Nitrogen-containing carbon/graphene composite nanosheets with excellent lithium storage performances

Abstract

Nitrogen-containing carbon/graphene composite (CGC) nanosheets have been synthesized by the in situ chemical polymerization of pyrrole on both surfaces of graphene oxide combined with high temperature carbonization. The CGC nanosheets show high specific surface area (106.22m2g−1), large pore volume (0.382m3g−1), and high nitrogen content (7.86at.%). The nitrogen-containing carbon coating with low graphitization degree on both sides of graphene can prevent effectively from the aggregation of graphene oxide during its thermal reduction process. When evaluated for lithium storage capacity, the CGC nanosheets exhibit enhanced electrochemical performances in comparison with polypyrrole derived nitrogen-containing carbon (NC) nanoparticles, including high reversible capacity (651.5mAhg−1 at 1Ag−1), excellent rate capability (363.7mAhg−1 at 10Ag−1), and good cycling stability (100% capacity retention after 100 cycles at 1Ag−1). The high lithium storage performances of the CGC electrodes can be attributed to the high electronic conductivity, abundant lithium adsorption sites, and short diffusion distance of lithium ions arising from the CGC nanosheets with nitrogen-containing carbon on both sides of graphene.