Epitaxial growth induced multilayer yolk-shell structured CoSe2 with promoting transport kinetics of sodium ion half/full batteries

Metal-organic framework (MOF)-derived yolk-shell structures are one of the most potential nanoarchitectures applied in second batteries and electrocatalysis. In this manuscript, a multilayer yolk-shell structured CoSe2 has been fabricated via post carbonization and selenization processes of step-by-step crystal epitaxial growth of multilayer solid zeolitic imidazolate frameworks (ZIFs) precursor. When used as the anode of a sodium-ion half battery, the obtained multilayer yolk-shell structured CoSe2 materials can maintain a discharge capacity of 352.9 mAh g−1 after the 2000 cycles at the current density of 1 A g−1, which can be attributed to the special multilayer yolk-shell structure by providing the fast sodium ion transport. Besides, it also delivers excellent electrochemical performance in the sodium-ion full batteries, which further demonstrate the outstanding electrochemical property of the obtained multilayer yolk-shell structured CoSe2 electrode material.