Metal-organic frameworks derived flower-like Co3O4/nitrogen doped graphite carbon hybrid for high-performance sodium-ion batteries

Abstract

In this work, a novel flower-like cobalt-based metal organic frameworks (MOFs) self-assembled by Co2+ and nicotinic acid have been designed and synthesized. After a simple annealing treatment, Co3O4 nanoparticles in-situ decorating on nitrogen doped graphite carbon-sheet (Co3O4/NC) were obtained. The resultant Co3O4/NC hybrid with unique flower-like structure and ration combination of Co3O4 nanoparticles and nitrogen doped graphite carbon, endowing the hybrid with enhanced electrical conductivity, short ion diffusion pathways and rich porosity to the materials, which can largely alleviate the problems of Co3O4 such as inferior intrinsic electrical conductivity, sluggish ion kinetics and large volume change upon cycling. When evaluated as anode material for sodium-ion batteries (SIBs), the Co3O4/NC hybrid exhibits satisfied reversible capacity (213.9 mAh g−1 after 100 cycles at 0.1 A g−1), excellent rate capability (145.4 mAh g−1 at 2 A g−1 and 130.1 mAh g−1 at 4 A g−1) and robust long-term cycling stability (120.1 mAh g−1 after 2000 cycles at 0.5 A g−1), showing great potential for high-performance SIBs.