Construction of CoS2-N-C sheets anchored on 3D graphene network for lithium storage performances

The construction of transition metal sulfides integrated into three-dimensional graphene network (3DGN) is a greatly attractive strategy for energy conversion and storage. Metal-organic framework (MOF) as template-derived CoS2 with N-doped carbon coating (CoS2-N-C) sheets (similar to 510nm) anchored on 3DGN (CoS2-N-C/3DGN) was designed and synthesized via a solution immersion reaction combined with a carbonization-sulfidation treatment. The formed ultra-small CoS2 nanoparticles are uniformly diffused and encapsulated in the N-rich carbon matrix, grown on 3DGN to obtain a self-supporting structure. The resulting CoS2-N-C/3DGN composites were evaluated as binder-free anode materials of lithium-ion batteries, delivering a high reversible gravimetric capacity of 409.5mAhg(-1) after 100cycles as well as great rate capability of 124mAhg(-1) at 1600mAg(-1). The enhanced electrochemical behaviors should be attributed to the synergistic interaction between CoS2-N-C with high electrochemical activities and 3DGN with high conductivity and macroscopically porous structure. This work provides new ideas to rational design of other metal sulfides applied on 3DGN for high-performance energy storage devices.