基于三维复合电极的新型能源存储器件的研究

发布时间：2018-01-26 03:53

本文关键词： 能源存储器件三维复合电极柔性可穿着性线状纳米材料锂离子电池超级电容器镁离子电池　出处：《华中科技大学》2014年博士论文　论文类型：学位论文

【摘要】：未来电子器件的主要发展趋势是柔性化、便携化、微型化,这就需要新型的高性能能源存储器件作为电源来驱动它们。但是,现有的电池存在着诸多缺陷,例如：笨重、不可弯折、价格昂贵、功率/能量密度偏低、微型化和集成化较差等,阻碍了新一代电子器件的发展。针对以上问题,本论文的主要内容是基于三维复合电极的新型能源存储器件的创新性研究,主要涵盖的工作有： (1)基于ZnCo2O4纳米线阵列/碳布三维复合电极的柔性锂离子电池：采用水热法构建出新颖的ZnCo2O4纳米线阵列/碳布三维复合电极,并且对样品的晶体结构和形貌等进行表征。进一步将这种材料分别封装于扣式和柔性锂离子电池之中进行各项电池器件测试。测试结果显示：在长达160次充放电循环中,该复合电极保持了较高的可逆比容量(1200～1340mAh-1),而且显示出良好的倍率性能。这说明ZnCo2O4纳米线材料的比容量远远高于现有的碳负极(372mAh g-1)。在反复弯折(120次)柔性电池的过程中,其比电容量未受到任何影响。为了验证柔性电池的实用性,我们已成功利用其驱动了LED灯、手机显示屏和掌上游戏机,即使在柔性电池弯曲或折叠情况下,这些器件也能够被其驱动。 (2)基于ZnCo2O4海胆状纳米结构/碳纤维三维复合电极的柔性锂离子电池：基于工作(1),调节实验参数,利用水热条件合成ZnCo2O4海胆状纳米材料/碳纤维三维复合电极。封装电池后进行测试,结果显示：在100次充放电循环之后,该电极的比容量依然能够达到1180mAhg-1,反映出ZnCo2O4本身具有高比容量特性和优良的循环稳定性。在高达18Ag-1的电流密度下,经过100次循环,测得该电极的可逆比容量为750mAh g-1(为ZnCo2O4材料理论比容量的83.3%),优于己报道的其他ZnCo2O4材料电极。实验结果表明,具有新颖三维结构的ZnCo2O4/碳纤维复合电极呈现出明显的电化学优势,对于提高电池性能具有重要作用。而且,基于ZnCo2O4材料负极的柔性电池也保证了良好的电化学性能和不同弯曲状态下的高稳定性。此外,这些柔性电池可以随意集成在衣物和旅行背包上,满足未来电子器件便携性和可穿着性的需求。 (3)基于Si纳米线/碳布三维复合电极的柔性锂离子电池：通过化学气相沉积法制备出高纯度的Si纳米线,之后用简易的喷涂法将Si纳米线溶液喷涂在高柔性的碳布上,制备成Si纳米线/碳布三维复合电极。对这些样品进行晶体和形貌表征,分别将其封装入扣式和柔性电池中进行电池测试。该三维复合电极具有高的可逆比容量(2950mAhg-1),稳定的循环性(长达200次)和增强的倍率性。而且,基于Si纳米线/／碳布三维复合电极的高柔性锂离子电池在外界不同温度、湿度和弯曲状态下均保持其电压和电容量的稳定性。通过此三维复合电极构建的柔性锂离子电池的各项电池性能良好,这为采用高性能的Si材料替代当前低容量的石墨负极材料提供了可行性。 (4)基于Mn2O3立方体阵列/碳线和ZnCo2O4纳米线阵列/碳线三维复合电极的线状超级电容器：采用水热法合成出Mn2O3立方体阵列/碳线三维复合电极,并且对样品进行了晶体和形貌表征以及电容器性能测试。这些三维线状复合电极首次被排列成直线型、曲线型和环型这三种线状超级电容器模型,经过5000次充放电,它们的电容量剩余率分别高达91%、93%和94%。实验数据显示,环型线状超级电容器电容量分别超出直线型线状超级电容器和曲线型线状超级电容器电容量的100%和83%。环型线状超级电容器的性能最优归因于环形电极间产生的协同增强的电容性效应。此外,该项工作阐明了不同电极长度和间距对三种线状超级电容器性能影响的研究。并我们首次引入了对这些线状能源存储器件的模拟计算,模拟结果与实验结论相一致。该项工作揭示出可以通过改变微型器件电极的集成方式来实现性能的最优化以及器件尺寸小型化和功能最大化的目标。此外,采用水热法成功制备出ZnCo2O4纳米线阵列/碳线三维复合电极,并将这些电极以平面集成的方式构建出柔性线状超级电容器。 (5)基于WSe2纳米线/钨箔三维复合电极的新型镁离子电池：采用化学气相沉积法制备出WSe2纳米线/钨箔三维复合电极,并且对样品进行晶体和形貌表征以及镁离子电池性能测试。实验结果发现新型WSe2/钨箔三维复合正极的比容量高达203mAhg-1,可以媲美锂离子电池正极材料。在160次充放电循环中,镁离子电池保持了非常好的稳定性。在相对较高的电流密度(800mAg-1)下,电极的比容量依然可以达到142mAh g-1,电容量剩余率高达83.5%,显示该三维复合电极具有高效的Mg2+嵌入脱出活性、良好的循环稳定性、增强的电容量值和优越的倍率性能。我们通过实验结果和计算模拟相结合的方式可以评估出WSe2的类石墨烯层状结构和三维复合电极的优势。本项工作证明了新颖的WSe2纳米线/钨箔三维复合物作为高性能镁离子电池理想正极的可行性,这将会推动替代性电池技术的进一步发展。
[Abstract]:The main development trend of future electronic devices is flexible, portable and miniaturization, which requires high performance energy storage model as the power to drive them. However, the existing battery has many defects, such as heavy, can not be bent, expensive, power / energy density is low, miniaturization and the integration of the poor, hindered the development of a new generation of electronic devices. In view of the above problems, the main content of this paper is to study the innovation of new energy storage device based on 3D composite electrode, mainly covers the work:
(1) flexible lithium ion battery ZnCo2O4 nanowires / carbon composite electrode based on 3D cloth: construct the ZnCo2O4 nanowire array / novel three-dimensional carbon cloth composite electrodes by hydrothermal method, and the samples of the crystal structure and morphology were characterized. The materials were further encapsulated in the buckle type lithium ion and flexible the battery the battery device test. The test results show that after 160 charge discharge cycles, the composite electrode to maintain a high reversible capacity (1200 ~ 1340mAh-1), and showed good rate capability. This indicates that ZnCo2O4 nanowire material than the capacity is far higher than that of carbon anode current (372mAh g-1) in the repeated bending. (120) the process of flexible batteries, the specific capacitance is not affected in any way. In order to verify the practicability of flexible batteries, we have succeeded in using the drive LED lights, mobile phone screen And handheld games, even when flexible batteries are bent or folded, these devices can also be driven by them.
(2) flexible lithium ion battery ZnCo2O4 urchinlike nanostructures / three-dimensional carbon fiber composite electrode based on: (1) based on the work, adjusting the experimental parameters, the use of water and heat conditions of the synthesis of ZnCo2O4 urchinlike nano materials / three-dimensional carbon fiber composite electrodes. The package of the battery after the test, the results showed: after 100 charge discharge in this cycle, the specific capacity of the electrode can still reach 1180mAhg-1, reflecting the ZnCo2O4 itself has high specific capacity and excellent cycle stability. The current density of up to 18Ag-1, after 100 cycles, the reversible measured the specific capacity of the electrode is 750mAh g-1 (for the ZnCo2O4 material theoretical capacity of 83.3%), other ZnCo2O4 electrode materials is better than reported. The experimental results show that ZnCo2O4/ has a carbon fiber composite electrode exhibits a novel 3D structure of electrochemical advantages, plays an important role in improving the performance and battery. The flexible battery based on ZnCo2O4 negative electrode also ensures good electrochemical performance and high stability under different bending conditions. Besides, these flexible batteries can be integrated on clothing and travel backpacks freely to meet the needs of portability and wearability of future electronic devices.
(3) Si nano flexible lithium ion battery wire / carbon cloth 3D composite electrode based on Preparation of high purity Si nanowires by chemical vapor deposition, followed by simple spraying Si nanowires solution sprayed on the high flexible carbon cloth, preparation of Si nanowires / three-dimensional carbon cloth composite electrode. The crystal and morphology of these samples, respectively. The package into the buckle and a flexible battery battery test. The three-dimensional composite electrode has a high reversible capacity (2950mAhg-1), cyclic stability (up to 200) and enhanced rate. Moreover, based on the Si nanowires / carbon cloth / 3D composite electrode high flexible lithium ion battery under various temperature, keep the stability of the voltage and capacitance humidity and bending condition. The performance of the flexible battery lithium ion battery is constructed by the three-dimensional composite electrode is good, this is the high The available Si materials provide the possibility of replacing the current low capacity graphite negative electrode materials.
(4) Mn2O3 cube array / carbon line and ZnCo2O4 nanowire arrays / carbon composite electrode line 3D linear super capacitor based on synthesized Mn2O3 cube array / carbon line 3D composite electrode by hydrothermal method, and the samples were crystal and morphology characterization and performance of capacitor test. These three dimensional linear composite electrode for the first time are arranged in a linear curve, and ring the three line super capacitor model, after 5000 charge discharge capacity, their residual rates were as high as 91%, 93% and 94%., the experimental data show that the linear ring of super capacitor electric capacity exceeds the optimal performance of linear linear linear and curve type super capacitor the super capacitor capacitance of 100% 83%. and linear ring of super capacitor is attributed to the ring electrode generated synergistically enhanced capacitive effect. In addition, this work illustrates the different electrode length Study on the degree and distance on the three line super capacitor performance. And we introduce a simulation calculation for the linear energy storage device, the simulation results are consistent with the experimental results. This work reveals that can be integrated through changing the micro electrode device to achieve optimal performance and device size and the function of maximization. In addition, successfully prepared ZnCo2O4 nanowires / carbon 3D composite electrode by hydrothermal method, and the electrode to construct the integrated planar flexible linear capacitors.
(5) the new magnesium ion battery WSe2 nanowires / tungsten foil 3D composite electrode was prepared based on WSe2 nanowires / tungsten foil 3D composite electrode by chemical vapor deposition, and crystal morphology and characterization and properties of magnesium ion battery testing of samples. Experimental results show that the new WSe2/ 3D composite cathode than tungsten foil capacity up to 203mAhg-1, comparable with that of cathode materials for lithium ion batteries. In 160 cycles, magnesium ion battery maintains good stability. In a relatively high current density (800mAg-1), the specific capacity of the electrode can still reach 142mAh g-1, capacitance residual rate as high as 83.5%, showing the three-dimensional composite electrode with efficient Mg2+ insertion and extraction activity, good cycle stability, enhanced capacitance value and superior rate performance. Through experimental results and numerical simulation method can evaluate The advantages of WSe2 like graphene layered structure and three-dimensional composite electrode are proved. The work proves that the novel WSe2 nanowire / tungsten foil 3D composite is feasible for high-performance cathode of magnesium ion battery, which will further promote the further development of alternative battery technology.

【学位授予单位】：华中科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM912

【共引文献】