Preparation and characterization of co-doped lithium vanadate solid solutions

Abstract

In this study, a class of inorganic materials Li3VO4, Li3-xNaxVO4, Li3-xKxVO4, LiV1-yCryO4, and Li3-xKxV1-yCryVO4 (where x = 0.01, 0.05 & 0.1; y = 0.01, 0.05 & 0.1) were effectively synthesized via citrate sol – gel method. Structural properties of the prepared inorganic materials were characterized by powder X – ray diffraction spectroscopy (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy (RS), Scanning Electron Microscopy (SEM) and Energy dispersive X – ray spectroscopy (EDS). The XRD data showed that the synthesized materials have an orthorhombic crystal structure (space group Pmn21). From the obtained XRD data, different structural parameters (a, b, and c) are also suggested. The Fourier transform infrared (FTIR) spectroscopy analysis showed one distinct strong absorption peak at 600 – 950 cm-1 due to the bending vibrations of the V – O – V bonds of VO4 tetrahedron. Raman study of un – doped and doped lithium vanadate, shows two distinct strong Raman modes which represent VO4 tetrahedra are identified in the Raman shift region of 790 cm-1 to 830 cm-1. The Energy dispersive X – ray spectroscopy (EDS) analysis shows the presence of vanadium and oxygen for undoped LVO, vanadium, oxygen, and sodium for Na-doped LVO, vanadium, oxygen, and potassium for K-doped LVO, vanadium, oxygen, and chromium for Cr-doped LVO and for K & Cr-doped LVO, vanadium, oxygen, potassium, and chromium are present. Surface morphology of the pure and doped Li3VO4 was examined by SEM and the average particle sizes were in between 600 nm and 1000 nm.