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1.
Solid biopolymers have gained much attention in the development of polymer electrolytes due to its biocompatibility, film-forming nature, and non-toxicity. In the present work, biopolymer membrane has been prepared using tamarind seed polysaccharide (TSP) as host polymer and various concentrations of lithium chloride (LiCl) salt as dopant by solution casting technique. The prepared biopolymer electrolyte has been characterized by XRD, FTIR, differential scanning calorimetry (DSC) analysis, AC impedance spectroscopy analysis, and transference number measurement. XRD analysis has been done to investigate the amorphous/crystalline nature of the polymer membrane. The highest amorphous nature has been found for 1 g of TSP with 0.4 g LiCl. FTIR spectrum analysis confirms the complex formation between TSP biopolymer with LiCl. From AC impedance conductivity analysis, the maximum ionic conductivity is of the order of 6.7?×?10?3 S cm?1 at room temperature for 1 g TSP with 0.4 g LiCl, whereas for pure TSP biopolymer membrane, the ionic conductivity is of the order of 5.48?×?10?7 S cm?1. The glass transition temperature for the highest conducting biopolymer membrane for the composition of 1 g TSP: 0.4 g LiCl has been found to be 44.25 °C using the DSC technique. Employing the maximum conducting biopolymer membrane, a lithium-ion conducting battery has been fabricated and its discharge characteristics have been studied.  相似文献   

2.
Nanocomposite polymer electrolyte (NCPE) films based on polyethylene oxide (PEO) complexed with lithium perchlorate (LiClO4) and nanosized ferroelectric ceramic fillers such as BaTiO3, SrTiO3 have been prepared using solution cast technique. The films showed very good mechanical stability when exposed to ambient atmospheres for prolonged periods. Lithium ion transport studies revealed that the conductivity is predominantly ionic. The effect of electric field on ionic conductivity of NCPE films was investigated. One order enhancement in conductivity due to the field was observed at 323 K. NCPE films exhibited conductivity of 3.46?×?10?5 Scm?1 at 323 K. NCPE films were characterized using differential scanning calorimetry (DSC) and X-ray diffraction (XRD) technique. The DSC and XRD studies revealed reduced crystallinity which confirmed the higher amorphous phase and hence the improved ionic conductivity.  相似文献   

3.
The green revolution has led to the study of biopolymer for development of polymer electrolyte for electrochemical devices. Cellulose acetate, pectin, chitosan, and carrageenan are some of the biopolymers. Biopolymer-based membrane for proton conduction and lithium ion conduction have developed and characterized by different techniques. But the study of biopolymer based on Mg2+ ion is rare in literature. So, biopolymer based on I-carrageenan with magnesium has been studied. I-carrageenan biopolymer membrane with different concentration of magnesium perchlorate has been prepared by solution casting technique. Developed biopolymer membrane have been characterized by X-ray diffraction analysis (XRD), FTIR, differential scanning calorimetry (DSC), and AC impedance techniques. Pure I-carrageenan has shown a conductivity value of 5.90?×?10?5 S/cm. I-carrageenan membrane with 0.6 wt% of magnesium perchlorate has shown a conductivity of 2.18?×?10?3 S/cm. A primary Mg2+ ion battery has been constructed and its performance is studied. XRD has been undertaken to study the amorphous/crystalline nature of the sample. I-carrageenan with 0.6 wt% of magnesium membrane has shown highest amorphous nature. FTIR study confirms the complex formation between polymer and salt. AC impedance technique has been used to study the conductivity of the samples.  相似文献   

4.
Poly(butylene sulfite) (poly-1) was synthesized by cationic ring-opening polymerization of butylene sulfite (1), which was prepared by the reaction of 1,4-butanediol and thionyl chloride, with trifluoromethanesulfonic acid (TfOH) in bulk. The polymer electrolytes composed of poly-1 with lithium salts such as bis(trifluoromethanesulfonyl)imide (LiN(SO2CF3)2, LiTFSI) and bis(fluorosulfonyl)imide (LiN(SO2F)2, LiFSI) were prepared, and their ionic conductivities, thermal, and electrochemical properties were investigated. Ionic conductivities of the polymer electrolytes for the poly-1/LiTFSI system increased with lithium salt concentrations, reached maximum values at the [LiTFSI]/[repeating unit] ratio of 1/10, and then decreased in further more salt concentrations. The highest ionic conductivity values at the [LiTFSI]/[repeating unit] ratio of 1/10 were 2.36?×?10?4 S/cm at 80 °C and 1.01?×?10?5 S/cm at 20 °C. On the other hand, ionic conductivities of the polymer electrolytes for the poly-1/LiFSI system increased with an increase in lithium salt concentrations, and ionic conductivity values at the [LiFSI]/[repeating unit] ratio of 1/1 were 1.25?×?10?3 S/cm at 80 °C and 5.93?×?10?5 S/cm at 20 °C. Glass transition temperature (T g) increased with lithium salt concentrations for the poly-1/LiTFSI system, but T g for the poly-1/LiFSI system was almost constant regardless of lithium salt concentrations. Both polymer electrolytes showed high transference number of lithium ion: 0.57 for the poly-1/LiTFSI system and 0.56 for the poly-1/LiFSI system, respectively. The polymer electrolytes for the poly-1/LiTFSI system were thermally more stable than those for the poly-1/LiFSI system.  相似文献   

5.
The polyvinylidene difluoride-co-hexafluoropropylene (PVdF-HFP) nanocomposite solid polymer electrolyte films were developed by solution-casting method. PVdF-HFP as a polymer host, lithium perchlorate (LiClO4) as a salt for lithium ion, and ZnO nanoparticles as fillers were used to form the nanocomposite solid polymer electrolyte films. All the prepared samples were characterized by X-ray diffraction (XRD), differential scanning calorimetry, and scanning electron microscopy. The XRD patterns of the pure and nanocomposite solid polymer electrolyte samples indicate the formation of amorphous phase with 17.5 wt.% of lithium salt and ZnO fillers up to 3 wt.%. The total conductivity and lithium ion transference number were studied at room temperature by using impedance spectroscopy and Wagner’s polarization methods. The highest conductivity at room temperature for solid polymer electrolyte and nanocomposite solid polymer electrolyte are found to be 3.208?×?10?4 and 1.043?×?10?3 S/cm, respectively. Similarly, the lithium ion transference number is evaluated for the optimized solid polymer electrolyte and nanocomposite solid polymer electrolyte films with 3 wt.% of ZnO fillers. And it is found that ionic transference number could be enhanced from 92 to 95 % with the addition of nanosized ZnO fillers to the solid polymer electrolyte.  相似文献   

6.
We investigate the influence of the pyrazole content on the polyvinylidene fluoride (PVDF)/KI/I2 electrolytes for dye-sensitized solar cells (DSSCs). The solid polymer electrolyte films consisting of different weight percentage ratios (0 20, 30, 40, and 50 %) of pyrazole doped with PVDF/KI/I2 have been prepared by solution casting technique using N,N-dimethyl formamide (DMF) as a solvent. The as-prepared polymer electrolyte films were characterized by various techniques such as Fourier transform infrared spectroscopy (FT-IR spectroscopy), differential scanning calorimetry (DSC), X-ray diffractometer (XRD), alternate current (AC)-impedance analysis, and scanning electron microscopy (SEM). The 40 wt% pyrazole-PVDF/KI/I2 electrolyte exhibited the highest ionic conductivity value of 9.52?×?10?5 Scm?1 at room temperature. This may be due to the lower crystallinity of PVDF and higher ionic mobility of iodide ions in the electrolyte. The DSSC fabricated using this highest ion conducting electrolyte showed an enhanced power conversion efficiency of 3.30 % under an illumination of 60 mW/cm2 than that of pure PVDF/KI/I2 electrolyte (1.42 %).  相似文献   

7.
Poly (acrylonitrile) (PAN) and ammonium chloride (NH4Cl)-based proton conducting polymer electrolytes with different compositions have been prepared by solution casting technique. The amorphous nature of the polymer electrolytes has been confirmed by XRD analysis. The FTIR analysis confirms the complex formation of the host polymer (PAN) with the salt (NH4Cl). DSC measurements show a decrease in Tg with the increase in salt concentration. The conductivity analysis shows that the 25 mol% ammonium chloride doped polymer electrolyte has a maximum ionic conductivity, and it has been found to be 6.4 × 10?3 Scm?1, at room temperature. The temperature dependence of conductivity of the polymer electrolyte complexes appears to obey the Arrhenius nature. The activation energy (Ea = 0.23 eV) has been found to be low for 25 mol% salt doped polymer electrolyte. The dielectric behavior has been analyzed using dielectric permittivity (ε*), and the relaxation frequency (τ) has been calculated from the loss tangent spectra (tan δ). Using this maximum ionic conducting polymer electrolyte, the primary proton conducting battery with configuration Zn + ZnSO4·7H2O/75 PAN:25 NH4Cl/PbO2 + V2O5 has been fabricated and their discharge characteristics have been studied.  相似文献   

8.
Solid polymer electrolytes based on potato starch (PS) and graphene oxide (GO) have been developed in this study. Blending GO with PS has improved the ionic conductivity and mechanical properties of the electrolytes. In this work, series of polymer blend consisting of PS and GO as co-host polymer were prepared using solution cast method. The most amorphous PS-GO blend was obtained using 80 wt% of PS and 20 wt% of GO as recorded by X-ray diffraction (XRD). Incorporation of 40 wt% lithium trifluoromethanesulfonate (LiCF3SO3) into the PS-GO blend increases the conductivity to (1.48 ± 0.35) × 10?5 S cm?1. Further enhancement of conductivity was made using 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]). The highest conductivity at room temperature is obtained for the electrolyte containing 30 wt% of [Bmim][Cl] with conductivity value of (4.8?0 ± 0.69) × 10?4 S cm?1. Analysis of the Fourier transform infrared spectroscopy (FTIR) spectra confirmed the interaction between LiCF3SO3, [Bmim][Cl], and PS-GO blend. The variation of the dielectric constant and modulus studies versus frequency indicates that system of PS-GO-LiCF3SO3-[Bmim][Cl] obeys non-Debye behavior.  相似文献   

9.
Dextran-chitosan blend added with ammonium thiocyanate (NH4SCN)-based solid polymer electrolytes are prepared by solution cast method. The interaction between the components of the electrolyte is verified by Fourier transform infrared (FTIR) analysis. The blend of 40 wt% dextran-60 wt% chitosan is found to be the most amorphous ratio. The room temperature conductivity of undoped 40 wt% dextran-60 wt% chitosan blend film is identified to be (3.84?±?0.97)?×?10?10 S cm?1. The inclusion of 40 wt.% NH4SCN to the polymer blend has optimized the room temperature conductivity up (1.28?±?0.43)?×?10?4 S cm?1. Result from X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis shows that the electrolyte with the highest conductivity value has the lowest degree of crystallinity (χ c) and the glass transition temperature (T g), respectively. Temperature-dependence of conductivity follows Arrhenius theory. From transport analysis, the conductivity is noticed to be influenced by the mobility (μ) and number density (n) of ions. Conductivity trend is further verified by field emission scanning electron microscopy (FESEM) and dielectric results.  相似文献   

10.
Solid polymer electrolytes (SPEs) based on poly (vinyl chloride)/poly (ethyl methacrylate) [PVC/PEMA] blend complexed with zinc triflate [Zn(CF3SO3)2] salt have been prepared using solution casting technique. Thin film samples containing various blend ratios of PVC/PEMA with fixed composition of salt have been examined by means of complex impedance analysis, and as a consequence, the typical composition corresponding to PVC (30 wt%)/PEMA (70 wt%) has been identified as the optimized blend exhibiting the highest room temperature ionic conductivity of 10?8 Scm?1. The ionic conductivity of the optimized blend was further enhanced from 10?8 to 10?6 Scm?1 by adding the chosen salt in different weight percentages at 301 K. The occurrence of complexation of the polymer blend and an evidence of interaction of cations, namely Zn2+ ions with the polymer blend, have been confirmed by Attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) spectroscopy measurement studies. The efficacy of ion-polymer interactions was estimated by means of an evaluation of transport number data pertaining to Zn2+ ions which was found to be 0.56. The apparent changes resulting in the structural properties of these polymer electrolytes possessing a honeycomb-like microporous structure were identified using X-ray diffraction (XRD) and scanning electron microscopic (SEM) studies. Such promising features of the present polymer blend electrolyte system appear to suggest possible fabrication of new rechargeable zinc batteries involving improved device characteristics.  相似文献   

11.
A. K. Nath  A. Kumar 《Ionics》2014,20(12):1711-1721
Swift heavy ion (SHI) irradiation has been used as a tool to enhance the electrochemical properties of ionic liquid-based nanocomposite polymer electrolytes dispersed with dedoped polyaniline (PAni) nanorods; 100 MeV Si9+ ions with four different fluences of 5?×?1010, 1?×?1011, 5?×?1011, and 1?×?1012 ions cm?2 have been used as SHI. XRD results depict that with increasing ion fluence, crystallinity decreases due to chain scission up to fluence of 5?×?1011 ions cm?2, and at higher fluence, crystallinity increases due to cross-linking of polymer chains. Ionic conductivity, electrochemical stability, and dielectric properties are enhanced with increasing ion fluence attaining maximum value at the fluence of 5?×?1011 ions cm?2 and subsequently decrease. Optimum ionic conductivity of 1.5?×?10?2 S cm?1 and electrochemical stability up to 6.3 V have been obtained at the fluence of 5?×?1011 ions cm?2. Ac conductivity studies show that ion conduction takes place through hopping of ions from one coordination site to the other. On SHI irradiation, amorphicity of the polymer matrix increases resulting in increased segmental motion which facilitates ion hopping leading to an increase in ionic conductivity. Thermogravimetric analysis (TGA) measurements show that SHI-irradiated nanocomposite polymer electrolytes are thermally stable up to 240–260 °C.  相似文献   

12.
S. Z. Yusof  H. J. Woo  A. K. Arof 《Ionics》2016,22(11):2113-2121
A polymer electrolyte system comprising methylcellulose (MC) as the host polymer and lithium bis(oxalato) borate (LiBOB) as the lithium ion source has been prepared via the solution cast technique. The electrolyte with the highest conductivity of 2.79 μS cm?1 has a composition of 75 wt% MC–25 wt% LiBOB. The mobile ion concentration (n) in this sample was estimated to be 5.70?×?1020 cm?3. A good correlation between ionic conductivity, dielectric constant, and free ion concentration has been observed. The ratio of mobile ion number density (n) at a particular temperature to the concentration n 0 of free ions at T?=?∞ (n/n 0) and the power law exponents (s) exhibit opposite trends when varied with salt concentration.  相似文献   

13.
Hyperbranched poly(glycidol) containing hydroxyl groups was firstly synthesized via anionic polymerization and then reacted with 2-bromoisobutyl bromide to form macroinitiator HPG-Br. Finally, a hyperbranched star polymer (HPG-PPEGMA) was successfully prepared by atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate using HPG-Br as macroinitiator. The structures and properties of the obtained polymers were characterized by 1H NMR, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The ionic conductivity of the polymer electrolytes composed of HPG-PPEGMA and lithium bis(trifluoromethanesulfonimide) (LiTFSI) was investigated via electrochemical impedance spectroscopy. The results showed that the room temperature ionic conductivity of the prepared hyperbranched star polymer electrolytes had a higher ionic conductivity. When [EO]/[Li] was 20, the ionic conductivity of the hyperbranched star polymer electrolyte was up to 1?×?10?4 Scm?1 at 30 °C. The onset decomposition temperature of the hyperbranched star polyether could reach 374 °C, indicating that the hyperbranched star polymer had a good thermal stability. The XRD results showed that the structure of the hyperbranched star polymer was beneficial to improve the ionic conductivity due to possessing a low degree of crystallinity.  相似文献   

14.
A series of gel polymer electrolytes (GPEs) containing lithium bis(oxalato)borate (LiBOB), propylene carbonate (PC), and ethylene carbonate (EC) have been investigated. Poly(ethylene oxide) (PEO) was used as the polymer. First, a series of liquid electrolytes was prepared by varying the Li:O ratio and obtained the best composition giving the highest conductivity of 7.1?×?10?3 S cm?1 at room temperature. Then, the PEO-based GPEs were prepared by adding different amounts of LiBOB and PEO into a mixture of equal weights of EC and PC (40 % of each from the total weight). The gel electrolyte comprises of 12.5 % of LiBOB, 7.5 % of PEO, 40 % of EC, and 40 % of PC gave the highest ionic conductivity of 5.8?×?10?3 S cm?1 at room temperature. From the DC polarization measurements, ionic nature of the gel electrolyte was confirmed. Fourier transform infrared (FTIR) spectra of electrolytes showed the Li+ ion coordination with EC and PC molecules. These interactions were exhibited in the peaks corresponding to ring breathing of EC at 893 cm?1 and ring bending of EC and symmetric ring deformation of PC at 712 and 716 cm?1 respectively. The presence of free Li+ ions and ion aggregates is evident in the peaks due to the symmetric stretching of O–B–O at 985 cm?1.  相似文献   

15.
An attempt has been made to prepare a new proton-conducting polymer electrolyte based on poly(vinyl alcohol) doped with ammonium fluoride (NH4F) by solution casting technique. The complex formation between polymer and dissociated salt has been confirmed by X-ray diffraction and Fourier transform infrared spectroscopy studies. The highest ionic conductivity has been found to be 6.9?×?10?6?Scm?1 at ambient temperature (303 K) for 85PVA:15NH4F polymer electrolyte. The conductance spectra contain a low frequency plateau region and high frequency dispersion region. The dielectric spectra exhibit the low frequency dispersion, which is due to space charge accumulation at the electrode–electrolyte interface. The modulus spectra indicate non-Debye nature of the material. The highest ionic conductivity polymer electrolyte 85PVA:15NH4F has low activation energy 0.2 eV among the prepared polymer electrolytes.  相似文献   

16.
Polysaccharide-based biopolymers have gained much attention in electrochemical devices recently. Tamarind seed polysaccharide (TSP) is a biopolymer obtained from the extract of tamarind seed. It is used as thickening and gelling agent in food and textile industries. There are no works in polymer electrolytes based on TSP in lithium-ion conducting membranes. A pure TSP membrane has been prepared by dissolving 1 g of TSP in distilled water by using solution-casting technique. The prepared biopolymer membranes are subjected to Fourier transform infrared (FTIR), X-ray diffraction (XRD), and AC-impedance techniques. FTIR analysis has been conducted to observe the possible interaction between the polymer and lithium salt based upon the changes in wave numbers of the peaks. The nature of the membrane (crystalline or amorphous) has been revealed by XRD. The electrical properties of the membranes have been analyzed by AC-impedance spectroscopy. The maximum ionic conductivity for the salt-doped membrane 1 g TSP:0.4 g lithium bromide (LiBr) has been found to be 4.83 × 10?4 S cm?1. The primary lithium-ion battery has been constructed using the best conductivity membrane, and the open circuit voltage (OCV) has been observed as 1.63 V.  相似文献   

17.
An attempt has been made to prepare and characterise ammonium thiocyanate (NH4SCN) salt and a multiwall carbon nanotube (MWNT)-doped polyvinyl alcohol-based nanofibre mats using an electrospinning process. The X-ray diffraction result shows an improvement in the amorphous nature of composite electrolyte fibre mats with increasing concentrations of the MWNT filler. The DSC behaviour of these nanofibre mat exhibits better thermal response upon dispersal of the filler. Composite electrolyte nanofibre mat doped with 6 wt% MWNT shows optimum conductivity, viz., 5.8?×?10?4 Scm?1. The temperature dependence of the bulk electrical conductivity displays a combination of Arrhenius and Vogel–Tammam–Fulcher nature. Dielectric loss studies have also been used to understand the conduction process in the system. Jonscher power law seems to be obeyed during ac conductivity measurements of the fibre mats.  相似文献   

18.
Nano-composite polymer electrolytes containing poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), ammonium tetrafluoroborate (NH4BF4), and nano-size fumed silica (SiO2) have been prepared and characterized by complex impedance spectroscopy. Ionic conductivity of polymer has been found to increase with the addition of NH4BF4, and a maximum conductivity of 3.62 × 10?6 S/cm has been obtained at 30 wt% NH4BF4. The formation of ion aggregates at high concentration of salt has been explained by Bjerrum’s law and mass action considerations. The conductivity of polymer electrolytes has been increased by three orders of magnitude (10?6 to 10?3 S/cm) with the addition of plasticizer, and a maximum conductivity of 1.10 × 10?3 S/cm has been observed at 80 wt% DMA. An increase in conductivity with the addition of nano-size fumed silica is attributed due to the formation of space-charge layers. A maximum conductivity of 7.20 × 10?3 S/cm has been observed for plasticized nano-composite polymer electrolytes at 3 wt% SiO2. X-ray diffraction analysis of polymer electrolyte system was also carried out. A small change in conductivity of nano-composite polymer electrolytes observed over the 30–130 °C temperature range and for a period of 30 days is also desirable for their use in various applications.  相似文献   

19.
This work examines the effect of lithium trifluoromethanesulfonate (LiCF3SO3) and glycerol on the conductivity and dielectric properties of potato starch-chitosan blend-based electrolytes. The electrolytes are prepared via solution cast technique. From X-ray diffraction (XRD) analysis, the blend of 50 wt.% starch and 50 wt.% chitosan is found to be the most amorphous blend. Fourier transform infrared (FTIR) spectroscopy studies show the interaction between the electrolyte materials. The room temperature conductivity of pure starch-chitosan film is found to be (2.85 ± 1.31) × 10?10 S cm?1. The incorporation of 45 wt.% LiCF3SO3 increases the conductivity to (7.65 ± 2.27) × 10?5 S cm?1. Further conductivity enhancement up to (1.32 ± 0.35) × 10?3 S cm?1 has been observed on addition of 30 wt.% glycerol. This trend in conductivity is verified by XRD and dielectric analysis. The temperature dependence of conductivity of all electrolytes are Arrhenian.  相似文献   

20.
A series of solid polymer electrolytes (SPEs) based on poly (ethylene oxide)/polylactic acid (PEO/PLA) with liquid crystal ionomer (LCI) intercalated montmorillonite (MMT) nanocomposites (LCI-MMT) has been prepared by solution blending method. The effects of LCI-MMT on the structural, crystallization, thermal, and ionic conductivity properties of solid polymer electrolytes have been analyzed. It is demonstrated that the incorporation of LCI-MMT into the blend suppressed the crystallinity of PEO and increased the crystallinity of PLA. The maximum ionic conductivity is found to be in the range of 1.05?×?10?5 S/cm for 0.5 wt% LCI-MMT, which is higher than that of the LCI-MMT-free polymer electrolyte (5.36?×?10?6 S/cm) at room temperature.  相似文献   

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