Study of double perovskite La2B(II)MnO6 (B: Ni, Co, Cu) as electrode materials for energy storage

Abstract

In this paper, the study of the potential capacity of energy storage in supercapacitors containing oxide La2B(II)MnO6 (with B = Cu, Co, Ni) as the electrode material is presented. The mixed oxides are prepared by route of citrate precursors, starting from the nitrates of the corresponding metallic cations. The samples were calcined at 800 °C. The material was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The electrochemical characterization was performed through cyclic voltammetry (CV), galvanostatic charge/discharge measurements (GCD) and electrochemical impedance spectroscopy (EIS) in a three-electrode cell at room temperature, using a platinum electrode and a hydrogen electrode as counter and reference electrodes, respectively. The working electrode was prepared by a dispersion of the nanocomposite and carbon black in an isopropanol solution added on glassy carbon and covered by a Nafion® thin film. Runs were carried out in 0.05-–0.95-V range in 0.5 M KOH solution. The cyclic voltamperograms were obtained at varying the scan rates from 10 to 100 mV s−1. The galvanostatic charge/discharge curves were realize at current density values in the 0.625–31.25 A g−1 range. The higher capacitance values were obtained for La2CuMnO6. Thus, a specific capacitance of 781.25 F g−1at a current density of 3.12 A g−1, and a power and an energy specific of 72.6 kW kg−1 and 113.4 Wh kg−1, were obtained.