On-site building of a Zn2+-conductive interfacial layer via short-circuit energization for stable Zn anode

V 2 O 5 ·nH 2 O (abbreviated as VO) is first used as the interface modification material of Zn anode. By simply transferring the prepared VO film to the surface of Zn metal foil via directly wet touching, a short-circuit cell reaction would be auto-induced in the presence of the electrolyte and further lead to the pre-intercalation of Zn 2+ into the VO interlayers. The on-site built Zn x V 2 O 5 ·nH 2 O (abbreviated as ZnVO) film can effectively reduce the interfacial impedance and behave as the Zn 2+ -conductive interfacial layer to facilitate a uniform and fast Zn 2+ flow into and out of the zinc anode, resulting in a dendrite-free anode. Aqueous zinc ion batteries (ZIBs) show great potential in large-scale energy storage systems for their advantages of high safety, low cost, high capacity, and environmental friendliness. However, the poor performance of Zn metal anode seriously hinders the application of ZIBs. Herein, we use the zinc-ion intercalatable V 2 O 5 · n H 2 O (VO) as the interface modification material, for the first time, to on-site build a Zn 2+ -conductive Zn x V 2 O 5 · n H 2 O (ZnVO) interfacial layer via the spontaneous short-circuit reaction between the pre-fabricated VO film and Zn metal foil. Compared with the bare Zn, the ZnVO-coated Zn anode exhibits better electrochemical performances with dendrite-free Zn deposits, lower polarization, higher coulombic efficiency over 99% after long cycles and 10 times higher cycle life, which is confirmed by constructing Zn symmetrical cell and Zn|ZnSO 4 + Li 2 SO 4 |LiFePO 4 full cell.