Details

Autor(en) / Beteiligte

• Nwokeke, Uche G
• Chadwick, Alan V
• Alcantara, Ricardo
• Alfredsson, Maria
• Tirado, Jose L

Titel

Nanocrystalline Fe sub(1-x)Co sub(x)Sn sub(2) solid solutions prepared by reduction of salts in tetraethylene glycol

Ist Teil von

• Journal of alloys and compounds, 2011-02, Vol.509 (6), p.3074-3079

Erscheinungsjahr

2011

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• In an effort to improve the electrochemical performance of tin intermetallic phases as electrode active material for lithium-ion batteries, Fe sub(1-x)Co sub(x)Sn sub(2) 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 super(57)Fe Moessbauer spectra were sensitive to the Co/Fe substitution and revealed a superparamagnetic behaviour. In lithium cells nanocrystalline Fe sub(1-x)Co sub(x)Sn sub(2) active materials delivered reversible capacities above 500 mAh g super(-1) that depended on the composition and cycling conditions. The intermediate compositions exhibit better electrochemical performance than the end compositions CoSn sub(2) and FeSn sub(2).