Disrupting Hydrogen Bond Network Connectivity With a Double-Site Additive for Long-Life Aqueous Zinc Metal Batteries

Irregular dendrite growth and complex side reactions pose critical challenges that significantly impede the further industrialization of aqueous zinc-ion batteries (AZIBs). The "competitive co-solvents" strategy could introduce hydrogen bond (H-bond) accepting sites to effectively alleviate the free water molecules. however, it suffers from low conductivity, high cost, and safety risks. Herein, we selected N, N'-methylenebisacrylamide (MBA) as a trace additive with amide groups to decrease the activity of water by disrupting the H-bond. The MBA additive, which incorporates both hydrogen bond donor and acceptor functionalities, successfully restricts H₂O molecules within a double-site anchoring configuration. This configuration enhances hydrogen-bonding interactions and breaks part of the original hydrogen bond network among H₂O molecules, thereby significantly restraining parasitic side reactions due to the decomposition of active water. Additionally, MBA molecules adsorbed on the surface of the Zn anode could regulate the desolvation and nucleation processes of zinc ions, achieving dense and flat zinc deposition. A high Zn reversibility with Coulombic efficiency (CE) of 99.74% and ultra-long lifespan of 2800 cycles at 1 and 0.5 mAh cm^-2 was demonstrated. Besides, a highly reversible Zn electrode significantly boosted the overall performance of Zn//Zn symmetric cells of 1500 h at 5 mA cm^-2 and Zn//V₂O₅ full cell of 2000 cycles at 5 A g^-1.