Artificial muscle using conducting polymers

We have investigated a method of preparing a large‐size anisotropic polypyrrole (PPy) film using a slab vessel consisting of poly(tetrafluoroethylene) (PTFE) walls as well as its actuation abilities. The PPy film can be grown along one side of the PTFE walls and exhibits morphological anisotropy of the PPy packing density along the thickness direction. A piece bends in a regular direction (the surface in contact with the PTFE wall) and reverts during a redox cycle without the use of any additional processes such as lamination. The actuation properties of the anisotropic PPy actuator strongly depend on the size of the cation in the driving electrolyte, and the bending behavior of this actuator at room temperature becomes slower for larger cations. On investigating the temperature dependence of actuation properties, the arrival time of the actuator (the time required for the tip of the actuator to touch the electrolyte surface upon stepwise potential change) was found to become shorter in all electrolyte solutions with different electrolytes. This result can be understood in terms of the thermally activated microscopic movement of the PPy main chains. Such behavior based on electrochemical stimulus not only provides information related to ionic transfer and storage but also suggests that the anisotropic PPy film can be put to practical use as an electrochemical actuator for artificial muscle which directly converts electrical energy into mechanical energy. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(4): 7–13, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20066     

Preparation and functions of conductive polymer/insulating polymer composite films using molecular self‐assembly

By exposing low‐density polyethylene to an atmosphere of fuming sulfuric acid, sulfonated low‐density polyethylenes (SPE) were prepared and the degree of surface sulfonation of the treated film was determined from the weight increase per unit area. Polypyrrole (PPy) films on the surface of SPE were grown by molecular self‐assembly and the properties of PPy/SPE composite films were investigated. Functional applications of PPy/SPE composite films are proposed, with particular attention to the movement properties of actuators using PPy/SPE composite films. © 1999 Scripta Technica, Electr Eng Jpn, 128(1): 1–8, 1999     

聚乙烯醇/硅酸镁锂碱性电池隔膜制备及表征

用溶液浇铸法制备含有聚乙烯醇(PVA)/硅酸镁锂(MLS)的有机无机复合碱性电池隔膜。采用扫描电镜、交流阻抗技术研究(PVA)/MLS复合隔膜的特性。在室温时(23℃),PVA/MLS复合隔膜离子电导率最高可达4.6×10-2S/cm。以PVA/MLS复合隔膜为隔膜组装氢镍电池,当以1倍率充放电时,在1.10～1.25 V有放电平台出现,电池经过300个循环后,放电效率仍然有91%,表明聚PVA/MLS复合隔膜的电化学性能很稳定。     

超级电容器用聚合物电解质的研究进展

针对聚合物电解质组成、结构和性能的差异,综述了近年来基于聚氧化乙烯(PEO)、聚偏氟乙烯(VDF)-六氟丙烯(HFP)[P(VDF-HFP)]、聚甲基丙烯酸甲酯(PMMA)、聚丙烯腈(PAN)和聚吡略(PPy)用于超级电容器聚合物电解质的研究进展.     

液晶离聚物/PEO固体聚合物电解质的研究

采用溶液铸膜法制备了含磺酸离子液晶离聚物(LCI)-PEO-高氯酸锂全固态聚合物电解质(SPE)。运用扫描电镜、数字显微镜、差示扫描量热法(DSC)、拉伸测试和交流阻抗对复合电解质膜的性能进行了表征,研究了液晶离聚物(LCI)对电解质结晶度、力学性能以及电导率的影响。结果表明,液晶离聚物(LCI)的加入虽然增加了聚合物电解质的结晶度,但是提高了电导率。当液晶离聚物(LCI)含量为3%时,电解质的室温电导率达最大值,为1.30×10-5S/cm。     

离子聚合物包覆的锂离子电池炭负极材料

用辐射聚合的方法在天然石墨颗粒表面包覆一层离子聚合物可以明显提高天然石墨的各种电化学性能,如首次库仑效率、循环性能.拉曼光谱研究表面包覆的离子聚合物可以明显抑制由于溶剂化锂离子共嵌入而造成的石墨层破坏,从而提高了石墨表面结构稳定性.扫描电镜照片显示包覆石墨表面形成的SEI膜在循环过程中保持稳定的形态,防止了石墨电极在循环过程中的阻抗增加现象.     

Space charge behavior in polymer film based on increment of capacitance under AC high field

Polymer materials have excellent dielectric and insulation properties; however, those properties in AC high field region have not been known well. Recently we established an evaluation method of high‐field AC dissipation current waveform of polymer materials 1 . AC dissipation current waveforms of polyethylene and polypropylene films show nonlinear distortion in AC high‐field region. This nonlinearity was thought to be related to the behavior of AC space charge formation in the sample near electrodes. The properties of space charge formed under AC high field at power frequency seem to differ from those formed under DC high field. The measurement of AC space charge distribution is not so easy due to the resolution limit of the space charge measurement. We studied the dielectric properties of biaxially oriented polypropylene (BOPP) film under AC high field up to 120 °C. It was found that tan δ, AC dissipation current (Ixr), and unbalanced component of capacitive current (ΔIxc) increased when the temperature became higher. In particular, ΔIxc increased above some threshold field and was considered to be due to the AC space charge formation. This AC space charge layer near electrode is thought to be formed due to carrier injection under AC high‐field application. Usually, the carrier mobility becomes smaller on lowering the temperature. Most of the carriers injected from the electrode are trapped near the electrode in the sample film. But in the high‐temperature region, the carrier mobility becomes larger and the carrier injection starts to increase from lower field. Many more carriers are injected from the electrode. It is thought that some of the injected carriers are trapped inside the sample film; the others go through the sample to the opposite side. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(2): 8–16, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10018     

聚苯胺/活性炭复合材料的制备及电化学性质

采用溶液聚合原位复合法制备出不同配比的聚苯胺/活性炭复合材料,在分别用扫描电镜(SEM)、红外光谱法(IR)、热重分析法(TG)和电阻率测试研究复合材料的形态、表面官能团、热性能和电导性能的基础上,使用恒流充放电和循环伏安(CV)技术研究了聚苯胺/活性炭复合材料作为双电层电容器电极时的电化学性质。实验结果表明:复合材料呈现较高的热稳定性,当炭含量达到20%时复合材料的导电性最好;50%活性炭含量的电极比电容高达400F/g;电极反应可逆性良好。     

锌镍电池用碱性聚合物电解质的研究进展

介绍了碱性聚合物电解质离子传输机理和性能要求,综述了近年来聚氧化乙烯(PEO)、聚乙烯醇(PVA)、聚丙烯酸钾(PAAK)用于锌镍电池碱性聚合物电解质的研究进展.     

聚吡咯/脲醛树脂多孔碳的超级电容性能

以脲醛树脂(UF)为前驱体,经高温碳化和氢氧化钾溶液活化处理,制备脲醛树脂多孔碳(UFC),采用原位化学聚合法制备聚吡咯(PPy)/UFC复合材料。通过SEM、XRD和红外光谱等分析复合材料的形貌和结构特征;采用循环伏安、电化学阻抗和恒流充放电测试复合材料的电化学性能。PPy/UFC复合材料比单独的PPy和UFC具有更高的比表面积和更好的电化学性能,以4 A/g在-1.0~0 V循环,比电容为545 F/g,循环2 000次的电容保持率为91%。     

Electrical, optical, and structural properties of ITO co-sputtered IZO films by dual target magnetron sputtering

We have investigated electrical, optical, and structural properties of indium tin oxide (ITO) co-sputtered indium zinc oxide (IZO) film prepared by a dual target direct current (DC) magnetron sputtering at room temperature in pure Ar ambient. It was shown that the resistivity and sheet resistance of ITO co-sputtered IZO films monotonically increased with increasing DC power of ITO target at constant DC power of IZO target. Synchrotron X-ray scattering and scanning electron microscope examination results show that addition of ITO in the IZO film lead to crystallization of IZTO film due to low transition temperature of the ITO from amorphous to crystalline. However, ITO co-sputtered IZO film (ITO/IZO power?=?100 W:100 W) exhibit higher work function than those of pure IZO and ITO film. It was found that the work function as well as the electrical, optical, and surface properties of the IZTO film could be controlled by varying the DC power of IZO and ITO targets, respectively.     

一种新型凝胶改性隔膜在MH-Ni蓄电池中的应用

研究了一种新型聚合物凝胶改性隔膜在MH-Ni蓄电池中应用的可能性。通过紫外接枝技术,在普通的聚丙烯隔膜两侧接枝了一层聚丙烯酸凝胶膜,当凝胶层吸附碱液后形成凝胶,使这个实验电池体系全固态化。对凝胶改性隔膜进行的电导率及循环伏安测试表明,其作为电解质的性能与KOH水溶液相当;对用凝胶改性隔膜组成的实验电池研究表明,电池的充放电性能及循环寿命均较好,特别是电池的储存性能很好,与相同条件下用KOH水溶液为电解质的实验电池相比,其容量保持率提高了近1倍。同时在整个实验过程中也没有发现凝胶改性隔膜发生降解反应,说明凝胶改性隔膜非常稳定,有可能运用于商业MH-Ni蓄电池。     

Barrier effect of treeing in composite insulating materials with heat-adhesive interfaces of different polymers

A polymer/polymer composite system is widely used in high-voltage equipment and power cables. The interface of this composite system plays an important role in the electrical degradation, such as electrical treeing or partial discharge, of the composite system. Therefore, it is important to study the effect of an interface on the electrical treeing of polymer/polymer-composite insulating materials. In this paper, we describe the tree growth and complete breakdown characteristics of specimens with a polymer barrier film layer molded in ethylene vinyl acetate copolymer (EVA), in which the interface of EVA and the barrier film is perpendicular to the electric field under an AC voltage. It is found that with a barrier film, the tree growth is retarded on the barrier film, which then punctures the film, or develops along the edge of the film. It is also found that the pressure of decomposing gas in the tree channels plays an important role in tree propagation.     

锂离子电池用P(PETMA)/P(VDF-HFP)基凝胶聚合物电解质

以季戊四醇和甲基丙烯酸为原料,制备具有多支链结构的不饱和羧酸酯,再与P(VDF-HFP)共混,经热聚合制备锂离子电池用凝胶聚合物电解质,用红外光谱、循环伏安、X射线衍射、交流阻抗等研究电解质的性质。结果表明,用该多支链羧酸酯制备聚合物电解质时,单体用量少,获得的凝胶粘性好,室温离子电导率为1.03 mS/cm,电化学稳定窗口达到5.2 V,以此制备的聚合物电池界面阻抗小,放电性能好。     

Microfabrication of ionic polymer actuators by selective plasma irradiation

A novel method for fabricating a miniaturized ionic polymer–metal composite (IPMC) with plated gold electrodes is developed by combining selective plasma irradiation and electroless plating. The membrane is irradiated by SF₆ or CF₄ plasmas through a stencil mask prior to plating to prevent deposition of a gold electrode in the plasma‐irradiated area. Miniaturized IPMCs are fabricated with a 400‐µm‐wide line‐and‐space pattern. The proposed method has the potential to realize miniaturized IPMCs combined with microelectromechanical system (MEMS) devices because this provides a direct and simple fabrication process. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Study on the electrical and optical properties of ITO and AZO thin film by oxygen gas flow rate

Transparent conductive oxide (TCO) thin films such as tin doped indium oxide (ITO), zinc doped indium oxide (IZO) and Al doped zinc oxide (AZO) have been widely used as transparent electrode for display. ITO and AZO thin films for display was prepared by the facing targets sputtering (FTS) system. The FTS method is called a plasma-free sputter method because the substrate is located apart from plasma. This system can deposit the thin film with low bombardment by high energetic particles in plasma such as γ-electrons, negative ions and reflected Ar atoms. ITO and AZO thin films were deposited on glass substrate at room temperature with oxygen gas flow rate and input power. And the electrical, structural and optical properties of the thin films were investigated. As a result, the resistivity of ITO, AZO thin film is 6?×?10^?4 Ω cm, 1?×?10^?3 Ω cm, respectively. And the optical transmittance of as-deposited thin films is over 80% at visible range.     

复合型聚合物电解质膜的研究

报导了一种复合聚合物电解质膜的制备方法,并对其结构和电化学性能进行了研究.与普通塑料化聚合物电解质膜相比,复合电解质膜具有机械强度高、变形性小、电导率高等特点,能满足聚合物锂离子电池的规模化生产.     

Ag/PVA纳米聚合物基复合材料的制备及其电性能研究

通过溶胶-凝胶法制备Ag/PVA纳米聚合物基复合材料，对复合材料的微观结构进行了表征，并对这种复合材料的电学性能进行了研究。结果表明，纳米银可以通过溶胶一凝胶法均匀分散在水溶性的PVA聚合物中，并且这种复合材料具有独特的电学性能，即在合适的纳米银含量时这种复合材料表现出高于其基体的电阻率和击穿场强，并且低温下这种现象更加显著，利用纳米金属粒子在绝缘体中的库仑阻塞效应对这些结果进行了解释。     

Electrochemical characteristics of semi conductive silicon anode for lithium polymer batteries

In this paper, the electrochemical characteristics of semi conductive silicon thin films (n-type and p-type silicon) anodes integrated with the solid polymer electrolyte for lithium polymer batteries were investigated. The charge/discharge cycling tests revealed that the phosphorus-doped n-type silicon electrode shows the most stable cyclic performance after the 40^th cycle and still maintains a reversible specific capacity of about 2,500 mAh/g. The enhanced electrochemical performance of the doped silicon anode was attributed to the enhancement of its electrical conductivity, which was further confirmed by impedance spectroscopy and surface analysis by XPS.     

纳米SiO2表面基团对复合聚合物电解质性质的影响

采用不同表面化学状态的纳米SiO2,制备了聚环氧乙烷[Poly(ethyleneoxide),PEO]基复合聚合物电解质(Compositepolymerelectrolytes,CPE),通过DSC技术和FTIR光谱研究了纳米填料对聚合物体系体相成分的影响,并对其离子电导率、锂离子迁移数、电化学稳定性等电化学性质进行了表征。结果表明,纳米填料的表面化学状态对CPE的影响很大,亲水性的SiO2对CPE的相组成几乎没有改变效果,但疏水性的SiO2明显降低了聚合物体系的晶相成分。电化学测试结果显示,采用表面烷基化的SiO2制备成的CPE比采用亲水性SiO2的CPE显出更高的离子电导率、锂离子迁移数和更宽的电化学稳定窗口,揭示了体系的相组成和PEO/SiO2相界层是影响CPE内离子传输的两个重要因素。