Effects of different chelating agents on the composition, morphology and electrochemical properties of LiV3O8 crystallites synthesized via sol–gel method

Abstract

Lithium trivanadate (LiV3O8) crystallites have been synthesized via sol–gel processing using oxalic, tartaric, citric and malic acid as the chelating agents. The thermal decomposition process of the as-prepared LiV3O8 precursor was investigated by thermogravimetric (TG) and differential scanning calorimetry (DSC). The structure, morphology and electrochemical performance of the as-synthesized LiV3O8 samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and the galvanostatic charge–discharge test. Different chelating agents were introduced to investigate their effects on the products composition, morphology and electrochemical properties. Result show that the samples prepared with oxalic and tartaric acid are similar to show thin rod-like morphology in submicron size distribution while the samples prepared with citric and malic acid are found consisting of block-like crystallities in micron size. Further electrochemical results exhibit that the LiV3O8 particles with oxalic, tartaric, citric and malic acid exhibit an initial discharge capacity of 304.4 mA h/g, 296.8 mA h/g, 268.7 mA h/g and 275.3 mA h/g, respectively. After 20 cycles, they retain discharge capacity of 250.2 mA h/g, 237.6 mA h/g, 198.5 mA h/g and 206.8 mA h/g, respectively.