Electrochemical performances of polyvanadate plate-like crystals

Layered hybrid compounds (H3N(CH2)(3)NH3)[V4O10] and (H3N(CH2)(4)NH3)[V6O14] have been synthesized via the hydrothermal method. Compounds were analyzed through X-ray powder diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of electrode materials was evaluated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). CV curves show only one electron transfer reaction, which is in accordance with insertion/extraction of the Li+ ion into/out from the material electrode. Furthermore, the kinetics of electrode reaction is controlled by charge transfer and diffusion processes. EIS measurements illustrate the lower charge transfer, which makes Li+ ion transfer quicker. In addition, values of lithium ion diffusion coefficient into these intercalation materials were found to be 0.1 x 10(-10) and 0.21 x 10(-11) cm(2) s(-1) for (H3N(CH2)(3)NH3)[V4O10] and (H3N(CH2)(4)NH3)[V6O14], respectively, after the 50th cycle.