Design of oxygen vacancies homologous heterojunction promoted reversible zinc ion storage

Abstract Zinc ion batteries (ZIBs) are promising for large‐scale energy storage applications, but the technology lacks high‐capacity and high‐stability cathode materials. Herein, oxygen vacancy‐VN/V 2 O 3 /C (Ov‐VN/V 2 O 3 /C) heterostructural composite was successfully designed and synthesized as high‐stability cathode to promote reversible ZIBs. Thanks to the oxygen‐vacancy heterojunction features and the transformed amorphous new phase V 10 O 24 ·12H 2 O, Ov‐VN/V 2 O 3 /C provides abundant channels and active sites for Zn 2+ diffusion and adsorption. Thus, Ov‐VN/V 2 O 3 /C as a cathode material for aqueous ZIBs exhibits excellent a high reversible capacity of 531 mAh g −1 at 0.3 A g −1 , good rate performance (446 mAh g −1 at a high current density of 10 A g −1 ), and good stability (115 mAh g −1 at 20 A g −1 after 5000 cycles). More importantly, Ov‐VN/V 2 O 3 /C//Zn assembled quasi‐solid‐state batteries also have excellent long‐term cycling performance. This work not only obtains high‐performance cathode materials, but also provides a new idea for the development of the synthesis of transformational new materials with the synergistic effect of vacancies (defects) and heterojunctions.