Accelerating High-Rate Li-Ion Storage in Graphite via a Thin-Layer Coating of Atomic Mo–NC

Abstract

Empowering the fast-charging capability of Li-ion batteries is of common interest in the fields of portable electronic devices and electric vehicles, yet it currently faces challenges from unsatisfactorily high cycling stability at high rates. Herein, a thin layer of atomic Mo/N-codoped carbon is grown on commercial graphite (Gr) and used to regulate the formation of the solid electrolyte interface (SEI) and accelerate charge transfer at the Gr interface. The atomic Mo/N species (in the form of Mo 1 −NC) enable graphite with significantly reduced charge transfer and contact resistances and improved Li + diffusion behavior through SEI and at the Gr interface. Electrochemical measurements show that compared to pristine Gr and Mo 2 C nanoparticle-modified Gr, Mo 1 −NC@Gr achieves much higher capacity and rate performance, rendering specific capacities of 443.7 and 159.9 mAh g −1 at 1.0 and 10.0 A g −1 , respectively, while maintaining more than 90% capacity at a high rate of 3.0 A g −1 after 2000 cycles.