Facile synthesis, characterization, and electrochemical performance of multi-scale AgVO3 particles

Abstract

Multi-scale AgVO3 particles were successfully synthesized from different organic acids using a facile sol–gel method; a series of techniques were then used to characterize the particles. The X-ray Diffraction (XRD) patterns showed that a main characteristic peak of element Ag is at around 38°. The X-ray photoelectron spectroscopy (XPS) spectra demonstrated the binding energies of Ag0 3d (5/2) and Ag0 3d (3/2), which further confirmed the existence of element Ag. In addition, the composition of the samples, including the amorphous phase, was determined with a quantitative X-ray diffraction (QXRD) analysis. With a heating rate of 10 °C/min, the products synthesized with citric acid at 450 °C had a larger amorphous phase (26.4% in wt.%) than the samples synthesized with citric acid at 500 °C. To obtain lesser amorphous phase, the precursors were treated at 500 °C with a slower heating rate of 5 °C/min. The electrochemical performance of these three samples, particularly their suitability as cathode materials for lithium ion batteries, were investigated. The products with minimum amorphous phase (9.4%) showed higher specific discharge capacity than other two samples at the first 40 cycles. However, with the increasing fading rate, only 27% of the initial capacity was retained after 100 cycles. Amorphous phase can stabilize the material and avoid the structural collapse during the cycles. Therefore, under the synergistic effect of amorphous content and particle size, the products obtained at 500 °C with quicker heating rate exhibited the optimal capacity and cycling stability. This electrode showed a high initial capacity of 243 mA h/g and retained 41% of the initial capacity after 100 cycles.