Monodispersed nickel phosphide nanocrystals in situ grown on reduced graphene oxide matrix with excellent performance as the anode for lithium-ion batteries

Abstract

By using cheap, stable, relative low-toxic precursors (the key of the design), a nanocomposite anode material composed of monodispersed nickel phosphide (Ni 2 P) nanocrystals in situ grown into three dimensional reduced graphene oxide (RGO) matrix has been fabricated through a “heating-up” synthesis method. With an average size of 5 nm, the Ni 2 P nanocrystals are wrapped within the interior as well as on the surface of the curling RGO matrix without aggregation. In this nanostructure, RGO has excellent conductivity and an interconnected porous network, enabling the Ni 2 P/RGO nanocomposites to provide ways for rapid electron transfer and lithium ion transport. Meanwhile, due to the small size and monodispersed phase of the Ni 2 P nanocrystals, it can adapt to the volume change during charging/discharging processes. As a result, the excellent lithium-storage performance has been shown by Ni 2 P/RGO nanocomposites, concerning a long-life cycling stability (389.9 mAh g −1 after 1000 cycles at 1 C) and a high rate capability (197.7 mAh g −1 at 50 C).