具有“限域调控”功能的纤维状光电容器电极的微流控制备及性能研究

Fiber-shaped photo-supercapacitor is a new type of “integrated energy device” that has been designed to efficiently integrates the solar cell and the supercapacitor together. The advantages of high flexibility, high integration and wearability of the fiber-shaped photo-supercapacitors have attracted great interests for the applications in portable consumer electronics. However, because of the difficulties of designing the electrodes with high performances of energy harvesting and storage simultaneously and the limited understanding of underlying mechanisms, the total conversion efficiency of the fiber-shaped photo-supercapacitors is still low, which greatly hinder its future applications. To address these issues, confined-space optimization strategy is proposed here to manipulate and optimize the properties of the fiber-shaped photo-supercapacitors. In our strategy, the coaxial PEDOT:PSS-based confined-space heterogeneous microfibers which can realize the confined-space functional optimization of energy harvesting and storage separately made from microfluidic-directed wet-spinning method are proposed to construct the fiber-shaped photo-supercapacitor. The fabrication of the fiber-shaped photo-supercapacitors with high performances might be achieved by separately manipulating and optimizing the functional confined-space parts of the dye-sensitized solar cell electrode and supercapacitor electrode. We will understand the key factors and mechanisms of the surfacial/interfacial structure manipulation of fiber electrode by microfluidics spinning method. We will disclose the relationships between the electrochemical performances of the integrated fiber-shaped photosupercapacitors and the microstructure of the fiber electrodes. Furthermore, the underlying mechanism and rule of the charge transport and storage in the integrated energy fiber will be also systematically studied aiming at the highly efficient device.This project will provide a new method to prepare functional fiber-shaped electrode and promote a new idea for fabrication a new type of fiber-shaped photosupercapacitors for wearable electronics.

纤维状光电容器是太阳能电池与电容器高效集成的一体化能源器件，具有柔性好、集成度高、易编织的特点，在可穿戴电子产品中具有广阔的应用前景。然而目前纤维状光电容器难于同时实现其功能单元的性能调控，一体化器件中能量转换和储存机制尚不清楚，器件能源转换效率偏低，极大的限制了其应用。为解决上述问题，本项目提出限域功能优化的策略，利用微流控纺丝技术制备具有功能分区的基于PEDOT:PSS的同轴“异质杂化”复合纤维电极，分段限域调控太阳能电池和电容器的性质，实现各功能单元性能最优，构建高性能的光电容器。本项目将了解微流控纺丝调控纤维表面和微观结构的关键条件和机理；揭示多功能同轴“异质杂化”纤维的结构和电化学性能之间的关系；掌握纤维电极构建一体化纤维状光电容器的关键技术，研究光电一体化器件中的能量转换、储存和电荷传输机制。本项目的开展，有望为设计和构建新型高性能的纤维状光电容器提供一定的科学指导。

针对纤维状光电容功能单元的电化学活性差、性能调控难，导致能源器件总体能源转换效率（TCE）偏低和可穿戴应用差的科学问题，本项目以微流控纺丝技术调控纤维电极结构为导向，分段限域调控太阳能电池和电容器的性质，实现各功能单元性能最优，构建高性能的光电容器。. 项目设计纺丝针头和调控纤维电极的注射参数与溶剂处理条件，发展了一系列结构和性能可控的纤维制备技术，成功构筑了实心、核壳、超薄中空、高褶皱中空等多种微纳结构的PEDOT:PSS复合纤维。研究了纳/微尺度下流体流速流场、介质层流扩散、化学反应组装对纤维结构和性能的影响，获得了微流控纺丝调控纤维表面和微观结构的关键条件和机理，揭示纤维的结构和电化学性能之间的关系。获得了具有高导电性、高电化学活性、高催化性能的多功能纤维电极，基于PEDOT-MS电极的超级电容器的能量密度高达19.6 μW h cm-2，循环 20，000次循环后，比电容保持率为76.1%。而基于PEDOT-MS电极的染料敏化太阳能电池（FDSSC）的光电转换效率（PCE）高达为8.4%，媲美铂电极。进一步对功能单元进行性能适配性优化研究，最终实现了总能量转换效率TCE高达5.1%，循环稳定性高达63天的长期稳定性的柔性纤维状光电容器自供电器件的制备，掌握了纤维电极构建一体化纤维状光电容器的关键技术，得到了光电一体化器件中的能量转换、储存和电荷传输机制。. 本课题研究中培养博士(联合)、硕士研究生10名，获得授权国家发明专利3项，发表SCI论文14篇，项目负责人入选“四川省万人计划"拔尖人才计划。相关成果可为柔性电源的研究提供一定的理论基础与技术支撑。