Ultrahigh-Rate Behavior Anode Materials of MoSe Nanosheets Anchored on Dual-Heteroatoms Functionalized Graphene for Sodium-Ion Batteries.

MoSe is a prospective anode material for Na-ion batteries because of its layered structure and high theoretical capacity, while the unsatisfied electrochemical performance limits its further development. Herein, we report MoSe nanosheets anchored on dual-heteroatoms functionalized graphene by a solvothermal method. The heteroatoms and carbon matrix coexist in the form of graphitic-N/pyridinic-N/pyrrolic-N and P-C/P═O bonds, which result in excellent electronic conductivity of the materials and provide abundant active sites for electrochemical process. Results indicated that organic intercalation increased the layer spacing of the materials to facilitate sodium-ion diffusion, and the in situ formed carbon networks improved the conductivity among the layers of the materials and alleviated volume expansion during the continued charge and discharge process. As an anode of Na-ion batteries, the nanosheets materials exhibited ultrahigh rate performance and deliver capacities of approximately 200 mAh g at the current density of 10 A g. The ultrahigh-rate performance can be attributed to its unique nanosheets structure, the dual-heteroatoms functionalized graphene, and the considerable pseudocapacitive quality of the material.