Hierarchical Co₂P microspheres assembled from nanorods grown on reduced graphene oxide as anode material for Lithium-ion batteries

Transition metal phosphides (TMPs) have been studied as promising electrodes for energy storage and conversion due to their large theoretical capacities and high activities. Herein, a hierarchically structured Co2P coupling with the reduced graphene oxide (RGO) composite (Co2P/RGO) was synthesized by a simple solid state method for Li storage. The Co2P/RGO hybrid composite exhibits a high reversible capacity of 61 mAh g−1 at 60 mA g−1, good rate capability of 327 mAh g−1 at 3000 mA g−1 and long cycle life (397 mAh g−1 at 500 mA g−1 for after 1000 cycles). The excellent electrochemical performance can be attributed to the synergistic effect of Co2P micro/nano architecture and graphene modulation, which provide more activity sites for Li+-ions and maintain the structural integrity of active material. This work may provide a new path for preparation of other metal phosphides as potential electrode materials for application in energy storage fields.