锂离子电池论文

摘要随着电力行业的高速发展，锂离子电池的研究已成为当代的热点研究课题。

研究锂离子电池，最主要的是对正极材料的研究，因为锂离子电池由于受到技术制约而使其性能得不到充分发挥。

锂离子电池在实际应用中有着循环使用寿命较长、首次充放电比容量高、对环境无污染等优点，已经成为21世纪绿色电源的首选。

目前常用的正极材料主要是LiCoO2，由于LiCoO2合成简单，充放电电压平稳，已经广泛用于各个领域，但是LiCoO2中钴材料价格较贵，毒性较大对环境污染严重，实际容量只有理论容量的二分之一，导致它的使用受到严重限制。

这就迫使研究者寻找新型的正极材料来代替LiCoO2。

LiNi1/3Co1/3Mn1/3O2正极材料价格低，热稳定性高，循环稳定性能良好，是目前高容量电极材料发展的主要方向。

本文将采用共沉淀法和溶胶-凝胶法制备锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2，然后利用XRD、SEM、充放电及循环性能测试对其进行结构、形貌研究并测试其电化学性能。

共沉淀法制备材料能有效节省材料的制备时间，选择合适的沉淀体系，加入一定量表面活性剂，严格控制反应体系PH在11，配锂量要大于一般的固相反应。

当配锂量在1.1时，前驱体经过500 ℃预处理，然后在850 ℃下焙烧20 h可得到粒径均匀，分散性好的细小颗粒；溶胶-凝胶法制备材料时，通过控制合适的络合剂、易分解的金属离子盐以及反应过程中的温度、时间、PH等条件，找到溶胶-凝胶法制备材料的最佳工艺条件。

实验表明，采用适当的反应过程和适宜的PH(6-6.3)值可以得到颗粒细小、均匀且分散性良好的粉状材料，使用这种粉体材料经过500 ℃预处理，然后在850 ℃下焙烧20 h 可以得到粒径在100～300 nm，均匀分布的粉末颗粒。

首次充放电实验表明，这种材料具有良好的循环稳定性能和较高的容量。

关键字：锂离子电池；正极材料；共沉淀；溶胶-凝胶法；LiNi1/3Co1/3Mn1/3O2AbstractWith the high-speed development of the power industry, the research of lithium ion battery has become a hot research topic in the contemporary. Research on lithium ion batteries, the most important is the study of the anode materials, because of the lithium ion batteries due to technical constraints and make not give full play to its performance. In actual application of lithium ion battery has a first charge and discharge cycle a long service life, the advantages of high specific capacity, on the environment pollution-free, has become a 21st century green power of choice. The positive materials of the commonly used at present is mainly LiCoO2, as a result of LiCoO2 synthesis is simple, stable charge and discharge voltage, has been widely used in every field, but in the LiCoO2 cobalt material price is more expensive, bigger toxicity to environment pollution is serious, the actual capacity is only half of the theory of capacity, led to its use is limited by serious. This forces the researchers looking for new to replace the LiCoO2 cathode material. LiNi1/3Co1/3Mn1/3O2 cathode material price is low, high thermal stability, stable cycle performance is good, is currently the main development direction of high capacity electrode materials.This thesis will use the coprecipitation method and sol-gel method of lithium ion battery cathode material LiNi1/3Co1/3Mn1/3O2, then using XRD, SEM, charge-discharge and cycle performance test research on the structure, morphology and test their electrochemical performance.Coprecipitation preparation material can effectively save the preparation time, select the appropriate system of precipitation, surface active agent was added into, strict control of reaction system PH in 11, with lithium content than ordinary solid phase reaction. Precursor when the amount of lithium in 1.1 after 500 ℃preprocessing, and then roasting 20 h under 850 ℃can get uniform particle size, good dispersion tiny particles; Sol-gel method materials, by controlling the appropriate complexing agent and metal ion salt and easy decomposition reaction conditions, such as temperature, time and PH on the find material optimum process conditions of sol-gel method. Experiments show that the proper reaction process and the suitable PH value (6-6.3) can be particles small, uniform and good dispersancy powder materials, the use of this powder materials after 500 ℃preprocessing, and then roasting 20 h under 850 ℃can get grain size in 100 ~ 300 nm, uniform distribution of powder particles. The first charge and discharge experiments show that the material has good cycle stability performance and higher capacity.Key Words:Lithium-ion battery, Cathode material,Coprecipitation,Sol-Gel method, LiNi1/3Co1/3Mn1/3O2目录摘要 (I)Abstract (II)1 绪论........................................................................................................................... - 1 -1.1 研究背景........................................................................................................ - 1 -1.2 锂离子电池概述............................................................................................ - 1 -1.2.1 锂离子电池的发展历程..................................................................... - 1 -1.2.2 锂离子的应用及前景......................................................................... - 2 -1.2.3 锂离子电池的结构和工作原理......................................................... - 2 -1.2.4 锂离子电池的特点............................................................................. - 4 -1.3 锂离子电池正极材料.................................................................................... - 4 -1.3.1 氧化镍锂(LiNiO2)正极材料 .............................................................. - 5 -1.3.2 氧化钴锂(LiCoO2)正极材料.............................................................. - 5 -1.3.3 氧化锰锂(LiMnO2)正极材料............................................................. - 6 -1.3.4 橄榄石结构(LiMPO4)正极材料......................................................... - 6 -1.3.5 尖晶石锰酸锂(LiMn2O4)正极材料.................................................... - 7 -2 实验条件与测试方法............................................................................................... - 8 -2.1 化学试剂及主要设备.................................................................................... - 8 -2.1.1 化学试剂............................................................................................. - 8 -2.1.2 主要设备............................................................................................. - 9 -2.2 电极的制备和电池的组装............................................................................ - 9 -2.2.1 电极的制备......................................................................................... - 9 -2.2.2 电池的组装....................................................................................... - 10 -2.3 主要测试方法...................................................................... 错误!未定义书签。