Facile method of synthesis of cobalt oxide nanoparticles for formation of supercapacitor electrodes with high specific capacitance

Electrochemical energy storage systems have a wide range of applications, including large-scale storage of energy generated by alternative green energy, as well as in electric vehicles and portable electronics. For the operation of electrochemical energy storage systems, supercapacitors play an important role in protecting such systems from failure during power surges. Hybrid metal oxide supercapacitors, particularly those based on cobalt oxide, are promising devices and are intensively investigated. To overcome high electrical resistance, as well as to increase the surface-to-volume ratio in the manufacture of electrodes, it is necessary to use oxides in the form of nanoparticles immobilized in a conductive matrix consisting of carbon materials or materials with higher conductivity than Co3O4. In the present work, a simple method for synthesizing cobalt oxide nanoparticles to form supercapacitor electrodes with high specific capacitance is developed. The method includes synthesis of metastable Zn-Co-O solid solution as an intermediate material. The specific capacitance of the obtained 1 cm(2) electrodes was 467.8 F g(-1) in CV characteristic measurement and scan rate of 3 mV s(-1) , 379 F g(-1) in GCD method at discharge current of 1 A g(-1) and 415 F g(-1) in EIS measurement at 0.01 Hz.