Corrosion Inhibition of Imidazolidinyl Urea-Based Zinc Anode Stabilization for Achieving Superbly Reversible Aqueous Zinc Metal Batteries

In this study, imidazolidinyl urea (IU) carrying multiple hydroxyl groups and amide groups was demonstrated by different means to display spontaneous adsorption on the zinc metal specimen surface in a ZnSO4 solution. Efficient corrosion inhibition performance and the mechanism of IU based on coplanarity, hydrogen bonding, amphilicity, and zincophilicity for a zinc metal plate in an aqueous ZnSO4 medium are presented and discussed. The corrosion reaction and isothermal adsorption of IU on a zinc metal plate in a ZnSO4 solution were further analyzed. It is shown that the hydrogen bond strength of the whole electrolyte system and zinc ion deposition could be regulated by an addition of trace IU to the electrolyte for zinc-ion batteries. Hence, IU could be used as an electrolyte additive in a ZnSO4 solution to enhance zinc anode stability in aqueous zinc-ion batteries. Therefore, additive IU might effectively inhibit corrosion and hydrogen evolution as well as generation and growth of zinc dendrites on the zinc anode surface. Consequently, the cycling of zinc-ion batteries might be improved by an introduction of dilute IU to the ZnSO4 electrolyte. For example, the symmetric Zn||Zn battery including the IU/ZnSO4 electrolyte could cycle stably for more than 5300 h at 1 mA cm–2 and 1 mAh cm–2, while the symmetric Zn||Zn battery including an electrolyte solution with only ZnSO4 could cycle stably for just 260 h.