新型聚合物固体电解质的导电性研究

采用溶液浇铸法制得以偏二氟乙烯与六氟丙烯共聚物P(VdF-HFP)为基质的聚合物固体电解质,并测定了该类电解质的电导率。讨论了锂盐浓度、增塑剂配比、纳米SiO2粉末掺入以及温度对膜的离子电导率的影响;结果表明:以P(VdF-HFP)为基质的电解质的室温电导率最高达到2.81×10-3S·cm-1。利用红外分析对聚合物固体电解质的导电性进行分析,探讨了聚合物固体电解质膜的各组分间相互作用的规律。     

聚氨酯基聚合物电解质的研究进展

聚合物锂离子电池因具有能量密度高、绿色环保等优点备受关注,聚合物电解质作为锂离子电池的重要组成部分,发展高效聚合物电解质成为研究热点。聚氨酯由不相容的软硬两段组成,结构可设计性强,硬段部分作为物理交联点提供机械强度和热稳定性,软段部分溶解碱金属盐提供离子导电性,因而聚氨酯是作为锂电池聚合物电解质的优良材料。通过改进聚氨酯基聚合物电解质的电化学性能和增加聚氨酯基聚合物电解质的功能性两个方面综述了国内聚醚型、聚酯型、有机硅氧烷改性、聚氧化乙烯改性、聚乳酸改性和功能型聚氨酯基电解质的研究进展,并展望了未来聚氨酯基聚合物电解质的发展前景。     

单离子型全氟凝胶聚合物固体电解质的结构与离子导电性能

从Nafion树脂出发,制备了一系列单离子型全氟凝胶聚合物固体电解质膜,其中有机极性介质为碳酸丙烯酯(PC)。通过溶胀曲线测定、红外光谱分析、复阻抗分析等手段对材料的结构与离子导电性能进行了研究。结果表明,PC与阳离子之间存在较强的相互作用,而且PC与Li+离子之间的相互作用强于PC与H+离子之间的相互作用。PC含量对材料的离子导电性能也有较大的影响。随着PC含量的增加,材料的离子电导率呈上升趋势。当PC含量较低时,Li+型样品的室温离子电导率高于H+型样品;而PC含量较高时,Li+型样品的室温离子电导率则低于H+型样品。Li+型样品和H+型样品的室温离子电导率均可达到1.25×10-4S·cm-1。     

增塑剂对聚氨酯型固体电解质离子导电性能的影响

利用溶液聚合方法合成了聚醚聚氨酯,并以聚氨酯、高氯酸锂和增塑剂为组分,制备了一系列新型聚合物固体电解质。运用差示扫描量热分析、动态力学分析、交流复阻抗谱、扫描电镜和原子力显微镜对体系性能和形态进行了研究。结果表明,在聚氨酯/高氯酸锂复合物中,增塑剂的加人会导致体系玻璃化转变温度和力学性能有所下降,离子导电性能显著增加。在所研究的6种增塑剂碳酸丙烯酯、碳酸二乙酯、二乙二醇二甲醚、N,N-二甲基甲酰胺、聚乙二醇400和丙三醇中,聚乙二醇400对聚氨酯/高氯酸锂复合物的增塑效果最好,该体系室温电导率达到10-4S／cm。     

光聚合PEO体系高分子固体电解质膜的制备及其性能

引　言由极性聚合物 -碱金属盐络合而成的高分子固体电解质 (ＳＰＥ)是一类很有前途的离子导电材料 ,除具备一般固体电解质的性能外 ,还具有质轻、黏弹性好、易成膜等独特的优点 ,尤其适合作为全固高能密度聚合物电池的电解质材料 ,从而给电源领域引入了电池技术的全新概念 .欲使高分子固体电解质材料实用化 ,必须解决高分子固体电解质薄膜的合成问题 .通常采用的成型方法如溶剂法、热熔法等或者消耗溶剂 ,或者需要基材加热 ,造成高生产成本和低生产效率 ,而且由于有机溶剂的挥发 ,又带来了电池工业环境污染问题[1] .本文针对高氯酸锂 -聚氧…     

新型共混的PEO/TPU/PVDF-HFP基聚合物电解质的制备及性能

通过相转化法制备基于聚氧化乙烯（PEO）/热塑性聚氨酯（TPU）/聚偏氟乙烯-六氟丙烯（PVDF-HFP）三种高聚物共混形成的电解质隔膜, 浸泡在1 mol/L六氟磷酸锂（LiPF6）的碳酸乙烯酯（EC）: 碳酸二甲酯（DMC）: 碳酸甲乙酯（EMC）=1:1:1的电解液中形成一种新型的凝胶态聚合物电解质（GPE）。采用SEM、FTIR、XRD、TG、DSC、拉伸性能和电化学性能进行了表征。结果表明，聚合物配比为3:1:4的隔膜具备均匀的多孔形貌，结晶峰面积最低，拉伸强度达到了15 MPa，离子电导率为7.9?10^(-3) S?cm，综合性能最佳。将聚合物配比为3:1:4的隔膜装配成CR2032纽扣电池进行电池循环性能测试，结果表明，在0.2 C下电池的充放电比容量分别达到了164 mAh/g和161 mWh/g，在150次循环后，放电比容量仍能保持在152 mAh/g 左右，库仑效率保持97%以上，是一种优异的电池材料。     

侧挂聚醚和烷基磺酸锂的单离子梳状聚合物电解质的合成与性能

采用α 烯丙基聚醚(UPEO)/烯丙基磺酸锂(LS)/苯乙烯(St)共聚反应,合成得到一种以聚烯烃链为主链、侧挂聚醚和烷基磺酸锂的新型单离子梳状聚合物电解质(CPPL)。通过元素分析、IR、GPC以及DSC等对其结构与形态进行了分析表征。研究了反应物料配比、催化剂、反应时间等因素对CPPL物理性能的影响。研究结果表明:该类聚合物电解质膜材料的θg值和成膜性能主要取决于单体原料配比,CPPL室温电导率可达9.3×10-3s/cm。     

PVDF-HFP型凝胶聚合物固体电解质的结构与离子导电性能

以PVDF-HFP为基体聚合物，制备了一系列凝胶聚合物固体电解质膜，其中有机极性介质为碳酸丙烯酯(PC)，电解质盐为LiClO4。通过红外光谱分析、差示扫描量热分析、复阻抗分析等手段对凝胶聚合物固体电解质的结构与离子导电性能进行了研究。结果表明，PC与阳离子之间存在较强的络合作用，PC对基体聚合物有很强的增塑作用。锂盐和PC含量对材料的离子导电性能有较大的影响。随着锂盐和PC含量的增加，材料的离子电导率呈上升趋势。     

PIN/PAN聚合物基电解质膜的制备及性能

利用静电纺丝技术制备了聚吲哚/聚丙烯腈(PIN/PAN)聚合物基电解质膜,代替纸基铝空气电池中的纤维素纸(C-P),并应用于固态铝空气电池。探究了PIN含量对电解质膜离子电导率及吸液率的影响。采用SEM和FTIR对PIN/PAN聚合物基电解质膜表面形貌及化学组成进行分析。借助电化学工作站和电池测试系统,分析了电解质膜离子电导率及固态铝空气电池放电特性。结果表明,采用PIN/PAN聚合物基电解质膜可有效提升固态铝空气电池性能,在3 mA.cm_^-2、5 mA.cm_^-2、7 mA.cm_^-2电流密度下,放电时长比纸基铝空气电池分别提升了21%、27%、34%,且放电时长与电解质膜的吸液率及离子电导率相关。其中4%PIN/PAN聚合物基电解质膜离子电导率可达6.7×10_^-4 S.cm_^-1,同时对碱性溶液具有良好的吸附能力,吸液率最高可达496%,为纤维素纸的3.2倍。     

共混改性的PEO/TPU/PVDF-HFP基聚合物电解质的制备及性能

通过相转化法制备基于聚氧化乙烯(PEO)/热塑性聚氨酯(TPU)/聚偏氟乙烯-六氟丙烯(PVDF-HFP)3种高聚物共混形成的电解质隔膜,将其浸泡在浓度为1 mol/L六氟磷酸锂(LiPF6)的碳酸乙烯酯(EC)-碳酸二甲酯(DMC)-碳酸甲乙酯(EMC)(三者体积比为1:1:1)电解液中形成一种凝胶态聚合物电解质(GPE).采用SEM、EDS、FTIR、XRD、TG、DSC、万能拉力机和交流阻抗法对隔膜进行了表征.结果表明,m(PEO):m(TPU):m(PVDF-HFP)=3:1:4的隔膜具有均匀的多孔形貌,结晶峰面积最低,拉伸强度达到15 MPa左右,离子电导率为7.9×10–3 S/cm,综合性能最佳.将该隔膜装配成CR2032纽扣电池进行电池循环性能测试,结果表明,在0.2 C倍率下电池的充放电比容量分别达到了164和161 mA·h/g,在150次循环后,放电比容量仍能保持在152 mA·h/g左右,库伦效率保持97％以上,表明该GPE是一种优异的电池材料.     

Ionic liquid mediated magnesium ion conduction in poly(ethylene oxide) based polymer electrolyte

Magnesium ion conduction in poly(ethylene oxide) (PEO) based polymer electrolyte incorporated with room temperature ionic liquid (RTIL) is reported. The electrolyte films comprise the PEO complexed with magnesium trifluoromethanesulfonate (or magnesium triflate) added with different amount of ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf). The polymer electrolyte with ∼50 wt.% of ionic liquid offers a maximum electrical conductivity of ∼5.6 × 10⁻⁴ S cm⁻¹ at room temperature (∼25 °C) with improved thermal and electrochemical stabilities. The Mg²⁺ ion conduction in the PEO-complex is confirmed from cyclic voltammetry, impedance and transport number measurements. A significant increase in the Mg²⁺ ion transport number (tMg2+) is observed with increasing content of the ionic liquid in PEO–Mg salt complex and the maximum value is obtained to be ∼0.45 for ∼50 wt.% of ionic liquid. The interaction of imidazolium cations with ether oxygen of PEO, as evidenced from FTIR and Raman studies, play an important role in the substantial enhancement in the tMg2+ value.     

Study of poly(ethylene oxide) electrolyte with polyurethane/sulfonate side chains

Sulfonated dimethyl fumarate (SDMF) was prepared. Poly(ethylene oxide) (PEO) with sodium sulfonate side chains (SPEO) was synthesized by transesterification between SDMF and PEO with molecular weights of 200, 400, 600, 800, and 1000. The SPEO was subsequently mixed as a plasticizer with PEO polyurethane (PU). Samples were characterized by elemental analysis, FTIR, ¹H-NMR, gel permeation chromatography, and impedance analysis. The mixture exhibited a homogeneous domain. The maximum conductivity of the CPU1000/SPEO600 was 2.6 × 10⁻⁷ S cm⁻¹ at room temperature. The relation between the ionic conductivity and the temperature was in agreement with the Arrhenius equation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 541–545, 2001     

Structure and properties of fluorinated polymer/poly(ethylene oxide) blends

BACKGROUND: In order to explore ways for improving the toughness of copolymers of vinylidene difluoride and chlorotrifluoroethylene (P(VDF‐CTFE)), polyethylene oxide (PEO) with ultrahigh molecular weight and good mechanical properties was applied for the first time to prepare P(VDF‐CTFE)/PEO blends for adhesives applications. RESULTS: The results show that with an increase of PEO content, the mechanical properties of the blends are improved markedly, and blends with high strength, modulus and toughness are obtained. The difference in the solubility parameters of P(VDF‐CTFE) and PEO is small, and only a single α‐relaxation peak is observed in the high‐temperature zone for the blends, indicating that the blend system is partially miscible. The experimental values for the glass transition temperature of the blend varying with PEO content are always higher than those predicted by the Fox equation, and a strong interaction is supposed to occur between the molecules of P(VDF‐CTFE) and PEO. The relative crystallinity of the blends increases with PEO content, and the PEO particles disperse homogeneously in the P(VDF‐CTFE) matrix, whose average size decreases with increasing PEO content. Phase‐inverted morphologies of the blends are observed above 60 wt% of PEO. CONCLUSION: The partial miscibility of P(VDF‐CTFE)/PEO blends leads to an improvement of the mechanical properties of the blends, which is an effective way to improve the toughness of fluorinated polymers. Copyright © 2009 Society of Chemical Industry     

Characteristics of a poly(ethylene oxide)-LiBF4 polymer electrolyte

The poly(ethylene oxide)-lithium tetrafluoborate complex, (PEO)₇ LiBF₄, has been characterized in terms of total and electronic conductivity, lithium transport number, stability versus lithium electrode and thermal properties. The results indicate that this polymeric electrolyte offers promises of application in lithium-based electrochemical devices.     

Ionic conductive polymer systems based on polyether and polyphosphazene blends

Several polymer electrolytes have been obtained, based on binary blends of polyethylene oxide (PEO), polyphosphazene by means of solvation with lithium triflate. The different samples were studied both as to their microstructure and for their electrical properties, either through the determination of their respective glass transition temperatures and melting enthalpies or by means of complex impedance spectroscopy. When comparing the results obtained for the synthesized binary systems with those known for PEO, the former systems prove to possess a better dimensional stability and a higher conductivity than PEO in itself. © 1996 John Wiley & Sons, Inc.     

Influences of poly(ether urethane) introduction on poly(ethylene oxide) based polymer electrolyte for solvent-free dye-sensitized solar cells

A poly(ether urethane) (PEUR)/poly(ethylene oxide) (PEO)/SiO₂ based nanocomposite polymer is prepared and employed in the construction of high efficiency all-solid-state dye-sensitized nanocrystalline solar cells. The introduction of low-molecular weight PEUR prepolymer into PEO electrolyte has greatly enhance the electrolyte performance by both improving the interfacial contact properties of electrode/electrolyte and decreasing the PEO crystallization, which were confirmed by XRD and SEM characteristics. The effects of polymer composition, nano SiO₂ content on the ionic conductivity and I₃⁻ ions diffusion of polymer-blend electrolyte are investigated. The optimized composition yields an energy conversion efficiency of 3.71% under irradiation by white light (100 mW cm⁻²).     

Crystallization of poly(ethylene oxide) in i-polypropylene–poly(ethylene oxide) blends

A two-stage stable system of isotactic polypropylene–poly(ethylene oxide) blend, in which poly(ethylene oxide) can be permanent either in molten or in crystallized states in the temperature range from 280 to 327 K, was described. The behavior of that blend was explained in terms of fractionated crystallization. A fine dispersion of poly(ethylene oxide) inclusions is required for efficient suppression of crystallization initiated by heterogeneous nuclei. The application of a thin film of polypropylene-poly(ethylene oxide) 9 : 1 blend obtained by quenching for multiuse erasable and rewritable carriers for visible information has been demonstrated. The same sample exhibits different dynamic mechanical properties when poly(ethylene oxide) inclusions are molten or crystallized. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 2047–2057, 1997     

Cocontinuous morphology in vinylidene fluoride based polymers/poly(ethylene oxide) blends

In this work, blends of three different vinylidene fluoride (VdF) based homopolymers and copolymers with poly(ethylene oxide) were investigated. We focused on the continuity domain and, more particularly, on the cocontinuous morphology of these systems. The melt‐mixed blends were characterized by different techniques. The morphology was identified through a selective extraction technique and was confirmed by scanning electron microscopy. Dynamic oscillatory shear measurements were performed with a constant stress rheometer in the linear viscoelastic domain in the whole composition range. Because of the high viscosities and long relaxation times of the VdF‐based polymers, the interfacial effects were hidden by the intrinsic behavior of the neat components. Nevertheless, the combination of the different techniques highlighted the similarity of the systems toward morphological development, whatever the VdF monomers. The experiments and theoretical analysis indicated that the rheological behavior dominated the interfacial effects in such systems with a large viscosity ratio and that it also dictated the boundaries of the continuity domain. The originality of this study came from the use of three different VdF‐based polymers. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Syntheses of poly(ethylene oxide) polyurethane ionomers

Sulfonated dimethyl fumarate (SDMF) was prepared with dimethyl fumarate (DMF) and sodium hydrogensulfite (NaHSO₃). Sodium sulfonate side‐chain poly(ethylene oxide) (SPEO) was synthesized by grafting sodium sulfonate onto the chain of PEO with molecular weights of 400, 600, 800, and 1000. SPEO was used subsequently in step‐growth polymerization to give a polyurethane ionomer (SPU). Samples were characterized by element analysis, FTIR, ¹H‐NMR, EDX mapping, X‐ray, gel permeation chromatography, and impedance analysis. The SPUs exhibited an amorphous structure. The maximum conductivity of the SPU was 1.02 × 10⁻⁶ S cm⁻¹ at the room temperature. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 184–188, 2000