Enhanced capacitive performance of nickel oxide on porous La _0·7 Sr _0·3 CoO _3-Δ ceramic substrate for electrochemical capacitors

Nickel oxide (NiO) nanoparticles loaded on porous strontium-substituted lanthanum cobaltite (La _0·7 Sr _0·3 CoO _3-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(NO ₃ ) 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.