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.