Metal-organic frameworks derived carbon-coated ZnSe/Co0.85Se@N-doped carbon microcuboid as an advanced anode material for sodium-ion batteries

Transition metal selenides attract significant attention as advanced anode materials for sodium-ion batteries (SIBs) in recent years due to their appropriate working potential and high theoretic capacity. However, the poor structural stability and rate capability limit their further practical applications. Herein, zeolite imidazole framework-8/zeolite imidazole framework-67 is used as a template to prepare Co0.85Se and ZnSe nanoparticles embed in N-doped carbon matrix successfully, and then coated a carbon layer (ZCS@NC@C) by in-situ polymerization. One side, the N-doped carbon matrix with rich pore structure not only shorten the diffusion path of Na+ and improve the conductivity of the electrode, but also prevent structural collapse and agglomeration of active particles during the sodium insertion/extraction process. On the other side, the carbon shell preparation by coating can form a protective layer to buffer the volumetric stress generated in the electrochemical process and further improve the electrical conductivity. As a result, the as-prepared ZCS@NC@C anode material exhibits an excellent electrochemical performance for SIBs. This investigation provides a promising approach to optimize the electrochemical performance of SIBs by incorporating active metal compounds into conductive carbons to form multidimensional structure.