集于一体的柔性电化学电容器的构建及其性能研究

Performance of electrochemical capacitor depends on the composition, structure and electrical conductivity of the electrode active materials, device's structure and assembly process of devices. This project will use the organic electrospinning fiber membrane, commonly used filter membrane, septum and paper as porous flexible substrates. By using the process of electroless plating, conductive metal layers will be deposited on the two surfaces of the porous membranes, thus the formed composite porous membranes contain two conductive surface layers and one insulating middle layer. Then the composites containing conducting polymer, graphene oxide, chemically modified graphene and carbon nanotubes will be deposited on the two conductive surface layers of the porous composite membranes with sandwich structure by using electrochemical deposition method. Therefore, the total mass and volume of the electrochemical capacitors can be effectively reduced because the two electrodes of capacitors containing electro-active materials and the separator for capacitors have been integrated into an organic whole, the electro-active material and the conductive metal layer will have a good contact due to the electrochemical deposition process, and the carbon nano-materials in the composites will improve the composites' microstructures and overcome the unfavorable factors caused by conducting polymers’ volume change in the process of charging and discharging. The research will be focused on the influences of the composition and structure of devices’ components on the performances of the all-in-one flexible capacitors in order to clarify the relationship between the compositions and structures of materials and the performances of flexible capacitor, and to develop the high-performance flexible electrochemical capacitors. The establishment and completion of this project will provide the theoretical basis and technical support for the development and application of the all-in-one flexible electrochemical capacitors.

电化学电容器的性能依赖于电极活性材料的组成、结构和导电性以及器件的结构和器件的组装过程。项目将利用电纺有机纤维膜、常用的滤膜、隔膜和纸张为柔性多孔材料，利用化学镀法在膜的两个表面沉积金属导电层，制得表层导电而中间绝缘的夹心多孔复合膜；然后以电化学共沉积的方法在夹心复合多孔膜两面的导电层沉积导电高分子与氧化石墨烯、化学修饰的石墨烯和碳纳米管的复合物；沉积有电活性物质的夹心电极集组成电容的两个电极和隔膜于一体能有效地减小器件的总质量和体积，电化学沉积能使电活性物质与金属导电层有良好的接触，与碳纳米材料复合可改善材料微结构并克服由导电高分子充放电过程中体积变化导致的不利因素。研究器件各组成部分的组成和结构对集于一体的柔性电容器性能的影响，阐明材料组成结构与柔性电容器性能之间的关系，研制出集于一体的高性能柔性电化学电容器。项目的确立与完成将为集于一体的柔性电化学电容器的研制提供理论依据和技术支撑。

电化学电容器通常由被隔膜分开的两个电极组成，在重复弯折过程中因电极与隔膜的分离将导致器件性能的急骤下降。为此，采用多孔有机膜为支撑体，通过化学镀在膜的两面沉积连续的金膜，得到中间多孔绝缘而两面导电的夹心结构。然后，在两个导电面上电沉积导电聚合物，加入电解质得到集于一体的柔性电化学电容器。如：沉积PPy/GO的器件有较大的面积比电容（108.0mF/cm2），良好的循环稳定性（10000次循环后电容值保留84.5%）。经2000次弯折后，器件能保留初始电容的93.4%，弯折5000次后仍有80%的保留。沉积PEDOT的器件有优良的循环稳定性（20000次循环后保留91.8%），其性能经5000次的弯折后仍可保留99.1%。在机纤维膜上化学沉积了连续的纳米镍膜，经硫化处理制得负载有Ni3S2的柔性电极，其拥有2.3 F/cm2的面积比电容（990.1F/g质量比电容），以其为正极组装的不对称柔性电容具有680.5mF/cm2的面比电容或81.9F/g的质量比电容，具有优异的循环稳定性（5000次循环后可保持86.1%），基于活性物其能量密度可达29.1Wh/kg，开拓了构建镍基柔性电极的新方法。研究了导电高分子基柔性及可压缩性的电容器件，以三聚氰胺海绵为基质，通过内串联的方式制备了单个器件可输出3.0V电压的超级电容器；可压缩电容在不同压缩状态下的电化学电容行为。在项目支持下，改进了氧化石墨然的制备方法，以氧化石墨烯为原料，在极少量的二酚存在下（1/80-1/40），制备了Cs可达250F/g的石墨烯凝胶体，该材料具有良好的循环稳定性和速率性能；用浓硫酸处理苯二氨衍生物修饰的石墨烯的方法制备了纯化的氮掺杂石墨烯，其Cs值可达519F/g且具有良好的稳定性和大的功率密度，以类似的思路，制备了具有高体积比电容的石墨烯膜。制备了可用于染料敏化太阳能电池的三元硫化物，调控了材料的结构，得到了与铂催化性能相当的非铂对电极催化材料；探索了金属有机卤化物钙钛矿膜的晶体调控及其光电池性能。项目的研究结果为开发新型超级电容材料和太阳能光电池材料奠定了一定基础。