Electrochemical mechanisms and performance regulation of ultrasonic-assisted zinc electrowinning

Ultrasound-assisted zinc electrodeposition represents a promising strategy for process intensification, though its fundamental electrochemical mechanisms require deeper exploration. This study systematically elucidates the sonoelectrochemical mechanisms governing zinc electrodeposition through a multi-technique approach. The effects of ultrasound (40 kHz, 0-30 W) on interfacial transport, nucleation kinetics, and deposit formation were investigated using chronopotentiometry, electrochemical impedance spectroscopy, Tafel analysis, and chronoamperometry. Results demonstrate that ultrasound induces a mechanistic transition from progressive to instantaneous nucleation while substantially enhancing mass transfer-reducing the diffusion layer thickness and charge transfer resistance by 28 %. Optimal performance at 10 W ultrasonic power yielded a 9 % reduction in cell voltage and 13 % lower energy consumption. Morphological and structural analyses confirmed that ultrasound promotes denser, smoother deposits with refined grains and preferred (002) orientation. This work provides both mechanistic insights and experimental validation for ultrasound-assisted zinc electrodeposition, establishing a foundation for its application in energy-efficient zinc production.