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1.
In the present work, biopolymer electrolyte films based on MC doped with NH4Br salt and plasticized with glycerol were prepared by solution casting method. Fourier transform infrared (FTIR) spectroscopy analysis confirms the interaction between MC, NH4Br, and glycerol. X-ray diffraction (XRD) explains that the enhancement of conductivity is affected by the degree of crystallinity. This result is verified by field emission scanning electron microscopy (FESEM). For unplasticized system, sample containing 25 wt% of NH4Br possesses the highest ionic conductivity of (1.89 ± 0.05) × 10?4 S cm?1. The addition of 30 wt% glycerol increases the conductivity value up to (1.67 ± 0.04) × 10?3 S cm?1. The conduction mechanism was best presented by the correlated barrier hopping (CBH) model. The linear sweep voltammetry (LSV) and cyclic voltammetry (CV) result confirms the suitability of the highest conducting electrolyte to be employed in the fabrication of electrochemical double layer capacitor (EDLC).  相似文献   

2.
Tania Basu  Sujata Tarafdar 《Ionics》2014,20(10):1445-1454
Gelatin films complexed with ionic salts are of current interest as potential solid polymer electrolytes. However, even without salt, gelatin films are found to have quite high ionic conductivity at room temperature (around 30 °C), when plasticized with an adequate fraction of glycerol. In the present work, the admittance and dielectric properties of gelatin are studied as a function of glycerol content and temperature. An enhancement in the ionic conductivity by four orders of magnitude to ~9.13?×?10?3 S/m at room temperature is obtained by adding 35.71 wt% of glycerol. This enhancement appears to be correlated with the changes in the local microstructure on plasticizer addition. Admittance and dielectric relaxation have been studied to understand the dynamics of the charge carriers. Differential scanning calorimetry, X-ray diffraction and scanning electron microscopy are also done.  相似文献   

3.
Biodegradable polymer electrolyte films based on poly(ε-caprolactone) (PCL) in conjunction with lithium tetrafluoroborate (LiBF4) salt and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid were prepared by solution cast technique. The structural, morphological, thermal, and electrical properties of these films were examined using X-ray diffraction (XRD), optical microscopy (OM), differential scanning calorimetry (DSC), and impedance spectroscopy. The XRD and OM results reveal that the pure PCL possesses a semi-crystalline nature and its degree of crystallinity decreases with the addition of LiBF4 salt and EMIMBF4 ionic liquid. DSC analysis indicates that the melting temperature and enthalpy are apparently lower for the 40 wt% EMIMBF4 gel polymer electrolyte as compared with the others. The ambient temperature electrical conductivity increases with increasing EMIMBF4 concentration and reaches a high value of ~2.83?×?10?4 S cm?1 for the 85 PCL:15 LiBF4 + 40 wt% EMIMBF4 gel polymer electrolyte. The dielectric constant and ionic conductivity follow the same trend with increasing EMIMBF4 concentration. The dominant conducting species in the 40 wt% EMIMBF4 gel polymer electrolyte determined by Wagner’s polarization technique are ions. The ionic conductivity of this polymer electrolyte (~2.83?×?10?4 S cm?1) should be high enough for practical applications.  相似文献   

4.
This paper reports on preparation and characterization of thin films of a new zinc ion conducting blended polymer electrolyte system containing polyethylene oxide [PEO] and polypropylene glycol [PPG] complexed with zinc triflate [Zn(CF3SO3)2] salt. The room temperature ionic conductivity (σ 298K) data of such PEO-PPG polymer blends prepared by solution casting technique were found to be of the order of 10?5 S cm?1, whereas the optimized composition containing 90:10 wt% ratio of PEO and PPG possessed an appreciably high ionic conductivity of 7.5?×?10?5 S cm?1. Subsequently, six different weight percentages of zinc triflate viz., 2.5, 5, 7.5, 10, 12.5 and 15, respectively, were added into the above polymer blend and resulting polymer-salt complexes were characterized by means of various analytical tools. Interestingly, the best conducting specimen namely 87.5 wt% (PEO:PPG)-12.5 wt% Zn(CF3SO3)2 exhibited an enhanced room temperature ionic conductivity of 6.9?×?10?4 S cm?1 with an activation energy of 0.6 eV for ionic conduction. The present XRD results have indicated the occurrence of characteristic PEO peaks and effects of salt concentration on the observed intensity of these diffraction peaks. Appropriate values of degree of crystallinity for different samples were derived from both XRD and DSC analyses, while an examination of surface morphology of the blended polymer electrolyte system has revealed the formation of homogenous spherulites involving a rough surface and relevant zinc ionic transport number was found to be 0.59 at room temperature for the best conducting polymer electrolyte system thus developed.  相似文献   

5.
Two water-soluble and biodegradable polymers: xanthan gum (XG) and poly(vinyl alcohol) (PVA) were used to synthesize ecologically friendly solid polymer electrolyte (SPE) matrices. While XG is a natural polymer, PVA is a synthetic one, but both are colorless and form transparent membranes. To obtain ionic conductivity properties, the samples were doped with acetic acid and characterized by electrochemical impedance spectroscopy (EIS), X-ray diffraction, UV-Vis spectroscopy, and tensile test. The best results of ionic conductivity of 1.97 × 10?4 and 7.41 × 10?4 S/cm at room temperature and 80 °C, respectively, were obtained for the sample containing 55 wt% of acetic acid. Moreover, this electrolyte was found to be predominantly amorphous with transmittance in the visible region of 80% and absorbance values below 0.5 between 240 and 375 nm. Tensile test of this sample, applied up to 18 N of maximum force, resulted in strain of 2322% and Young’s modulus of 0.02 MPa. The obtained results showed that these new eco-friendly materials are promising for use as electrolytes in electrochemical devices.  相似文献   

6.
Optical, mechanical, and electric properties of solid polymer electrolyte (SPE) were affected by the order of addition of corn starch (S), lithium perchlorate (Li), and glycerol (G) during the preparation process. Four formulations were made based on whether Li was added prior to S gelatinization (simultaneous formulations SGLi and SLi+G) or whether it was added after S was gelatinized (sequential formulations SG+Li and S+LiG). Simultaneous formulations produced films with smaller elongation-at-break response (60–75%) relative to their sequential counterparts (75–82%). The simultaneous formulations exhibited higher electrical conductivity (~0.7 mS cm?1) and capacitance (~0.017 F cm?2) and electrochemical stability than the sequential formulations (~0.9 mS cm?1 and ~0.012 F cm?2) at room temperature. Results from FTIR and DSC analyses indicated that starch re-crystallization in casting phase could lead to variations on electrical properties for the different SPE formulations. It was postulated that Li cations replace hydrogen ions inside starch molecules, retarding the re-crystallization of starch molecules.  相似文献   

7.
The studies on solid polymer electrolyte (SPE) films with high ionic conductivity suitable for the realization of all solid-state Na-ion cells? form the focal theme of the work presented in this paper. The SPE films are obtained by the solution casting technique using the blend solution of poly (ethylene oxide) (PEO) with ethylene carbonate (EC) and propylene carbonate (PC) and complexed with sodium nitrate. Structural and thermal studies of SPE films are done by XRD, FTIR spectroscopy, and TGA techniques. Surface morphology of the films is studied using the FESEM. The ionic conductivity of SPE films is determined from the electrochemical impedance spectroscopy studies. For the SPE film with 16 wt% of NaNO3 used for reacting with the polymer blend of PEO with EC and PC, the ionic conductivity obtained is around 1.08 × 10?5 S cm?1. Addition of the Al2O3 as the filler material is found to enhance the ionic conductivity of the SPE films. The studies on the Al2O3 modified SPE film show an ionic conductivity of 1.86 × 10–4 S cm?1, which is one order higher than that of the SPE films without the filler content. For the SPE film dispersed with 8 wt% of Al2O3, the total ion transport number observed is around 0.9895, which is quite impressive from the perspective of the applications in electrochemical energy storage devices. From the cyclic voltammetry studies, a wide electrochemical stability window up to 4 V is observed, which further emphasizes the commendable electrochemical behavior of these SPE films.  相似文献   

8.
Polymer blended films of polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):lithium perchlorate (LiClO4) embedded with silver (Ag) nanofiller in different concentrations have been synthesized by a solution casting method. The semi-crystalline nature of these polymer films has been confirmed from their X-ray diffraction (XRD) profiles. Fourier transform infrared spectroscopy (FTIR) and Raman analysis confirmed the complex formation of the polymer with dopant ions. Dispersed Ag nanofiller size evaluation study has been done using transmission electron microscopy (TEM) analysis. It was observed that the conductivity increases when increasing the Ag nanofiller concentration. On the addition of Ag nanofiller to the polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ electrolyte system, it was found to result in the enhancement of ionic conductivity. The maximum ionic conductivity has been set up to be 1.14?×?10?5 S cm?1 at the optimized concentration of 4 wt% Ag nanofiller-embedded (45 wt%) polyethylene oxide (PEO)?+?(45 wt%) polyvinyl pyrrolidone (PVP):(10 wt%) Li+ polymer electrolyte nanocomposite at room temperature. Polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ +Ag nanofiller (4 wt%) cell exhibited better performance in terms of cell parameters. This is ascribed to the presence of flexible matrix and high ionic conductivity. The applicability of the present 4 wt% Ag nanofiller-dispersed polyethylene oxide (PEO)?+?polyvinyl pyrrolidone (PVP):Li+ polymer electrolyte system could be suggested as a potential candidate for solid-state battery applications. Dielectric constants and dielectric loss behaviours have been studied.  相似文献   

9.
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   

10.
Biosourced carboxymethyl cellulose polymer electrolytes have been studied for potential application in electrochemical devices. The carboxymethyl cellulose was obtained by reacting cellulose derived from kenaf fibre with monochloroacetic acid. Films of the biosourced polymer electrolytes were prepared by solution-casting technique using ammonium acetate salt and (1-butyl)trimethyl ammonium bis(trifluoromethylsulfonyl)imide ionic liquid as charge carrier contributor and plasticizer, respectively. The shift of peak of carboxyl stretching in the Fourier transform infrared spectra confirmed the interactions between the host biosourced polymer with the ionic liquid. Scanning electron microscopy indicated that the incorporation of ionic liquid changed the morphology of the electrolyte films. The room temperature conductivity determined using impedance spectroscopic technique for the film without ionic liquid was 6.31 × 10?4 S cm?1 while the highest conductivity of 2.18 × 10?3 S cm?1 was achieved by the film integrated with 20 wt% (1-butyl)trimethylammonium bis(trifluoromethanesulfonyl) imide. This proved that the incorporation of ionic liquid into the salted system improved the conductivity. The improvement in conductivity was due to an increase in ion mobility. The results of linear sweep voltammetry showed that the electrolyte was electrochemically stable up to 3.07 V.  相似文献   

11.
The present article reports the synthesis and characterisation of a highly conducting composite polymer gel electrolyte, namely polyethylene glycol–polyvinyl alcohol (PVA)–ammonium succinate system. Formation of an amorphous composite gel electrolyte has been evidenced in differential scanning calorimetry experiments. Thermogravimetric analysis of the composite gel electrolyte has shown better thermal stability of films containing 25 wt% PVA. Composite gel system containing 10 wt% PVA exhibits optimal ionic conductivity (4.0 × 10?4 s cm?1) and its variation with temperature follows Vogel, Tamman and Fulcher relationship. The magnitude of variation in ionic conductivity (with temperature) of these composite electrolytes and its Williams, Landel and Ferry fit reveals liquid-like charge transport. Composite electrolyte with 25 wt% PVA appears to be a suitable candidate for device applications on the basis of experimental findings.  相似文献   

12.
Nanocomposite biopolymer electrolyte was prepared by solution-casting technique. Carboxymethyl cellulose from kenaf bast fibre, ammonium acetate, (1-butyl)trimethyl ammonium bis(trifluoromethylsulfonyl)imide ionic liquid and silica nanofiller was used to prepare the biopolymer electrolyte samples. The films were characterized by Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, scanning electron microscopy, transference number measurement and linear sweep voltammetry. The interactions of doping salt, ionic liquid and inorganic nanofiller with the host biopolymer were confirmed by FTIR study. The highest conductivity achieved was 8.63 × 10?3 S cm?1 by the incorporation of 1 wt% of SiO2 at ambient temperature. The electrochemical stability of the highest conducting sample was stable up to 3.4 V, and the ion transference number in the film was 0.99.  相似文献   

13.
Two systems (salted and plasticized) of starch–chitosan blend-based electrolytes incorporated with ammonium chloride (NH4Cl) are prepared via solution cast technique. The incorporation of 25 wt% NH4Cl has maximized the room temperature conductivity of the electrolyte to (6.47?±?1.30)?×?10?7 S cm?1. Conductivity is enhanced to (5.11?±?1.60)?×?10?4 S cm?1 on addition of 35 wt% glycerol. The temperature dependence of conductivity for all electrolytes is Arrhenian, and the value of activation energy (E a ) decreases with increasing conductivity. Conductivity is found to be influenced by the number density (n) and mobility (μ) of ions. The complexation between the electrolytes components is proven by Fourier transform infrared analysis. The relaxation time (t r ) for selected electrolytes is found to decrease with increasing conductivity and temperature. Conduction mechanism for the highest conducting electrolyte in salted and plasticized systems is determined by employing Jonscher’s universal power law.  相似文献   

14.
Based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and lithium tetrafluoroborate (LiBF4) salt along with blending plasticizers, ethylene carbonate (EC) and propylene carbonate (PC), high Li-ion-conducting gel polymer electrolyte films are developed. Their properties are characterized by various techniques. The ambient temperature ionic conductivity of the 85PVdF-HFP:15LiBF4 + 150(EC + PC) electrolyte film has a high value of 8.1 × 10?4 S cm?1. Its crystallinity, melting point, and electrochemical stability window are 9.5%, 115 °C, and 4.6 V, respectively. The mechanical testing shows that the Young’s modulus, yield strength, and breaking strain of this electrolyte film are 36.8 MPa, 3.4 MPa, and 320%, respectively. Lithium-ion batteries based on the gel polymer electrolyte film exhibit remarkable charge–discharge and cycling performances. The initial discharge capacity of this battery is as high as 165.1 mAh g?1 at 0.1 C and just shows a small capacity fading of 4.8% after 120 cycles, indicating that the 85PVdF-HFP:15LiBF4 + 150(EC + PC) system is an excellent electrolyte candidate for lithium-ion battery applications. The charge–discharge performance of the Li-ion cell fabricated with this gel polymer electrolyte film is apparently better than that of the previously reported Li-ion cells fabricated with other PVdF-HFP-based gel polymer electrolyte films.  相似文献   

15.
High molecular weight polymer poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP), ionic liquid 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMIMFSI), and salt lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)-based free-standing and conducting ionic liquid-based gel polymer electrolytes (ILGPE) have been prepared by solution cast method. Thermal, electrical, and electrochemical properties of 80 wt% IL containing gel polymer electrolyte (GPE) are investigated by thermogravimetric (TGA), impedance spectroscopy, linear sweep voltammetry (LSV), and cyclic voltammetry (CV). The 80 wt% IL containing GPE shows good thermal stability (~?200 °C), ionic conductivity (6.42?×?10?4 S cm?1), lithium ion conductivity (1.40?×?10?4 S cm?1 at 30 °C), and wide electrochemical stability window (~?4.10 V versus Li/Li+ at 30 °C). Furthermore, the surface of LiFePO4 cathode material was modified by graphene oxide, with smooth and uniform coating layer, as confirmed by scanning electron microscopy (SEM), and with element content, as confirmed by energy dispersive X-ray (EDX) spectrum. The graphene oxide-coated LiFePO4 cathode shows improved electrochemical performance with a good charge-discharge capacity and cyclic stability up to 50 cycles at 1C rate, as compared with the without coated LiFePO4. At 30 °C, the discharge capacity reaches a maximum value of 104.50 and 95.0 mAh g?1 for graphene oxide-coated LiFePO4 and without coated LiFePO4 at 1C rate respectively. These results indicated improved electrochemical performance of pristine LiFePO4 cathode after coating with graphene oxide.  相似文献   

16.
Gelatin-HCl protonic gel polymer electrolytes were obtained by crosslinking with formaldehyde in the presence of hydrochloric acid and glycerol as plasticizer and characterized in present study. The ionic conductivity measurements revealed the best value of 5.35?×?10?5 S cm?1 at room temperature. Factorial design analysis showed that influence of glycerol is more pronounced than influence of acid on ionic conductivity values. Moreover, the 90 % transparent membranes evidenced a linear increase of ionic conductivity values of 5.35?×?10?5 S cm?1 at 26.5 °C to 5.77?×?10?4 S cm?1 at 82.8 °C following Arrhenius type mechanism of charge mobility.  相似文献   

17.
Sodium ion conducting solid polymer blend electrolyte thin films have been prepared by using polyvinyl alcohol (PVA)/poly(vinyl pyrrolidone) (PVP) with NaNO3 by solution cast technique. The prepared films were characterized by various methods. The complexation of the salt with the polymer blend was identified by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR), Differential scanning calorimetry was used to analyze the thermal behavior of the samples, and the glass transition temperature is low for the highest conducting polymer material. The scanning electron microscopy gives the surface morphology of the polymer electrolytes. The frequency and temperature dependent of electrical conductivities of the films were studied using impedance analyzer in the frequency range of 1 Hz to 1 MHz. The highest electrical conductivity of 50PVA/50PVP/2 wt% NaNO3 concentration has been found to be 1.25 × 10?5 S cm?1 at room temperature. The electrical permittivity of the polymer films have been studied for various temperatures. The transference number measurements showed that the charge transport is mainly due to ions than electrons. Using this highest conducting polymer electrolyte, an electrochemical cell is fabricated and the parameters of the cells are tabulated.  相似文献   

18.
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   

19.
Polymer electrolyte system based on poly(vinyl alcohol) (PVA)-chitosan blend doped with ammonium bromide (NH4Br) has been prepared by solution cast method. Fourier transform infrared (FTIR) spectroscopy analysis confirms the complexation between salt and polymer host. The highest ionic conductivity obtained at room temperature is (7.68?±?1.24)?×?10?4 S cm?1 for the sample comprising of 30 wt% NH4Br. X-ray diffraction (XRD) patterns reveal that PVA-chitosan with 30 wt% NH4Br exhibits the most amorphous structure. Thermogravimetric analysis (TGA) reveals that the electrolytes are stable until ~260 °C. The conductivity variation can also be explained by field emission scanning electron microscopy (FESEM) study. Dielectric properties of the electrolytes follow non-Debye behavior. The conduction mechanism of the highest conducting electrolyte can be represented by the correlated barrier hopping (CBH) model. From linear sweep voltammetry (LSV) result, the highest conducting electrolyte is electrochemically stable at 1.57 V.  相似文献   

20.
Solid polymer electrolyte thin films based on polyacrylamide-co-acrylic acid (PAAC) doped with sodium iodide (NaI) with different ratios of polymer and salt added with fixed amount of additive of propylene carbonate (PC) were prepared by using solution casting method. The PC was added to the mixture of the solution to provide more flexibility to the polymer film by increasing the plasticity of the thin film membrane. The conductivity and dielectric studies were carried out on these thin films to understand the ion transport properties of the polymer electrolytes. The highest conductivity obtained was 1.88?×?10?5 S cm?1 for the 30% NaI salt-doped polymer electrolyte system at room temperature. The temperature-dependent conductivity agrees with Arrhenius relationship which shows that hopping mechanism of ions in the polymer matrix. The dielectric properties especially the loss tangent used to analyze the segmental relaxation of the polymer chain as more concentration of salt was incorporated. The electric modulus was studied to understand the electrical relaxation processes to overcome electrode polarization effect.  相似文献   

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