The aim of the present study - development of a hydrothermal technique of V₂O₅ based whiskers preparation and investigation of their physical and chemical properties for subsequent use as a cathode material in lithium-ion batteries.

V₂O₅·nH₂O xerogel was applied as precursor for preparing of whiskers. The xerogel was received by addition of V₂O₅ powder to H₂O₂ (15 % water solution). Then it was mixed with Ba(NO₃)₂ water solution. Ba-whiskers were prepared by hydrothermal treatment of Ba-replaced xerogel. H-whiskers were obtained at the same conditions but using initial non-replaced xerogel.

According to SEM and TEM data, whiskers had 50-100 nm thickness and about 3-4 mm length (aspect ratio reached up 40000/1).

Element composition of whiskers was established by EDX analysis. XPS data has shown, that H-whiskers contains only V⁵⁺, while during Ba²⁺ ion exchange oxidation state of vanadium ions are partially reduced to 4+.

Thermal stability of Ba-whiskers was investigated by TG and XRD methods. Structure of samples due to water less is transformed up to ~280°C. At more high temperature phase transformation occurs and V₂O₅ is formed.

Electrochemical properties of Ba-whiskers were investigated by charge-discharge curves and cycle voltammogramm data. The main advantage of prepared whiskers is high (~140 mAh/g) discharge capacity which does not change during process. UV-vis spectrometry data shows that whiskers are semiconductors with gap energy 1 eV (Ba-whiskers) and 2.5 eV (H-whiskers).

This work was supported by RFBR (grant No. 07-03-00654).

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