Enhanced Pseudocapacitance of the LaNiO3 Perovskite in p‐Phenylenediamine as Redox‐Active Electrolyte

Abstract

Perovskite oxides are well known for their excellent properties such as catalytic activity, oxygen ion mobility and structure stability. These properties make it a most suitable material for energy storage devices like fuel cells, batteries and supercapacitors. In the present work, LaNiO3 perovskite was synthesized using the sol-gel method and its morphological parameters were characterized by XRD, SEM and FTIR. The anion-intercalated pseudocapacitive nature of LaNiO3 powder was studied in 2M KOH as well as in the mixture of 2M KOH with p-phenylenediamine (PPD) as an alkaline aqueous and redox-active electrolyte respectively. Electrochemical performance characteristics cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy (EIS) of LaNiO3 has shown pseudocapacities of 300.60 Fg−1 at a scan rate of 5 mV s−1 and 440 F g−1 at a current density of 1 A g−1 in KOH+PPD electrolyte. Furthermore, a symmetrical pseudocapacitor has been fabricated using LaNiO3 as electrode active material with 2M KOH+PPD as an redox-active electrolyte. The device delivered an energy density of 13.75 Wh kg−1 at the power density of 500 W kg−1 at a potential of 1 V. This excellent performance may be due to the synergic effect of both redox active electrode (LaNiO3) and electrolyte (KOH+PPD) that together demonstrated a great combination for high performance pseudocapacitors for future applications.