废旧锂离子电池阴极材料中钴的回收

发布时间：2018-06-27 19:19

  本文选题：废弃锂离子电池 + 甘蔗渣　； 参考：《广西大学》2017年硕士论文

【摘要】：手机和便携式计算机等移动设备的广泛使用促进了锂离子电池生产量和使用量的大量增长,但是锂离子电池的使用寿命不过区区数年,因此中国每年废弃锂离子电池的产生量持续增加。废弃的锂离子电池如果不经过无害化处理就进入环境,不仅仅会对环境造成很大的污染,对人类的健康产生极大地危害。同时,废旧的锂离子电池中含有大量的有价值金属,尤其是金属钴,实现废弃锂离子电池中有价值金属资源的回收和再利用具有很大的价值。本研究选取18650型锂离子电池为研究对象,此型号电池广泛应用于便携式笔记本电脑。首先对废旧锂离子电池进行了放电及破碎拆解,对拆解后的电池阴极材料进行碱浸,分离其中的活性物质LiCoO2和铝箔。获得废旧锂离子电池中的活性物质LiCoO2后,采用硫酸-甘蔗渣体系进行酸浸,将钴从废旧锂离子电池电极材料中浸出,研究各反应因素对钴的浸出率的影响,通过响应面优化实验得出硫酸-甘蔗渣体系酸浸的最佳条件。探讨甘蔗渣提高浸出效果的反应机理。然后与常规体系的酸浸效果进行对比,探讨硫酸-甘蔗渣体系酸浸的可行性。最后利用草酸铵溶液沉淀浸出液中的钴,研究各反应因素对钴回收的影响,并利用扫描电子显微镜、电感耦合等离子发射光谱分析仪和X射线衍射分析仪对产物进行表征分析。研究结果表明:1.钴酸锂活性物质与铝箔的分离实验中,最优条件为室温,NaOH溶液浓度2.5mol/L,反应时间9h,并不进行粉碎。硫酸-甘蔗渣体系酸浸实验响应面优化最佳条件:硫酸溶液硫酸溶液浓度2.54mol/L,硫酸溶液的量20mL,反应温度80℃,液固比199.20mL/g,甘蔗渣的添加量0.59g,甘蔗渣的粒径0.50mm,金属Co浸出率为97.35%。对比常规酸浸体系,硫酸-甘蔗渣体系的浸出效果较好。2.甘蔗渣作为还原剂参与浸出反应,甘蔗渣中的醛基以及反应后的中间产物RCOO.H2,都可与Co3+反应,将其还原成Co2+,提高了金属钴的浸出率。3.钴的回收实验中,沉淀草酸钴最佳实验条件是:pH为2,反应温度70℃,反应时间60min,[C2042-]/[Co2+]比值1.10。通过表征分析发现回收得到的草酸钴沉淀样品中的纯度较高且晶型良好。综上所述,采用硫酸-甘蔗渣体系对电极材料进行酸浸,采用草酸铵作为沉钴剂对金属Co进行回收取得了一定的效果,同时回收了金属锂,并实现了甘蔗渣的二次利用,采用该方法回收废旧锂离子电池阴极材料中钴具有一定的应用前景。
[Abstract]:The widespread use of mobile devices such as mobile phones and portable computers has contributed to a large increase in the production and use of lithium-ion batteries, but the lifetime of lithium-ion batteries has been limited to a few years. As a result, the annual production of discarded lithium ion batteries in China continues to increase. If the discarded lithium ion battery enters the environment without harmful treatment, it will not only cause great pollution to the environment, but also cause great harm to human health. At the same time, the waste lithium ion battery contains a large number of valuable metals, especially cobalt, so it is of great value to realize the recovery and reuse of valuable metal resources in the waste lithium ion battery. In this study, 18650 type lithium ion battery, which is widely used in portable notebook computer, is selected as the research object. Firstly, the waste lithium ion battery was disassembled by discharge and broken, and the cathode material was soaked to separate the active material LiCoO2 and aluminum foil. After obtaining LiCoO2, an active substance in waste Li-ion battery, acid leaching was carried out with sulfuric acid and bagasse system. Cobalt was leached from the electrode material of waste lithium ion battery. The influence of various reaction factors on the leaching rate of cobalt was studied. The optimum conditions for acid leaching of sulphuric acid-bagasse system were obtained by response surface optimization experiment. The reaction mechanism of bagasse to improve leaching effect was discussed. The feasibility of acid leaching in sulphuric acid-bagasse system was discussed. Finally, the effect of various reaction factors on cobalt recovery was studied by precipitation of cobalt in leaching solution of ammonium oxalate solution. The products were characterized by scanning electron microscope, inductively coupled plasma emission spectrometer and X-ray diffraction analyzer. The results of the study show that 1: 1. In the separation experiment of lithium cobalt oxide and aluminum foil, the optimum conditions are as follows: the concentration of NaOH solution at room temperature is 2.5 mol / L, the reaction time is 9 h, and the powder is not comminuted. The optimum conditions of acid leaching experiment were as follows: the concentration of sulfuric acid solution was 2.54 mol / L, the amount of sulfuric acid solution was 20 mL / L, the reaction temperature was 80 鈩，

本文编号：2075010