锂离子电池锰系5V正极材料的研究【毕业设计】.doc

- PAGE I - （20 届） 本科毕业设计 锂离子电池锰系5V正极材料的研究 Research on Manganese-Based Material as 5V Class Cathode for Lithium-Ion Battery 所在学院 专业班级 化学 学生姓名 学号 指导教师 职称 完成日期 年 月 锂离子电池锰系5V正极材料的研究 PAGE 4 PAGE 5 宁波大学材料科学与化学工程学院本科毕业设计 摘要 【摘要】本文采用高温固相法制备LiNi0.5Mn1.5O4 和 LiNi0.4Mn1.4Cr0.2O4。并用X-射线衍射（XRD）和红外光谱（IR）对纯样品和掺杂样品的结构进行表征。通过循环充放电和电化学交流阻抗的测试研究尖晶石的电化学性能。结果表明掺杂Cr后的样品比容量的保持率从原来的93.68%增长95.72%。此外，LiNi0.4Mn1.4Cr0.2O4的首次放电容量为128mAh/g，LiNi0.5Mn1.5O4的首次放电容量为113mAh/g。且LiNi0.4Mn1.4Cr0.2O4在经过15个循环后其库伦效率保持在高于纯物质的92.5%。因此可以得知，Cr的掺杂能改善LiNi0.5Mn1.5O4的电化学性能。 【关键词】：能源；锂离子电池；正极材料；LiNi0.5Mn1.5O4；掺Cr Research on Manganese-Based Material as 5V Class Cathode for Lithium-Ion Battery Abstract 【ABSTRACT】LiNi0.5Mn1.5O4 and LiNi0.4Mn1.4Cr0.2O4 was prepared by solid-state pyrolysis method in this thesis. The structure characteristics of the pristine and doped samples were examined by X-ray diffraction (XRD) and infrared spectroscopy (IR). Electrochemical properties of these spinels were studied by charge-discharge cycling and electrochemical alternating current impedance spectroscoy. The results show that the capacity retention of cathode material has an increase from 93.68 % to 95.72 % after Cr doping. Furthermore, the initial discharge capacities are 128 mAh/g for LiNi0.4Mn1.4Cr0.2O4 and 113 mAh/g for LiNi0.5Mn1.5O4. Besides, the coulombic efficiency of LiNi0.4Mn1.4Cr0.2O4 can be remained at 92.5 % after 15 cycles, which is higher than the one obtained from the pristine compound. Therefore, it is known that the electrochemical perpormance of LiNi0.5Mn1.5O4 can be improved by Cr doping. 【KEYWORDS】Energy; Lithium-ion battery; Cathode material; LiNi0.5Mn1.5O4; Cr doping 目录 TOC \o 1-3 \h \z \u HYPERLINK \l _Toc2