Size effect of tin oxide nanoparticles on high capacity lithium battery anode materials

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 (∼ 10 μm) 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 (∼ 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.