Preparation and Chracteristion of Graphite Doped Tin Oxide Anode Material for Lithium-Ion Battery

A citric acid assisted sol gel method has been used to prepare a composite of tin oxide doped with 10% and 20% graphite. The structure, morphology and the electrochemical properties of the composite powders were investigated. The x-ray diffraction(XRD) pattern showed crystalline tetragonal structure and presence of nanoparticles were detected from field-mission scanning electron microscopy (FE-SEM). The active anodes prepared using a mixture of composite powder and a conductive binder(teflonized acetylene black) were cycled electrochemically versus lithium. The initial reversible capacity obtained for both composite powders; Sn0.9C0.1O2 and Sn0.8C0.2O2 were around 200mAh/g. However, the capacity fades significantly upon further cycling. Ex-situ microscopic method using FE-SEM revealed that repeated charge-discharge cycling of this anode within the range of 0.5-2.0V was found to have a significant influence on the morphology of the anode material. The morphological changes were due to the effects of volume change that occurs during the insertion and extraction of lithium-ion during repeated cycling of this anode.