废旧磷酸亚铁锂电池制备锂铁氧体的研究

发布时间：2018-03-12 21:37

  本文选题：废旧锂离子电池　切入点：磷酸亚铁锂　出处：《河南师范大学》2014年硕士论文　论文类型：学位论文

【摘要】：二十一世纪被称为能源的时代，全人类面临着能源枯竭的世界性难题，伴随着日益尖锐的能源问题，环境污染的问题也愈发严峻。近年来为了同时缓解能源与环境问题，世界各国都在大力推行高效清洁的电动汽车。随着电动汽车的发展，以磷酸铁锂作为正极材料的动力电池得到了广泛的应用，导致废旧磷酸亚铁锂电池的数量逐年递增。对这些废旧电池的回收利用，不仅可以减少对环境的污染，同时还能推动新兴产业的发展，带来非常可观的经济效益。然而目前在回收废旧磷酸亚铁锂电池再利用方面的研究较少。 废旧锂电池的回收再利用主要集中在对其中正极活性物的回收再利用。本论文研究了废旧磷酸铁锂电池正极活性物与金属集流体的分离回收；经盐酸溶解正极活性材料为原料，采用溶胶-凝胶法制成附加值较高的锂铁氧体材料；在此基础上进一步提出了掺杂Mn、Zn来提高产品的性能。并借助于XRD、IR、SEM、TG-DSC和VSM等技术，对制备过程进行跟踪检测并对铁氧体产品的微观结构、形貌和磁性能等进行表征。 通过研究表明：废旧磷酸亚铁锂电池正极片氮气氛围中400℃煅烧2h，可以很好的去除正极活性材料和金属集流体间的胶黏剂——PVDF。盐酸溶解废旧磷酸亚铁锂电池正极活性材料的最佳条件：盐酸浓度采用Vol（HCl）:Vol（H2O）=1:5，固液比为100g/L，温度为60℃，，反应时间为30min。采用溶胶-凝胶法制备锂铁氧体的最佳条件是：金属离子与柠檬酸的摩尔比是1:1，溶胶pH为6，干凝胶煅烧温度为800℃，煅烧时间3h。该条件下所制备锂铁氧体的磁性能参数是：饱和磁化强度（Ms）为53.372emu/g，矫顽力（Hc）为101.07G，剩余磁化强度（Mr）为13.387emu/g。Mn2+、Zn2+的掺杂不仅没有改变锂铁氧体的尖晶石结构，而且提高了锂铁氧体的磁性能，其中Zn2+的掺入对其磁性能的改善比较明显。 本论文的创新点是：以废旧磷酸亚铁锂电池为原料采用溶胶-凝胶法制备出具有尖晶石结构的锂铁氧体；同时以废旧磷酸亚铁锂电池为原料制备了掺杂取代锂铁氧体，来改善材料的各方面性能，研究了不同掺杂元素与不同掺杂量对锂铁氧体性能的影响。 本文为废旧磷酸亚铁锂回收再资源化提出了新的发展方向，对废旧磷酸亚铁锂的回收再利用具有一定的指导意义。为废旧磷酸亚铁锂离子电池再资源化的工业化生产提供有益的基础数据，具有良好的应用前景，对资源的充分利用以及环境保护意义重大。
[Abstract]:In 21th century, called the era of energy, all mankind is faced with the worldwide problem of energy depletion. With the increasingly acute energy problem, the problem of environmental pollution is becoming more and more serious. In recent years, in order to alleviate the energy and environment problems at the same time, With the development of electric vehicles, the power battery with lithium iron phosphate as cathode material has been widely used. The number of waste lithium ferrous phosphate batteries is increasing year by year. The recycling of these batteries can not only reduce pollution to the environment, but also promote the development of new industries. However, little research has been done on recycling waste lithium ferrous phosphate batteries. The recovery and reuse of the waste lithium battery is mainly focused on the recovery and reuse of the cathode active material. In this paper, the separation and recovery of the cathode active material from the metal collector of the waste lithium iron phosphate battery are studied. Lithium ferrite materials with high added value were prepared by sol-gel method by using hydrochloric acid dissolved positive active materials as raw materials, and further improved the properties of the products by doping Mn-Zn. The TG-DSC and VSM techniques were also used to improve the properties of the products. The microstructure, morphology and magnetic properties of ferrite products were characterized. The results show that after calcined at 400 鈩

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