摘要:本实验采用草酸共沉淀法制备尖晶石型锂镍锰氧化物(LiNi0.5Mn1.5O4)正极材料,即通过控制前体溶液的PH值,在前驱体中引入过多的锂元素。含少量P4332的Fd3m空间群是通过这种方法合成的样品。前体溶液的PH值确实影响目标材料的形态、化学计量和晶体结构,而导致不同数量的锰(即无序程度不同)。过量的锂元素可以弥补锂在高温烧结过程中的损失和消除LixNi1-xO杂质。优化的工艺条件下,获得高纯尖晶石型LiNi0.5Mn1.5O4材料同时具有增强的电化学性能。经过电化学性能测试发现,LiNi0.5Mn1.5O4放电比容量、循环稳定性能较好。50265
毕业论文关键词: 尖晶石型锂镍锰氧化物、共沉淀法、水热法、电化学性能
Abstract A spinel lithium nickel manganese oxide (LiNi0.5Mn1.5O4) cathode material is synthesized with a modified oxalate co-precipitation method by controlling pH value of the precursor solution and introducing excessive Li source in the precursor. All the samples synthesized through this method are of Fd3m phase with a small amount of P4332 phase. It is found that pH value of the precursor solution considerably affects the morphology, stoichiometry and crystallographic structure of the target material, thereby resulting in different amounts of Mn3+ (i.e., different degree of disorder).Excessive lithium can make up for the loss of lithium in the high temperature sintering process and eliminate LixNi1-xo impurities. Excessive lithium can make up for the loss of lithium in the high temperature sintering process and eliminate LixNi1-xo impurities. After the electrochemical performance test, it was found that the LiNi0.5Mn1.5O4 discharge specific capacity and better cycle stability.
KeyWords:lithium nickel manganese oxide; co-precipitation method; hydrothermal method; Electrochemical properties
目 录
1绪论 1
1.1 锂离子电池简介 1
1.1.1锂离子电池的主要结构及工作原理 1
1.1.2锂离子电池的主要特点 3
1.1.3锂离子电池正极材料 3
1.1.4锂离子电池负极材料 3
1.1.5锂离子电池对正极材料的要求 3
1.1.6 锂离子电池的性能表征 4
1.2 尖晶石型LiNi0.5Mnl.5O4正极材料的结构 5
1.3 尖晶石型LiNi0.5Mnl.5O4正极材料制备方法 7
1.3.1共沉淀法 7
1.3.2 固相法 8
1.3.3溶胶凝胶法 8
1.4研究的目的 8
1.4.1研究的目的 8
2实验部分 9
2.1实验药品 9
2.2仪器和设备 9
2.3实验内容 9
2.3.1 拟采取的实验方案 9
2.3.2实际实验方案与步骤 10
2.4 研究和测试方法 12
2.4.1 电化学测试 12
2.4.2 扫描电子显微镜(SEM)的测定 12
3结果与分析 13
3.1 电化学分析 13
3.2扫描电子显微镜(SEM)的分析