锂离子电池富镍三元材料振实密度与一次颗粒研究

发布时间：2018-04-24 23:21

本文选题：镍钴锰酸锂材料 + 振实密度　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：技术革新是当今时代的潮流,而技术变革实现的基础又往往要依赖于能源的更新换代。锂离子电池作为新能源的典型代表,对信息社会中的产业革新有着不可替代的重要作用。富镍组分的镍钴锰酸锂材料,被认为是一种具有良好应用前景的一种锂离子电池中正极材料,具有重要的研究价值。经过近些年的研究和发展,镍钴锰酸锂材料在实际应用方面有了长足的进步,但仍然面临着振实密度不够理想及前驱体制备过程中的内部变化过程不清晰等问题,这些问题的存在不利于其更广泛的应用,也阻碍了人们对其的深入理解。本文的主要研究内容即为对镍钴锰酸锂材料振实密度、一次颗粒以及前驱体所含杂质的研究。通过控制影响镍钴锰酸锂振实密度的三个主要因素:粒度分布跨度、颗粒内部堆积紧密度以及颗粒形状规整度,本文实现了对镍钴锰酸锂前驱体及烧结后材料振实密度的优化,在实验过程中,结合振实密度测试、粒度分布测试、比表面积测试以及扫描电子显微镜测试等手段考察优化过程中三个主要因素的变化情况。最终,实现制备出的镍钴锰酸锂前驱体材料振实密度2.10 g/cm3,烧结后材料振实密度2.77 g/cm3。通过改变镍钴锰酸锂前驱体材料制备过程中的反应时间、p H值、温度以及氨/金属离子进料比例,本文主要研究了在单个工艺条件发生变化时,镍钴锰酸锂材料的一次颗粒变化情况。结合扫描电子显微镜测试、振实密度测试、比表面积测试等手段考察在变化工艺条件时,一次颗粒尺寸、形貌以及堆积紧密度等的变化情况。最终,发现了不同工艺条件对镍钴锰酸锂材料的影响情况并给出影响成因。提出了不同工艺条件对一次颗粒的影响程度的高低顺序为:p H值反应时间氨/总金属离子进料速率比反应温度。通过结合XRD、XPS、CV等多种测试表征手段,本文研究了在采用共沉淀法制备镍钴锰酸锂前驱体材料时常会引入的深颜色杂质。探究了杂质存在对电化学性能的影响并分析了杂质的成分。提出了杂质生成的诱因,为其他研究人员提供了参考。
[Abstract]:Technological innovation is the trend of the times, and the foundation of technological change often depends on the renewal of energy. As a typical representative of new energy, lithium ion battery plays an irreplaceable role in industrial innovation in information society. Nickel-rich lithium nickel-cobalt manganese oxide is considered to be a kind of cathode material in lithium ion batteries which has a good prospect of application and has important research value. Through the research and development in recent years, the Ni-Co LiMnO _ 4 material has made great progress in practical application, but it still faces the problems of not ideal density and unclear internal change process during the preparation of precursor. The existence of these problems is not conducive to its wider application, but also hinders the in-depth understanding of them. The main research content of this paper is to study the vibrational density, primary particle and impurity in the precursor of nickel cobalt manganese oxide material. By controlling the three main factors that affect the vibrational density of lithium nickel-cobalt manganese oxide, such as the particle size distribution span, the compactness inside the particle and the shape regularity of the particles, the vibratory density of the precursor and the sintered materials are optimized in this paper. In the course of the experiment, the changes of three main factors in the optimization process were investigated by means of vibrational density test, particle size distribution test, specific surface area test and scanning electron microscope test. Finally, the vibrational density of the prepared precursor is 2.10 g / cm ~ (3), and that of the sintered material is 2.77 g / cm ~ (3). By changing the reaction time (pH), temperature and the ratio of ammonia to metal ions in the preparation of Ni-Co LiMnO _ 4 precursor, this paper mainly studied when the single process conditions changed. Primary particle variation of nickel-cobalt-lithium manganese oxide materials. Scanning electron microscopy (SEM), vibrational density measurement and specific surface area measurement were used to investigate the change of primary particle size, morphology and packing tightness when the technological conditions were changed. Finally, the influence of different technological conditions on the nickel-cobalt-manganese-manganese material was found and the cause of the influence was given. The order of the influence of different technological conditions on the primary particle is: the reaction time of the ratio of ammonia to the feed rate of the total metal ions is 1: pH and the reaction temperature is the same as that of the reaction temperature. By combining with XRDX XPS CV and other means of measurement and characterization, the dark color impurities often introduced in the preparation of Ni-Co-Mn precursor materials by co-precipitation method were studied. The influence of impurity on electrochemical performance was investigated and the composition of impurity was analyzed. The inducement of impurity formation is put forward, which provides reference for other researchers.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM912

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