Synthesis of Hierarchical Cobalt Phosphate Nanoflakes and Their Enhanced Electrochemical Performances for Supercapacitor Applications

摘要

Hierarchical structured cobalt phosphate (Co3(PO4)2) nanoflakes were synthesized by simple co-precipitation method and employed as electrodes for supercapacitor. The purity and phase formation of the synthesized (Co3(PO4)2) nanoflakes were ascertained by XRD and XPS measurements. The surface morphology and elemental composition of the Co3(PO4)2 nanoflakes were observed by using FE-SEM, TEM and EDS. The electrochemical behaviour of the present material as an anode material for supercapacitor was explored by cyclic voltammetric measurements and galvanostatic charge-discharge analysis. The specific capacitance for the as-synthesized and calcined (Co3(PO4)2) nanoflakes electrodes was 132 and 210 Fg~(-1) at a scan rate of 10 mV s~(-1). The enhanced electrochemical behaviour of the calcined Co3(PO4)2 nanoflakes might be due to its well crystalline nature which offers more active sites for faradaic reactions, good conductivity and rapid diffusion of the electrolyte ions. The fabricated Co3(PO4)2 electrode displayed an excellent cyclic stability with 95% retention of initial specific capacitance after 800 cycles. An enhanced effect on the electrochemical properties of the Co3(PO4)2 nanoflakes has been proposed.