High-performance supercapacitors based on Ni_(2)P@CNT nanocomposites prepared using an ultrafast microwave approach

摘要

We present a one-step route for the preparation of nickel phosphide/carbon nanotube(Ni_(2)P@CNT)nanocomposites for supercapacitor applications using a facile,ultrafast(90 s)microwave-based approach.Ni2P nanoparticles could grow uniformly on the surface of CNTs under the optimized reaction conditions,namely,a feeding ratio of 30:50:25 for CNT,Ni(NO_(3))_(2)-6H_(2)0,and red phosphorus and a microwave power of 1000 W for 90 s.Our study demonstrated that the single-step microwave synthesis process for creating metal phosphide nanoparticles was faster and simpler than all the other existing methods.Electrochemical results showed that the specific capacitance of the optimal Ni2P@CNT-nanocomposite electrode displayed a high specific capacitance of 854 F•g^(-1) at 1 A•g^(-1) and a superior capacitance retention of 84% after 5000 cycles at 10 Ag^(-1).Finally,an asymmetric supercapacitor was assembled using the nanocomposite with activated carbon as one electrode(Ni_(2)P@CNT//AC),which showed a remarkable energy density of 33.5 W•h•kg^(-1) and a power density of 387.5 W·kg^(-1).This work will pave the way for the microwave synthesis of other transition metal phosphide materials for use in energy storage systems.