Structural Engineering of Vanadium Oxide Cathodes by Mn2+ Preintercalation for High-Performance Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) have attracted muchattentionbecause of their high theoretical capacity and inherent safety. Anessential requirement is to design robust cathodes to match the excellentelectrochemical properties of zinc anodes. Herein, we report a facilestrategy that designed an intercalation-type cathode by incorporatinginterlayer engineering of Mn2+ and oxygen defects intotunnel-type VO2 nanoribbons. The embedded Mn2+ ions act as pillars to extend the tunnel structure of VO2 with an improved fast and reversible intercalation/deintercalationof Zn2+ in the ZIBs, enhancing electrical conductivityand improving redox activity. In addition, oxygen vacancies in theMnVO nanoribbons can provide extra electrochemically active sitesfor Zn2+ storage. As a result, the MnVO electrode deliversan excellent capacity of 462.5 mA h g(-1) at 0.1 Ag-1, an outstanding rate performance (120 mA h g(-1) at 5 A g(-1) after 2500 cycles),and ultralong cycling at 10 A g(-1) with a remainingcapacity of 52 mA h g(-1) over 10,000 cycles. Therefore,this work provides an enlightened strategy for a superior vanadium-basedoxide cathode toward the advanced electrochemical performance of ZIBs.