Metal–Organic Framework-Derived Metal Oxide Embedded in Nitrogen-Doped Graphene Network for High-Performance Lithium-Ion Batteries

Abstract

Metal-organic frameworks (MOFs) are hybrid inorganic-organic materials that can be used as effective precursors to prepare various functional nanomaterials for energy-related applications. Nevertheless, most MOF-derived metal oxides exhibit low electrical conductivity and mechanical strain. These characteristics limit their electrochemical performance and hamper their practical application. Herein, we report a rational strategy for enhancing the lithium storage performance of MOF-derived metal oxide. The hierarchically porous Co₃O₄@NGN is successfully prepared by embedding ZIF-67-derived Co₃O₄ particles in a nitrogen-doped graphene network (NGN). The high electrical conductivity and porous structure of the NGN accelerates the diffusion of electrolyte ions and buffers stress resulting from the volume changes of Co₃O₄. As an anode material, the Co₃O₄@NGN shows high capacity (1030 mA h g^-1 at 100 mA g^-1), outstanding rate performance (681 mA h g^-1 at 1000 mA g^-1), and good cycling stability (676 mA h g^-1 at 1000 mA g^-1 after 400 cycles).