电纺技术制备石墨烯修饰的碳纤维及其在锂电池负极材料方面的应用研究
发布时间：2019-02-28 14:54
【摘要】：随着人口数量的逐渐增多与经济的快速增长,人们对化石能源需求逐渐增大,作为不可再生能源,总有一天会被消耗殆尽,并且,化石燃料的燃烧带来的环境污染问题已经不可小觑,开发高效清洁的新能源成为当今科研的重点,同时,开发高效的能源转化与储存设备也变得极为重要。锂离子电池是一种安全高效、有利于可持续发展的绿色电池。石墨材料成为了当前使用最为广泛的商业化锂离子电池负极材料。但是由于石墨材料的尺寸较大导致了锂离子和电子传输路径长,从而使得锂离子电池的倍率性能变差。以聚丙烯腈为原料,采用静电纺丝技术,非常简便地制备出了一种纳米碳纤维的纤维毡,且具有自支撑性,并做成电极测试其电化学性能,并且与商用石墨电极做对比,我们发现,随着电流密度的逐渐增大,纳米碳纤维的性能明显增强,但是在较小电流密度下,电池的容量没有得到大的提升。将纳米碳纤维直接作为锂离子电池的负极材料,电池表现了较低的容量,为了解决这一问题,本文通过静电纺丝技术,成功地制备出了石墨烯修饰的复合碳纤维毡,将其作为自支撑的锂离子电池负极材料。因为纤维本身的纳米尺寸,以及纤维间的纳米多孔特性,将复合碳纤维直接用作自支撑的电极片(不含导电剂和粘结剂)。研究并探索由于添加石墨烯含量的不同而对碳纤维的结晶性、导电性的影响;研究锂离子和电子在复合材料三维导电网络中的输运状态与存储性能;研究碳纤维经过石墨烯修饰后,作为锂离子电池负极材料的性能,本论文所研究的内容对制备具有安全性能好、价格低廉、无污染等特点的锂离子电池具有极为深刻的意义。
[Abstract]:With the gradual increase in population and rapid economic growth, the demand for fossil energy is gradually increasing. As a non-renewable energy source, it will one day be exhausted, and, The environmental pollution caused by the burning of fossil fuels can not be underestimated. The development of efficient and clean new energy sources has become the focus of scientific research. At the same time, the development of efficient energy conversion and storage equipment has become extremely important. Lithium ion battery is a safe, efficient and sustainable green battery. Graphite has become the most widely used anode material for lithium-ion batteries. However, due to the large size of graphite materials, the lithium ion and electron transport paths are long, which makes the performance of lithium-ion batteries worse. Using polyacrylonitrile (pan) as raw material and electrospinning technology, a kind of nano-carbon fiber felt was prepared, which was self-supporting, and was made into electrode to test its electrochemical performance, and compared with commercial graphite electrode. We found that with the increasing of the current density, the performance of carbon nanofibers was obviously enhanced, but the capacity of the cells did not increase greatly at the lower current density. Nano-carbon fiber is directly used as anode material of lithium-ion battery, and the battery has low capacity. In order to solve this problem, graphene modified composite carbon fiber felt was successfully prepared by electrospinning technology in this paper. It is used as a self-supporting anode material for lithium-ion batteries. Because of the nano-size of the fiber itself and the nano-porous properties between the fibers, the composite carbon fiber is directly used as a self-supporting electrode sheet (without conductive agents and binders). The effects of graphene addition on the crystallinity and conductivity of carbon fibers were studied, and the transport state and storage properties of lithium ions and electrons in the three-dimensional conductive network of composites were studied. Carbon fiber modified by graphene is used as cathode material for lithium-ion battery. The content of this paper is of great significance for the preparation of lithium-ion battery with the characteristics of good safety, low price and no pollution.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ342.742;TM912
本文编号：2431900
[Abstract]:With the gradual increase in population and rapid economic growth, the demand for fossil energy is gradually increasing. As a non-renewable energy source, it will one day be exhausted, and, The environmental pollution caused by the burning of fossil fuels can not be underestimated. The development of efficient and clean new energy sources has become the focus of scientific research. At the same time, the development of efficient energy conversion and storage equipment has become extremely important. Lithium ion battery is a safe, efficient and sustainable green battery. Graphite has become the most widely used anode material for lithium-ion batteries. However, due to the large size of graphite materials, the lithium ion and electron transport paths are long, which makes the performance of lithium-ion batteries worse. Using polyacrylonitrile (pan) as raw material and electrospinning technology, a kind of nano-carbon fiber felt was prepared, which was self-supporting, and was made into electrode to test its electrochemical performance, and compared with commercial graphite electrode. We found that with the increasing of the current density, the performance of carbon nanofibers was obviously enhanced, but the capacity of the cells did not increase greatly at the lower current density. Nano-carbon fiber is directly used as anode material of lithium-ion battery, and the battery has low capacity. In order to solve this problem, graphene modified composite carbon fiber felt was successfully prepared by electrospinning technology in this paper. It is used as a self-supporting anode material for lithium-ion batteries. Because of the nano-size of the fiber itself and the nano-porous properties between the fibers, the composite carbon fiber is directly used as a self-supporting electrode sheet (without conductive agents and binders). The effects of graphene addition on the crystallinity and conductivity of carbon fibers were studied, and the transport state and storage properties of lithium ions and electrons in the three-dimensional conductive network of composites were studied. Carbon fiber modified by graphene is used as cathode material for lithium-ion battery. The content of this paper is of great significance for the preparation of lithium-ion battery with the characteristics of good safety, low price and no pollution.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ342.742;TM912
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