Template-assisted synthesized hollow sphere-like NiCoP/carbon nanoparticles composites for high-performance asymmetric supercapacitors

Abstract

Abstract Binary transition metal phosphides have been considered as promising electrode materials for high-performance supercapacitors. Herein, NiCoP/carbon nanoparticles (NiCoP/CNPs) hollow microspheres electrode material has been rationally prepared by using a facile and efficient strategy, and the synergistic effect of NiCoP and CNPs on the enhanced electrochemical performance is explored. The optimized NiCoP/CNPs electrode with capacitive dominated feature can deliver a high specific capacitance of 2599.8 F g −1 at 1 A g −1 and as well as a long cycling life with 89.4% retention after 6000 cycles at 20 A g −1. Charge storage analysis reveals that the capacitive dominated feature of NiCoP/CNPs electrode is observed. Additionally, the as-synthesized asymmetric supercapacitor by using NiCoP/CNPs electrode exhibited a maximum energy density of 54.7 Wh kg−1 at 794.7 W kg−1 and a maximum power density of 16,040.0 W kg−1 (for an energy density of 4.1 Wh kg−1). Besides, it displays excellent cyclic stability with 90.6% capacity retention after 10,000 cycles at 20 A g−1. These remarkable electrochemical performances demonstrate that NiCoP/CNPs composite has excellent potential applications in high efficient electrochemical supercapacitor.