Reinforcing the Symmetry of Stripping/plating Behavior via In-situ Interface Construction for Long-lasting Zinc Metal Batteries

Zn metal batteries (ZBs) are considered promising candidates for next-generation energy storage systems. Cyclic reversibility of ZBs is strictly associated with the interfacial evolution of the Zn anode during the initial stripping. In this contribution, the asymmetry of the stripping/plating behavior is identified as the culprit for short circuits and failure of ZBs due to the uncontrollable growth of dendritic Zn. Accordingly, an electrolyte containing N, N′‑dimethylpropyleneurea (DU) is designed to regulate the initial stripping behavior for enhancing the cyclic reversibility of Zn anode. Specifically, DU absorbs on the Zn surface to concentrate perchlorate anions (ClO4−), constructing an initial buffer solid-electrolyte interphase to reduce the stripping energy barrier and regulate the stripping kinetics. With DU, a water-poor solvated structure, Zn[DU]2[ClO4]2[H2O]2, further enhances the symmetry of stripping/plating behavior of Zn anode. On the above basis, Zn anode enables reversible cycling for over 6000 hours, and NH4V4O10||Zn full cell exhibits cycling stability over 5000 cycles with a capacity retention of 85.3%. Even at a low N/P ratio of 3, NH4V4O10||Zn cell retains 91.54% of original capacity after 300 cycles. This study provides crucial insight into regulating stripping/plating symmetry of Zn anode via electrolyte chemistry, fostering applications of ZBs energy storage systems.