【作者】 梁静；

【导师】 吴伟；

【作者基本信息】 武汉大学 ， 图像传播工程， 2021， 博士

【摘要】 下一代便携式柔性电子器件（例如微机电系统、植入式生物传感器和可穿戴式个人电子器件）正朝着小型化、轻薄、柔性和智能的方向发展。为了满足当前柔性电子器件的需求,开发与之相匹配的柔性能源成为了一个重大的挑战。柔性超级电容器（Flexible supercapacitor,FSCs）因其功率密度高、循环寿命长、充放电速度快、轻便和安全的特点,被认为是可穿戴电子产品中最有前途的供能器件。迄今为止,已经开发了很多技术用来制备柔性超级电容器。传统的微制造技术,包括光刻和激光划刻,其价格昂贵,易产生大量的材料浪费并且很难集成到可穿戴基材上（例如,织物和纸张等）,无法满足未来可穿戴电子器件产业化的需求。本论文针对这些问题,致力于开发高性能电极材料和寻求新的制造工艺,实现低成本和高性能印刷柔性超级电容器的制备,以推动可穿戴电子器件的发展。研究内容包括新型电极材料的制备,可印刷功能油墨的配制,印刷工艺的优化,印刷电子器件的性能表征以及其应用研究。（1）首先为了得到具有优异储能性能的超级电容器,需要开发一种具有框架结构和多个反应位点的新型赝电容电极材料。为此,本文利用化学共沉淀法和溶剂热法合成了具有框架结构的插入型赝电容电极材料Fe HCFs,研究了不同合成方法下Fe HCFs电极材料的结晶度和形貌对电化学性能的影响。结果表明,利用水热法制备出的Fe HCFs纳米花具有较好的结晶度,在电流密度1 A/g的条件下,具有高达313 F/g的比电容。因此,从电极材料合成的角度出发,提出一种低成本、规模化制备高性能电极材料的方法。通过不同的合成方法调节电极材料的结构,形貌,结晶度,从而实现性能调控,并对新型Fe HCFs电极材料的性能进行了深入研究。（2）为了提高电极材料的循环稳定性和电容性能,本文提出了用金属Ni掺杂Fe HCFs制备Ni HCFs电极材料,并利用简单的刻蚀方法来增加活性位点提高能量密度。优化结构后所制备的Ni HCFs的比电容可达到230.5 F/g,同时具有优异的循环稳定性,循环10000次后,比电容仍保持初始的91%。随后从工艺制备的角度出发,优化了油墨的组成成分,建立了通用的丝网印刷油墨配方,将该Ni HCFs功能油墨成功印刷在纸和PET基材上。通过结构设计,组装成叉指结构和夹层结构的印刷超级电容器,最高比电容可达到3 m F/cm²。这种全印刷的策略,为制备柔性超级电容器提供了新的思路。（3）随后,为了进一步提高HCF新型电极材料的电化学性能,本体系构筑了掺杂高导电性的Co离子的CoHCFs。通过共沉淀法,获得了形貌均一,粒径尺寸在400 nm左右的纳米立方体结构的CoHCFs。该电极材料兼具大框架离子运输和高导电性,比电容可达到425 F/g（电流密度在1 A/g）,库伦效率高达94%。随后,成功将该油墨印刷在柔性PET基材上,制备了多种图案化（正方形、花朵状和鲤鱼等）的印刷超级电容器,比电容可达12.5 m F/cm²,能量密度可达到0.0011 m Wh/cm²。循环8000次后,比电容仍可保持90%。这种全印刷柔性超级电容器不仅具有良好的电化学性能,还具有良好的柔性性能,在多种弯曲角度后,比电容没有明显降低。通过串联或并联使用多个器件,能够持续驱动LED,在可穿戴电子的柔性能源器件领域具有新的应用前景。（4）本文首次提出同时进行金属掺杂和结构优化的电极材料构建策略,进一步提升了HCFs基印刷超级电容器的电化学性能。通过自模板法在Mn HCFs电极上引入新的花状赝电容Mn O₂,该复合结构MOFs材料电容性能可以达到417 F/g,是单纯Mn HCFs材料的2.4倍。随后利用丝网印刷方法,制备了多种印刷图案的柔性超级电容器,通过引入高导电性的r GO,其面积电容达到16.8 m F/cm²,能量和功率密度分别为0.0023 m Wh/cm²和0.5 m W/cm²。该图案化的印刷超级电容器表现出优异的柔性,即使弯曲多个角度和经过百次弯曲循环,电容也能保持稳定。该电极材料和超级电容器的制备方法为研发高能量密度、大批量和柔性可印刷储能器件提供了可能。更多还原

【Abstract】 The next generation of portable flexible electronic devices（such as MEMS,implantable biosensors and wearable personal electronic devices）are becoming small,thin,flexible and smart.In order to satisfy the current demand of flexible electronic devices,it is a major challenge to develop the flexible energy matching with it.Flexible supercapacitors（FSCs）are considered as the most promising energy supply device in wearable electronic products due to their high-power density,long cycle life,fast charging and discharging speed,portability and safety.Until now,many technologies have been developed to fabricate the flexible supercapacitor,including traditional microfabrication techniques,lithography and laser microfabrication.But they are expensive and difficult to integrate into other wearable substrate（cloth and paper,etc.）,which hinder the future industrialization of wearable electronic devices.To solve these issues,this paper is committed to developing novel high-performance printable electrode materials and manufacturing processes to manufacture the low-cost flexible supercapacitors,promoting the development of wearable electronic devices.The research contents mainly include the synthesizing of novel electrode materials,formulating of printable functional inks,the optimization of printing process,boosting the electrochemical performance of printing electronic devices and their applications.First,to obtain electrode materials with excellent electrochemical performance,it is necessary to develop a new type of pseudocapacitive electrode material with a framework structure and multiple reaction sites.We have synthesized the pseudocapacitive electrode material（Fe HCFs）with a frame structure by using the chemical co-precipitation method and solvothermal method.It is significant to study the effect of the crystallinity and morphology of Fe HCFs electrode materials on the electrochemical performance.The results showed that the Fe HCFs nanoflowers prepared by the hydrothermal method possess good crystallinity,and exhibits specific capacitance as high as 313 F/g at current density of 1 A/g.From the perspective of electrode material synthesis,a low-cost,large-scale method for preparing high-performance electrode materials is proposed.To further improve the cycle stability and capacitance of electrode materials,this section proposes the Ni-doping and Na OH etching strategy to prepare Ni HCFs electrode materials with excellent stability and more active sites.The specific capacitance of the prepared Ni HCFs after the optimized structure can reach to 230.5F/g.After 10000 cycles,the specific capacitance still maintains that of the initial 91%.From the perspective of process optimized,the composites of the printable ink were formulated.Then,a general screen-printing ink system was established.The Ni HCFs-based functional ink was successfully printed on PET substrates.And by exploring the printed supercapacitors with the interdigital structure and the sandwich structure,the specific capacitance can reach 3 m F/cm².This all-printing strategy provides a new idea for the preparation of flexible supercapacitors.Subsequently,in order to further improve the electrical conductivity of the new HCF electrode material,this system constructed CoHCFs electrode materials by doping Co ions.CoHCFs was prepared by using the co-precipitation method,possessing uniform nanocube structure with diameter particle size of about 400 nm.The electrode material combines large-frame ion transport and high conductivity.The specific capacitance can reach to 425 F/g（at current density of 1 A/g）,and the coulombic efficiency is as high as 94%.Subsequently,the ink was successfully printed on flexible PET substrate,and a variety of patterned（square,flower-like,carp,etc.）printed supercapacitors were obtained.The specific capacitance was high to 12.5 m F/cm²,and the energy density can reach 0.0011 m Wh/cm².After 8000 cycles,the specific capacitance can still maintain 90%.This fully printed flexible supercapacitor not only shows excellent electrochemical performance,but also outstanding flexibility.After a variety of bending angles and hundreds of bending cycles,the specific capacitance is not significantly reduced.After connected the printed flexible supercapacitor in series or in parallel,the device can stable power the LEDs,showing new application prospects in the field of flexible energy equipment for wearable electronics.Based on the above chapters,for the first time,a strategy for constructing electrode materials with metal doping and structural optimization is proposed,which further improves the capacitance performance of HCF electrode materials.In general,the electrochemical performance of the composite electrode material is better than that of a single electrode material.We constructed Mn HCFs electrode materials with flower-like Mn O₂ by the self-template method.The multi-structure MOFs material exhibits capacitance of 417 F/g,which is 2.4 times than that of the pure Mn HCFs material.Subsequently,screen printing methods were utilized to prepare flexible supercapacitors with various patterns.The areal capacitance is high to 16.8 m F/cm²,and the energy and power density were 0.0023 m Wh/cm² and 0.5 m W/cm²,respectively.This strategy paves a road to the development of printable energy storage devices with high energy density,capacitance and flexibility.更多还原