidature for electrode in asymmetric supercapacitor application.
