Enhanced capacitive performance of nickel oxide on porous La₀·₇Sr₀·₃CoO₃-δ ceramic substrate for electrochemical capacitors

Abstract

Nickel oxide (NiO) nanoparticles loaded on porous strontium-substituted lanthanum cobaltite (La0·7Sr0·3CoO3-δ, LSC) ceramic substrate is fabricated as a novel binder-free electrode (NiO/LSC) for electrochemical capacitors. The LSC substrate is synthesized through a simple solid-state method. NiO nanoparticles are loaded onto the porous LSC substrate by infiltrating a nickel nitrate (Ni(NO3)2) solution into the pores, followed by calcination. The composite electrode NiO/LSC with a high mass loading of NiO (∼10 mg cm−2) exhibits an appreciable areal capacitance of 10.6 F cm−2, a specific capacitance of 1064.1 F g−1 and remarkable cycling stability (80.1% retention after 3000 cycles at 20 mA cm−2). Moreover, an asymmetric electrochemical capacitor, with NiO/LSC as the positive electrode and carbon cloth as the negative electrode, confirms the excellent capacitive properties, with high energy density of 9.27 mWh cm−3 under a wide potential of 1.65 V. This work indicates the promising application of NiO/LSC as an advanced electrode for electrochemical capacitors.