锂离子电池氧化锡基负极材料的研究.pdf

哈尔滨工程大学硕士学位论文锂离子电池氧化锡基负极材料的研究姓名:韩文伟申请学位级别:硕士专业:应用化学指导教师:陈猛 20070301 哈尔滨T程大学硕士学位论文摘要本文首先概述了锂离子电池及其负极材料的研究进展情况。在此基础上, 以sn02基负极材料为研究对象,围绕比容量、循环性能和倍率性能等主要性能指标,、均匀沉淀法制备了Sn02基负极材料,运用XRD、 TEM、IR等分析测试技术对合成材料进行了结构形貌表征、运用电化学测试手段对材料电化学性能以及相关机理进行了系统研究。以SnCh·5H20和氨水为原料,。。研究表明,经500 ℃热处理6h得到的样品粒度分布均匀,。对纳米Sn02粉末的电化学测试发现:热处理温度、充放电截止电压、电流密度以及粉末粒度大小对Sn02电极的电化学性能具有较大的影响。500℃热处理6h制备的纳米Sn02的电化学性能最好:(放电区间为O~ )时,其放电比容量达到746mAh/g,经25次循环后的容量衰减率为 %;(放电区间为O~)时,其可逆容量达到531 mAh/g, %。采用电化学阻抗法对纳米Sn02电极的界面过程进行了研究,得到了不同荷电状态下Sn02电极电化学阻抗图谱。,研究了复合材料的表面形貌和电化学性能。结果表明,经600℃热处理6h后的含30%; 经30次循环后的容量保持率达到82%。%%,表明复合材料具有很高的可逆容量、较好的倍率性能和循环寿命。实验表明,,说明石墨和sn02两个组分之问存在着某种协同作用。关键词:锂离子电池;负极; sn02; ABSTRACT On thebasisofreviewing thedevelopments oflithium ionbattery andanode Imaterials indetail,谢t11 tinoxide-based anode materialsasobjects ofthestudy, focusing studies on thespecific capacity,cyclability and rate capability of tin oxide·based materials were prepared bY sol—gel and homogeneous precipitationmethods,and characterized bY variouselectrochemical methods bination with powder X-ray diffraetion(XRD),Transmission ElectronMicroscope(TEM),Infrared(IR)spectroscopy and SO on. Nanosized Sn02powders were essfully prepared bysol—bined with heattreatmentsusing tintetrachloride and Ammonia water as starting reaction hanisms ofthesol—gel process age proposed. Results indicatethatpowders、Ⅳith uniform sizearound 10-15 nnlcan beobtained at500℃for6hours. Results 011the electrochemical properties ofnanosized Sn02powders show that heattreatmenttemperature,voltage windows,current density forcharge and particle sizeeffect on apacities,cyclability and rate powders obtained at 500℃for 6hours shows the best electrochemica