Effects of CeCl3 on the Nickel Electrodeposition Behavior and Microstructure

Abstract

This study is based on an industrial electrolyte system provided by a specific company and systematically investigates the regulatory mechanisms of the rare earth element cerium on the crystallization behavior of nickel electroplating and the resulting coating performance. The aim is to improve the theory of nickel electrocrystallization in industrial electrolytes, prepare electrolytic nickel plates with specific microstructures and properties, and overcome the common key technologies in the short-process direct rolling process of nickel plates. The multifaceted regulatory influence of cerium on the nickel electroplating process is examined in detail, encompassing electrochemical reaction kinetics, the structural evolution of the deposited layer, and elemental distribution. A comprehensive regulatory pathway is thus established. The findings reveal that the incorporation of 0.5 g/L CeCl₃ significantly reduces charge transfer resistance, accelerates the reduction kinetics of Ni²⁺, and enhances nucleation rate and density, thereby improving the uniformity and compactness of the deposited layers. Although Ce³⁺ does not alter the fundamental nucleation mechanism, it effectively modulates crystallographic orientation and promotes the synergistic growth of crystalline planes. XRD, TEM, and XPS analyses indicate that Ce exists in the stable form of Ce₁₀OS₁₄, mainly distributed at the grain boundaries, which is beneficial for enhancing the performance of the deposited layer. EBSD results further confirm that cerium facilitates grain refinement and increases the proportion of high-angle grain boundaries. However, excessive CeCl₃ addition (1.5 g/L) leads to pronounced adsorption effects, resulting in grain coarsening and diminished coating quality.