锂离子电池负极材料SnO_2的制备及其性能研究

Synthesis and characterization of SnO_2 anode material for lithium-ion batteries

以NaOH为沉淀剂,聚乙二醇400(PEG400)为分散剂,采用改进的化学沉淀法制备了前驱体粉末Sn(OH)2,在不同温度下煅烧得到了SnO2纳米颗粒。运用X射线衍射、扫描电镜、恒流充放电、循环伏安法等手段对所制材料的结构、表面形貌和电化学性能进行了研究。结果表明:采用改进的化学沉淀法可以得到平均粒度为80nm左右的SnO2纳米颗粒,其中700℃下煅烧合成的SnO2性能最佳,其首次放电比容量和充电比容量分别为1 576.3mAh/g和836.7 mAh/g,首次库仑效率为53.1%。经过20次循环充放电后,其比容量仍有411.4 mAh/g。

A series of nano-size SnO2 samples were synthesized by the pyrolysis of Sn（OH）2 precursor at different temperature via a modified chemical precipitation method,with sodium hydroxide as precipitation agent and polyethylene glycol 400（PEG400） as dispersing agent.The crystalline structure,grain morphology and electrochemical performance of the prepared powders were characterized by X-ray diffraction（XRD）,scanning electron microscope（SEM）,galvanostatic charge/discharge（DC） and cyclic voltammetry（CV） methods.The results show that the average size of SnO2 nanoparticles are about 80 nm.And the samples prepared at 700 ℃ exhibit the best electrochemical performance,the initial discharge and charge specific capacity are 1 576.3 mAh/g and 836.7 mAh/g,respectively.The first coulombic efficiency is 53.1% and the specific capacity still retain at a high level of 411.4 mAh/g after 20 cycles.