Constructing oxygen deficiency‐rich V 2 O 3 @PEDOT cathode for high‐performance aqueous zinc‐ion batteries

Abstract Aqueous zinc‐ion batteries (AZIBs) have attracted widespread attention due to the advantages of high safety and environmental friendliness. Although V 2 O 3 is a promising cathode, the strong electrostatic interaction between Zn 2+ and V 2 O 3 crystal, and the sluggish reaction kinetics still limit their application in AZIBs. Herein, the oxygen defects rich V 2 O 3 with conducive poly (3,4‐ethylenedioxythiophene) (PEDOT) shell (V 2 O 3 ‐O d @PEDOT) was fabricated for AZIBs by combining the sulfur‐assisted thermal reduction and in‐situ polymerization method. The introduced oxygen vacancies of V 2 O 3 –O d @PEDOT weaken the electrostatic interaction between Zn 2+ and the host material, improving the interfacial electron transport, while the PEDOT coating enhances the structural stability and conductivity of V 2 O 3 , thus accelerating the reaction kinetics. Based on the advantages, V 2 O 3 –O d @PEDOT electrode delivers a reversible capacity of 495 mAh·g −1 at 0.1 A·g −1 , good rate capability (189 mAh·g −1 at 8.0 A·g −1 ), and an impressive cycling stability with 90.1% capacity retention over 1000 cycles at 8.0 A·g −1 . The strategy may provide a path for exploiting the other materials for high performance AZIBs.