PAN-Encapsulated Nanocrystalline CoSn2 Particles as Negative Electrode Active Material for Lithium-Ion Batteries

Composite electrodes were prepared throughout the reduction of tin and cobalt ions in the presence of polyacrylonitrile (PAN). The resulting product consists of tin-cobalt intermetallic nanoparticles surrounded by a PAN-based shell, the main intermetallic phase being nanocrystalline CoSn2. The organic molecules prevented the growth of the intermetallic grains upon annealing and formed an amorphous carbon layer. The observed maximum reversible capacities are around 600 mAh/g. Excellent capacity retention was achieved for PAN-CoSn2 composite electrodes. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3368696] All rights reserved.