The effect of rare earth element cerium on electrocrystallization and microstructure of nickel deposits

Abstract To meet the demand for high-quality, precisely controllable organizational structure of high-end nickel foil, this study employed cerium rare earth as an additive to improve the quality of the nickel deposition layer in industrial electrolytes. The effects of adding different concentrations of CeCl₃ (ranging from 0 g·L⁻¹ to 1.0 g·L⁻¹) on the electrocrystallization behavior of nickel deposition were investigated using linear sweep voltammetry (LSV), cyclic voltammetry (CV), and chronoamperometry (CA). Additionally, the impact of CeCl₃ on the surface morphology and crystal structure of nickel deposits was analyzed using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The results indicated that adding 0.8 g L⁻¹ CeCl₃ not only promoted the electro-deposition process of nickel, accelerating the nucleation rate and shortening the nucleation relaxation time, thereby refining the grain size of the deposited layer, but also improved the structure of the coating, facilitating grain refinement. Surface morphology and micro-area composition analysis revealed that adding 0.8 g L⁻¹ CeCl₃ enhanced the preferred orientation of the nickel deposition layer, resulting in a more uniform distribution of crystal-face preference on the surface of the deposition layer and multi-directional growth. The apparent quality of the nickel deposition layer was improved, with a uniform and smooth surface and finer grains. Detection found that the cerium content in the deposition layer was extremely low, which did not affect the purity of the nickel deposition layer.