不同形貌金属氧化物材料的制备及其锂离子电池性能研究

发布时间：2018-01-16 19:28

本文关键词：不同形貌金属氧化物材料的制备及其锂离子电池性能研究　出处：《西北大学》2017年硕士论文　论文类型：学位论文

【摘要】：目前,可充放电锂离子电池作为一种重要的能量储存器件,被认为是下一代能源技术发展的核心。金属氧化物因具有高能量密度、强稳定性和长寿命等优点而成为锂离子电池负极研究焦点。本论文通过一系列物理化学方法制备出了不同形貌金属化合物(CuO和NiO),Fe2O3-SnO2/石墨烯(GNs)复合膜材料。采用一系列的表征手段对这些材料的形貌、结构、组成等进行了测试分析,继而将这些材料作为锂离子电池负极,分析其电化学性能。研究内容如下:1.以Fe2O3-SnO2微球、氧化石墨为原料,通过物理混合、真空抽滤、热还原三个步骤成功合成了二维多层自支撑Fe2O3-SnO2/GNs复合膜。该自支撑膜可以直接作为工作电极,不需要添加任何导电剂和粘结剂,简化了极片制作工艺。并对Fe2O3-SnO2/GNs复合膜的电化学性能进行了系统研究。Fe2O3-SnO2/GNs复合膜负极材料半电池、全电池容量分别为538(循环90圈)和334 mAh g-1(循环30圈),相较于Fe2O3、Fe2O3-SnO2电极,显示了良好的循环稳定性。2.通过水浴、高温煅烧的方法合成六面体CuO(cubic CuO)、八面体CuO(octahedral CuO)和十二面体CuO(dodecahedral CuO),将其分别作为锂离子电池负极材料进行电化学性能的研究,以此探讨形貌和电化学性能之间的相关联系。在电流密度为 100 mA g-1 条件下,cubic CuO、octahedral CuO 和 dodecahedral CuO 电极经过 100圈充放电循环,其容量分别为221、283和339mAhg-1;且在0.1、0.25、0.5、1和2 A g-1不同电流密度下,dodecahedral CuO电极放电比容量为524、413、334、256和175 mAhg 1,表现出了更为优异的倍率性能。3.通过模板辅助法制备出了大小均一,棱角分明,结构对称的空心六面体NiO(HC-NiO)、空心八面体NiO(HO-NiO)和空心十二面体NiO(HD-NiO),将其分别作为锂离子电池负极材料进行了电化学性能研究。相较于HC-NiO和HO-NiO,HD-NiO表现出更为优异的循环稳定性和倍率性能。在电流密度为100 mA g-1时,HC-NiO、HO-NiO和HD-NiO电极经过100次循环,容量分别为652、852、980 mAh g-1;且在0.1、0.25、0.5、1和2Ag-1不同电流密度下,HD-NiO放电比容量为1179、1026、944、825和730 mAh g-1,展现了良好的电化学性能。
[Abstract]:At present, the rechargeable lithium ion battery as an energy storage device, is considered to be the core development of next-generation technology. Metal oxides due to their high energy density, high stability and long life and other advantages become the research focus of the lithium ion battery anode. This paper through a series of physical and chemical methods of preparation the different morphologies of metal compounds (CuO and NiO), Fe2O3-SnO2/ graphene (GNs) composite membrane material. The characterization of a series of morphology of the material structure and composition were tested and analyzed, then these materials as anode for lithium ion batteries and its electrochemical performance analysis. The contents are as follows: 1. to Fe2O3-SnO2 microspheres, graphite oxide as raw material, through the physical mixing, vacuum thermal reduction, the three step synthesis of two-dimensional multilayer free-standing Fe2O3-SnO2/GNs composite membrane. The membrane can be directly used as self support The working electrode, do not need to add any conductive agent and binder, simplifies the fabrication process and electrochemical properties of the electrode. The Fe2O3-SnO2/GNs composite membrane of composite membrane cathode material system research on.Fe2O3-SnO2/GNs battery, the battery capacity was 538 (90 Cycles) and 334 mAh g-1 (30 cycles), compared with Fe2O3. The Fe2O3-SnO2 electrode shows good cycling stability of.2. by water bath, high-temperature calcination synthesis of CuO (cubic CuO), hexahedral eight surface CuO (octahedral CuO) and twelve CuO (dodecahedral CuO), the body of the other as anode materials for lithium ion batteries are electrochemical properties, in order to explore the relationship between morphology and electrochemical performance. At a current density of 100 mA under the condition of g-1, cubic CuO, octahedral CuO and dodecahedral CuO electrode ring after 100 charge discharge cycles, the capacity is 221283 and 339 respectively. MAhg-1; and at 0.1,0.25,0.5,1 and 2 A g-1 under different current densities, dodecahedral CuO electrode discharge capacity of 524413334256 mAhg 1 and 175, showed more excellent rate performance of.3. prepared by template assisted with uniform size, angular, symmetrical structure of the hollow hexahedron NiO (HC-NiO), eight hollow face NiO (HO-NiO) and hollow NiO twelve surface body (HD-NiO), which were used as anode materials for lithium ion batteries were studied. The electrochemical performance compared with HC-NiO and HO-NiO, HD-NiO showed more excellent cycle stability and rate for 100 times. MA g-1, HC-NiO HO-NiO and HD-NiO in the current density. The electrode after 100 cycles, the capacity was 652852980 mAh g-1; and 0.1,0.25,0.5,1 and 2Ag-1 in different current density, HD-NiO discharge capacity of 11791026944825 mAh and 730 g-1, showing good electrochemical performance.

【学位授予单位】：西北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.2;TM912

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