Nanocrystalline Fe1-xCoxSn2 solid solutions prepared by reduction of salts in tetraethylene glycol

作者：Nwokeke Uche G; Chadwick Alan V; Alcantara Ricardo; Alfredsson Maria; Tirado Jose L^*

来源：Journal of Alloys and Compounds, 2011, 509(6): 3074-3079.

DOI：10.1016/j.jallcom.2010.11.202

• Cobalt tin intermetallic compound
• Iron tin intermetallic compound
• Lithium batteries anode
• Mossbauer spectroscopy

In an effort to improve the electrochemical performance of tin intermetallic phases as electrode active material for lithium-ion batteries, Fe1-xCoxSn2 solid solutions with x = 0.0, 0.25, 0.3, 0.5, 0.6 and 0.8 were prepared by chemical reduction in tetraethylene glycol. Precise control of the synthesis conditions allowed single-phase nanocrystalline materials to be prepared, with particle diameters of about 20 nm and cubic, nanorods, and U-shaped morphologies. The substitution of iron by cobalt induced a contraction of the unit cell volume. The hyperfine parameters of the Fe-57 Mossbauer spectra were sensitive to the Co/Fe substitution and revealed a superparamagnetic behaviour. In lithium cells nanocrystalline Fe1-xCoxSn2 active materials delivered reversible capacities above 500 mAh g(-1) that depended on the composition and cycling conditions. The intermediate compositions exhibit better electrochemical performance than the end compositions CoSn2 and FeSn2.

• 出版日期2011-2-10