可控气相沉积原位固相聚合导电高分子及其在柔性纤维及多孔电极上的应用

Conductive polymer has been widely used in the replacement of traditional metal conductive film due to its unique advantages. With the development of energy, sensors, catalysis, wearable and portable electronics, the requirements of conductive polymers (mostly as electrodes) applied to these areas are getting higher and higher. The application process from the polymerization of the monomer to the functionalization of the device tends to the seamless convergence; the application form evolves from the traditional planar structure to the complex non-planar porous structure, and the demand for uniform film and clear interface is higher. Traditional solution methods and solid-state polymerization are difficult to meet these requirements. Vapor deposition polymerization can generate uniform films, but the polymerization conditions are harsh with high cost and complex process. In the study of the vapor deposition of DBEDOT to which solid-state polymerization would occur at low temperature, we have found that DBEDOT can diffuse into the porous substrate with high permeability and polymerize to form a highly conductive and uniform film. Therefore, we intends to systematically study the preparation of conductive polymer film via the vapor deposition and in suit polymerization. The mechanism and influencing factors of polymerization could be clarified. More monomers suitable for the new method are obtained. The study may also establish a set of universal methods to build a uniform and highly conductive film on porous medium and flexible substrate, and solve the scientific issues and technical problems of related fields.

导电高分子因其独特优势在取代传统金属导电膜方面被广泛应用。随着新能源、传感器、催化和可穿戴等领域的不断发展，对应用于这些领域的导电高分子（电极）的要求也越来越高。具体表现为从单体的聚合成膜化到器件功能化的过程正趋于无缝衔接的连续化过程，应用形态从传统平面结构发展到复杂的非平面多孔结构，对膜层均匀性及表/界面清晰程度等提出更高要求。传统的液相及固相聚合已难以满足这些要求；虽然气相聚合可以得到均匀膜层，但条件苛刻，成本高、过程复杂。我们在对可固相聚合单体DBEDOT在真空下的气相沉积聚合的研究中发现，DBEDOT能以极高的渗透性扩散进入多孔基底并聚合生成导电性高的均匀膜层。因此，本项目拟系统研究这种可气相沉积原位固相聚合制备导电高分子薄膜的方法；阐明聚合机理及影响因素；筛选出更多适合该法的单体，获得在多孔介质及柔性基底上制备均匀的高导电膜层的普适性方法；解决这一领域的重要科学问题和技术难题。

导电高分子因其柔性好、易成膜、具有优异的电化学性能等优势已经被广泛应用。但是对于柔性电极常用的多孔基底，传统的液相聚合法存在浸渍率差、孔隙渗透不足的问题，难以在基底表面生成均匀的导电薄膜。针对以上问题，本项目研究了一种新型的气相沉积聚合方法，制备得到性能优异的聚3，4乙撑二氧噻吩（PEDOT），并成功应用于高性能纤维型电极及其超级电容器的制备。主要研究内容包含：1、在聚合方法的研究方面，设计并搭建了聚合装置，首次详细探索了温度、时间和真空度等因素对导电性、成膜性和稳定性方面的影响，确定80 ℃聚合24 h的最聚合条件。2、采用新型的气相沉积聚合法制备PEDOT，不需要催化剂和溶剂，在减压或真空环境中于较低温度诱导单体升华或气化经过扩散深入到多孔基底内部沉积后发生原位聚合生成导电高分子，制备导电率高的均匀高分子薄膜。3、利用气相沉积聚合制备PEDOT的高导电性和高均匀性，创新地引入了商业化的缝纫线作为基底，通过温和的气相沉积聚合法和电化学沉积成功地将这些商业缝纫线转化为具有电化学活性的导电线，最终制备得到复合电极的长度比电容达97.11 mF/cm，超级电容器器件的长度比电容达53.89 mF/cm，对应的面积比电容和体积比电容分别为132.02 mF/cm2和8.17 F/cm3，并且具有优异的可弯折性能。4、高效纤维钙钛矿太阳能电池的制备以及光伏-储能集成系统的构建。制备得到的纤维太阳能电池光电转换效率高达10.70%，光伏—储能一体化能源系统的总体能量转化效率为2.06%。