宏观石墨烯网状薄膜超级电容器及其交流滤波性能研究

The directional alignment of graphene sheets can construct large external surface area, achieving effective alternating current (ac) line-filtering. However researchers pay less attention to the effect of external surface area in graphene assembly on the adsorbtion and transmittion of charges between the electrode-electrolyte interface, while it is essential to have underlying understanding about the above mechanism aiming at highly effective devices. In this proposal, we mainly focus on the three aspects: (1) Freeze-drying, combining with thermal annealing, is facilitated to fabricate a macroscopic graphene mesh aerogel (mGMAs) with directed ordered hierarchical structure, large external surface area and supercompressibility, which serves as supporting template of different constitutional units (zero dimentional graphene oxide quantum dots, one dimentional graphene oxide nanoribbons) to achieve regulation of external surface area in aerogel. The interconnecting effect of different constitutional units on external surface area in aerogel was systematically analysed. (2) Ultrathin macroscopic graphene mesh films (mGMFs) with large size are obtained by directly cutting compressible aerogel or convenient paraffin section. (3) The supercapacitor with noval mGMFs electrodes is assembled and used to study the 120 Hz filtering. The effect of external surface area on the adsorption and transportation of charges between interface will be systematically studied. Our proposal will provide new method for obtaining macroscopic graphene mesh films, supply new materials and theoretic and experimental support for fabricating facinating capacitor for ac line-filtering.

石墨烯片的定向排列可构造出大的外比表面积，从而实现高效交流滤波。但人们较少关注石墨烯组装体的外比表面积对于电荷在电极-电解液界面间吸附及传输的影响，而深入理解此作用机理对制备高效交流滤波电容至关重要。本项目将从三方面进行研究：(1)利用冷冻干燥-热退火，制得具有定向有序分级结构、大的外比表面积、超可压缩宏观石墨烯网状气凝胶，并以其为不同结构单元(氧化石墨烯的零维量子点、一维纳米带)的支撑模板，实现气凝胶外比表面积的调控。系统分析不同结构单元间交连作用对气凝胶外比表面积的影响。(2)利用气凝胶的可压缩性直接切割或通过石蜡切片切割获得大面积超薄宏观网状薄膜。(3)以新型材料宏观石墨烯网状薄膜为电极，组装超级电容器并研究其交流滤波性能，同时研究外比表面积对电荷在界面间输送的影响。本项目对大规模制备具有大的外比表面积的宏观石墨烯网状薄膜提供了新方法，对获得交流滤波电容提供了新材料及理论和实验支撑。

本项目主要研究材料外比表面积对离子在电极-电解质界面间吸附和传输的影响，进而深入理解材料的外比表面积、微结构调控对组装的电化学电容器滤波性能的作用机理，以获得高效滤波电容。因此，本项目在以下三个方面开展了研究：(1)制备基于不同微结构石墨烯薄膜的电容器，比较其电化学、滤波性能，发现在高频电压下，具有垂直导向微结构石墨烯薄膜的电容器可在电极表面实现定向离子传输，因而呈现出超快速频率响应性。(2)设计合理的形貌调控策略，获得具有高导电、相互交联的聚(3,4-乙烯二氧噻吩)-聚苯乙烯磺酸连续纳米网薄膜，其具有超高能量密度和杰出滤波特性，进而深入探究聚合物微观形貌对电容器滤波性能的作用机理。(3)选择聚(3,4-乙烯二氧噻吩)-聚苯乙烯磺酸和碳化钛组装成非对称水系电容，以拓宽单个电容的电位窗口，拟对其进行精巧集成。该研究拓展了我们对滤波电容的认识，为实现电化学电容器在滤波领域的应用奠定坚实理论基础和实验支撑，同时对其它高倍率能源存储器件的研究具有重要意义。