One-step facile synthesis of graphene-decorated LiVPO4F/C nanocomposite as cathode for high-performance lithium ion battery

Abstract

Graphene-decorated LiVPO4F/C nanocomposite is prepared by one-step soft chemical route with assistance of mechanical activation. The graphene constructs a conductive network, which enhances the electronic conductivity of the composite. XRD results reveal that the addition of graphene oxide has no effect on the crystal structure of LiVPO4F. SEM and TEM images demonstrate that the LiVPO4F/C nanoparticles are dispersed uniformly into the graphene layers. When used as cathode for lithium ion battery, the graphene modified LiVPO4F/C composite (G-LVPF/C) exhibits better cycle performance and rate capability than the pristine one. Particularly, G-LVPF/C delivers 139, 132, 114mAhg−1 at 1, 2, 8C, and maintains 89.0%, 84.9%, 77.9% after 200 cycles, respectively. EIS tests indicate that the graphene modified sample owns smaller charge transfer resistance than the bare one.