【作者】 岳彬彬；

【导师】 丁辛；

【作者基本信息】 东华大学 ， 纺织工程， 2013， 博士

【摘要】 纺织技术与信息技术、电子技术及纳米技术等的结合,赋予纺织品更多的附加功能,使得纺织品朝着智能化的方向发展,成为“智能纺织品”。智能纺织品包含传感、驱动、计算及提供能源等功能,其植入设备可以进行多功能交互设计,进一步提高了人们的生活品质,并在生物医学、运动、军用、娱乐及时尚等等领域具有广泛的应用。智能纺织品上所有的传感器、驱动器等电子元件等都需要有电源的提供,然而传统的电源皆为刚性结构,非柔性的电源装置使得整个系统的可穿戴性受到极大的挑战。若要实现理想的可穿戴,就需要发展柔性、轻质、便携的能源转换或存储装置。另外,为了与服装结合良好,且不影响人体的运动,对于可穿戴的电源装置也要求其具有良好的可拉伸性能,即在拉伸的状态下不会发生性能的衰减,理想的技术措施是将其制备成可拉伸的织物结构。超级电容器是一种新兴的能量储存装置,具有高功率密度、短充电时间、高循环性能和节约能源等特点,在轻薄、柔性的可穿戴电源领域得到广泛的关注,但目前研究较多的柔性超级电容器,虽具备一定的柔性,但基本不具备可拉伸性,即不能在小应力下实现与纺织品类似的大变形。课题选择聚吡咯(PPy)涂层织物作为研究对象,探讨其作为超级电容器电极材料的可行性,并针对其拉伸过程中及拉伸前后的电化学性能及性能改善来开展探索工作。课题的内容包括：(1)利用普通的棉织物,通过原位化学聚合(CP)、气相沉积聚合(CVD)及界面聚合(P),制备聚吡咯涂层织物,探索不同聚合方式对涂层织物性能的影响。气相沉积及界面聚合得到的PPy涂层棉织物的表面电阻分别为310Ω/□和1200Ω/(?)。CP、CVD织物与IP织物同样显示出了一定的电化学性能,且CVD和CP织物优于IP织物。利用原位化学聚合制备PPy涂层锦纶/氨纶织物,探讨实验条件对结果的影响。掺杂剂和聚合时间的不同会影响涂层织物的导电性能,最佳聚合时间为2h,在最佳聚合时间下,pTS(对甲苯磺酸,p-toluenesulfonic acid)掺杂的织物表面电阻最高,为32,500Ω/(?); Na2NDS(吡咯,2,6-萘二磺酸二钠盐,naphthalene-2,6-disulfonic acid disodium salt)最低,其电阻为149Ω/□。聚合后,由于聚吡咯涂层的影响,锦纶/氨纶织物拉伸拉伸应力稍微增大,但绝对数值不大,基本保持织物原有的拉伸性能。循环伏安测试时,不同电解液也会对测试结果造成影响,采用1M的NaCl溶液时,PPy涂层锦纶/氨纶织物的电化学性能最好,在扫速为10mV s-1时最高比容量达123.3Fg-1。当扫速进一步增大时,由于溶剂化离子迁移时的弛豫时间影响,比容量逐渐减小。(2)选择原位化学聚合得到的PPy涂层锦纶/氨纶织物为对象,探讨其拉伸时及拉伸前后电学性能和电化学性能的变化。聚吡咯与织物结合紧密,并呈现出良好的拉伸性能。在纵向拉伸过程中,聚毗咯涂层织物的电阻随着拉伸量的增加而减小。在反复拉伸1,000次后,织物的电阻变大。拉伸应变越大,电阻的增幅越大。但是,在反复高强度拉伸后,聚吡咯涂层织物依然能保持较高的电化学性能,如：1,000次100%的拉伸后,织物比容量的减少不到10%。聚吡咯涂层织物的电化学性能随着拉伸程度(范围为0%～60%)而逐渐改善。在三电极体系中,当织物伸长到60%时,其比容量从未伸长时的69.7F g-1(50mVs-1)和：(?)9.4Fg-1(100mVs-1)分别增长到101.9(50mV s-1)和88.2Fg-1(100mV s-1)。在两电极体系中,电流密度为1.0Ag-1时,当织物伸长为20%、40%和60%时,比容量从未拉伸时的108.5Fg-1分别增长到117.6、119.6和125.1Fg-1。另外,拉伸也进一步改善聚吡咯涂层织物的循环性能,在多次充放电之后能保持更多的容量：充放电500个循环后,未拉伸织物剩余比容量为初始值的12.5%；拉伸分别为20%、40%和60%时,剩余的容量分别为其初始容量的45%、53%和55%。但是,考虑到实际应用的需要,其比容量及循环性能还需要进一步提高。(3)利用磁控溅射对棉织物进行金涂层,然后在有机溶剂中进行聚吡咯电化学聚合,成功制备了聚吡咯涂层棉织物。所得织物的表面电阻为105Ω/□。在纵向拉伸的过程中,金涂层织物的电阻在初始阶段(3%-25%)有较大波动,之后保持平稳,聚吡咯涂层织物的电阻随着拉伸先增大再减小,但两者在拉伸高达140%时电阻都能保持稳定,显示出良好的拉伸电性能。聚吡咯涂层织物循环拉伸时,织物电阻随着拉伸先增大再减小,应力回复时呈现同样的变化趋势。在反复拉伸1,000次后,聚吡咯涂层织物的电阻变大,但仍保持较低的数值(约1,645Ω/□)。循环伏安测试结果显示出该聚吡咯涂层织物具有良好电容性能,在扫速为10、50、100、200及300mV s-1时的比容量分别为254.9、216.7、196.8、166.4和144.8Fg-1。与化学聚合得到的聚吡咯涂层织物相比,比容量有很大提高。在拉伸状态下测试时发现,与化学聚合织物结果不同的是,拉伸30%和未拉伸的织物循环伏安结果基本一致,在扫速为10、50、100、200及300mV s-1时的比容量分别为256.3、225.0、203.4、175.0和149.8g-1。循环性能测试结果表明,电化学聚合得到的聚吡咯涂层织物循环性能有所改善,而且在拉伸30%时循环性能还有进一步提高,即500个循环后剩余比容量为初始值的51%。但是在3,000个循环后,比容量的衰减仍十分严重,剩余比容量仅为初始值的13%。锦纶/氨纶织物和棉织物的拉伸性能不同,因此经过聚吡咯涂层后其电化学性能随拉伸的变化也不同：聚吡咯涂层锦纶/氨纶织物的电化学性能随着拉伸(0%～60%)而不断改善,聚吡咯涂层棉织物则是在不同拉伸状态下(0%和30%)保持不变。这也会为以后的实际应用中超级电容器电极材料的选择提供一定的参考,可以根据不同的需要来选择不同拉伸性能的织物基体。(4)为进一步改善聚合物的电化学性能,引入了共聚的概念。通过电化学聚合,利用1M LiC104作为掺杂剂,成功地在乙腈溶剂中制备了吡咯和3-(4-叔丁基苯)噻吩的共聚物。SEM、元素分析和FTIR的结果显示共聚物特征较接近聚吡咯,但其中同时包含Py和TPT单体。将得到的共聚物和各单体聚合物分别组装成对称型超级电容器,并进行电化学测试。结果发现,虽然PTPT本身性能较差,但少量PTPT的加入却能明显改善聚吡咯的电化学表现。这可能是因为PTPT的加入,增大了聚合物的比表面积,使其电活性表面最大化,且促进了离子的传递。共聚物超级电容器表现出最高的比容量,在扫描速度为5和500mV s-1时分别为291和203Fg-1。与此相比,在同样条件下,PPy电容器的比容量为216和166F g-1, PTPT电容器为26和6Fg-1。在充放电测试中,共聚物电容器在0.5Ag-1的电流密度下比容量值为279Fg-1,远高于PPy的227Fg-1和PTPT的45Fg-1。在1,000个循环充放电测试后,PPy和PTPT电容器比容量的损失分别为16%和60%,而共聚物电容器的比容量衰减仅为9%,显示了其循环性能的明显改善。利用CV在100mV s-1对共聚物超级电容器进行10,000个循环测试后,其比容量仍能保持为初始值的67%,与此相比,PPy可保持的比容量为48%,PTPT为46%。更多还原

【Abstract】 The incorporation of electronics into wearable items has demonstrated significant advances in terms of miniaturisation, functionality and comfort. These e-textiles have found broad applications in continuous personal health monitoring, high performance sportswear, wearable displays and a new class of portable devices. Being an indispensable part of these applications, lightweight, stretchable and wearable power sources including batteries and supercapacitors are strongly demanded. To have good combination with fabric, and to make people comfortable while wearing them, the energy source should be flexible and stretchable, the ideal wearable power sources would be made into breathable textile formats with stretchability (i.e. mechanical resilience) being conformal to the curved surface and sustain its function during the body movement. As one type of power sources, supercapacitors possess the advantages of higher power densities, excellent reversibility and long cycle life. They are gaining increasing interest in the application of light weight, ultrathin energy management devices for wearable electronics. Recently, there has been an emerging interest in flexible or stretchable supercapacitors. However, most research works are about flexible supercapacitors, and stretchable ones have been reported rarely. To the best of the authors’ knowledge, the application of conducting polymer coated fabric in stretchable supercapacitors has not been reported yet.Here we describe a daily-used Nylon Lycra fabric or cotton fabric coated with polypyrrole (PPy) as electrode for stretchable supercapacitors. And different polymerization methods have been investigated to further improve the electrochemical properties of the resultant polymer.(1) Conductive PPy coated cotton fabric has been successfully fabricated via different polymerization methods:in-situ polymerization (CP), chemical vapour deposition (CVD) and interfacial polymerization (IP). And fabrics obtained though different polymerization methods displayed different surface morphology. The surface resistances of CVD and IP fabrics were310Ω/(?) and1200Ω/(?), respectively. CVD fabric showed better electrochemical properties than CP and IP fabrics.For the in-situ polymerizied PPy coated Nylon Lycra fabric, the conductivity of the fabric could be affected by reaction time and dopants. The best reaction time was2hours. When pTS was used as dopant, the surface resistance was highest (32,500Ω/(?)), while the lowest surface resistance of149Ω/(?) could be obtained when Na2NDS was used as dopant with the reaction time of2h at4℃. Compared with the original Nylon Lycra fabric, slightly higher drawing force was shown for PPy coated fabric, which might be attributed to the stiff PPy layer coating. EIS test proved that the sample obtained after2h polymerization showed the best electrochemical properties. The type of electrolyte used in CV test also had an influence on the electrochemical performance of PPy coated fabrics and highest specific capacitance of123.3F g-1was obtained in1M NaCl at a scan rate of lOmV s-1. However, the specific capacitance decreased when the scan rate increased. This might be explained by the entering into/ejecting and diffusion of counter ions being too slow compared to the transfer of electrons in the PPy matrix at high scan rates.(2) PPy coated Nylon Lycra fabric obtained via in-situ chemical polymerization of was investigated as electrode material of stretchable supercapacitor. Such a conductive fabric showed outstanding flexibility and stretchability, and demonstrated strong adhesion between the PPy and the fabric of interest. During stretching at wale direction, the resistance of this PPy coated Nylon Lycra fabric decreased with increasing elongation. After being stretched for1000times, the resistance of this conductive fabric was irreversibly increased. Higher irreversible resistance increase was induced with higher strain applied. Nevertheless, PPy coated Nylon Lycra still sustained its electrochemical properties with less than10%specific capacitance loss after being stretched to100%for1000times. Interestingly, its electrochemical properties could be improved with in-situ strain applied and exhibited a higher specific capacitance. The capacitance increased from69.7and39.4F g-1with0%elongation to101.9and88.2F g-1with60%strain applied at the scan rate of50and100mV s-1, respectively. In a two-electrode system at a current density of1.0A g-1the specific capacitance increased from108.5F g-1with0%strain to117.6,119.6and125.1F g-1with20%,40%and60%elongation, respectively. Also the cycling stability was improved with the applied strain. After500charging/discharging cycles, only12.5%of the initial capacitance was retained for the fabric with no strain applied. The retained capacitance of the fabric increased to45%,53%and55%with20%,40%and60%elongation, respectively. However, we should point out the cycling stability need to be improved for practical applications.(3) Electrochemical polymerization was used to obtain PPy coated cotton fabric with better electrochemical performance. The cotton fabric displayed a surface resistance of105Ω/(?) after being sputter coated with gold and electrochemically coated with PPy with50%strain applied. For the Au coated cotton fabric, the normalized electrical resistance increased rapidly with strain at the initial stage of stretching with violent vibration. Then the resistance was decreased and gradually stabilized. The electrical resistance of PPy coated cotton fabric showed a much smaller initial increase with strain after which the resistance was gradually stabilized. They both exhibited excellent stretch ability and sustained their conductivity even at140%elongation. During cycling test, the normalized resistance initially increased and then decreased with elongation. When the strain was released, the resistance was also increased first and then decreased. After being stretched to50%for1000times, the resistance of this conductive fabric was irreversibly increased to1645Ω/(?).CV results showed good capacitive behaviour of this PPy coated cotton fabric even at high scan rates. It delivered a specific capacitance of254.9,216.7,196.8,166.4and144.8F g-1at a scan rate of10,50,100,200and300mV s-1, respectively. Those values were much higher than that of the fabric obtained via chemical polymerization. While30%strain was applied to the fabric, its specific capacitance slightly increased to256.3,225.0,203.4,175.0and149.8F g-1at a scan rate of10,50,100,200and300mV s-1, respectively. The cycling stability of the PPy coated fabric obtained via electrochemical deposition was also better than that of the chemically polymerized fabric,51%of the initial capacitance was remained after500CV cycles at a scan rate of100mV s-1. And it was further improved while the fabric was tested with30%strain applied. However, after3000cycles of CV, the specific capacitance still decreased severely, only13%of the initial capacitance was retained.Due to the different stretchability of Nylon Lycra fabric and cotton fabric, their electrochemical properties also exhibited different variation trends with strain applied. For the Nylon Lycra fabric, its electrochemical properties could be improved with in-situ strain applied (0%-60%) and exhibited a higher specific capacitance. As to the cotton fabric, its specific kept nearly unchanged with or with30%strain applied. This could provide a reference for the supercapacitor electrode material choosing according to the different needs for various occasions.(4) Copolymerization was introduced to improve the performance of the resultant polymer. The copolymer of pyrrole and3-(4-tertbutylphenyl)thiophene (TPT) was synthesized via electropolymerization in acetonitrile with ClO4-as dopant. SEM, FTIR and elemental analysis results showed that the copolymer included both Py and TPT units while the amount of TPT unit was much smaller than Py unit. The resultant homopolymers and copolymer were assembled into supercapacitors to investigate their electrochemical performances. Though the homopolymer PTPT displayed very poor electrochemical properties, an introduction of small amounts of TPT units leads to superior electrochemical properties in comparison with the homopolymer PPy or PTPT. It might be ascribed to the introduction of the PTPT units into PPy improved its available surface area. Copolymer delivered the highest capacitance of291and203F g-1at a scan rate of5and500mV s-1, in comparison with216and166F g"1for PPy,26and6F g-1for PTPT, respectively. In charge/discharge tests, the copolymer electrode exhibited a capacitance of279F g-1at0.5A g-1, much higher than that of PPy (227F g-1) and PTPT (45F g-1). The copolymer electrode also showed an improved cycling stability. After1000charge/discharge cycles at a current density of5A g-1only a9%decrease of capacitance was observed, while PTPT and PPy electrodes lost60%and16%of their initial capacitance, respectively. The cycling stability has also been tested via CV at a scan rate of100mV s-1. After10000CV cycles,67%of the initial capacitance was remained for the copolymer supercapacitor, while the remained values were48%and40%for supercapacitors based on PPy and PTPT, respectively.更多还原