共查询到20条相似文献,搜索用时 15 毫秒
1.
Seyedeh Nooshin Banitaba Dariush Semnani Elahe Heydari‐Soureshjani Behzad Rezaei Ali A Ensafi Ahmadreza Taghipour‐Jahromi 《Polymer International》2020,69(8):675-687
In this study, solvent‐free nanofibrous electrolytes were fabricated through an electrospinning method. Polyethylene oxide (PEO), lithium perchlorate and ethylene carbonate were used as polymer matrix, salt and plasticizer respectively in the electrolyte structures. Keggin‐type hetero polyoxometalate (Cu‐POM@Ru‐rGO, Ni‐POM@Ru‐rGO and Co‐POM@Ru‐rGO (POM, polyoxometalate; rGO, reduced graphene oxide)) nanoparticles were synthesized and inserted into the PEO‐based nanofibrous electrolytes. TEM and SEM analyses were carried out for further evaluation of the synthesized filler structures and the electrospun nanofibre morphologies. The fractions of free ions and crystalline phases of the as‐spun electrolytes were estimated by obtaining Fourier transform infrared and XRD spectra, respectively. The results showed a significant improvement in the ionic conductivity of the nanofibrous electrolytes by increasing filler concentrations. The highest ionic conductivity of 0.28 mS cm?1 was obtained by the introduction of 0.49 wt% Co‐POM@Ru‐rGO into the electrospun electrolyte at ambient temperature. Compared with solution‐cast polymeric electrolytes, the electrospun electrolytes present superior ionic conductivity. Moreover, the cycle stability of the as‐spun electrolytes was clearly improved by the addition of fillers. Furthermore, the mechanical strength was enhanced with the insertion of 0.07 wt% fillers to the electrospun electrolytes. The results implied that the prepared nanofibres are good candidates as solvent‐free electrolytes for lithium ion batteries. © 2020 Society of Chemical Industry 相似文献
2.
Hybrid solid polymer electrolytes (HSPE) of high ionic conductivity were prepared using polyethylene oxide (PEO), polyacrylonitrile (PAN), propylene carbonate (PrC), ethylene carbonate (EC), and LiClO4. These electrolyte films were dry, free standing, and dimensionally stable. The HSPE films were characterized by constructing symmetrical cells containing nonblocking lithium electrodes as well as blocking stainless steel electrodes. Studies were made on ionic conductivity, electrochemical reaction, interfacial stability, and morphology of the films using alternating current impedance spectroscopy, infrared spectroscopy, and scanning electron microscopy. The properties of HSPE were compared with the films prepared using (i) PEO, PrC, and LiClO4; and (ii) PAN, PrC, EC, and LiClO4. The specific conductivity of the HSPE films was marginally less. Nevertheless, the dimensional stability was much superior. The interfacial stability of lithium was similar in the three electrolyte films. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2191–2199, 1997 相似文献
3.
Crosslinked polymer electrolyte networks were prepared from poly(ethylene glycol) diglycidyl ether blended with an epoxy resin (diglycidyl ether of bisphenol A) in different ratios and then cured with α,ω‐diamino poly(propylene oxide) in the presence of lithium perchlorate (LiClO4) as a lithium salt. The ionic conductivities of these polymer electrolytes were determined by alternating current (AC) impedance spectroscopy. Propylene carbonate (PC) was used as a plasticizer to form gelled polymer electrolyte networks. The conductivities of the polymer electrolytes containing 46 wt % PC plasticizer were approximately 5 × 10?4 S cm?1 at 25°C and approximately 10?3 S cm?1 at 85°C. These polymer electrolytes were homogeneous and exhibited good mechanical properties. The effects of the polymer composition, plasticizer content, salt concentration, and temperature on the ionic conductivities of the polymer electrolytes were examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1264–1270, 2004 相似文献
4.
Weihua Zhu Bing Yang Xinling Wang Lei Wang Xiaozhen Tang Changzheng Yang 《应用聚合物科学杂志》2002,83(1):103-111
A series of polyurethanes (PUs) with different polyether soft segments [polydioxolane (PDXL), polyethylene glycol (PEG), or PDXL/PEG] were synthesized successfully, and solid polymer electrolytes based on PU/LiClO4 complexes were prepared. The relations between structure and the ionic conductive properties of the PU‐based electrolytes were investigated by means of Fourier transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and complex impedance analysis. Results showed that the glass‐transition temperature (Tg) of PDXL–PU was lower than that of PEG–PU. Doped lithium perchlorate (LiClO4) salt could be dissolved well in soft segments of PDXL–PU. The ionic conductivity of the PDXL–PU/LiClO4 complex could reach a value of 2 × 10?5 S/cm at room temperature without the addition of an organic plasticizer. The system with PDXL/PEG as a soft segment had a higher Tg and a lower ionic conductivity than the one with PDXL as a soft segment. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 103–111, 2002 相似文献
5.
The study presents preparation of poly methyl methacrylate (PMMA) based nanocomposite gel polymer electrolytes consisting of, salt lithium perchlorate (LiClO4), plasticizer PC/DEC and different proportions of SiO2 nanofiber by solution casting process. The effect of the composition of the electrolytes on their ionic, mechanical and thermal characteristics was investigated. Morphology of the nanocomposite electrolyte films has been observed by scanning and transmission electron microscopes. Interactions among the constituents of the composite and structural changes of the base polymer were investigated by Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The maximum conductivity i.e. 10?3 Scm?1 at room temperature is obtained with the electrolyte composition of 0.6(PMMA)-0.15(PC + DEC)-0.1LiClO4 (wt%) containing 10 wt% SiO2 nanofiber and the temperature dependent conductivity data of the electrolyte follows Vogel-Tamman-Fulcher (VTF) behavior. 相似文献
6.
The polymer electrolytes composed of a blend of poly(ethylene oxide) (PEO) and poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) as a host polymer, mixture of ethylene carbonate (EC) and propylene carbonate (PC) as a plasticizer, and LiClO4 as a salt were prepared by a solution casting technique. SEM micrographs show that P(VDF-HFP) is very compatible with PEO. The ionic conductivity of the electrolytes increases with increasing plasticizer content, while the mechanical properties become obviously worse. By addition of a certain content of PEO in P(VDF-HFP) matrix, a good compromise between high ionic conductivity and mechanical stability can be obtained. 相似文献
7.
The potential of poly(ethylene oxide) (PEO) and 49% poly(methyl methacrylate) grafted natural rubber (MG49) as a polymer host in solid polymer electrolytes (SPE) was explored for electrochemical applications. PEO–MG49 SPEs with various weight percentages of lithium perchlorate salt (LiClO4) was prepared with the solution casting technique. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and impedance spectroscopy was done to investigate the effect of LiClO4 on the morphological properties, chemical interaction, and ionic conductivity behavior of PEO–MG49. Scanning electron microscopy analysis showed that the surface morphology of the sample underwent a change from rough to smooth with the addition of lithium salts. Infrared analysis showed that the interaction occurred in the polymer host between the oxygen atom from the ether group (C? O? C) and the Li+ cation from doping salts. The ionic conductivity value increased with the addition of salts because of the increase in charge carrier up to the optimum value. The highest ionic conductivity obtained was 8.0 × 10?6 S/cm at 15 wt % LiClO4. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
8.
A blend of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (PSAN) has been evaluated as a composite polymer electrolyte by means of differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, ac impedance measurements, and linear sweep voltammetry (LSV). The blends show an interaction with the Li+ ions when complexed with lithium perchlorate (LiClO4), which results in an increase in the glass‐transition temperature (Tg) of the blends. The purpose of using PSAN as another component of the blend is to improve the poor mechanical properties of PMMA‐based plasticized electrolytes. The mechanical property is further improved by introducing fumed silica as inert filler, and hence the liquid electrolyte uptake and ionic conductivity of the composite systems are increased. Room‐temperature conductivity of the order of 10?4 S/cm has been achieved for one of the composite electrolytes made from a 1/1 blend of PSAN and PMMA containing 120% liquid electrolyte [1M LiClO4/propylene carbonate (PC)] and 10% fumed silica. These systems also showed good compatibility with Li electrodes and sufficient electrochemical stability for safe operation in Li batteries. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1319–1328, 2001 相似文献
9.
Flexible, transparent, and crosslinked polymer films were synthesized by polymerization of PEG‐modified urethane acrylate using a simple method. A series of novel solid polymer electrolytes and gel electrolytes were prepared based on this type of polymer film. To understand the interactions among salt, solvent, and polymer, the swelling behaviors of the crosslinked polymer in pure propylene carbonate (PC) and liquid electrolyte solutions (LiClO4/PC) were investigated. The results showed that the swelling rate in the electrolyte solution containing moderate LiClO4 was greater than that in pure PC. Thermogravimetric analysis (TGA) also supported the interaction between the solvent and polymer. The morphology and crystallinity of the crosslinked polymer and polymer electrolytes were studied using atomic force microscopy (AFM) and wide‐angle X‐ray diffraction (WAXD) spectroscopy. The effects of the content of the electrolyte solution on the ionic conductivity of gel electrolytes were explored. The dependence of the conductivity on the amount of the electrolyte solution was nonlinear. With a different content of the plasticizer, the ionic conduction pathway of the polymer electrolytes would be changed. The best ionic conductivity of the gel electrolytes, which should have good mechanical properties, was 4 × 10r?3 S cm?1 at 25°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 340–348, 2003 相似文献
10.
Hybrid polymer dry electrolytes comprised of poly(ethylene oxide) (PEO), polyacrylonitrile (PAN), and LiClO4 were investigated. The impedance spectroscopy showed that the effect of PAN on the ion conductivity of PEO‐based electrolytes depends on the concentration of lithium salt. When the mole ratio of lithium to oxygen is 0.062 (15%LiClO4‐PEO), adding PAN will increase the ionic conductivity. Differential scanning calorimetry, NMR, and IR data suggested that the enhanced conductivity was due to both the decreasing of the PEO crystallinity and increasing of the degree of ionization of lithium salt. There was obviously no interaction between PAN and lithium ions, and PAN acts as a reinforcing filler, and hence contributes to the mechanical strength besides reducing the crystallinity of the polymer electrolytes. When the LiClO4‐PEO‐PAN hybrid polymer electrolyte was heated at 200°C under N2, PAN crosslinked partially, which further decreased the crystallinity of PEO and increased the ionic conductivity, and at the same time prevented the recrystallization of PEO upon sitting at ambient environment. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 1530–1540, 2006 相似文献
11.
A novel CuI-based iodine-free gel electrolyte using polyethylene oxide (PEO, MW = 100,000) as plasticizer and lithium perchlorate (LiClO4) as salt additive was developed for dye-sensitized solar cells (DSSCs). Such CuI-based gel electrolyte can avoid the problems caused by liquid iodine electrolyte and has relative high conductivity and stability. The effects of PEO and LiClO4 concentrations on the viscosity and ionic conductivity of the mentioned iodine-free electrolyte, as well as the performance of the corresponding quasi solid-state DSSCs were investigated comparatively. Experimental results indicate that the performance of DSSCs can be dramatically improved by adding LiClO4 and PEO, and there are interactions (Li+–O coordination) between LiClO4 and PEO, these Li+–O coordination interactions have important influence on the structure, morphology and ionic conductivity of the present CuI-based electrolyte. Addition of PEO into the electrolyte can inhibit the rapid crystal growth of CuI, and enhance the ion and hole transportation property owing to its long helix chain structure. The optimal efficiency (2.81%) was obtained for the quasi solid-state DSSC fabricated with CuI-based electrolyte containing 3 wt% LiClO4 and 20 wt% PEO under AM 1.5 G (1 sun) light illumination, with a 116.2% improvement in the efficiency compared with the cell without addition of LiClO4, indicating the promising application in solar cells of the present CuI-based iodine-free electrolyte. 相似文献
12.
Effect of additives in PEO/PAA/PMAA composite solid polymer electrolytes on the ionic conductivity and Li ion battery performance 总被引:1,自引:0,他引:1
Sang Yong An Il Chen Jeong Mi-Sook Won Euh Duck Jeong Yoon-Bo Shim 《Journal of Applied Electrochemistry》2009,39(9):1573-1578
Polyethylene oxide (PEO) based-solid polymer electrolytes were prepared with low weight polymers bearing carboxylic acid groups
added onto the polymer backbone, and the variation of the conductivity and performance of the resulting Li ion battery system
was examined. The composite solid polymer electrolytes (CSPEs) were composed of PEO, LiClO4, PAA (polyacrylic acid), PMAA (polymethacrylic acid), and Al2O3. The addition of additives to the PEO matrix enhanced the ionic conductivities of the electrolyte. The composite electrolyte
composed of PEO:LiClO4:PAA/PMAA/Li0.3 exhibited a low polarization resistance of 881.5 ohms in its impedance spectra, while the PEO:LiClO4 film showed a high value of 4,592 ohms. The highest ionic conductivity of 9.87 × 10−4 S cm−1 was attained for the electrolyte composed of PEO:LiClO4:PAA/PMAA/Li0.3 at 20 °C. The cyclic voltammogram of Li+ recorded for the cell consisting of the PEO:LiClO4:PAA/PMAA/Li0.3:Al2O3 composite electrolyte exhibited the same diffusion process as that obtained with an ultra-microelectrode. Based on this electrolyte,
the applicability of the solid polymer electrolytes to lithium batteries was examined for an Li/SPE/LiNi0.5Co0.5O2 cell. 相似文献
13.
Spectroscopic characterisation of γ-LiAlO2 composite polymeric electrolytes based on poly-(ethylene oxide)(PEO)/perfluorinated polyphosphazene blends and LiPF6 as electrolyte was studied by means of FTIR and X-ray spectroscopy. Ionic conductivity was analysed by using complex impedance. A parallel study was made on samples containing propylene carbonate as plasticizer instead of γ-LiAlO2. The results obtained indicate, in a first approximation, that there is a drastic change in PEO morphology resulting from the co-ordination with the lithium salt and, at the same time, that the morphology of the composite polymer electrolytes is dependent on the nature of the polymer host. Complex impedance data show that the incorporation of γ-LiAlO2 enhances the ionic conductivity of the composite polymer electrolyte, a reverse behaviour is found for the composite systems plasticized with PC. 相似文献
14.
All solid-state poly(ethylene oxide) (PEO) nanocomposite electrolytes were made containing nanoscale fillers of layered double
hydroxides (LDHs). Two kinds of oligo(ethylene oxide) modified LDHs were prepared by template method, and added into PEO/LiClO4 matrix (with EO/Li molar ratio of 8) to study the effect on the ionic conductivity of PEO/LDH nanocomposite electrolytes.
The structures of the modified LDHs were characterized by infrared spectra, thermogravimetric analysis and wide-angle X-ray
diffraction. The results show that the oligo(ethylene oxide) with phosphonate anion can be effectively intercalated into the
gallery region of LDHs and formed as an organic-inorganic hybrid (PLDH). With enhanced compatibility of LDH sheets by oligo(ethylene
oxide) surface modification, the PEO/PLDH nanocomposite exhibits fully exfoliation morphology. The well dispersed LDH layers
in PEO/LiClO4/PLDH nanocomposite electrolytes rendering the formation of amorphous phase, results in an enhancement of ionic conductivity
by three orders of magnitude compared to the pure PEO/LiClO4 polymer electrolyte. This novel nanocomposite electrolytes system with high ionic conductivity will be benefited to fabricate
the thin-film type of Li-polymer secondary battery.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
15.
Structural and dielectric studies of amorphous and semicrystalline polymers blend‐based nanocomposite electrolytes
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The solid polymeric nanocomposite electrolyte (SPNE) films based on the blend of amorphous poly(methyl methacrylate) (PMMA) and semicrystalline poly(ethylene oxide) (PEO) (PMMA:PEO = 80:20 wt %) doped with lithium perchlorate (LiClO4) salt and montmorillonite (MMT) clay nanofiller were prepared by classical solution cast, ultrasonic assisted solution cast and ultrasonication along with microwave irradiated solution cast followed by melt‐pressing methods. The X‐ray diffraction study of these electrolytes revealed the amorphous behavior with intercalated MMT structures. The suppressed crystallinity of PEO in the blend electrolyte complexes confirmed the existence of single discrete PEO chains confined within the PMMA domains. The dielectric relaxation spectroscopy of these materials was performed over the frequency range 20 Hz to 1 MHz, at ambient temperature. The presence of a singular relaxation peak in the loss tangent and electric modulus spectra of these electrolytes confirms a coupled cooperative chain segmental dynamics of the blend polymer owing to their miscible amorphous morphology. The behavior of transient complexes formed between the polymers functional groups, lithium cations and the intercalated MMT nanoplatelets was explored. The ambient temperature ionic conductivity of these electrolytes depends on the structural dynamics and the sample preparation methods. It is revealed that the presence of PEO in the PMMA matrix mainly governs the structural, dielectric, and ionic properties of these SPNE films. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41311. 相似文献
16.
Thermoplastic polyurethane (TPU) was employed as the polymer matrix for ion conduction as gelled electrolytes with lithium perchlorate (LiClO4) in propylene carbonate (PC) solution. The TPU was prepared by methylene bis(p‐cyclohexyl isocyanate) as the hard segment while employing both poly(ethylene glycol) (PEG) and poly(tetramethylene glycol) (PTMG) as the soft segments. The copolymer comprising both PEG and PTMG was prepared such that it possessed the combined characteristics of good conductivity from the former and good mechanical properties from the latter. All the polymers were characterized by gel permeation chromatography, differential scanning calorimetry, and Fourier transform IR spectroscopy. The conductivity data were obtained from alternating current impedance experiments. The results revealed that the copolymer containing both PEG and PTMG as the soft segments showed better performance than TPU containing either PEG or PTMG. The copolymer TPU(PEG/PTMG) proved to be a good gelled electrolyte from 5 to 85°C. This copolymer, impregnated with 150% LiClO4/PC, possessed good mechanical strength and conductivity as high as 10?3 S/cm. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 935–942, 2001 相似文献
17.
The transparent and flexible solid polymer electrolytes (SPEs) were fabricated from polyacrylonitrile‐polyethylene oxide (PAN‐PEO) copolymer which was synthesized by methacrylate‐headed PEO macromonomer and acrylonitrile. The formation of copolymer is confirmed by Fourier‐transform infrared spectroscopy (FTIR) measurements. The ionic conductivity was measured by alternating current (AC) impedance spectroscopy. Ionic conductivity of PAN‐PEO‐LiClO4 complexes was investigated with various salt concentration, temperatures and molecular weight of PEO (Mn). And the maximum ionic conductivity at room temperature was measured to be 3.54 × 10?4 S/cm with an [Li+]/[EO] mole ratio of about 0.1. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 461–464, 2006 相似文献
18.
Three kinds of modified montmorillonites were prepared by ion exchange method, and added into (PEO)16LiClO4 matrix to study the effect on the ionic conductivity of (PEO)16LiClO4 electrolytes. The structure of the modified montmorillonites and polymer composites were characterized by wide-angle X-ray diffraction. HP 4192A was used to measure the ionic conductivity of the polymer electrolytes. The results show that the addition of optimum content of 250-Li-mont enhances the ionic conductivity of the PEO based electrolyte by nearly 30 times more than the plain system and that is much higher than the other two modified montmorillonites. The difference of enhancement in conductivity caused by adding these three montmorillonites can be attributed to the difference in structure of the samples as characterized by wide-angle X-ray diffraction. 相似文献
19.
Polymer nanocomposite gel electrolytes consisting of high molecular weight poly(methyl methacrylate) PMMA-clay nanocomposite, ethylene carbonate (EC)/propylene carbonate (PC) as plasticizer, and LiClO4 electrolyte are reported. Montmorillonite clay was ion exchanged with a zwitterionic surfactant (octadecyl dimethyl betaine) and dispersed in methyl methacrylate, which was then polymerized to synthesize PMMA-clay nanocomposites. The nanocomposite was dissolved in a mixture of EC/PC with LiClO4, heated and pressed to obtain polymer gel electrolyte. X-ray diffraction (XRD) of the gels indicated intercalated clay structure with d-spacings of 2.85 and 1.40 nm. In the gel containing plasticizer, the clay galleries shrink suggesting intercalation rather than partial exfoliation observed in the PMMA-clay nanocomposite. Ionic conductivity varied slightly and exhibited a maximum value of 8 × 10−4 S/cm at clay content of 1.5 wt.%. The activation energy was determined by modeling the conductivity with a Vogel-Tamman-Fulcher expression. The clay layers are primarily trapped inside the polymer matrix. Consequently, the polymer does not interact significantly with LiClO4 electrolyte as shown by FTIR. The presence of the clay increased the glass transition temperature (Tg) of the gel as determined by differential scanning calorimetry. The PMMA nanocomposite gel electrolyte shows a stable lithium interfacial resistance over time, which is a key factor for use in electrochemical applications. 相似文献
20.
Seyedeh Nooshin Banitaba Dariush Semnani Elahe Heydari‐Soureshjani Behzad Rezaei Ali Asghar Ensafi 《Polymer International》2019,68(10):1787-1794
Nanofibrous solid polymer electrolytes were prepared using the electrospinning method. These nanofibres were constructed from poly(ethylene oxide), lithium perchlorate and ethylene carbonate, which were incorporated with multi‐walled carbon nanotube (MWCNT) and graphene oxide (GO). The morphological properties of the as‐prepared electrolytes and the interaction between the components of the composites were characterized using scanning electron microscopy and Fourier transform infrared spectroscopy, respectively. X‐ray spectra and differential scanning calorimetry indicated an increase in amorphous regions of the nanofibrous electrolytes on addition of the fillers. However, the crystalline regions were increased on incorporation of fillers into polymeric film electrolytes. The conductivity values of the nanofibrous electrolytes reached 0.048 and 0.057 mS cm?1 when 0.35 wt% MWCNT and 0.21 wt % GO were introduced into the nanofibrous structures, respectively. The capacity and cycling stability of the nanofibrous electrolytes were improved by incorporation of MWCNT filler. Furthermore, stress and elongation modulus were improved at low MWCNT and GO filler contents. Results revealed that the nanofibrous structures could be promising candidates as solvent‐free electrolytes applicable in lithium ion batteries. © 2019 Society of Chemical Industry 相似文献