Triple‐Functional Polyoxovanadate Cluster in Regulating Cathode, Anode, and Electrolyte for Tough Aqueous Zinc‐Ion Battery

Despite a promising outlook due to the intrinsic low cost and high safety, the practical application of aqueous Zn-ion battery is impeded by the severe mutual problems of cathode dissolution, electrolyte parasitic reactions, and metallic anode dendrite growth. Herein, a triple-functional strategy is proposed that a polyoxovanadate (POV) cluster of K-10[(V16V18O82)-V-IV-O-V] as a promising Zn2+ host can concomitantly stabilize the cluster cathode, aqueous electrolyte, and metallic Zn anode. An in situ generated cathode electrolyte interface via anodic oxidation is identified as effective in preventing the dissolution of POV cathode. Molecular dynamics simulation and density functional theory calculation confirm that the [(V16V18O82)-V-IV-O-V](10-) polyoxoanions can synergistically suppress electrolyte side reactions by modulating the primary solvation shell of Zn2+-6H(2)O, and random anode dendrite growth by in situ constructing a stable solid electrolyte interface of Zn-POV. As a result, the Zn//POV battery exhibits unprecedented cycling durability over 10 000 cycles at high rates of 5 and 12 A g(-1). In a systematic consideration, the findings enlighten the origin of triple-functional polyoxometalates and will significantly propel the practical development of aqueous batteries.