Electrochemical supercapacitor development based on electrodeposited nickel oxide film

A nickel oxide (NiO) electrode has been synthesized electrochemically, which is envisaged for supercapacitor application. The structural, morphological, and phase-purity confirmation studies of NiO films were undertaken using X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy, and contact angle measurements. Films of NiO were amorphous in phase, as there were no reflecting planes in the X-ray diffraction pattern. The presence of characteristic bands in FTIR and X-ray photoelectron spectroscopy analysis corroborated the NiO structure. The NiO film surface was smooth with very fine elongated particles (similar to 70 nm) and hydrophilic in character (57 degrees). The supercapacitive performance of an NiO electrode tested using cyclic voltammetry measurement in 0.5 M Na2SO4 electrolyte within the potential range of -1.2 to +1.2 V demonstrated a specific capacitance as high as 458 F g(-1) at 5 mV s(-1). The obtained specific energy, specific power and Coulomb efficiency of NiO electrode were 10.90 W h kg(-1), 0.89 kW kg(-1), and 98%, respectively.