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

• layered Na1.2V3O8 was synthesized by simplified soft chemistry method
• fast insertion of Li, Na and Mg ions from aqueous solutions was evidenced
• reproducible insertion reactions were observed even at highest scanning rates
• promising behavior for aqueous recahrgeable metal-ion batteries was evidenced

Single phase nanobelt-like Na1.2V3O8 was synthesized by precipitation from aqueous solution of V2O5, H2O2 and NaOH, and subsequent annealing at 400 oC. 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.

XRD pattern, microphotography of nanocrystal particle shape, and cyclovoltammograms in aqueous Li, Na and Mg nitrate solutions of layered Na1.2V3O8.Figure optionsDownload as PowerPoint slide