Facile Synthesis of Three-Dimensional Ordered Porous Amorphous Ni-P for High-Performance Asymmetric Supercapacitors

Abstract

Recently, transition metal phosphides have attracted great interest of researchers as potentially promising electrode materials for supercapacitors. In this paper, three-dimensional (3D) ordered porous nickel phosphorus (Ni-P) has been facilely synthesized by a three-steps process including electrodeposition of polystyrene colloidal templates, electrodeposition of Ni-P and removing polystyrene. Compared with porous Ni, porous Ni-P exhibits ultrahigh charge storage performance (2270.26 F g−1 at 1 A g−1) and super-long cycle stability (86.6% capacity retention after 4800 cycles at 100 mV s−1). Furthermore, a flexible asymmetric supercapacitor (ASC) device assembled with porous Ni-P and activated carbon (AC) has been evaluated its performance in practical application. The ASC device displays ultrahigh energy density 20.1 Wh kg−1 at a power density of 12.8 kW kg−1, and the mass specific capacitance maintains 147.8% of the initial value after 3000 cycles. Furthermore, the energy storage mechanism of porous Ni-P and the reasons for its performance improvement have been explored. The superior performance of 3D ordered porous Ni-P makes it become the most promising material for supercapacitor.