钠离子电池碳基负极材料研究

发布时间：2018-05-01 06:18

本文选题：钠离子电池 + 负极材料　；参考：《北京化工大学》2017年博士论文

【摘要】：由于具有原材料资源丰富、价格低廉、比容量较高等特点,钠离子电池被认为是最适合大规模储能的一种新型二次电池体系。与正极材料相比,钠离子电池负极材料的研究相对滞后,开发具有高容量、长寿命和优异倍率性能的负极材料是推动钠离子电池获得实际应用的关键。本论文从层间距调控、杂原子掺杂、构建纳米/多孔结构和与金属氧化物复合等思路出发,制备了 5种新型的碳基负极材料(包括氮掺杂硬碳/石墨烯复合材料、氮掺杂多孔硬碳材料、花状介孔碳材料、生物质基氮掺杂介孔碳材料和Fe3O4量子点/石墨烯复合材料),研究了其电化学储钠性能,并对碳基负极材料的组成和结构对其电化学性能的影响进行了探索。(1)在苯胺溶液中加入氧化石墨烯,经过原位聚合、高温热解制备了三明治结构氮掺杂碳/石墨烯(NCG)复合材料。由于具有大的层间距离(0.360 nm)和高的氮含量(7.54 at.%),NCG在30 mA g-1电流密度下的可逆储钠容量达到336 mAh g-1。位于三明治结构中的高导电性石墨烯夹层保证了电子的快速传递,从而使NCG具有优异的倍率性能,5 A g-1电流密度下比容量还保持有94 mAh g-1。NCG还表现出良好的循环稳定性,在50 mAg-1的电流密度下循环200次后,容量保持率为89%。(2)在苯胺溶液中加入纳米CaCO3模板,经过原位聚合、高温碳化并用稀盐酸除去模板,制备出聚苯胺基氮掺杂介孔碳材料。氮吸附测试表明其具有多孔结构,XPS分析表明其氮含量高达7.78 at.%。聚苯胺基氮掺杂介孔碳材料在30 mA g-1电流密度下的首次可逆容量为338 mAh g-1,循环耐久性突出,500 mA g-1电流下循环800周后容量还可保持110.7 mAh g-1。(3)以柠檬酸锌为碳源,在惰性气氛下高温热解制备出具有高比表面和发达介孔结构的花状碳材料。柠檬酸锌高温热解产生的纳米氧化锌同时充当了介孔模板,制备的碳材料BET比表面积和孔容分别达到1382 cm 2g-1和2.02 cm 3-1。独特的花状结构、发达的介孔和大的层间距(0.42 nm),赋予该碳材料超高的可逆容量和优异的倍率性能。在30 mAg-1电流密度下的首次可逆容量高达438.5 mAh g-1,当电流密度提高到10 A g-1,仍具有68.7 mAh g-1的放电比容量。(4)以虾皮为原料,将其高温热解简便制备出兼有高氮含量和发达介孔结构的碳材料。虾皮是由胶原蛋白和无机矿物质组成的天然有机/无机纳米复合材料,高温热解过程中,胶原蛋白作为富氮的碳源转化为富氮炭,均匀分散在其中的纳米无机矿物质作为硬模板被洗去后留下丰富的介孔。随热解温度升高,比表面和孔容呈增大的趋势,氮含量减小。700 ℃制备的样品兼有高的比表面(531 m2g-1)和高的氮含量(7.26 at %),表现出突出的电化学储钠性能。在30 mA g-1电流密度下的可逆钠存储容量高达434.6 mAh g-1,循环和倍率性能优异。以天然纳米复合材料为原料制备高性能钠离子电池负极材料,方法简单,成本低廉,变废为宝,符合可持续发展的要求。(5)采用水热法制备了 Fe3O4量子点与三维石墨烯(3D-0DFe3O4/石墨烯)的复合材料。Fe3O4量子点的平均尺寸为4.9 nm,镶嵌在石墨烯的三维立体网络结构中。Fe3O4量子点具有高的电化学活性,充放电过程中体积变化较小,3D石墨烯一方面可抑制Fe3O4纳米粒子的团聚及其在充电放电过程中的体积变化,另一方面可构建电子传导和离子迁移的快速通道。因此,3D-0DFe3O4/石墨烯复合材料表现出了超高的储钠容量(30 mA g-1电流密度下的可逆储钠容量高达525 mAh g-1),优异的循环稳定性(50 mA g-1电流下循环200周容量保持312 mAh g-1)和倍率性能(10 A g-1电流密度下比容量保持56 mAh g-1)。
[Abstract]:Because of the rich raw material resources, low price and higher specific capacity, sodium ion battery is considered to be the most suitable for large-scale energy storage of a new type of two battery system. Compared with the cathode material, the research of sodium ion battery negative electrode is relatively lagging, and the development of negative electrode with high capacity, long life and excellent performance ratio is a kind of negative material. In this paper, 5 new carbon based negative electrode materials (including nitrogen doped hard carbon / graphene composite, nitrogen doped porous hard carbon material, and flower like mesoporous carbon material) are prepared from interlayer spacing regulation, heteroatom doping, nano/ porous structure and metal oxide composite. Biomass based nitrogen doped mesoporous carbon materials and Fe3O4 quantum dots / graphene composite materials were used to study the electrochemical properties of its electrochemical properties. The effects of the composition and structure of carbon based anode materials on their electrochemical properties were explored. (1) the sandwich structure was prepared by in-situ polymerization and high temperature pyrolysis in the aniline solution. Nitrogen doped carbon / graphene (NCG) composites. Due to the large interlayer distance (0.360 nm) and high nitrogen content (7.54 at.%), the reversible sodium capacity of NCG at 30 mA g-1 current density reached 336 mAh g-1. high conductivity graphene interlayer in the sandwich structure ensuring the rapid transmission of electrons, thus making NCG with excellent multiplier. Performance, the specific capacity of 5 A g-1 current density remains 94 mAh g-1.NCG and has good cyclic stability. After 200 cycles of 50 mAg-1 current density, the capacity retention rate is 89%. (2) adding nano CaCO3 template in aniline solution, after in situ polymerization, high temperature carbonization and removal of template with dilute hydrochloric acid to prepare polyaniline based nitrogen doping. The nitrogen adsorption test shows that it has porous structure. XPS analysis shows that the nitrogen content is up to 7.78 at.%. polyaniline based mesoporous carbon materials at the 30 mA g-1 current density, the first reversible capacity is 338 mAh g-1, the cycle durability is prominent, the capacity of 500 mA g-1 current is 800 weeks after 800 weeks and 110.7 mAh g-1. (3) can be maintained. Zinc citrate is a carbon source. High specific surface and developed mesoporous carbon materials are prepared at high temperature under inert atmosphere. The nano Zinc Oxide produced by high temperature pyrolysis of zinc citrate simultaneously acts as a mesoporous template, and the prepared carbon material BET has a unique flower structure of 1382 cm 2g-1 and 2.02 cm 3-1., respectively. The developed mesoporous and large interlayer spacing (0.42 nm) gives the carbon material a high reversible capacity and excellent multiplier performance. The first reversible capacity at 30 mAg-1 current density is up to 438.5 mAh g-1, and when the current density increases to 10 A g-1, it still has a discharge specific volume of 68.7 mAh g-1. (4) the high temperature pyrolysis of the dried shrimps is prepared. It has high nitrogen content and developed mesoporous carbon. The shrimp skin is a natural organic / inorganic nanocomposite made up of collagen and inorganic minerals. During the high temperature pyrolysis process, collagen is converted to nitrogen rich carbon as a carbon rich source of nitrogen rich. With the increase of thermal decomposition temperature, the specific surface and pore volume are increasing. The reduction of nitrogen content at.700 C has both high specific surface (531 m2g-1) and high nitrogen content (7.26 at%), showing outstanding electrochemical sodium storage performance. The reversible sodium storage capacity at 30 mA g-1 current density is up to 434.6 mAh g-1, cycle and multiplying ratio. Excellent performance. The preparation of high performance sodium ion battery anode material with natural nano composite material is simple, low cost and waste into treasure, which meets the requirements of sustainable development. (5) the average size of.Fe3O4 quantum dots of Fe3O4 quantum dots and 3D-0DFe3O4/ graphene (graphene) is prepared by hydrothermal method, and the average size of the.Fe3O4 quantum dots is 4.9 nm, In the three-dimensional network structure embedded in graphene,.Fe3O4 quantum dots have high electrochemical activity, and the volume change is small during charge discharge. In one aspect, 3D graphene can inhibit the aggregation of Fe3O4 nanoparticles and their volume changes during charging and discharging. On the other hand, the rapid channel of electronic conduction and ion migration can be constructed. The 3D-0DFe3O4/ graphene composite exhibits super high sodium storage capacity (the reversible sodium capacity of 30 mA g-1 current density is up to 525 mAh g-1), excellent cyclic stability (50 mA g-1 current for 200 weeks capacity to maintain 312 mAh g-1) and multiplying performance (10 A g-1 current density under the capacity of 56 mAh).

【学位授予单位】：北京化工大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM912

【参考文献】