Abstract
In this study, tin oxide nanostructures were synthesized by hydrothermal approach using SnCl2, PVP (Polyvinylpyrrolidone) and NaOH in deionized water / ethanol mixed solution under different time and temperature. By tuning different volume ratio of H2O/ethanol and reaction time, pure phase Sn3O4 nanosheets were obtained. Furthermore, the reaction pathway could be verified by analyzing individual oxide synthesized with variant factors. In addition, the anode of lithium ion battery made by PVP-removed Sn3O4 nanosheets was examined at 0.1C. The reversible discharge capacity is 129 mAhg-1 after 20 charge-discharge cycles. In order to increase the conductivity and resist volume expansion, the as-synthesized Sn3O4 nanosheets were coated carbon by heating it in argon atmosphere to form Sn3O4/C composite via PVP pyrolysis process. The lithium ion battery anodes made by the composite have an improved discharge capacity, 278 mAhg-1, after 20 discharge-charge cycles at 0.1C. As mentioned above, carbon coating process can be accomplished by polymer pyrolysis under certain temperature. The self-carbonized Sn3O4 keeping the nanosheets morphology increases the conductivity during charge-discharge progress and leads to great charge-discharge cycle performance.