Hollow Co2P nanoflowers assembled from nanorods for ultralong cycle-life supercapacitors

Abstract

Hollow Co₂P nanoflowers (Co₂P HNFs) were successfully prepared via a one-step, template-free method. Microstructure analysis reveals that Co₂P HNFs are assembled from nanorods and possess abundant mesopores and an amorphous carbon shell. Density functional theory calculations and electrochemical measurements demonstrate the high electrical conductivity of Co₂P. Benefiting from the unique nanostructures, when employed as an electrode material for supercapacitors, Co₂P HNFs exhibit a high specific capacitance, an outstanding rate capability, and an ultralong cycling stability. Furthermore, the constructed Co₂P HNF//AC ASC exhibits a high energy density of 30.5 W h kg⁻¹ at a power density of 850 W kg⁻¹, along with a superior cycling performance (108.0% specific capacitance retained after 10 000 cycles at 5 A g⁻¹). These impressive results make Co₂P HNFs a promising candidate for supercapacitor applications.