Effect Of Hydrochloric Acid Cleaning On Nickel Foam Current Collector For Supercapacitor

• Main Author: Abu Bakar, Nor Atikah
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: T Technology; TA401-492 Materials of engineering and construction. Mechanics of materials
• Online Access: http://eprints.usm.my/47513/1/Effect%20Of%20Hydrochloric%20Acid%20Cleaning%20On%20Nickel%20Foam%20Current%20Collector%20For%20Supercapacitor.pdf; http://eprints.usm.my/47513/

Supercapacitors are well known as energy storage that have higher power density than battery with longer cycling life. Current collector electrode is one of the important components that plays a vital role in performance of supercapacitor. In this work, effects of cleaning with different concentrations of hydrochloric (HCl) solution on nickel (Ni) foam current collector, and the effect after cleaning on electrochemical properties in supercapacitor were studied. The Ni foams were successfully cleaned using sonication method for 10 minutes in HCl solution (0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 4.0 and 5.0 M) at room temperature. The results of material characterization for optimum cleaning concentration (2.5 M HCl solution) of Ni foam showed the sample has uniform thickness (0.034 μm) and good attachment of oxide (NiO and Ni(OH)2) layers on the surface of the Ni foam. Phase and functional group analysis confirmed the presence of the NiO and Ni(OH)2 with no other impurities. The cycle behaviour of Ni foam cleaned with 2.5 M HCl solution responsed with supercapacitor characteristic such as redox peaks with small potential difference (0.398 V at scan rate of 10 mV s-1). The performance of this concentration also showed an outstanding areal discharge capacity (1758.2 F cm-2 at current density of 8 mA cm-2) and reversibility in 1.0 M potassium hydroxide (KOH) lectrolyte. The effect in the electrochemical performance was supported by the impedance analysis. A small difference (27.263 Ω) in the charge transfer resistance indicates that the ectrochemical reaction was welldiffused during the intercalation/de-intercalation process. Thus, the maximum concentration for Ni foam cleaning should be less than 2.5 M HCl solution in order to avoid supercapacitor responses.