Controllable MOF-Derived Hierarchical Hollow CoNiSe₂ with Enhanced Mechanics and Kinetics for Extraordinary Rate Performance and Durable Anode of Sodium-Ion Batteries

High rates and durable anodes are the eternal pursuits of sodium ion batteries (SIBs). Constructing bimetal selenide is an efficient strategy to improve Na + storage. Herein, a hierarchical hollow CoNiSe 2 /carbon compound (CoNiSe 2 /C) was designed as an anode of SIBs via selenizing the modified MOFs precursor. During the high-rate test, CoNiSe 2 /C electrodes exhibited an outstanding specific capacity of 301.9 mA h g –1 even at 20 A g –1, while an impressive cycle life over 2000 at 5 A g –1 was achieved with a residual capacity of 368.9 mA h g –1 . The high-rate capability is attributed to the significantly reduced energy barrier of reaction activation and the strong microstructure of the hierarchical hollow CoNiSe 2 /C. It indicates that the CoNiSe 2 /C synthesized in this work is highly desirable and promising as a SIB anode material and sheds light on the design and development of anode materials.