锂离子混合超级电容器的材料制备及其研究
发布时间：2018-08-19 13:27
【摘要】：由于现代社会的便携式电子设备发展的驱动,可再生能源的产品,以及对电气或混合电动车辆的需求不断增加,对具有高性能、低成本的环境友好的能量储存设备的研究已经显著地增加。超级电容器和锂离子电池是目前公认的两个最具有发展前景的能量储存系统。因而在当今社会,对电能存储装置的设计制造时,将具有高功率密度的超级电容器(SC)和具有高能量密度的锂离子电池(LIB)作为新型环保、低制造成本和高性能的两种优秀的能量存储装置的备选,以满足现阶段能量存储高需求。LIB通常可以存储高达150～200 Wh·kg~(-1)的能量,但是它们的低功率密度(低于100 W·kg~(-1))和较差的循环寿命常小于1000次循环)限制了它的发展及应用,相反,超级电容器则可以提供高得多的功率密度(10kW.kg~(-1)),更长的循环寿命(超过1000个循环)和快速充电-放电过程(大电流,约在几秒钟以内),但是其较低的能量密度一直是影响它实际应用的一个大问题。在追求更高的能量密度而不牺牲功率密度的情况下,超级电容器-电池混合能量存储装置,即锂离子混合超级电容器,组合了电化学双电层电容(EDLC)型正极电极与锂离子电池型负极电极的混合型电容器便应运而生了。然而,在对锂离子混合超级电容器的研究过程中依然存在很多的问题等待解决,各项性能也有待提高。本文旨在构建一个以石墨烯纸为正极材料的layer-by-layer形式的锂离子混合超级电容器,即在扣式电池双电极体系下构成的锂离子混合超级电容器。第一个工作就是设计并制备石墨烯paper作为锂离子混合电容器的正极材料。将石墨烯的三维多孔碳纸(Graphenepaper)作为正极材料,充分利用其高表面积(～800 m2·g~(-1))的特性。除此之外,将石墨烯paper作为正极材料,不同于传统电极材料制备过程中需要加入super-p、PVDF等导电剂、粘结剂,这样做的优势就在于在减少电极质量的同时也降低了制备电极材料的成本。第二个工作,我们通过二次水热法和一种较为简单的化学方法制备了比容量很高的MnCO_3@FGS和FeS_2@FGS来作为锂离子混合电容器的负极材料。MnCO_3@FGS在100 mA.g~(-1)的电流密度下,能达到1360 mAh·g~(-1)的容量,并且从第二周开始衰减很少,在100个循环后还能保留912 mAh·g~(-1)的容量。在组装成锂离子混合超级电容器后,在能量密度达到36.2Wh·kg~(-1)时,功率密度能够达到250W·kg~(-1)。我们还通过一种相对简单的方法制备了不同碳含量的Fe_2O_3@FGS以及FeS_2@FGS,能够控制氧化物或者硫化物的颗粒大小以及在石墨烯基上的分布,增大了整体材料的比表面积,增大了电极材料与电解液的接触面积,提高了材料的利用效率,提高了材料的导电性和能量密度。FeS_2@FGS在电流密度为0.2 A·g~(-1)第一周能得到882 mAh·g~(-1)的比容量,并且在100次循环之后还能保留665 mAh·g~(-1)的容量。通过构建量子点与石墨烯的复合结构,大大增强了材料的电化学性能,应用于石墨烯paper组装成锂离子混合超级电容器,在能量密度达到34.6Wh·kg~(-1),功率密度达到250W·kg~(-1)。这些都显示了MnCO_3@FGS和FeS_2@FGS作为锂离子混合超级电容器负极的优异性能。
[Abstract]:Driven by the development of portable electronic devices in modern society, renewable energy products and the increasing demand for electric or hybrid electric vehicles, research on environmentally friendly energy storage devices with high performance and low cost has increased significantly. Therefore, in today's society, supercapacitors (SC) with high power density and lithium-ion batteries (LIB) with high energy density are used as alternatives to two excellent energy storage devices with environmental protection, low manufacturing cost and high performance in order to meet the needs of today's society. LIBs can usually store up to 150-200 Wh.kg-1 of energy, but their low power density (less than 100 W.kg-1) and poor cycle life (often less than 1,000 cycles) limit their development and application. On the contrary, supercapacitors can provide much higher power density (10 kW.kg-1) and longer power density. Cycle life (more than 1,000 cycles) and rapid charge-discharge (high current, less than a few seconds), but its low energy density has always been a major problem affecting its practical application. Hybrid capacitors with sub-hybrid supercapacitors, which combines electrochemical double-layer capacitor (EDLC) cathode electrode with lithium-ion battery cathode electrode, have emerged as the times require. However, there are still many problems to be solved in the research of lithium-ion hybrid supercapacitors and their performances need to be improved. A layer-by-layer lithium-ion hybrid supercapacitor with graphene paper as cathode material, i.e. a lithium-ion hybrid supercapacitor with button-type battery double-electrode system, was developed. The first task was to design and prepare graphene paper as cathode material for lithium-ion hybrid capacitors. Graphenepaper is used as cathode material to make full use of its high surface area (~800m2 (-1)). In addition, graphene paper is used as cathode material, which is different from the traditional electrode material in the preparation process of super-p, PVDF and other conductive agents, binder, the advantage of this way is to reduce the quality of the electrode and also reduce the production. Second, we prepared MnCO_3@FGS and FeS_2@FGS with high specific capacity as anode materials for lithium-ion hybrid capacitors by secondary hydrothermal method and a simpler chemical method. MnCO_3@FGS can reach the capacity of 1360 mAh.g~(-1) at the current density of 100 mA.g~(-1) and from the second one. After assembling the lithium-ion hybrid supercapacitor, the power density can reach 250W.kg-1 at the energy density of 36.2Wh.kg-1. We also prepared Fe_2O_3@FGS and FeS_2@FGS with different carbon content by a relatively simple method. It can control the particle size of oxide or sulfide and its distribution on graphene, increase the specific surface area of the whole material, increase the contact area between electrode material and electrolyte, improve the material utilization efficiency, improve the conductivity and energy density of the material. The specific capacity of 882 mAh g (- 1) was obtained and 665 mAh G All these show the excellent performance of MnCO_3@FGS and FeS_2@FGS as anodes for lithium-ion hybrid supercapacitors.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53
本文编号：2191792
[Abstract]:Driven by the development of portable electronic devices in modern society, renewable energy products and the increasing demand for electric or hybrid electric vehicles, research on environmentally friendly energy storage devices with high performance and low cost has increased significantly. Therefore, in today's society, supercapacitors (SC) with high power density and lithium-ion batteries (LIB) with high energy density are used as alternatives to two excellent energy storage devices with environmental protection, low manufacturing cost and high performance in order to meet the needs of today's society. LIBs can usually store up to 150-200 Wh.kg-1 of energy, but their low power density (less than 100 W.kg-1) and poor cycle life (often less than 1,000 cycles) limit their development and application. On the contrary, supercapacitors can provide much higher power density (10 kW.kg-1) and longer power density. Cycle life (more than 1,000 cycles) and rapid charge-discharge (high current, less than a few seconds), but its low energy density has always been a major problem affecting its practical application. Hybrid capacitors with sub-hybrid supercapacitors, which combines electrochemical double-layer capacitor (EDLC) cathode electrode with lithium-ion battery cathode electrode, have emerged as the times require. However, there are still many problems to be solved in the research of lithium-ion hybrid supercapacitors and their performances need to be improved. A layer-by-layer lithium-ion hybrid supercapacitor with graphene paper as cathode material, i.e. a lithium-ion hybrid supercapacitor with button-type battery double-electrode system, was developed. The first task was to design and prepare graphene paper as cathode material for lithium-ion hybrid capacitors. Graphenepaper is used as cathode material to make full use of its high surface area (~800m2 (-1)). In addition, graphene paper is used as cathode material, which is different from the traditional electrode material in the preparation process of super-p, PVDF and other conductive agents, binder, the advantage of this way is to reduce the quality of the electrode and also reduce the production. Second, we prepared MnCO_3@FGS and FeS_2@FGS with high specific capacity as anode materials for lithium-ion hybrid capacitors by secondary hydrothermal method and a simpler chemical method. MnCO_3@FGS can reach the capacity of 1360 mAh.g~(-1) at the current density of 100 mA.g~(-1) and from the second one. After assembling the lithium-ion hybrid supercapacitor, the power density can reach 250W.kg-1 at the energy density of 36.2Wh.kg-1. We also prepared Fe_2O_3@FGS and FeS_2@FGS with different carbon content by a relatively simple method. It can control the particle size of oxide or sulfide and its distribution on graphene, increase the specific surface area of the whole material, increase the contact area between electrode material and electrolyte, improve the material utilization efficiency, improve the conductivity and energy density of the material. The specific capacity of 882 mAh g (- 1) was obtained and 665 mAh G All these show the excellent performance of MnCO_3@FGS and FeS_2@FGS as anodes for lithium-ion hybrid supercapacitors.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM53
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相关期刊论文 前2条
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2 Jianfei Yu;Lin Zhu;Cheng Fan;Cheng Zan;Ling Hu;Shuhui Yang;Qiang Zhang;Wancheng Zhu;Lin Shi;Fei Wei;;Highly dispersed Mn_2O_3 microspheres:Facile solvothermal synthesis and their application as Li-ion battery anodes[J];Particuology;2015年05期
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