In this work, we have developed a novel nanocomposite material of ceria (CeO 2 )-reduced graphene oxide (RGO) by sonochemical route for the application as symmetric supercapacitors. CeO 2 nanoparticles have been anchored on RGO sheets in order to maximize the specific capacitances of these materials. Nanostructure studies and electrochemical performances of the CeO 2 nanoparticles on the RGO sheets were systematically investigated. The morphology and crystalline structure of nanocomposites were examined by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR), and X-ray diffraction (XRD). Electrochemical properties of the nanocomposite electrodes were examined by cyclic voltammetry (CV), galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) measurements. CeO 2 -RGO nanocomposite electrodes exhibited excellent supercapacitive behavior with high specific capacitance of (211 F g -1 at 2 mV s -1 and 185 F g -1 at 2.0 A g -1 ), high rate capability and well reversibility. Cycling stability of electrode was measured by continues cyclic voltammetry (CCV) technique. Upon 4000 cycles, the specific capacitance of the electrode increases and reaches a maximum value of 105.6 % of the initial value. ARTICLE Journal NameWhere SC is the specific capacitance (F g -1 ), ν is the potential scan rate (mV s -1 ), V c -V a is the potential range and I denotes the response current (mA g -1 ) based on the mass of electroactive material. Fig. 6b and 6c show the CV curves of

A Ni/Co–MOF-based supercapacitor electrode exhibited high specific capacitance, and good rate and cycling performance.

No abstract