Nucleation mechanism and energy storage of Co3Ni thin films electrodeposited on indium tin oxide substrate

This study investigates the electrodeposition of a cobalt–nickel binary alloy on an indium tin oxide (ITO) substrate, focusing on the electrochemical behavior and nucleation mechanism using cyclic voltammetry (CV) and chronoamperometry (CA). The CV results revealed that the Co 3 Ni electrodeposition follows a quasi–reversible process controlled by the diffusion of Co 2+ and Ni 2+ ions. Furthermore, CA analysis and Scharifker–Hills (SH) model revealed a three–dimensional (3D) growth initiated by instantaneous nucleation as confirmed by Astley analysis and scanning electronic microscope observations. The Energy Dispersive X–ray Spectroscopy confirmed the formation of a cobalt–rich Co 3 Ni film with a Co/Ni atomic ratio close to 3:1. The cyclic voltammetry and charge–discharge curves were conducted to investigate the electrochemical performances of the electrodeposited thin films as a promising electrode material for energy storage applications. The obtained film at a potential of –1.04 V/SCE reveals a higher areal capacitance of 28.14 mF cm -2 at scan rate of 10 mV s -1 . In addition, electrochemical impedance spectroscopy revealed a low internal resistance, and favorable interfacial charge–transfer characteristics for the electrodeposited Co 3 Ni film.