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 arethe eternal pursuits of sodiumion batteries (SIBs). Constructing bimetal selenide is an efficientstrategy to improve Na+ storage. Herein, a hierarchicalhollow CoNiSe2/carbon compound (CoNiSe2/C) wasdesigned as an anode of SIBs via selenizing the modified MOFs precursor.During the high-rate test, CoNiSe2/C electrodes exhibitedan outstanding specific capacity of 301.9 mA h g(-1) even at 20 A g(-1), while an impressive cycle lifeover 2000 at 5 A g(-1) was achieved with a residualcapacity of 368.9 mA h g(-1). The high-rate capabilityis attributed to the significantly reduced energy barrier of reactionactivation and the strong microstructure of the hierarchical hollowCoNiSe(2)/C. It indicates that the CoNiSe2/C synthesizedin this work is highly desirable and promising as a SIB anode materialand sheds light on the design and development of anode materials.