Ni2P nanosheets were fabricated on carbon fiber using the hydrothermal method and subsequent phosphatization process. The highly conductive Ni2P nanosheet arrays could not only facilitate electron transport but also shorten the ion diffusion path. The in-situ grown Ni2P nanosheet arrays could be applied as the cathode in Zn battery without any additives and binder. The Ni2P/ /Zn battery based on Ni2P nanosheet arrays and metal Zn electrode exhibits excellent electrochemical performance, such as high operating voltage (1.78 V), specific capacity of 231 mAh g(-1), and energy density of 318 Wh Kg(-1). In addition, the Ni2P/ /Zn battery can maintain a specific capacity retention similar to 80% after 1500 continuous cycles. In view of the excellent electrochemical properties of Ni2P/ /Zn battery, the Ni2P will be a potential material for next-generation energy storage devices.