Heterostructures Coupling with Oxygen Vacancies Enable High Performance V 2 O 3 /Zn 3 V 3 O 8 @C Cathode for Aqueous Zinc‐Ion Batteries

ABSTRACT Aqueous zinc ion batteries (AZIBs) have received increasing attention due to their intrinsic safety, low cost, and environmental friendliness, and the design of advanced cathode materials is crucial for their practical application. Herein, the V 2 O 3 /Zn 3 V 3 O 8 @C heterostructured materials derived from polyoxovanadates are developed as advanced cathodes for AZIBs. The formation of a carbon protective layer originated from the coated polypyrrole leads to the abundant oxygen vacancies during the pyrolysis process. Density functional theory calculation reveals that the construction of the heterostructure effectively regulates the electronic properties of the V 2 O 3 . The collaborative effect of heterostructures with oxygen vacancies significantly facilitates the electron/ion transport and mechanical stability of V 2 O 3 /Zn 3 V 3 O 8 @C. As expected, the V 2 O 3 /Zn 3 V 3 O 8 @C cathode delivers a high specific capacity of 419.0 mAh g −1 at 0.1 A g −1 and excellent cycling stability with 80.6% capacity retention after 1000 cycles at 2 A g −1 .