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

• Published in: Applied surface science 2018-11, Vol.459, p.665-671
• Main Authors: Zhang, Chi, Jiao, Guanghua, Kong, Fanjun, Wang, Jian, Tao, Shi, Zhang, Lei, Qian, Bin, Chao, Yimin
• Format: Article
• Language: English
• Subjects: Anode; Cobalt phosphide; Graphene; Hierarchical structure; Lithium-ion batteries
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.08.043

Reduced graphene oxides (RGO) decorating Co2Pmicrospheres with hierarchically structure are synthesized, using a simple solid-state method. The hybrids with small Co2P nanorods are well incorporated with RGO. Such unique micro/nano structure can effectively provide more contact between Co2P nanoparticles each other and alleviate the volume expansion and enhance the electrochemical performance. [Display omitted] •Hierarchically structured Co2P microspheres anchored on RGO are synthesized.•The microspheres are assembled from monodispersed Co2P nanorods.•Co2P/RGO are used as high-performance anode material for lithium-ion battery.•Electrochemical properties of Co2P/RGO are investigated. 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.