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

摘要

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 severemutual problems of cathode dissolution, electrolyte parasitic reactions,and metallic anode dendrite growth. Herein, a triple-functional strategyis proposed that a polyoxovanadate (POV) cluster of K_(10)[V~Ⅳ_(16)V~Ⅴ_(18)O_(82)] as apromising Zn~(2+) host can concomitantly stabilize the cluster cathode, aqueouselectrolyte, and metallic Zn anode. An in situ generated cathode electrolyteinterface via anodic oxidation is identified as effective in preventing the dissolutionof POV cathode. Molecular dynamics simulation and density functionaltheory calculation confirm that the [V~Ⅳ_(16)V~Ⅴ_(18)O_(82)]~(10?) polyoxoanions cansynergistically suppress electrolyte side reactions by modulating the primarysolvation shell of Zn~(2+)-6H_2O, and random anode dendrite growth by in situconstructing a stable solid electrolyte interface of Zn-POV. As a result, theZn//POV battery exhibits unprecedented cycling durability over 10 000 cyclesat high rates of 5 and 12 A g~(?1). In a systematic consideration, the findingsenlighten the origin of triple-functional polyoxometalates and will significantlypropel the practical development of aqueous batteries.