Highly conductive supercapacitor based on laser-induced graphene and silver nanowires

One of the foremost necessary desires of energy systems has been the existence of efficient, flexible, transportable, and eco-friendly devices. Among all the energy storage systems, supercapacitors have attracted plenty of attention thanks to their distinctive properties. Among all capacitor technologies, laser-induced graphene (LIG)-based capacitors are within the spotlight nowadays due to their high flexibility and simple manufacture. The most downside with LIG-based capacitors is their low conductivity and low charge capacity. During this work, to overcome this problem, the surface of LIG is covered with silver nanowires (AgNWs) and LIG/AgNWs composite is employed to form supercapacitor. In this study, all the electrochemical properties of the prepared composite were investigated, and therefore the results showed that AgNWs could increase the electrical conductivity of LIG by about 2.25 times, improve electrode–electrolyte interaction, and increase areal capacitance by 1.3 times. Additionally, the synthesized supercapacitor shows stable cyclic behavior and retention capacity equal to 78% after 1000 charge–discharge cycles. A singular increase in LIG conductivity and improved in its cyclic performance. Furthermore, galvanostatic charge/discharge curves indicated acceptable charge capacity of the LIG/AgNWs supercapacitor.

     

MWNTs/PANI composite materials prepared by in-situ chemical oxidative polymerization for supercapacitor electrode

Multi-walled carbon nanotubes (MWNTs)/polyaniline (PANI) composite materials were prepared by in-situ chemical oxidative polymerization of an aniline solution containing well-dispersed MWNTs. The supercapacitive behaviors of these composite materials were investigated with cyclic voltammetry (CV), charge–discharge tests, and ac impedance spectroscopy, respectively. The composites based on the charge-transfer complex between well-dispersed MWNTs and PANI matrixes show much higher specific capacitance, better thermal stability, lower resistance, and were more promising for applications in supercapacitors than a pure PANI electrode. The highest specific capacitance value of 224 Fg⁻¹ was obtained for the MWNTs/PANI composite materials containing MWNTs of 0.8 wt%. The improvement mechanisms of the capacitance of the composite materials were also discussed in detail.     

SPS/PANI复合颗粒的制备与性能研究

掺杂态聚苯胺(PANI)在碱性环境下易脱掺杂是影响其应用的一个不利因素．本文通过对乳液聚合的聚苯乙烯(PS)颗粒进行磺化．得到表面磺化的PS颗粒(SPS)．然后在颗粒表面原位合成PANI．进一步得到表面由磺酸掺杂的PANI包覆的复合颗粒(SPS／PANI)。研究了PANI的原位聚合过程、复合颗粒的电导率和复合颗粒的耐碱性等．结果表明这种复合颗粒在弱碱性(pH=7～9)介质中的稳定性得到显著改善。     

基于电沉积技术构建聚苯胺/海藻酸膜及电化学性能研究

基于电沉积技术的方法在电极表面构建聚苯胺(PANI)/海藻酸膜,直接构建PANI/海藻酸修饰电极,结合了海藻酸的阳极电沉积和苯胺的电化学聚合,具有条件温和以及后处理简便的特点。PANI/海藻酸膜呈现出与PANI类似的深绿色,其不仅可以稳定的存在于电极表面,而且还可以从电极表面取下来作为独立的膜材料。X射线衍射、红外光谱以及扫描电镜的测试结果均表明利用电沉积技术在电极表面制备得到了PANI/海藻酸膜。电化学性能分析结果表明,与PANI修饰电极相比,PANI/海藻酸修饰电极的电荷转移电阻更小,具备更高的电化学电容、更好的电荷储存能力和循环稳定性。     

聚吡咯涂层织物的介电性能研究

采用原位聚合法以棉机织物、尼龙为基布,以吡咯为单体,制备了具有良好介电性能的柔性聚吡咯涂层棉织物和聚吡咯涂层尼龙织物,探讨了掺杂剂种类、掺杂剂浓度对聚吡咯涂层棉织物、聚吡咯涂层尼龙织物介电性能和表面电阻的影响.结果表明,掺杂剂对聚吡咯复合材料的介电性能和表面电阻的影响较大.所制备的聚吡咯涂层棉织物、聚吡咯涂层尼龙织物均具备良好的介电性能和导电性,为最终开发出较为实用的多功能吸波复合材料奠定了基础.     

TiO_2光阳极表面原位聚合聚苯胺的制备及表征

为有效解决染料敏化太阳能电池(DSSC)的固态电解质与光阳极界面接触差的问题,文中采用化学原位聚合法在染料敏化TiO2光阳极表面制备聚苯胺(PANI)导电膜,研究了PANI成膜的最佳工艺参数。通过微观形貌观察及电导率测试说明,低温条件用樟脑磺酸(CSA)掺杂PANI薄膜颗粒细小均匀,电导率高达6.297S/cm。红外光谱分析表明,用CSA掺杂PANI较盐酸掺杂的电荷离域更充分,掺杂效果更好。PANI/Dye-TiO2复合膜在可见光区的吸收峰增多,吸收频带增宽;最后通过DSSC电池性能测试得到以PANI为电解质的DSSC较液态DSSC开路电压高,短路电流低的结果。     

Preparation and microwave absorbing properties of nickel-coated carbon fiber with polyaniline via in situ polymerization

Electric conductive and microwave absorbing material PANI/Ni/CF was prepared by in situ polymerization of polyaniline on the surface of nickel-coated carbon fiber (Ni/CF). The morphologies and structures of CF, Ni/CF, PANI and PANI/Ni/CF were characterized by scanning electron microscope and X-ray diffraction. Results show that the CF was wrapped tightly around the nickel layer, and the Ni/CF was coated by PANI. Measurement of four probes resistance tester indicates that the electrical conductivity of PANI/Ni/CF was great improved compared with PANI and PANI/CF. Vibrating sample magnetometry shows that the magnetic saturation intensity of Ni/CF and PANI/Ni/CF was 13.8 and 2.3 emu/g, respectively. According to the vector network analyzer, the microwave absorbing properties of PANI/Ni/CF were better than those of PANI and PANI/CF, and its minimum loss value is ?12.4 dB at 8.8 GHz.     

Fabrication of Polyaniline/Graphene/Tb3+ Conductive Composite Material

Polyaniline/graphene/Tb³⁺(PANI/GN/Tb³⁺) composite material was successfully prepared by the method of in-situ polymerization. The morphology of this as-formed composite material has been confirmed by scanning electron microscope (SEM) analysis. SEM images illustrated that the PANI were uniformly deposited on GN nanosheets. PANI/GN/Tb³⁺ composite material exhibited high electrical conductivity than the pristine PANI. What's more, results also demonstrated that the synthesized composite material has found wide promising applications in capacitors. Finally, the conductive mechanism of PANI/GN/rare earth composite is discussed in this paper, the conductivity of nanocomposites offered upgrade first than descending latter tendency with different content of Tb³⁺ ions. The results should be attributed to the special electronic structure and excellent magnetic of rare earth ions, which can influence the polymer chains.     

A thin PANI and carrageenan–gold nanoparticle film on a flexible gold electrode as a conductive and low-cost platform for sensing in a physiological environment

In this work, we report the production of a layer-by-layer (LbL) film of gold nanoparticles stabilized with carrageenan (carr-AuNPs) interspersed with a conductive polyaniline (PANI) layer. Conventionally, PANI has poor electroactivity in physiological buffers, limiting its using in electrochemical biosensors. The films were prepared on low cost and easy to manufacture flexible gold electrodes (FEAu). Two adsorption sequences were tested for production of the films—PANI/carr-AuNP and carr-AuNP/PANI. The gold nanoparticle size and colloidal stability were characterized. The films were characterized by cyclic voltammetry, UV–visible spectroscopy and atomic force microscopy. The results showed the synergistic effects of the carr-AuNPs (120 nm) and PANI, which improved both the electrochemical response and the stability of the conductive polymer in physiological medium by three times. The presence of the carr-AuNPs in the film caused a significant increase in roughness of the FEAu-modified electrode compared to that of an unmodified electrode, resulting in an increased active electrode area. Studies of film growth by UV–Vis spectroscopy indicated that the deposition mechanisms of both films involved an auto-regulating adsorption process, with the same amount of material adsorbed in each coating step. The PANI/carr-AUNP film showed considerable improvement in stability and conductivity compared to PANI-only films in the physiological environment, which confers advantages for use as a biosensor.     

AgNWs-TPU/PVDF柔性薄膜电容传感器的制备和性能

用醇还原法制备长径比约为800的银纳米线(AgNWs)并分散成网状结构,用溶液流延法使用聚偏氟乙烯(PVDF)和不同质量分数的聚氨酯(TPU)制备柔韧性PVDF/TPU复合薄膜,然后将AgNWs网固定在PVDF/TPU柔性薄膜的表面作为电容的极板制备出柔性薄膜电容式传感器。用扫描电子显微镜(SEM)、紫外-可见光谱和X射线衍射(XRD)等手段表征了AgNWs的结构,使用电子强力拉伸仪、方块电阻仪、三电极系统和LCR数字电桥检测了柔性薄膜电容式传感器的性能。结果表明：网状结构的AgNWs电容单侧极板上的方阻为15.635 mΩ/sq;TPU与PVDF质量比为2∶8的薄膜其断裂伸长率为91.2%,韧性最好,其比电容为375 μF/g;随着传感器弯曲角度的增大其输出电容值随之增大,输出电容值与弯曲角度在一定范围内呈线性关系,弯曲角度为180°时输出最大电容为436 μF。     

聚苯胺/聚丙烯复合导电纤维的结构与性能

采用现场吸附聚合法(原位聚合法)制备了聚苯胺/聚丙烯复合导电纤维,讨论了掺杂酸浓度、氧化剂浓度、苯胺单体含量对纤维导电性能的影响。通过扫描电镜(SEM)、红外光谱分析(FT-IR)、纤维物理力学性能测定等,对导电纤维的结构与性能进行了研究。实验表明采用此法制得的复合纤维导电性能优良,电导率达到10-1数量级。     

Preparation process and properties of LiCoO2/PANI/dodecylbenzenesulfonate composite electrode materials

Composite materials that combine the lithium exchanging material LiCoO₂ and the conductive polymer poly(aniline) (PANI) have been investigated regarding their possible application to electrode materials of lithium batteries. Such composite materials have been prepared by means of polymerization of aniline in acidic suspensions of LiCoO₂ particles. PANI was synthesized by oxidative polymerization of aniline by ammonium persulfate in the presence of sodium dodecylbenzenesulfonate (SDBS) as a micellar template and dopant. The composite material consisted in LiCoO₂ particles dispersed in a continuous matrix of PANI. The ribbon-like morphology of the powdered material was distinctly different of the morphologies of the parent materials. The conductive material had conductivity close to that of PANI because the LiCoO₂ content of the composite material was low. The presence of the poorly conductive inorganic phase caused a significant loss of conductivity, showing that LiCoO₂ blocked electronic transfers between PANI crystallites. Ammonium persulfate caused the loss of lithium from LiCoO₂ when it was used at high concentration in the polymerization recipe. In this case a new phase made of Co₃O₄ formed by chemical decomposition of Li_xCoO₂. Thin films prepared from stable suspensions of composite materials in water show comparable electrical performance to that measured for bulk materials.     

Ultra-Stretchable Spiral Hybrid Conductive Fiber with 500%-Strain Electric Stability and Deformation-Independent Linear Temperature Response

Stretchable configuration occupies priority in devising flexible conductors used in intelligent electronics and implantable sensors. While most conductive configurations cannot suppress electrical variations against extreme deformation and ignore inherent material characteristics. Herein, a spiral hybrid conductive fiber (SHCF) composed of aramid polymeric matrix and silver nanowires (AgNWs) coating is fabricated through shaping and dipping processes. The homochiral coiled configuration mimicked by plant tendrils not only enables its high elongation (958%), but also generates a superior deformation-insensitive effect to existing stretchable conductors. The resistance of SHCF maintains remarkable stability against extreme strain (500%), impact damage, air exposure (90 days), and cyclic bending (150 000 times). Moreover, the thermal-induced densification of AgNWs on SHCF achieves precise and linear temperature response toward a broad range (−20 to 100 °C). Its sensitivity further manifests high independence to tensile strain (0%–500%), allowing for flexible temperature monitoring of curved objects. Such unique strain-tolerant electrical stability and thermosensation hold broad prospects for SHCF in lossless power transferring and expeditious thermal analysis.     

Fabrication of conductive network formed by polyaniline-ZnO composite on fabric surfaces

A conductive network consisting of polyaniline (PANI) and PANI/nm-ZnO immobilized on the surfaces of poly(ethylene terephthalate) (PET) fabrics was synthesized by a route involving a wet-chemical technique and in-situ chemical oxidative polymerization procedures. Morphological, structural, thermal and electrical properties of the PET fabrics modified with PANI-ZnO composites were analyzed. X-ray diffraction (XRD) measurements of the composites revealed that the crystal structure of incorporated ZnO undergone a weak distortion during the polymerization reaction and the XRD pattern of PANI was predominate. Attenuated total reflection Fourier transform infrared spectroscopic studies indicated the presence of interaction between ZnO nanorods and molecular chains of PANI in the ZnO/PANI layers. Field emission scanning electron microscope images implied the thin composite layers showed a submicro-sized rod like network and the homogeneous distribution on the substrates. Thermogravimetric studies exhibited that the PET-ZnO/PANI composite had a higher thermal stability than anyone of PET and PET-PANI. The surface resistance of ZnO/PANI conductive films was found to be smaller than the PANI film, which was declined as aniline concentration in adsorption bath increased and reached a relatively low value when Zn(NO₃)₂ concentration was at 0.03 mol/L in the precursor solution.     

有机化学合成法制备碳纳米管/聚苯胺复合材料

通过有机化学合成法使苯胺单体接枝到碳纳米管表面,然后再经化学原位聚合法制备碳纳米管/聚苯胺复合材料.用傅立叶变换红外光谱和扫描电子显微镜对复合材料的成分和形貌进行表征.用循环伏安法、恒流充放电和电化学阻抗等电化学测试手段来表征复合材料的电化学性能.研究结果表明,所制备的复合材料比容量可达到152F/g(有机电解液),显著高于同样条件下的纯聚苯胺、纯碳纳米管及由原位化学聚合法所制备碳纳米管/聚苯胺复合材料的电化学容量(65、25、80F/g),显示出良好的应用前景.     

基于界面相互作用构建纳米纤维素-羧基化碳纳米管-石墨/聚吡咯柔性电极复合材料

以纳米纤维素(CNF)、羧基化碳纳米管(CNTs—COOH)、铅笔石墨(PGr)、聚吡咯(PPy)为原料,通过真空抽滤、涂覆、氧化聚合等方法,同时基于氢键界面相互作用的原理,制备出具有石墨层结构的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料。结果表明,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料在平直、折叠和拉伸时不会断裂,展现出较强的力学性能,其拉伸强度达到28.90 MPa。亲水性CNF与CNTs—COOH构筑的多孔结构增强了离子和电子的扩散路径。PGr的加入有效增加了CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的导电路径,赋予其优良的导电性能。氧化聚合后得到的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的电导率达到5.403 S·cm?1。在1 mol·L?1 H₂SO₄溶液中,0.5 A·g?1电流密度下,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具有521 F·g?1的高比电容量,且经过1 500次充放电循环后,其电容保持率高达68%。基于柔性电极优良的力学性能、电化学性能和导电性能,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具备成为柔性储能器件电极材料的基本特性。      

原位聚合法制备PANI/EP导电防腐蚀涂层

传统方法制备的聚苯胺防腐蚀导电涂层,聚苯胺易下沉,使涂层电导率差.为此,借用原位聚合方法制备了聚苯胺/环氧树脂(PANI/EP)复合防腐蚀涂层.利用相应的性能测试方法检测和比较了不同反应条件下(如苯胺单体用量、引发剂的用量、酸量、聚合时间)合成的聚苯胺复合涂层的导电性能,并将其与传统方法制备的涂层进行了比较.结果表明:降低了氧化剂、酸的用量;因为降低了聚苯胺的粒径而减轻了聚苯胺粒子在涂层中的下沉,从而提高了涂层的导电性能,电导率达到1.6×10-2S/m.     

聚苯胺/硫复合材料作锂二次电池正极的研究

采用在化学氧化聚合苯胺的反应介质中分散单质硫的方法制备了聚苯胺/硫复合材料,借助扫描电镜对样品的微观形貌进行表征,表明苯胺的聚合倾向于在单质硫颗粒表面进行,形成聚苯胺包覆良好的硫复合材料.通过恒电流充放电、循环伏安、电化学交流阻抗等电化学测试研究了聚苯胺原位包覆对硫电极电化学性能的影响.结果得出,聚苯胺对硫的包覆能显著地改善硫电极的电化学性能,当充放电电流密度为0.2 mA/cm2时,初始放电比容量高达1134.01 mAh/g,循环30次后放电比容量仍可达526.89 mAh/g.电化学交流阻抗谱研究表明,聚苯胺的包覆有助于锂硫电池交流阻抗的降低.     

聚苯胺-石墨烯/聚酰亚胺复合导电纱的制备及其超电容特性

为了提高石墨烯/聚酰亚胺(rGO/PI)复合纱线电极的电化学性能,采用电化学聚合法在rGO/PI复合纱线表面沉积聚苯胺(PANI)颗粒,研究了沉积时间对PANI-rGO/PI复合导电纱的形貌及增重的影响。结果表明, PANI在rGO/PI复合纱线表面均匀沉积,且沉积量随着沉积时间的增加而增大。采用循环伏安法(CV)、恒流充放电法(GCD)研究了PANI-rGO/PI复合导电纱线的电化学行为。结果表明, PANI沉积时间对纱线电极的循环伏安特性、恒流充放电曲线等有很大的影响,当PANI沉积时间为900 s时,所得PANI-rGO/PI复合纱线电极的循环伏安特性和恒流充放电性能表现均最优,比电容为81.22 F·cm^-3,而rGO/PI纱线电极仅为16.4 F·cm^-3。以最优工艺制得的PANI-rGO/PI复合导电纱作为电极组装了纤维状超级电容器,采用交流阻抗谱法(EIS)、 CV及GCD对器件进行电化学性能表征。结果表明,该器件体积比电容可达41.73 F·cm^-3,在充放电3 000次后比电容依然能够维持在85%左右,所得纤维状超级电容器经过串联可成功驱动LED灯。     

碳纤维/棉纤维/聚吡咯柔性复合材料的制备及性能研究

柔性超级电容器作为一种储能器件,具有功率密度高、充电时间短、循环寿命长、比电容高等优点,可满足可穿戴器件的需求,而柔性电极材料是决定柔性超级电容器发展的关键因素,它决定着电容器的主要性能指标。采用混纺的方法制备了碳纤维含量为20%(质量分数)的碳纤维/棉纤维混纺纱线,然后通过电化学沉积法在碳纤维/棉纤维混纺纱线上生长聚吡咯颗粒,成功制备了20%(质量分数)碳纤维/棉纤维/聚吡咯柔性复合材料。利用扫描电子显微镜、拉曼光谱分析仪和电化学工作站研究了复合材料的形貌、聚吡咯沉积情况以及复合材料的电容性能。结果表明,20%(质量分数)碳纤维/棉纤维/聚吡咯柔性复合材料中,聚吡咯颗粒直径为30~60 nm,且沉积均匀,化学活性较高;在1.02 mA/cm^2电流密度下,复合材料的最大比电容达到1.28 F/cm^2,其高比电容归因于电极的独特结构;复合材料具有良好的柔韧性、机械稳定性和充放电循环寿命,其经过6000次弯曲循环后,电容保持率仍有80%以上,可以用作柔性可穿戴超级电容器的电极材料。