摘 要

消费级电子产品的不断进步对各类电子设备的便携性与可穿戴性提出了更高的要求，柔性设备成为电子产品发展的新方向。柔性化的储能器件是近年来的研究热点，而储能器件电极的柔性化则是制约柔性器件发展的关键。超级电容器是一类新型的储能器件，具有功率密度大、循环寿命长、充放电速度快等优点，适合作为新一代电子产品的电源器件。将柔性技术与超级电容器结合，进行一种既具有较好的电化学特性，又能够满足在弯曲、折叠条件下正常工作的储能器件的研究与开发，是一项具有前瞻性与创新性的工作。

本文受到纸张结构与其他同行工作的启发，将钒氧化物制备成为纳米线结构并组装成超级电容器纸电极，针对钒氧化物纳米线的制备、纸电极的成型效果、微观结构与电化学特性等几个方面进行观察、性能测试与数据分析，最终确定以水热法制备钒氧化物纳米线，通过抽滤的方法得到钒氧化物超级电容器纸电极，对纸电极进行物相、成膜效果、微观结构以及电化学性能测试分析。主要结果如下：

采用水热法，以V₂O₅·1.6H₂O粉末、H₂O₂溶液为原料，在180℃下水热不同时间制备钒氧化物纳米线。从XRD结果来看，水热24h后得到的为V₂O₅·1.6H₂O干凝胶，水热48h后得到的为V₃O₇·H₂O。对比V₂O₅·1.6H₂O和V₃O₇·H₂O的成膜效果可知，V₂O₅·1.6H₂O抽滤速度慢，但是成膜效果较好，膜厚度均匀，附着牢固，可弯曲程度大。使用不同的滤膜进行抽滤，亲水PVDF膜成膜效果最好，普通滤纸其次。TEM结果显示V₂O₅·1.6H₂O为长纤维状结构，V₃O₇·H₂O为片层状结构。长纤维经过抽滤干燥后可形成纸状结构，因此成膜效果较好，与实验预期、成膜结果相符。电化学测试结果表明，V₂O₅·1.6H₂O主要表现为赝电容性质，经过一定的循环后出现了容量的衰减；而添加氧化石墨烯改性的V₂O₅·1.6H₂O则主要表现为双电层电容性质，且经过一定的循环后容量没有明显变化，说明氧化石墨烯的加入对V₂O₅·1.6H₂O电极的容量保持有积极作用。

关键词：超级电容器；柔性；钒氧化物纳米线；纸电极

Abstract

The continuous improvement of consumption electronics products put forward more advanced properties on electronic equipment, such as portability and wearability. Flexible equipment has become a new direction for the development of electronic products. Flexible energy storage devices are the hotspots in recent years, and the flexibility of electrode is the key to the development of flexible devices. Supercapacitor is a new type of energy storage devices with a high power density, long cycle life, charge and discharge speed, etc. ,which is suitable as power device of new generation of electronic products. It is a kind of forward-looking and innovative method to combine the flexible technology with the supercapacitor to carry on the research and development of the energy storage device which has the good electrochemical characteristic meanwhile maintaining its working condition under the bending and folding conditions.

In this paper, vanadium oxide nanowires were prepared and assembled into supercapacitor paper electrodes inspired by the paper structure and other research. The preparation of vanadium oxide nanowires, the forming effect of paper electrodes, the microstructure and electrochemistry characteristics and other aspects were observed, tested and analyzed. Finally, the vanadium oxide nanowires were prepared by hydrothermal method, and the vanadium oxide supercapacitor paper electrodes were obtained by suction filtration. The phase, film effect, microstructure and electrochemical properties of the paper electrodes were analyzed.

The hydrothermal method was used to prepare vanadium oxide nanowires at different temperatures at 180 ℃ with V₂O₅•1.6H₂O powder and H₂O₂ solution as raw materials. The XRD results indicated that the V₂O₅•1.6H₂O xerogel was obtained after 24 hours of hydrothermal heat, and after hydrothermal treatment for 48h was V₃O₇•H₂O. Compared with V₃O₇•H₂O, the V₂O₅•1.6H₂O had a slower filtration speed, but the film formation effect was better with the average film thickness. The adhesion was also firm and the bending performance was better than V₃O₇ • H₂O. In the test of using different filters for filtration, hydrophilic PVDF film had the best result, followed by ordinary filter paper. TEM results showed that V₂O₅•1.6H₂O was a long fibrous structure and V₃O₇•H₂O was a lamellar structure. Long fiber can be formed paper-like structure after the filter and drying, so it was according with the film-forming result and the experimental expect. The electrochemical test results showed that V₂O₅•1.6H₂O is mainly pseudostructure, and the capacity decay occured after a certain cycle. The graphene oxide-modified V₂O₅•1.6H₂O mainly shows the double layer capacitance, and after a certain cycle the capacity did not change significantly, indicating the positive influence of the addition of graphene oxide to the V₂O₅•1.6H₂O electrode capacity about maintain its capacity.

Key Words: Supercapacitor, Flexibility, Vanadium oxide Nanowires, Paper Electrodes

目录

第1章 绪论 1

1.1引言 1

1.2超级电容器 1

1.2.1超级电容器储能机理 2

1.2.2超级电容器电极材料 2

1.3柔性超级电容器 4

1.3.1柔性超级电容器电极 4

1.3.2柔性超级电容器电解质 6

1.3.3柔性超级电容器的应用前景 6

1.4 柔性超级电容器电极中钒氧化物电极材料的制备方法 6

1.4.1钒氧化物的制备 6

1.4.2水热合成法 7

1.4.3水热法合成过程 7

1.4.4水热合成的优势 7

1.5超级电容器电极材料的表征 7

1.5.1物相与形貌表征 8

1.5.2电化学性能表征 8

1.6本课题的研究内容 9

第2章 实验方案与材料表征方法 10

2.1实验原料与仪器 10

2.1.1实验原料 10

2.1.2实验设备与仪器 10

2.2钒氧化物纳米线的制备 10

2.3柔性钒氧化物电极的制备 11

2.4柔性钒氧化物电极的性能测试 12

2.4.1柔性钒氧化物电极的物相组成与微观形貌测试 12

2.4.2柔性钒氧化物电极的电化学性能测试 12

第3章 柔性钒氧化物电极性能表征结果与讨论 13

3.1 XRD测试结果分析 13

3.2不同纳米线成膜效果分析 13

3.3不同滤膜成膜效果分析 14

3.4 TEM测试结果分析 15

3.5循环伏安法测试结果分析 16

第4章 结论 19

参考文献 21

附录 攻读学士学位其间论文发表情况 23

致谢 24

第1章 绪论

1.1引言

由于近年来电子科技不断进步，电子产品的普及率不断提高，人们也对消费级电子产品的性能提出了更高的要求，集成微型化、智能化、多功能化成为电子产品发展的新目标，其中柔性可穿戴设备是研究的热点。柔性技术作为最近出现的全新技术，具有应用范围广、研究潜力大等优点，是未来电子设备发展的必经之路，柔性技术的研究与发展也吸引了广大研究人员的关注^{[1, 2]}。随着柔性屏幕、植入式医疗设备等概念的提出与逐步实现，柔性技术的前景被各国所看好，很快便成为了研究前沿领域之一^[3-5]。