Tin oxide anode materials have a high reversible capacity for secondary lithium ion batteries. However, the volume expansion of tin oxide is known to reduce the battery cycle life. Nanocomposite anode materials were thus synthesized using a sol-gel method to solve this problem. The nanocomposite materials (SnO2/C) have a core-shell structure. The core is made of commercial graphite (similar to 10 gm) and the shell is made of the tin oxide nanoparticles. The morphology and the nanostructure were characterized by SEM (JSM-6500F) and the results of electrochemical tests were analyzed using an Arbin BT2400 battery tester. The tin oxide nanoparticles (similar to 20 nm) uniformly dispersed on the surface of commercial graphite. The tin oxide nanoparticles had a markedly greater cyclability than the micro-tin oxide particles. The tin oxide nanoparticles are believed to reduce the effect of volume expansion. It is apparent that the nanocomposite structure (SnO2/C) inhibits the volume expansion of the tin oxide anode materials. (c) 2007 Published by Elsevier B.V.