The exploration of Lanthanum based perovskites and their complementary electrolytes for the supercapacitor applications

Abstract

In this study, four different kinds of perovskite powders (LaMnO3, LaFeO3, LaCrO3, and LaNiO3) were prepared and investigated as anode materials for supercapacitor. The as-prepared powders were blended with active carbon and subsequently coated on the nickel plates as the collector layer of the supercapacitors. Three different types of the aqueous solutions (3 M KCl, 1 M LiOH, and 3 M LiOH) were respectively served as the electrolytes for the supercapacitor. The morphology and crystalline phase were characterized by transmission electron microscopy and XRD. The electrical capacity and impedance were measured by the electrochemical capacitance voltage analyzer and impedance spectroscopy. The profiles of specific capacitance of the four different anodic electrodes and three different electrolytes were implemented. The impedance results indicated that four asymmetric pseudocapacitors didn’t show any Warburg-type line and semi-circle line in the low-frequency region. According to the CV profiles, the intrinsic LaNiO3 exhibits the highest specific capacitance of 106.58 F/g in 3 M LiOH. Furthermore, the 98% of the initial capacitance of LaNiO3 was retained after 500 charge-discharge life cycles at the maximum current density of 1 A/g. The efficient charge storage of LaNiO3 was attributed by the anion intercalated redox reactions along with the suitability of electrode-electrolyte interactions. Keywords: Perovskite, Lanthanum nickel oxide, Pseudocapacitance, Asymmetric supercapacitor, Oxygen de-intercalation