Versatile insertion capability of Na₁.₂V₃O₈ nanobelts in aqueous electrolyte solutions

By Vujković, M.; Paunković, B. Sljukić; Simatović, I. Stojković; Mitrić, M.; Sequeira, C.A.C. & Mentus, S.
Published in Electrochimica Acta NULL 2014

Abstract

Single phase nanobelt-like Na₁.₂V₃O was synthesized by precipitation from aqueous solution of V₂O₅, H₂O₂ and NaOH, and subsequent annealing at 400° C. The product was characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. As measured by both galvanostatic charging/discharging and cyclic voltammetry methods, in air-equilibrated aqueous electrolyte solutions containing nitrates of lithium, sodium and magnesium, this compound displayed fast intercalation/deintercalation reactions. The galvanostatic charging and discharging curves observed at rates ranging 500-7000 mA g⁻¹, did not display clear plateaus characteristic of phase changes. The discharging capacities were found to range 101-35, 55-17 and 67-22 mAh g⁻¹ for Li, Na and Mg intercalation, respectively. By cyclic voltammetry, for the sweep rates increasing in the range 5-400 mV s⁻¹ (roughly 9-700 C), the capacity was found to decrease within the limits 63-35 mAh g⁻¹ for Li⁺ intercalation, and 40 -11 mAh g⁻¹ for Na⁺ and Mg²⁺ intercalation, respectively. By analyzing the dependence log (current) versus log (sweep rate), the interval of potentials corresponding to preferably diffusion control of intercalation/deintercalation processes was determined.

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