Speaker
Description
Copper phosphate (Cu$_2$P$_2$O$_7$) nanostructures were synthesized by hydrothermal method. The precursor products were calcined at 500, 600 and 700 oC in air for 3 h. Thermogravimetric/differential thermal analysis (TG/DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR) were used to study the phase formation, crystalline structure, morphology and functional group of samples. Electrochemical properties were measured by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD). XRD analysis confirms a monoclinic crystal structure of Cu$_2$P$_2$O$_7$ with space group C2/c. SEM micrographs of calcined samples show a fused grain structure for smaller crystals with more porous and rough surfaces. The CV results show the redox peaks in all curves, exhibiting reversible electron-transfer for Faradaic redox reactions with the largest CV areas for sample calcined at 600°C. The Cu$_2$P$_2$O$_7$ positive electrodes show a maximum high specific capacitance. In addition, the result of the electron-active sites participated in the Faradaic redox reaction indicat a valence interchange or charge hopping of cations
