Synthesis of 3D Flower-like Nanocomposites of Nitrogen-Doped Carbon Nanosheets Embedded with Hollow Cobalt(II,III) Oxide Nanospheres for Lithium Storage

Despite a high theoretical specific capacity (890mAhg(-1)) as an anode material for Li-ion batteries, Co3O4 has not been used in practice due to its inferior mechanical stability and poor electrical conductivity. Herein, we synthesized three-dimensional (3D) flower-like nanocomposites consisting of nitrogen-doped carbon nanosheets decorated with hollow Co3O4 nanospheres (H-Co3O4@N-CNSs) with an ultrahigh loading mass (83wt%) of Co3O4. The H-Co3O4@N-CNSs exhibited excellent performance of 750mAhg(-1) at 500mAg(-1) and 700mAhg(-1) at 1000mAg(-1) after 400cycles and a high capacity retention rate of 93.75% at 500mAg(-1). This excellent electrochemical performance was attributed to a synergistic effect between the hollow Co3O4 nanospheres, the N-doped carbon nanosheets, and the pores between adjacent carbon nanosheets. Our suggested fabrication strategy for creating a hierarchical structure has great potential for the design of high-performance anode materials.