Rapid hydrothermal synthesis of cobalt oxyhydroxide nanorods for supercapacitor applications
Cobalt oxyhydroxide (CoOOH) nanorods were synthesized by fast hydrothermal process for supercapacitor electrodes. The structural and morphological studies revealed the formation of CoOOH with hexagonal rhomb-centered crystal structure and excellent rod like morphology of approx. 5-10 nm diameter. The electrochemical characterization was performed for both half cell and symmetric full cell configuration using cyclic voltammetry, galvanostatic charge/discharge test and impedance spectroscopy in 3 M KOH aqueous electrolyte. The fabricated CoOOH electrodes showed maximum specific capacitance value of 198 F g−1 for a half cell and 94 F g−1 for a symmetric capacitor of 10 mg cm−2 active material per electrode and showed better energy and power densities. Moreover, the CoOOH electrode exhibits good capacitance retention (83%) after 5000 charge/discharge cycles.