Employing ZIF-67 architectures into 1D binder-free Co3O4-based carbon fiber composites for advanced sodium-ion storage application

Abstract

Metal-organic frameworks (MOFs) have drawn numerous attention as precursors to fabricate porous materials owing to their inherent highly controllable composition and tunable porosities. Nevertheless, the construction of an efficient and low cost anode material derived from zeolitic imidazole framework-67 (ZIF-67) to pursue enhance rate capability and specific capacity remains attractive and challenging. Herein, the fabrication of the Co3O4-based hierarchical carbon fiber composites with the ZIF-67/Co2+ ions derivatives embedded (Co3O4@CNF) by a facile electrospinning technique and a two-step annealing is reported. When evaluate as a binder-free anode for SIBs, the resultant electrode delivers a superior sodium-ion storage capacity of 380mAhg−1 after 150 cycles at 100 mA g−1, a remarkable rate performance and an outstanding long-cycling stability of 129mAhg−1 after 500 cycles at 3.2 A g−1, which is better than other MOFs-derived free-standing anode materials for SIBs reported previously. The 1D carbon fibers can serve as a buffer framework to ensure the structural stability. In addition, the conductive matrix formed by the interleaving of carbon fibers can facilitate electronic transport along their 1D geometry. Furthermore, the dispersed ZIF-67/Co2+ ions derivatives in fibers provide the composite with high surface exposure to the electrolyte, which is conducive to chemical reactions.