Macromolecules Promoting Robust Zinc Anode by Synergistic Coordination Effect and Charge Redistribution

Zn dendrite formation is the main obstacle to commercializing aqueous zinc-ion batteries (ZIBs). α-cyclodextrin (α-CD) is proposed as an environmentally friendly macromolecule additive in the ZnSO -based electrolyte to obtain stable and reversible Zn anodes. The results show that α-CD molecules' unique 3D structure can effectively regulate the mass transfer of the electrolyte components and isolate the Zn anode from H O molecules. The α-CD provides abundant electrons to the Zn (002) crystallographic plane, which induces charge density redistribution. Such an effect relieves the reduction and aggregation of Zn cations while protecting the Zn metal anode from water molecules. Finally, a small amount of α-CD additive (0.01 M) can enhance the performance of Zn significantly in Zn||Cu cells (1980 cycles with 99.45% average CE) and Zn||Zn cells (8000 h ultra-long cycle life). The excellent practical applicability was further verified in Zn||MnO cells.