Impact of surface pre-treatment on electrochemical performance of B4C-coated nickel foam electrodes

Abstract

In this study, the influence of surface pre-treatment conditions on the electrochemical behavior of boron carbide (B₄C)-coated nickel foam electrodes for supercapacitor applications was systematically investigated. Nickel foam substrates were subjected to surface cleaning in 2M hydrochloric acid (HCl) treatment to effectively eliminate surface contaminants to enhance their conductivity and electrochemical activity. Two different techniques were employed: the first involved magnetic stirring for 30 minutes, while the second consisted of magnetic stirring followed by high-power probe ultrasonication for 10 minutes. Post-treatment, the nickel foam substrates were coated with 40µl B₄C slurry using drop casting technique. The resulting composite electrodes were characterized by using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to assess their capacitive performance. The findings reveal that the nature of the acid-cleaning process significantly affects the adhesion, uniformity, and electrochemical efficacy of the B₄C layer, thereby impacting the overall performance of the electrode. Application of the treatment led to an increase of 163.8783 F/g in specific capacitance relative to the untreated nickel foam, accompanied by a minor rise of 0.032 Ω in internal resistance as revealed by electrochemical impedance spectroscopy (EIS). These results underscore the critical role of optimizing surface modification parameters prior to active material deposition in the development of high-performance electrode architectures for advanced energy storage systems.