Exploration of La2O3-CuO nanocomposite as an effective electrode material for asymmetric supercapacitor applications

Abstract

Supercapacitors (SCs) were recently developed as an inexpensive and high-efficiency energy storage technology. A synergistic effect on binary metal oxide composites has been regarded as the desired strategy for enhancing energy storage. In this research work, a binary metal oxide La2O3-CuO nanocomposite was prepared by an ultrasonic-assisted hydrothermal approach. The electrochemical performance is estimated using techniques such as cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electro-impedance spectroscopy (EIS). The La2O3-CuO nanocomposites attained a maximum specific capacity of 930 mAh g−1 at current density of 0.5 A/g and a better cycling stability of 85.25 % even after 2000 continuous charge-discharge cycle. The electro impedance spectroscopy EIS revealed the La2O3-CuO nanocomposites have lower solution resistance (Rs), charge transfer resistances (Rct) of Rs 0.469 Ω and Rct 0.414 Ω, respectively. Moreover, the synthesised La2O3-CuO electrode material attained energy density 13.02 Wh/kg and excellent power density 1205 W/kg along with significant capacitive retention 88.63 % even after 10,000 cycles.The outstanding electrochemical performance makes the binary nanocomposite La2O3-CuO promising electrode material for electrochemical energy storage supercapacitors.