Hydrothermal synthesis of cerium‐doped <scp> Co <sub>3</sub> O <sub>4</sub> </scp> nanoflakes as electrode for supercapacitor application
Faisal Ali, N.R. Khalid, Ghulam Nabi, Anwar Ul‐Hamid, Muhammad Ikram
Abstract
In this work, cerium was doped in various concentrations ranging from 1.0 to 7.0 at. % by means of a facile hydrothermal synthesis route with an intention to improve the capacitive properties of Co3O4. X-ray powder diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (EDX) and HRTEM were employed to study the structural characteristics, morphology, elemental constitution and d-spacing of the synthesized material. The capacitive characteristics were analyzed through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) test and electrochemical impedance spectroscopy (EIS). Materials characterizations revealed the formation of pristine and Ce-doped Co3O4 nanoflakes, and their average size was in the range of 45 to 55 nm and possessing excellent elemental purity. The CV test showed that 5.0 at. % Ce-doped Co3O4 nanoflakes deliver outstanding specific capacitance, that is, 1309.6 F/g and excellent cyclic stability of 90.86% after 2000 CV cycles at a scan rate 5 mV/s. The GCD test at 1-10 A/g showed excellent rate capability, that is, 82.87% at high current density of 10 A/g. The EIS test revealed excellent electrical conductivity of the material. Experimental results suggest that Ce-doped Co3O4 has an outstanding potential for use in energy storage devices.