Kunduracı, MuharremÇirmi, DoğanDoğan Çalhan, SeldaÇağlayan, Uğur2023-08-182023-08-182021Kunduraci, M., Çirmi, D., Çalhan, S.D., (2021). Significance of surface roughness in the supercapacitor activity of nickel-based electrodes. Applied Physics A, 127, 618.https://doi.org/10.1007/s00339-021-04784-31432-0630https://doi.org/10.1007/s00339-021-04784-3https://hdl.handle.net/20.500.13099/165Nickel-based thin film electrodes were electrodeposited onto copper substrate using a deep eutectic solvent. The supercapacitor performance of these electrodes in alkaline KOH solution was greatly enhanced by altering surface roughness of coatings. In order to create a rougher surface, two paths were followed. In the first path, Ni-only coatings were prepared at different deposition potentials and smooth-to-rough transition in surface morphology took place at higher potentials due to increasing emission of hydrogen bubbles. In the second path, Ni-Zn binary coatings with varying zinc concentration were electrodeposited and surface roughness was formed by dealloying zinc element from the electrodes as corroborated by Scanning Electron Microscopy and Atomic Force Microscopy results. In both paths, noticeable improvements in the capacitance of nickel electrodes were observed upon the apperance of rougher surface. A linear relationship was discovered between cathodic peak currents and polarization values in the cyclic voltammetry scans of electrodes, possibly for the first time here in literature. The increase in polarization was explained by the decrease in electrode conductivity proved by dwindling of metallic nickel peaks in X-ray diffraction upon electrochemical testing.eninfo:eu-repo/semantics/openAccessSupercapacitorDESNickelThin filmAtomic force microscopyCyclic voltammetryDealloyingElectrodepositionMorphologyNickel metallographyPolarizationPotassium hydroxideScanning electron microscopySupercapacitorSurface morphologySurface roughnessZinc coatingsZinc metallographyCopper substratesDeep eutectic solventsDeposition potentialElectrochemical testingLinear relationshipsNickel electrodeThin-film electrodeZinc concentrationElectrochemical electrodesArticle10.1007/s00339-021-04784-31278Q3WOS:0006914429000022-s2.0-85111317240Q2