Nano-(V1/2Sb1/2Sn)O4: a high capacity, high rate anode material for Li-ion batteries

• Published in: Journal of materials chemistry Vol. 21; no. 27; pp. 10003 - 10011
• Main Authors: Reddy, M. V., Subba Rao, G. V., Chowdari, B. V. R.
• Format: Journal Article
• Language: English
• Published: 01.01.2011
• Subjects: Antimony; Cycles; Density; Electric potential; Nanocomposites; Nanomaterials; Nanostructure; Rutile
• ISSN: 0959-9428; 1364-5501
• DOI: 10.1039/c0jm04140h

Vanadium antimony tin oxide, M (micron size)-(V1/2Sb1/2Sn)O4 with tetragonal rutile structure is prepared for the first time. The N (nanosize, 10-20 nm)-analogue is obtained by high energy ball milling of the above. They are characterized by Rietveld refinement of the X-ray diffraction data, high resolution transmission electron microscopy (HR-TEM), selected area electron diffraction (SAED), density and BET surface area studies. The Li-cycling properties were studied at ambient temperature (24 [degree]C) and at 54 [degree]C by galvanostatic discharge-charge cycling and cyclic voltammetry. Nano-(V1/2Sb1/2Sn)O4 shows stable cycling performance at 24 [degree]C with capacities 450, 435 and 360 (+/-5) mA h g-1 at rates of 0.43, 1.0 and 3.5 C, respectively, in the range, 0.005-1.0 V vs. Li. These values are stable up to 100 cycles at 0.43 C and up to at least 50 cycles at 1 C and 3.5 C. At 54 [degree]C and at 0.43 C, N-(V1/2Sb1/2Sn)O4 delivers a stable capacity of 440 (+/-5) mA h g-1 in the range, 5-100 cycles. Under similar conditions the cycling performance of M-(V1/2Sb1/2Sn)O4 is inferior to that of the N-analogue. The M- and N-(V1/2Sb1/2Sn)O4 showed main cathodic and anodic peaks at [similar]0.2 V and [similar]0.5 V, respectively, by CV. Complementary impedance studies are reported at various voltages and as a function of cycle number to support the Li-cycling mechanism involving alloying-de-alloying reactions of Sn and Sb with Li using (VO) as an inert matrix.