锂离子电池SnO_2-Si/C负极材料的电化学性能  

Electrochemical Performance of SnO_2-Si/C Composite for Anode Materials of Lithium-Ion Battery

作　　者：邓洪贵[1] 金双玲[1] 赵跃[1] 李文成[1] 詹亮[1] 凌立成[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2011年第6期679-683,共5页Journal of East China University of Science and Technology

摘　　要：利用水热法合成了SnO2-Si/C复合材料,利用X射线衍射(XRD)和扫描电子显微镜(SEM)分析了材料的物相和电极的微结构,结果表明,合成的复合材料中SnO2颗粒平均尺寸为5.3 nm,碳的加入抑制了活性中心Si和SnO2在循环过程中较大的结构变化,且SnO2和Si颗粒均匀地分散在碳的网络结构中,增加了复合材料的电接触。合成样品的电化学测试表明,碳的网络结构提高了SnO2-Si复合材料的可逆容量和循环性能,经过400℃N2处理的SnO2-Si/C电极在100 mA/g的充放电密度下首次可逆容量为1 050 mAh/g,50个循环后复合材料仍然有589 mAh/g的可逆容量,库仑效率接近99.7%。在600 mA/g电流密度下,可逆容量仍然达390 mAh/g。A one-pot hydrothermal synthesis method was designed to synthesize SnO2-Si/C composites for anode materials of lithium-ion battery. The prepared composites were characterized by X-ray diffraction （XRD）, transmission electron microscope （TEM）, scanning electron microscope （SEM）. Results show that the average size of SnO2 particles is 5.3 nm. The addition of carbon restrains the structure change of Si and SnO2 particles as active centers. The uniform dispersion of Si and SnO2 particles in the carbon network enhances the electric contact of composites. The electrochemical characterization shows that the reversible capacity and electrochemical performance of the composites are improved by the carbon network. The composite treated at 400℃ under nitrogen, shows reversible capacities of 589 mAh/g after 50 cycles with Coulomb efficiencies close to 99. 7%. High specific capacity of 390 mAh/g is still sustained upon cycling at high current density up to 600 mA/g.

关 键 词：锂离子电池 复合材料 负极 水热合成 

分 类 号：O613[理学—无机化学] TM912[理学—化学]