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

Abstract

Aqueous zinc-ion batteries (ZIBs) have attracted much attention because of their high theoretical capacity and inherent safety. An essential requirement is to design robust cathodes to match the excellent electrochemical properties of zinc anodes. Herein, we report a facile strategy that designed an intercalation-type cathode by incorporating interlayer engineering of Mn2+ and oxygen defects into tunnel-type VO2 nanoribbons. The embedded Mn2+ ions act as pillars to extend the tunnel structure of VO2 with an improved fast and reversible intercalation/deintercalation of Zn2+ in the ZIBs, enhancing electrical conductivity and improving redox activity. In addition, oxygen vacancies in the MnVO nanoribbons can provide extra electrochemically active sites for Zn2+ storage. As a result, the MnVO electrode delivers an excellent capacity of 462.5 mA h g–1 at 0.1 A g–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 remaining capacity of 52 mA h g–1 over 10,000 cycles. Therefore, this work provides an enlightened strategy for a superior vanadium-based oxide cathode toward the advanced electrochemical performance of ZIBs.