锂离子电池正极三元材料产业化工艺研究
发布时间：2018-09-13 09:59
【摘要】：锂离子电池是人类应对能源危机最重要的手段之一,正极材料作为锂电池重要的组成部分,其性能好坏直接影响电池的各项性能。开发高性能、低成本的新型正极材料一直是锂离子电池的研究方向。作为锂离子电池正极材料,层状三元镍钴锰酸锂具有比容量高、循环性能好,成本低、安全性好等优点,被认为是最具开发应用前景、实现替代Li CoO2电极材料的新型正极材料之一,目前该材料已经逐步走向市场,应用领域不断扩大,尤其是在电动汽车(EV)和混合电动汽车领域(HEV),也具有相当大的发展空间。本文采用共沉淀法作为层状镍钴锰酸锂的合成方法,通过液相共沉淀方法制备前驱体Ni1/3Co1/3Mn1/3(OH)2,通过高温固相反应制备三元正极材料LiNi_(l/3)Co_(1/3)Mn_(l/3)O_2。以LiNi_(l/3)Co_(1/3)Mn_(l/3)O_2正极材料为研究对象,系统研究了不同合成工艺对目标材料物化性能及电性能的影响,主要通过X射线衍射(XRD)分析、扫描电子显微镜(SEM)分析、热重差热(TG-DTA)分析、恒电流充放电测试等方法分别对产品形貌、晶体结构和电化学性能进行表征和测试。在采用液相共沉淀方法制备Nil/3Co1/3Mnl/3(OH)2前驱体过程中,本论文着重研究了pH值、金属离子浓度、沉淀剂浓度、络合剂浓度对前驱体的影响。实验结论证明,将反应溶液的pH值控制在10.5左右,金属离子浓度2 mol·L-1,沉淀剂浓度为4mol·L-1,络合剂浓度为3 mol·L-1,此时的Nil/3Co1/3Mnl/3(OH)2前驱体颗粒粒径整体分布窄,形貌类似球体。在采用高温固相法制备LiNi_(l/3)Co_(1/3)Mn_(l/3)O_2正极材料过程中,本论文着重研究了固相反应温度、固相反应时间,以及不同Li/(Ni+Co+Mn)摩尔配比对产物的影响。实验结论证明,Li/M(Ni+Co+Mn)=1.05/1,高温烧结900℃恒温12h,得到三元层状正极材料LiNi_(l/3)Co_(1/3)Mn_(l/3)O_2。充放电电压区间为4.3~2.75V,倍率为0.2C,首次放电比容量为154.50mAh·g-1,容量保持率高,经过20次循环后容量保持率为92.91%。
[Abstract]:Lithium ion battery is one of the most important means to deal with the energy crisis. As an important component of lithium battery, the performance of cathode material directly affects the performance of the battery. Developing new cathode materials with high performance and low cost has always been the research direction of lithium ion batteries. As a cathode material of lithium ion battery, layered lithium nickel cobalt manganese oxide has many advantages, such as high specific capacity, good cycling performance, low cost and good safety, so it is considered to be the most promising for development and application. One of the new cathode materials to replace the Li CoO2 electrode material has gradually moved to the market, and the application field has been expanding constantly, especially in the electric vehicle (EV) and hybrid electric vehicle field (HEV), also has a considerable development space. The precursor Ni1/3Co1/3Mn1/3 (OH) _ 2 was prepared by liquid phase coprecipitation, and the ternary cathode material LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 was prepared by high temperature solid state reaction. Taking LiNi_ (1 / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 cathode material as the research object, the effects of different synthetic processes on the physical and chemical properties and electrical properties of the target materials were systematically studied. The results were analyzed by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) (SEM) analysis and thermogravimetric differential thermogravimetry (TG-DTA) analysis. The morphology, crystal structure and electrochemical properties of the products were characterized and tested by constant current charge-discharge test. In the process of preparing Nil/3Co1/3Mnl/3 (OH) _ 2 precursor by liquid-phase coprecipitation, the effects of pH value, metal ion concentration, precipitation agent concentration and complexing agent concentration on the precursor were studied in this paper. The experimental results show that the pH value of the reaction solution is about 10. 5, the concentration of metal ions is 2 mol L -1, the concentration of precipitator is 4mol L -1, and the concentration of complex agent is 3 mol L -1. The particle size distribution of the precursor of Nil/3Co1/3Mnl/3 (OH) 2 is narrow and the morphology is similar to that of the sphere. In the process of preparing LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 cathode material by high temperature solid state method, the effects of solid state reaction temperature, solid state reaction time and different molar ratio of Li/ (Ni Co Mn) on the product were studied in this paper. The experimental results show that the ternary layered cathode material LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2s can be obtained by sintering at 900 鈩，
本文编号：2240856
[Abstract]:Lithium ion battery is one of the most important means to deal with the energy crisis. As an important component of lithium battery, the performance of cathode material directly affects the performance of the battery. Developing new cathode materials with high performance and low cost has always been the research direction of lithium ion batteries. As a cathode material of lithium ion battery, layered lithium nickel cobalt manganese oxide has many advantages, such as high specific capacity, good cycling performance, low cost and good safety, so it is considered to be the most promising for development and application. One of the new cathode materials to replace the Li CoO2 electrode material has gradually moved to the market, and the application field has been expanding constantly, especially in the electric vehicle (EV) and hybrid electric vehicle field (HEV), also has a considerable development space. The precursor Ni1/3Co1/3Mn1/3 (OH) _ 2 was prepared by liquid phase coprecipitation, and the ternary cathode material LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 was prepared by high temperature solid state reaction. Taking LiNi_ (1 / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 cathode material as the research object, the effects of different synthetic processes on the physical and chemical properties and electrical properties of the target materials were systematically studied. The results were analyzed by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM) (SEM) analysis and thermogravimetric differential thermogravimetry (TG-DTA) analysis. The morphology, crystal structure and electrochemical properties of the products were characterized and tested by constant current charge-discharge test. In the process of preparing Nil/3Co1/3Mnl/3 (OH) _ 2 precursor by liquid-phase coprecipitation, the effects of pH value, metal ion concentration, precipitation agent concentration and complexing agent concentration on the precursor were studied in this paper. The experimental results show that the pH value of the reaction solution is about 10. 5, the concentration of metal ions is 2 mol L -1, the concentration of precipitator is 4mol L -1, and the concentration of complex agent is 3 mol L -1. The particle size distribution of the precursor of Nil/3Co1/3Mnl/3 (OH) 2 is narrow and the morphology is similar to that of the sphere. In the process of preparing LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2 cathode material by high temperature solid state method, the effects of solid state reaction temperature, solid state reaction time and different molar ratio of Li/ (Ni Co Mn) on the product were studied in this paper. The experimental results show that the ternary layered cathode material LiNi_ (l / 3) Co_ (1 / 3) Mn_ (l / 3) O _ 2s can be obtained by sintering at 900 鈩，
本文编号：2240856
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