發(fā)布時間：2019-02-28 14:54

【摘要】：隨著人口數(shù)量的逐漸增多與經(jīng)濟(jì)的快速增長,人們對化石能源需求逐漸增大,作為不可再生能源,總有一天會被消耗殆盡,并且,化石燃料的燃燒帶來的環(huán)境污染問題已經(jīng)不可小覷,開發(fā)高效清潔的新能源成為當(dāng)今科研的重點(diǎn),同時,開發(fā)高效的能源轉(zhuǎn)化與儲存設(shè)備也變得極為重要。鋰離子電池是一種安全高效、有利于可持續(xù)發(fā)展的綠色電池。石墨材料成為了當(dāng)前使用最為廣泛的商業(yè)化鋰離子電池負(fù)極材料。但是由于石墨材料的尺寸較大導(dǎo)致了鋰離子和電子傳輸路徑長,從而使得鋰離子電池的倍率性能變差。以聚丙烯腈為原料,采用靜電紡絲技術(shù),非常簡便地制備出了一種納米碳纖維的纖維氈,且具有自支撐性,并做成電極測試其電化學(xué)性能,并且與商用石墨電極做對比,我們發(fā)現(xiàn),隨著電流密度的逐漸增大,納米碳纖維的性能明顯增強(qiáng),但是在較小電流密度下,電池的容量沒有得到大的提升。將納米碳纖維直接作為鋰離子電池的負(fù)極材料,電池表現(xiàn)了較低的容量,為了解決這一問題,本文通過靜電紡絲技術(shù),成功地制備出了石墨烯修飾的復(fù)合碳纖維氈,將其作為自支撐的鋰離子電池負(fù)極材料。因?yàn)槔w維本身的納米尺寸,以及纖維間的納米多孔特性,將復(fù)合碳纖維直接用作自支撐的電極片(不含導(dǎo)電劑和粘結(jié)劑)。研究并探索由于添加石墨烯含量的不同而對碳纖維的結(jié)晶性、導(dǎo)電性的影響;研究鋰離子和電子在復(fù)合材料三維導(dǎo)電網(wǎng)絡(luò)中的輸運(yùn)狀態(tài)與存儲性能;研究碳纖維經(jīng)過石墨烯修飾后,作為鋰離子電池負(fù)極材料的性能,本論文所研究的內(nèi)容對制備具有安全性能好、價格低廉、無污染等特點(diǎn)的鋰離子電池具有極為深刻的意義。
[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.
【學(xué)位授予單位】：東北師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TQ342.742;TM912

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本文編號：2431900