中文摘要：

便携式电子设备和电动汽车等的发展对高性能电池的需求日益迫切．锂离子电池由于其高能量密度、长循环寿命、环境友好等优点受到广泛关注．决定锂离子电池性能的重要因素是电极材料．SnO2因其具有较高的理论容量、较低的嵌锂电压，常被用作负极材料．但是商品化SnO2在嵌／脱锂过程中引起的体积变化会导致材料的聚集和粉末化，使材料的电化学性能大大减弱．构建纳米结构的SnO2可以缓解这个问题．最近的研究表明二维原子层厚度纳米片具有优异的电化学性能，由此我们得到启发，通过一步溶剂热法合成了原子层厚度纳米片组装而成的SnO2纳米花．该纳米花用作锂离子电池负极材料，显示出较大的可逆容量和良好的循环性能．SnO2纳米花良好的电化学性能与SnO2纳米花具有疏松结构、超薄原子层厚度的纳米片、大的比表面积等有关．与商品化SnO2相比较，SnO2纳米花电化学性能得到显著提高．

英文摘要：

Hierarchical SnO2 nanoflowers assembled by atomic thickness nanosheets were prepared by facile one-pot solvothermal method with acetone/water mixture as solvent. The crystal structure, morphology and the microstructure of the as-prepared products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and atomic force microscope （AFM）. Results revealed that the nanoflowers （2-4 μm） were assembled by the ultrathin SnO2 nanosheets （3.1 nm esti- mated by AFM）. When tested as anode material for lithium ion batteries, the SnO2 nanoflowers showed improved cy- cling stability comparing with the commercial SnO2 parti- cles. The reversible charge capacity of SnO2 nanoflowers maintained 350.7 mAh/g after 30 cycles, while that of the commercial SnO2 was only 112.2 mAh/g. The high re- versible capacity and good cycling stability could be ascri- bed to the hierarchical nanostructure, atomic thickness nanosheets and large surface area of the SnO2 nanoflowers.