Three-dimensional (3D) graphene with novel nano-architectures exhibits many excellent properties and is promising for energy storage and conversion applications. Herein, a new strategy based on the fluidized bed chemical vapor deposition (FB-CVD) process was proposed to prepare 3D graphene networks (3DGNs) with various nano-architectures. Specially designed SiC-C@graphene core/shell nanoparticles were prepared taking the advantages of the FB-CVD system, and 3DGNs with hierarchical nanostructures were obtained after removing the SiC core. The 3DGNs performed well as electrodes of lithium-sulfur batteries. The C-S cathode showed good rate performance at the current density of 0.1-2.0 C, and an initial discharge capacity of 790 mAhg-1 cathode was achieved at a current density of 0.2 C. The Li-S batteries showed stabilized coulombic efficiency as high as 94% and excellent cyclic performance with an ultra low cyclic fading rate of 0.075% for the initial 280 cycles at a current density of 1.0 C. The improved electrochemical performance was ascribed to the enhanced conductivity by the connective graphene networks and the weakened shuttle effect by the special outer graphene layers. Mass production of the products was realized by the continuous FB-CVD process, which opens up new perspectives for large scale application of 3D graphene materials.
Keywords: CVD; electrodes; graphene network.