Investigation of Electrochemical Performance of NiO Nano Rods/PlatesPrepared by Cathodic Electrochemical Deposition—Heat-treatment (CEDHT)Method

In pseudocapacitors, the structure of electrode materials plays an important role in determiningthe electrolyte accessibility and electrode stability, and thus the device performance. To this end,extensive research efforts have been devoted to the control of structures of NiO electrodematerials. Uniform NiO structures in a variety of forms, such as nanocapsules and nanoparticleshave been found that exhibit superior supercapacitive performance [1,2]. Up now,nanostructured NiO has been produced by electrochemical deposition (ED) methods includinganodic and cathodic routes. In this research, cathodic electrochemical deposition-heat treatment(CED-HT) was used as an effective method for synthesis of nanostructured NiO. In this way,nickel hydroxide precursor was first deposited through CED step. Then, the final oxide wasobtained by applying the HT procedure. The structural and morphological evaluations by XRDand SEM revealed that the prepared oxide has crystalline NiO structure (Fig. 1a) with mixedrod/plate texture at nanoscale (Fig. 1b). The supercapacitive performance of the prepared NiOnanoplates/rods was studied by techniques of cyclic voltammetry (CV) and galvanostaticcharge-discharge (GCD) within the potential window of -0.1 to 0.5V in 1 M KOH electrolyte.The measurements (Figs. 1c and d) revealed that the prepared sample have high reversibility(ΔEp =15 mV), high specific capacitance (1265 F g–1 at 1 A g–1) and proper long-term cyclingstability of 92.4% capacity retention after 3000 cycling at the current density of 1 A g–1.

کلیدواژه ها:

NiO ، Nano-plates/rods ، electrochemical synthesis ، Heat-treatment ، Electrochemicalperformance