Rhombic dodecahedron hetero-structure Zn/Co–Se@C as cathode material for aluminum batteries with excellent electrochemical performance

At present, selenides show excellent comprehensive electrochemical properties in cathode electrode materials of aluminum batteries. Herein, the rhombic dodecahedron bimetallic hetero-structure Zn/Co–Se is successfully prepared by the zeolitic imidazolate framework (ZIF) induction. It is found by electrochemical analysis that in bimetallic hetero-structure Zn/Co–Se cathode materials, the Co element participates in the electrochemical reactions, providing a certain electrochemical capacity, and the generated metal Co dissolves into the electrolyte to reduce its cycle stability. While the Zn does not participate in the electrochemical reaction, which stabilizes the structure and improves its stability. Therefore, the bimetallic hetero-structure Zn/Co–Se takes into account the advantages of both CoSe2 and ZnSe and thus exhibits excellent electrochemical performance in aluminum batteries. The discharge capacity of Zn/Co–Se is 614.8 mAh g−1 at 200 mA g−1, and the capacity is 108.9 mAh g−1 even at 1000 mAg−1. After 400 cycles, its capacity is still 79.1 mAh g−1 at 1000 mA g−1. Therefore, the bimetallic hetero-structure Zn/Co–Se may plays a vital role in further improving and optimizing the energy density of aluminum batteries.