采用溶胶—凝胶法合成尖晶石型钛酸锂负极材料毕业设计论文.doc

摘要 钛酸锂因其零应变效应成为极具潜力的锂离子电池负极材料，但因其低的理论容量阻碍了它的应用。因此，本文采用溶胶—凝胶法合成尖晶石型钛酸锂负极材料；并对其进行Fe3+及纳米金刚石掺杂改性。采用XRD、SEM分析材料的晶体结构和表面形貌；通过循环伏安（CV）、交流阻抗（EIS）和充放电测试分析钛酸锂基负极材料的电化学性能。 采用溶胶—凝胶法合成尖晶石型钛酸锂负极材料。XRD结果表明，材料晶体结构的特征峰与尖晶石型钛酸锂的标准图谱基本一致，说明合成材料为钛酸锂；金属离子掺杂不会改变材料的尖晶石型的结构，但当掺杂量较大时，材料中会有一定量的杂质出现。充放电测试结果表明，得到的前驱体在900℃条件下保温20h得到的材料电化学性能最好；EIS结果表明Li4Ti5O12表面不会形成钝化膜，将其作为锂电池的负极材料比碳负极材料更安全。 　　采用同样的方法对钛酸锂进行Fe3+掺杂。电化学测试结果表明，Fe3+的掺杂能够有效降低锂离子电池负极材料的放电电压平台，掺杂比例为5%时电化学性能较好。进一步对钛酸锂进行纳米金刚石掺杂改性，纳米金刚石掺杂量为6g/L时，电化学性能相对较好。 关键字：锂离子电池；负极材料；钛酸锂；掺杂改性 Abstract 　　Lithium titanate as its zero strain effects become highly promising anode material for lithium-ion batteries, but because of the low theoretical capacity hindered its application. Therefore, this sol - gel synthesis of lithium titanate spinel anode material; and its Fe3+ and nano-doped diamond. By XRD, SEM surface morphology and crystal structure analysis of materials; through cyclic voltammetry (CV), electrochemical impedance (EIS) and electrochemical properties of the charge-discharge test analysis lithium titanate anode materials. 　　Sol - gel synthesis of lithium titanate spinel anode material. XRD results showed the characteristic peaks of the lithium titanate spinel crystal structure standard pattern consistent with the material, to illustrate the synthesis of lithium titanate material; metal ion doping does not change the structure of the spinel type material, but when the doping amount is large, the material will have a certain amount of impurities there. Charge-discharge test results indicate that the electrochemical performance of the precursor at 900 ℃ insulation 20h get the best conditions; EIS Li4Ti5O12 results show that the surface does not form a passivation film, which was used as anode material of lithium than carbon anode materials safer. Using the same method on Fe3+-doped lithium titanate. The electrochemical test results show, Fe3+ doping can effectively reduce the lithium-ion battery cathode materi