新型MOFs材料及其衍生物的制备和电化学性能研究

发布时间：2018-02-12 06:30

本文关键词： MOFs材料羧酸类配体溶剂热法制备锂离子电池电极材料　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：金属有机骨架(Metal organic frameworks,MOFs)材料是由有机配体与中心金属离子通过配位键,π-π键或氢键等作用自行组装而成的具有二维层状或三维网状结构的新型功能材料,具有迷人的拓扑结构和永久的孔隙率,比表面积大、结构易控可调、功能多样化,在催化、分子识别、磁性等领域具有潜在的应用价值。此外,目前以MOFs材料为前躯体热解后得到的金属氧化物已广泛应用于锂离子电池的电极材料,且显示了优异的电化学性能。但随着大功率电子设备的迅速发展,目前商业化锂离子电池电极材料的稳定性能、倍率性能及安全性亟待进一步提高,故开发具有优异电化学性能的电极材料具有十分重要的意义。本文利用两种羧酸类配体3,3',5,5'-偶氮联苯四羧酸(3,3',5,5'-azobenzenetetracarboxylic acid,H_4ABTC)和4-苯并咪唑-1-苯甲酸(4-bezimidazole-1-benzoic acid,HCPBm)与金属离子Co~(2+)、Ni~(2+)、La~(3+)、Eu~(3+)、Tb~(3+)、Gd~(3+)通过溶剂热法制备了7种结构新颖的MOFs材料:{[Eu(HABTC)(H_2O)_2]·2H_2O}_n(1),{[Tb(HABTC)(H_2O)_2]·2H_2O}_n(2),{[Gd(HABTC)(H_2O)_2]·2H_2O}_n(3),{[La_2(ABTC)(H_2O)_6]·2H_2O}_n(4),{[Ni_2(ABTC)(H_2O)_3(DMF)]·2H_2O}_n(5),[Co(CPBm))2]_n(6)和[Ni(CPBm)_2]_n(7);其中,MOFs材料1-3配位模式相同,MOFs材料1-4皆为二维层状结构,MOFs材料5具有三维网状结构,MOFs材料6和7均为二维层状结构,具有一维孔道;深入分析MOFs材料的结构特点,以MOFs材料6和7为前躯体热解后成功制备了Co_3O_4和Ni O锂离子电池电极材料,对其进行了电化学性能测试并对充放电循环前后的Co_3O_4和NiO电极材料进行了SEM、TEM及高分辨TEM表征,结果显示,在2000 m A/g高电流密度下充放电循环50次后,Co_3O_4和Ni O电极材料依然能保持良好的形态,维持98.0%和96.2%的高库伦效率,此外,Co_3O_4电极材料依然能保持569.9 m Ah/g的高比容量,展示了更为优异的循环稳定性。
[Abstract]:Metal organic skeleton metal organic frames (MOFs) is a novel functional material composed of organic ligands and central metal ions through coordination bonds, 蟺-蟺 bonds or hydrogen bonds. Attractive topology and permanent porosity, large specific surface area, adjustable structure, diverse functions, potential applications in catalysis, molecular recognition, magnetism and so on. Metal oxides obtained by pyrolysis of MOFs materials have been widely used in electrode materials of lithium ion batteries and have shown excellent electrochemical properties. However, with the rapid development of high-power electronic equipment, At present, the stability, rate performance and safety of commercial lithium ion battery electrode materials need to be further improved. Therefore, it is of great significance to develop electrode materials with excellent electrochemical properties. In this paper, two kinds of carboxylic acid ligands, 3AZA3, Tacarboxylic acid (H4ABTCm) and 4-bezimidazidazidazidazidazidazole-1-benzoic acid (HCPBm), are used in this paper. Seven novel MOFs materials have been prepared by solvothermal method: {[Eu(HABTC)(H_2O)_2] 路2H _ 2O} NJ _ 1, {[Tb(HABTC)(H_2O)_2] 路2H _ 2O} n _ 2n _ 2s, {[Gd(HABTC)(H_2O)_2] 路2H _ 2O} n _ 2s _ 3, {[La_2(ABTC)(H_2O)_6] 路2H _ 2O} n _ 4, {[La_2(ABTC)(H_2O)_6] 路2H _ 2O} n _ 4, {[Ni2ABT _ 2H _ 2O _ 2O _ 3DMF] 路2H _ 2O} n _ 5o _ 5, [Co(CPBm))2] n6s) and [Ni(CPBm)_2] n6s] and [Ni(CPBm)_2] nfs ~ (7) and [Ni(CPBm)_2] nfs ~ (7). The electrode materials of Co_3O_4 and Ni O lithium-ion batteries were successfully prepared by pyrolysis of MOFs materials 6 and 7. Co_3O_4 and NiO electrode materials before and after charge-discharge cycle were characterized by Co_3O_4 and high resolution TEM. At high current density of 2000mA-1 / g, after 50 cycles of charge and discharge cycles, Co3OStup4 and NiO electrode materials can still maintain good morphology and maintain high Coulomb efficiency of 98.0% and 96.2%. In addition, Co3OSn4 electrode materials can still maintain a high specific capacity of 569.9m Ah/g. Better cyclic stability is shown.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4;TM912

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