Influence of annealing on the morphological, structural and electrochemical properties of Co3O4 spinel electrodes

Effectual use of energy requires the conversion and storage device with great ability. In this research, Co3O4 nanoparticles are achieved via facile and low-cost reflux method. The consequence of annealing treatment on morphological, structural, and electrochemical behaviors of produced Co3O4 (350, 550, 750 and 950 °C) nanoparticles are investigated. XRD analysis exposes the formation of cubic Co3O4 spinel above 300 °C annealing temperature. SEM and EDX study demonstrate that the morphology of Co3O4 nanoparticles changes with different annealing temperatures. The electrochemical performance of prepared Co3O4 (350–950 °C) nanoparticles was determined via charge-discharge experiment, and electrochemical impedance, cyclic voltammetry studies. It exposes that the annealing treatments have an important effect on the specific capacitances. Among them, the optimized Co3O4 (950 °C) electrode demonstrates the best capacitive behaviors in the three-electrode cell, which exhibitions the best capacitance value of 1388 Fg−1 at 5 mVs−1 and outstanding cycling capability of 97.2 % capacitance even after 5000 cycles. The asymmetric supercapacitor device assembled by Co3O4 (950 °C) displays a capacitance value of 519.3 Fg−1 for 5 mVs−1 and long reversible capacity (92.7 % capacitance retains after 5000 cycles) and a high-power density (26.7 W h Kg−1). These outcomes exposed that the Co3O4 (950 °C) nanoparticles could be a perfect candidate for eminent electrochemical application as electrode materials. These results state that Co3O4 nanoparticles are a multipurpose material and thus can be applied in numerous applications namely gas sensors, fuel cells, solar cells, electrochemical sensors, and photocatalysis.