CNFs基柔性电致变色薄膜超级电容器制备及性能研究

发布时间：2018-06-21 07:59

本文选题：纤维素纳米纤维 + 层层自组装　；参考：《北京理工大学》2014年硕士论文

【摘要】：纤维素纳米纤维（CNFs）具有优良的透明性，良好的柔性以及很低的热膨胀系数，这使其成为潜在的可以用于制备柔性超级电容器电极的材料，本论文论证了以CNFs膜为基材，以聚3，4-乙烯二氧噻吩：聚苯乙烯磺酸钠（PEDOT:PSS）或还原氧化石墨烯（RGO）为导电层，以聚苯胺（PANI）为电致变色层，采用层层自组装法和原位聚合法制备柔性透明薄膜电极的可行性，免去了传统柔性基体在进行层层自组装时要进行表面处理的复杂过程。通过对薄膜电极及使用这些电极制备的超级电容器的表征，分析了不同电极及柔性电致变色超级电容器的性能特征，阐述了电极微观结构对电解质离子的扩散乃至超级电容器的电性能的影响规律。以CNFs膜、PANI、PEDOT:PSS分散液为原料，采用层层自组装方法制备的CPP-n电极光学透明度高，表面均匀，但是薄膜结构致密，不利于电解质离子的传输。利用CPP-8电极制备的超级电容器S-PP-8虽然整体的电化学性能并不十分理想，但是其光学透明度高，在550nm处透光率达到47.1%，可以发生明显的电致变色现象。以CNFs膜、PANI、氧化石墨烯（GO）分散液为原料，采用层层自组装方法制备的CPG-n复合膜，经过HI处理后，得到CPRG-n复合膜，其表面均匀，结构疏松，有利于电解质离子的传输。利用CPRG-8电极制备的超级电容器S-PG-8受到RGO的影响，其透明度不理想，在550nm处的透光率为30.6%，难以直接观察到电致变色现象，但是其兼有双电层和赝电容超级电容器的优点，性能稳定且单位面积电容较大。研究还采用层层自组装法制备CNFs/RGO5薄膜，然后利用原位聚合法制备CRGP薄膜电极，结果表明，，薄膜表面不均匀，但是疏松多孔，有利于电解质离子的传输。利用CRGP电极制备的超级电容器S-RGP在2mV·s-1的扫描速率下单位面积电容达到19.76mF·cm-2，但其透明性低，在550nm处的透光率只有16.8%。进一步利用层层自组装法制备CNFs/[Cu2+-GO]5/[PANI-PEDOT:PSS]10复合膜，并采用HI将其还原后得到CRGPP-10薄膜电极，其表面均匀，但是结构致密，不利于电解质离子的传输。由于RGO的存在，利用CRGPP-10电极制备的超级电容器S-RGPP的电化学性能明显优于S-PP-8，其透明性较好，在550nm处的透光率为37.8%。
[Abstract]:Cellulose nanofiber (CNFs) has excellent transparency, good flexibility and low thermal expansion coefficient, which makes it a potential material for the preparation of flexible supercapacitor electrodes. The feasibility of preparing flexible transparent thin film electrode by layer self-assembly and in-situ polymerization using poly (3-triethylenedioxythiophene): sodium polystyrene sulfonate (PEDOT: PSS) or reduced graphene oxide (RGOO) as conductive layer and Polyaniline (pan) as electrochromic layer was studied. It eliminates the complex process of surface treatment for conventional flexible matrix during layer by layer self-assembly. The characteristics of different electrodes and flexible electrochromic supercapacitors were analyzed by the characterization of thin film electrodes and supercapacitors prepared with these electrodes. The effect of electrode microstructure on the diffusion of electrolyte ions and the electrical properties of supercapacitors is described. The CPP-n electrode prepared by layer self-assembly method has high optical transparency and uniform surface, but the structure of the CPP-n electrode is dense, which is not conducive to the transport of electrolyte ions. Although the overall electrochemical performance of the supercapacitor S-PP-8 prepared by CPP-8 electrode is not very ideal, its optical transparency is high, the transmittance reaches 47.1 at 550nm, and obvious electrochromic phenomenon occurs. CPG-n composite membrane was prepared by layer self-assembly method from the dispersion of CNFs (PANIO). After HI treatment, CPRG-n composite film was prepared. The CPRG-n composite film was obtained with uniform surface and loose structure, which was beneficial to the transport of electrolyte ions. The S-PG-8 supercapacitor prepared by CPRG-8 electrode is affected by RGO, and its transparency is not ideal. The transmittance at 550nm is 30.6. it is difficult to observe electrochromic phenomenon directly, but it has the advantages of double electric layer and pseudo-capacitor supercapacitor. Stable performance and larger capacitance per unit area. CNFs / RGO5 thin films were prepared by layer-by-layer self-assembly method, and CRGP thin film electrodes were prepared by in-situ polymerization. The results show that the surface of the films is uneven, but porous, which is conducive to the transport of electrolyte ions. The supercapacitor S-RGP prepared by using CRGP-electrode has a unit area capacitance of 19.76mF cm-2 at the scanning rate of 2mV s-1, but its transparency is low, and the transmittance at 550nm is only 16.8%. Furthermore, CNFs / [Cu2-GO] 5 / [PANI-PEDOT: PSS] 10 composite films were prepared by layer-by-layer self-assembly method. CRGPP-10 thin film electrode was prepared by HI reduction. The CRGPP-10 thin film electrode was uniform in surface, but compact in structure, which was not conducive to the transport of electrolyte ions. Because of the existence of RGO, the electrochemical performance of supercapacitor S-RGPP prepared by CRGPP-10 electrode is obviously better than that of S-PP-8, and the transparency of S-RGPP is better than that of S-PP-8. The transmittance of S-RGPP at 550nm is 37.8%.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM53;TB383.2

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