柔性阶层多孔石墨烯复合膜的制备及电容性能研究

The hierarchical porous flexible graphene composite film exhibits an important application value in the field of electrochemical capacitor. In this project, we are going to realize this task as the following steps: firstly, the hierarchical porous flexible graphene composite films will be prepared through self assembly method by taking graphene oxide as a sourece, polyamine compounds including o-phenylendiamine, m-phenylenediamine, ethylenediamine, etc. as curing agent and urea for porous templates. And then electroactive transition metal oxides were deposited on the assembly through chemical or electrochemical deposition methods，in which the electrically active material and the porous flexible graphene will be assembled well in the microstructure and the multi scale. Graphene，with high conductivity and lager specific surface area, can increase the effective usage of electroactive material. The hierarchical structure of composite film resolve those problems such as too large diffusion distanceand transfer resistance, too small easy-contact surface in electrolyte ions, and thus improve the rate performance of flexible materials. Our research should be very hopeful expound the relationship between microstructure and capacitance performance through investigating the ratio of composition, pore structure and size distribution of composites. The present project will set a foundation for design and synthesis of flexible electrode materials.

柔性阶层多孔石墨烯复合膜在电化学电容器储能领域中有重要的应用价值。本项目以氧化石墨烯为原料，邻苯二胺、间苯二胺、乙二胺等多胺分子为凝固剂，尿素为多孔模板，通过组装法制备柔性阶层多孔石墨烯膜。采用化学或电化学方法将电活性过渡金属氧化物沉积到石墨烯膜，制备柔性阶层多孔石墨烯复合膜，实现电活性物质和石墨烯微结构的多尺度复合。利用石墨烯导电性高和比表面积大的特点，增加对电活性物质的有效利用。阶层多孔结构解决电解质离子扩散距离和传递电阻大，电解质离子易接触比表面积小的问题，改善柔性复合膜的速率性能。通过研究各组分的组成、比例、复合膜孔隙结构对电容性能的影响，阐明柔性阶层多孔石墨烯复合膜微观结构与其电容性能的关系。该项目的设立将为设计与合成柔性复合电极材料奠定一定的基础。

分别以甲醛、甲酸为还原剂，用气相反应和液相反应还原氧化石墨烯(GO)，详细研究了还原条件对氧化石墨烯还原程度的影响；通过对氨基苯磺酸重氮盐功能化氧化石墨烯制备的磺酸功能化的石墨烯（S-rGO）具有良好的水溶性，其的比电容值能达到205 F g-1；以氧化石墨烯为原料，对苯二胺为凝固剂，尿素为多孔模板，结合低温自组装、冷冻干燥法制备柔性多孔石墨烯膜（PUGF），在1 mV S-1的扫速下，PUGF比电容可高达430 F g-1。以棉花为原料得到的活性炭与氧化石墨烯复合制备柔性无粘合剂石墨烯复合膜其质量比电容可达202 F g-1；采用浓硫酸纯化致密石墨烯膜制备了密度高（2.04 g cm-3），体积比电容大（494.3 F cm-3）的柔性石墨烯膜；通过浓硫酸纯化提高N掺杂石墨烯水凝胶的电容性能；结合低温自组装法制备金线/还原氧化石墨烯（WAu@rGO）柔性复合纤维，当扫描速度为1 mV s-1时，WAu@rGO纤维的长度和质量比电容分别可达5.47 mF cm-1和176.7 F g-1; 在NaH2PO2与氧化石墨烯水热反应过程中，通过改变NaH2PO2浓度可以有效调控石墨烯水凝胶的微结构和电容性质；分别用(邻、间、对)苯二酚水热还原氧化石墨烯，调控石墨烯水凝胶的结构与性能，最佳条件对应的石墨烯水凝胶电极o-rGOHG80，p-rGOHG40和m-rGOHG40 在1 mV s−1时的比电容值分别为253, 240和238 F g−1；以玉米杆芯为原料制备的多孔碳（PCM）在扫描速率为1 mV s−1时，最佳条件下PCM-T800的电容器比电容高达317 F g−1；结合滴涂法和原位聚合法制备的聚吡咯/(聚乙烯/聚丙烯)柔性复合膜，以其为电极材料，H3PO4/ PVA为凝胶电解质组装的固体电容器具有较好的柔韧性（2，000次反复弯曲后，电容保持率可达90.0%，3，000次后可保持81.3%）。