Structure and electrochemical performance of nanostructured Sn-Co alloy/carbon nanotube composites as anodes for lithium ion batteries

Nanoparticles of Sn-Co alloy were deposited on the surface of multi-walled carbon nanotubes (CNTs) by reductive precipitation of solution of chelating metal salts within a CNTs suspension. The Sn-Co/CNTs nano-composite revealed a high reversible capacity of 424 mA h g(-1) and stable cyclic retention at 30th cycle. The improvement of reversible capacity and cyclic performance of the Sn-Co/CNTs composite is attributed to the nanoscale dimension of the Sn-Co alloy particles and the network of CNTs. Inactive Co as glue matrix of Sn prevents the possible pulverization of nanosized alloy particles. The CNTs could be pinning the Sn-Co alloy particles on their surfaces so as to hinder the agglomeration of Sn-Co alloy particles, while maintaining electronic conduction as well as accommodating drastic volume change during Li insertion and extraction reactions. (C) 2009 Elsevier B.V. All rights reserved.