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聚乙二醇(PEG,Mn=400,600),季戊四醇与CH2Cl2在碱性条件下,通过williamson反应合成以季戊四醇为核、以聚氧化乙烯的嵌段物为臂的星形网状聚合物.FTIR和1H-NMR分析表明,聚合物分子为C[CH2-OCH2O-(CH2CH2O)n-CH2O-]4的重复单元结构.季戊四醇的加入明显地改善了聚合物电解质的成膜性、力学性能和热稳定性.对聚合物电解质进行交流阻抗导电性研究表明:在25℃,离子电导率随着锂盐浓度的变化相继出现两个峰值,当w(Li-ClO4/聚合物)=8%时,离子电导率达1.03× 10-4S/cm;离子电导率随着温度的升高而迅速增加,且呈非Arrhenius变化. 相似文献
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Polymer is an important constituent of polymer gel electrolytes along with salt and solvent. The salt provides ions for conduction
and the solvent helps in the dissolution of the salt and also provides the medium for ion conduction. Although the polymer
added provides mechanical stability to the electrolytes yet its effect on the conductivity behaviour of gel electrolytes as
well as the interaction of polymer with salt and solvent has not been conclusively established. The conductivity of lithium
ion conducting polymer gel electrolytes decreases with the addition of polymer whereas in the case of proton conducting polymer
gel electrolytes an increase in conductivity has been observed with polymer addition. This has been explained to be due to
the role of polymer in increasing viscosity and carrier concentration in these gel electrolytes. 相似文献
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以甲基丙烯酸甲酯(MMA)、醋酸乙烯酯(VAc)和丙烯酸锂(LiAA)为单体,采用种子乳液聚合法制备了(P(MMA-VAc-LiAA)三元共聚物.利用红外光谱(FTIR),核磁共振(~1HNMR),差示扫描量热(DSC) /热重分析(TG),X射线衍射(XRD),扫描电镜(SEM)等方法对聚合物的结构进行了表征.将P(MMA-VAc-LiAA)与LiClO_4共混,采用流延法制备了聚合物电解质膜,用交流阻抗方法测试了电解质膜的电导率,结果表明,该聚合物电解质室温离子电导率可以达到10~(-3)S/cm.而且离子电导率随着温度的升高而迅速增加,电导率-温度曲线符合Arrhenius方程.机械性能测试结果表明,在P(MMA-VAc)的基础上,引入第三单体LiAA可以改善膜的收缩性与力学性能. 相似文献
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聚硅氧烷对水性聚氨酯聚合物电解质结构形态及电化学性能的影响 总被引:1,自引:0,他引:1
将PDMS引入到WPU中,合成了PEO-PDMS混合软段WPU嵌段共聚物,通过改变PDMS的含量得到一系列固态聚合物电解质膜。测试结果表明,PDMS的加入会对聚合物电解质材料的力学性能、微观形态、电化学性能产生显著影响。PDMS的加入可有效地提高聚合物电解质的室温电导率及电化学稳定性,30℃时样品C17-10电导率为1.05×10-4S/cm,其电化学稳定窗口达到5.5V。 相似文献
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Ionic conductivity studies in the temperature range 304–373 K for PVC---Li2SO4---dibutylphthalate polymer electrolyte systems are reported and discussed. Poly(vinylchloride) (PVC) has an electrical conductivity 10−8 S cm−1. The prepared films were studies by X-ray diffraction, Fourier transformation infrared, scanning electron microscopy and thermal analysis. The temperature dependence of the conductivity of the polymer films obeys the Vogel–Tammann–Fulcher relation. 相似文献
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Recent theoretical approaches to the understanding of superionic conductivity in polycrystalline, glassy and polymeric materials
are briefly reviewed. Phase transitions to the superionic conducting state in the AgI family are apparently triggered by cluster
formation and strong mobile ion interaction within the clusters. Anomalous conductivity and related physical properties are
explained in the cluster induced distortion model. Ionic composites such as AgX : Al2O3 (X = Cl, Br and I) involve conducting and non-conducting phases and the all-important interface between the two whose space
charge enhances the conductivity and also trigger phase transitions to exotic polymorphic phases, for which the mechanisms
are yet to be explored. Ion hopping dynamics controls the conductivity of superionic glasses. Mode coupling and jump relaxation
theories account for the non-Debye relaxation observed in a.c. conductivity of these glasses. The theory of conductivity in
polymer electrolytes—still in its infancy—involves their complex structure and glass transition behaviour. Preparative and
thermal history, composition and crystallinity control ionic conductivity. New approaches to the synthesis of optimal polymer
electrolytes such as rubbery electrolytes, crystalline polymers and nanocomposites must be considered before achieving a comprehensive
theoretical understanding.
Based on an invited talk given by the first author at the National Workshop on Solid State Ionics and its Applications, Bharatiar
University, Coimbatore, 18–23 January 2002. 相似文献
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We have prepared, characterized and investigated a new PEG-2000 based solid polymer electrolyte (PEG)
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: NH4NO3. Ionic conductivity measurements have been made as a function of salt concentration as well as temperature in the range 265–330
K. Selected compositions of the electrolyte are exposed to a beam of 8 MeV electrons and 60Co γ-rays to an accumulated dose of 10 kGy to study the effect on ionic conductivity. The electrolyte samples are also quenched
at liquid nitrogen temperature and conductivity measurements are carried out. The ionic conductivity at room temperature exhibits
a characteristic peak for the composition, x = 46. Electron beam irradiation results in an increase in conductivity for all compositions by a factor of 2–3. Exposure
to γ-rays enhances the conductivity by one order of magnitude. Quenching at low temperature has resulted in an increase in conductivity
by 1–2 orders of magnitude. The enhancement of conductivity upon irradiation and quenching is interpreted as due to an increase
in amorphous region and decrease in crystallinity of the electrolyte. DSC and NMR measurements also support this conclusion. 相似文献
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以N-乙烯基咪唑、溴乙酸甲酯和二(三氟甲基磺酰亚胺)锂(LiTFSI)为原料,采用溶液聚合法制备了聚(1-乙烯基-3-乙酸甲酯基咪唑二(三氟甲基磺酰亚胺))(PMVIm-TFSI)。将其与LiTFSI和聚(甲基丙烯酸甲酯-醋酸乙烯酯)(P(MMA-VAc))共混制得了不同质量比的聚合物电解质。核磁共振(1 HNMR)、红外光谱(FT-IR)、示差扫描量热计(DSC)、热重分析(TGA)、X射线衍射(XRD)、扫描电镜(SEM)、交流阻抗(AC impedance)等对电解质的测试结果表明,PMVIm-TFSI掺杂到P(MMA-VAc)和LiTFSI组成的电解质中后其电导率得到了极大的改善,30℃下最高可达4.71×10-4S/cm,同时热稳定性也得到了极大的提高。此外,该共混电解质(透过率≥90%)还可以运用到电致变色器件(ECD)导电离子材料中,也显示出了优良的电化学性能。 相似文献
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水性聚氨酯-聚二甲基硅氧烷共混体系固态聚合物电解质的光谱学研究 总被引:1,自引:0,他引:1
以水性聚氨酯(WPU)-聚二甲基硅氧烷(PDMS)共混体系为聚合物基体,通过添加不同质量分数的高氯酸锂(LiClO4)得到一系列固态聚合物电解质.交流阻抗测试结果显示,当LiClO4质量分数为15 %时体系电导率最高,并且温度与电导率关系基本符合Arrhenius方程.采用傅立叶红外光谱(FT-IR)对聚合物电解质中锂离子与羟基及醚氧基之间的相互作用分析显示,当LiClO4质量分数为15%时,锂离子与羰基及醚氧基的配位作用均达到饱和状态.拉曼光谱(Raman)研究结果表明,该聚合物体系对盐具有较好的溶解能力,增加盐浓度后,可使体系中有效离子的相对比例增加,有利于离子传输. 相似文献
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通过简单方法合成了一种新型有机碘盐N-甲基吡啶碘,以苯乙烯-丙烯腈共聚物(AS树脂)为聚合物凝胶电解质基体,丙烯碳酸酯及乙烯碳酸酯双组分有机溶剂为液相,制备了含有机碘盐(N-甲基吡啶碘)和无机碘盐(NaI)的AS树脂基聚合物凝胶电解质,比较了两种碘盐对聚合物凝胶电解质导电性能及染料敏化纳米晶太阳电池光电性能的影响,发现含有机碘盐的聚合物凝胶电解质具有较高的电导率,所制备的DSSC光电性能也较好。 相似文献
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电解质作为超级电容器的重要组成部分,对器件性能起着关键性作用。本文对近些年来超级电容器各种电解质,包括水系、有机液体、离子液体、固态/准固态聚合物电解质和氧化还原体系电解质的特点和最新研究成果进行了描述;重点介绍了固态/准固态聚合物电解质的分类及其性能研究概况。提出了发展电位窗口宽、离子电导率高、电化学性能稳定的离子液体和机械强度等综合性能优良的凝胶聚合物电解质是将来超级电容器电解质发展领域的趋势,最后对超级电容器电解质的发展前景进行了展望。 相似文献
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