Conductive coating, cation‐intercalation, and oxygen vacancies co‐modified vanadium oxides as high‐rate and stable cathodes for aqueous zinc‐ion batteries

Abstract

Abstract Layered vanadium oxides are promising cathode materials for zinc‐ion batteries (ZIBs) owing to their high capacity, but the sluggish electron/ion migration kinetics and structural collapse/dissolution severely limit their Zn2+‐storage performance. Herein, poly(3,4‐ethylenedioxythiophene) coated and Mn2+‐intercalated vanadium oxides with rich oxygen vacancies (MnVOH@PEDOT) are prepared as the cathodes for ZIBs. The PEDOT coating, synergistic with oxygen vacancies, tailors the electron conductivity, and the Mn2+‐intercalation enlarges the interlayer spacing for rapid Zn2+‐ions diffusion. In addition, the pre‐intercalated Mn2+‐ions act as “pillars” to stabilize the structure, and the PEDOT coating prevents the direct contact of vanadium oxides with electrolyte to inhibit its dissolution during cycling. Thus, the MnVOH@PEDOT cathode exhibits superior discharge capacity, favorable rate capability (336.0 mAh g−1 at 8 A g−1), and satisfying cyclic durability (84.8% capacity retention over 2000 cycles). This work offers a facile and synergistic design strategy for achieving favorable cathodes for ZIBs.

Keywords

• oxygen vacancies
• PEDOT coating
• pre‐intercalation
• stability
• zinc‐ion batteries