Synthesis, magnetic properties, and electrochemical evaluation of La2NiMnO6 double perovskite as electrode materials for supercapacitor applications

Abstract

Perovskite oxides have attracted significant attention in energy storage performances, because of its eccentric physical and chemical features. Herein, we aim to study the electrochemical characterization of double perovskite La2NiMnO6 (LNM) prepared through a facile sol-gel route. XRD profile portraited the formation of monoclinic structure with a space group P21/n. The X-ray photoelectron spectroscopy highlighted the presence of La, Ni, Mn and O ions in La2NiMnO6. SEM images validated the presence of uniformly distributed particles. The MnO6 and NiO6 octahedra's stretching “breathing” vibrations are assigned to the Ag mode, whereas the combined modes of antistretching or/and bending motions are represented by the Bg mode. Subsequent electrochemical performance evaluations of LNM electrode were conducted using cyclic voltammetry, galvanic charge-discharge studies, electroscopic Impedance spectroscopy and Ragone plot to interpret the nature of prepared sample. For a scan rate 10 mV/s, LNM shows specific capacitance of 9.16 mF/g and at current density of 0.1 A/g, it showed specific capacitance of 20.13 mF/g. The DC magnetic measurement shows the persistence of a dominating ferromagnetic long-range ordering below the Curie temperature (TC∼286 K). Hence the result provides an opportunity to develop LNM for supercapacitor applications.