Enabling High-Quality and Efficient Zinc Electrodeposition with Enhanced Ammonia System Using Synergistic Additives

The ammonia system—compared to traditional acid system—presents considerable benefits when treating zinc (Zn) secondary resources that contain high concentrations of iron, fluorine, chlorine, and low Zn. However, the ammonia-based approach is still facing challenges in maintaining high-quality and efficient Zn electrodeposition. Herein, we propose an efficient ammonia system—enhanced with polyethylene glycol with a molecular weight of 20,000 (PEG20000) and bone glue (BG)—for smooth, compact, and fine-grain Zn electrodeposition. In the bench-scale operation, we achieve a notably low energy consumption of 2415.58 kW h/t Zn and a high current efficiency of 97.46%, with smooth and compact zinc deposit in fine-grained size of 25.4 nm. Electrochemical behavior analysis indicates that introducing the synergistic PEG20000 and BG promotes electrodeposition polarization and a three-dimensional instantaneous nucleation mode. Overall, the integration of PEG20000 and BG as additives in the ammonia system emerges as a technically and economically feasible strategy for zinc electrodeposition.