Conductive MOF on ZIF-Derived Carbon Fibers as Superior Anode in Sodium-Ion Battery

Superior specific capacity, high-rate capability, andlong-termcycling stability are essential to anode materials in sodium-ion batteries,and conductive metal-organic frameworks (cMOF) with good electronicand ionic conductivity may satisfy these requirements. Herein, conductiveneodymium cMOF (Nd-cMOF) produced in situ on thezeolitic imidazolate framework (ZIF)-derived carbon fiber (ZIF-CFs)platform is used to synthesize the Nd-cMOF/ZIF-CFs hierarchical structure.Four types of ZIFs with different pore diameters are prepared by electrospinning.In this novel structure, ZIF-CFs provide the electroconductivity,flexible porous structure, and mechanical stability, while Nd-cMOFprovides the interfacial kinetic activity, electroconductivity, amplespace, and volume buffer, consequently giving rise to robust structuralintegrity and excellent conductivity. The sodium-ion battery composedof the Nd-cMOF/ZIF-10-CFs anode has outstanding stability and electrochemicalproperties, such as a specific capacity of 480.5 mAh g(-1) at 0.05 A g(-1) as well as capacity retention of84% after 500 cycles.