WorldWideScience

Sample records for blend polymer electrolytes

  1. Lithium ion conducting solid polymer blend electrolyte based on bio-degradable polymers

    Indian Academy of Sciences (India)

    Natarajan Rajeswari; Subramanian Selvasekarapandian; Moni Prabu; Shunmugavel Karthikeyan; C Sanjeeviraja

    2013-04-01

    Lithium ion conducting polymer blend electrolyte films based on poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) with different Mwt% of lithium nitrate (LiNO3) salt, using a solution cast technique, have been prepared. The polymer blend electrolyte has been characterized by XRD, FTIR, DSC and impedance analyses. The XRD study reveals the amorphous nature of the polymer electrolyte. The FTIR study confirms the complex formation between the polymer and salt. The shifts in g values of 70 PVA–30 PVP blend and 70 PVA–30 PVP with different Mwt% of LiNO3 electrolytes shown by DSC thermograms indicate an interaction between the polymer and the salt. The dependence of g and conductivity upon salt concentration has been discussed. The ion conductivity of the prepared polymer electrolyte has been found by a.c. impedance spectroscopic analysis. The PVA–PVP blend system with a composition of 70 wt% PVA: 30 wt% PVP exhibits the highest conductivity of 1.58 × 10-6 Scm-1 at room temperature. Polymer samples of 70 wt% PVA–30 wt% PVP blend with different molecular weight percentage of lithium nitrate with DMSO as solvent have been prepared and studied. High conductivity of 6.828 × 10-4 Scm-1 has been observed for the composition of 70 PVA:30 PVP:25 Mwt% of LiNO3 with low activation energy 0.2673 eV. The conductivity is found to increase with increase in temperature. The temperature dependent conductivity of the polymer electrolyte follows the Arrhenius relationship which shows hopping of ions in the polymer matrix. The relaxation parameters () and () of the complexes have been calculated by using loss tangent spectra. The mechanical properties of polymer blend electrolyte such as tensile strength, elongation and degree of swelling have been measured and the results are presented.

  2. FTIR AND IONIC CONDUCTIVITY STUDIES ON BLEND POLYMER ELECTROLYTES

    Directory of Open Access Journals (Sweden)

    J. Senthil

    2011-08-01

    Full Text Available Investigations on structural and conductivity properties of solid polymer complexes have attracted a high degree of attention. The main applications of solid polymer electrolytes (SPEs are found in varioussecondary batteries and energy conversion units. In view of the abundant resources, low costs and relatively low reactivity of magnesium, solid-state batteries using magnesium metal are worthy of investigations. The polymer electrolytes were prepared using poly methyl methacrylate (PMMA, poly vinyl chloride (PVC and magnesium chloride (MgCl2 by solvent casting technique. The complex formation and ionic conductivity were characterized by Fourier Transform Infra Red spectroscopy (FTIR and impedance spectroscopy respectively.The FTIR studies provide the evidence of interaction of cation Mg2+ with the polymers. The maximum conductivity found for PMMA-MgCl2 is 0.57 x 10-7 Scm-1 at room temperature.

  3. Impedance studies of a green blend polymer electrolyte based on PVA and Aloe-vera

    Science.gov (United States)

    Selvalakshmi, S.; Mathavan, T.; Vijaya, N.; Selvasekarapandian, Premalatha, M.; Monisha, S.

    2016-05-01

    The development of polymer electrolyte materials for energy generating and energy storage devices is a challenge today. A new type of blended green electrolyte based on Poly-vinyl alcohol (PVA) and Aloe-vera has been prepared by solution casting technique. The blending of polymers may lead to the increase in stability due to one polymer portraying itself as a mechanical stiffener and the other as a gelled matrix supported by the other. The prepared blend electrolytes were subjected to Ac impedance studies. It has been found out that the polymer film in which 1 gm of PVA was dissolved in 40 ml of Aloe-vera extract exhibits highest conductivity and its value is 3.08 × 10-4 S cm-1.

  4. Electrochemical characterization of electrospun nanocomposite polymer blend electrolyte fibrous membrane for lithium battery.

    Science.gov (United States)

    Padmaraj, O; Rao, B Nageswara; Venkateswarlu, M; Satyanarayana, N

    2015-04-23

    Novel hybrid (organic/inorganic) electrospun nanocomposite polymer blend electrolyte fibrous membranes with the composition poly(vinylidene difluoride-co-hexafluoropropylene) [P(VdF-co-HFP)]/poly(methyl methacrylate) [P(MMA)]/magnesium aluminate (MgAl2O4)/LiPF6 were prepared by the electrospinning technique. All of the prepared electrospun P(VdF-co-HFP), PMMA blend [90% P(VdF-co-HFP)/10% PMMA], and nanocomposite polymer blend [90% P(VdF-co-HFP)/10% PMMA/x wt % MgAl2O4 (x = 2, 4, 6, and 8)] fibrous membranes were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy. The fibrous nanocomposite separator-cum-polymer blend electrolyte membranes were obtained by soaking the nanocomposite polymer blend membranes in an electrolyte solution containing 1 M LiPF6 in ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1, v/v). The newly developed fibrous nanocomposite polymer blend electrolyte [90% P(VdF-co-HFP)/10% PMMA/6 wt % MgAl2O4/LiPF6] membrane showed a low crystallinity, low average fiber diameter, high thermal stability, high electrolyte uptake, high conductivity (2.60 × 10(-3) S cm(-1)) at room temperature, and good potential stability above 4.5 V. The best properties of the fibrous nanocomposite polymer blend electrolyte (NCPBE) membrane with a 6 wt % MgAl2O4 filler content was used for the fabrication of a Li/NCPBE/LiCoO2 CR 2032 coin cell. The electrochemical performance of the fabricated CR 2032 cell was evaluated at a current density of 0.1 C-rate. The fabricated CR 2032 cell lithium battery using the newly developed NCPBE membrane delivered an initial discharge capacity of 166 mAh g(-1) and a stable cycle performance.

  5. Investigations on Poly (ethylene oxide) (PEO) - blend based solid polymer electrolytes for sodium ion batteries

    Science.gov (United States)

    Koduru, H. K.; Iliev, M. T.; Kondamareddy, K. K.; Karashanova, D.; Vlakhov, T.; Zhao, X.-Z.; Scaramuzza, N.

    2016-10-01

    Polymer blend electrolytes based on Polyethylene oxide (PEO) and polyvinyl pyrrolidone (PVP), complexed with NaIO4 salt and Graphene oxide (GO) are investigated in the present report. The electrolytes are prepared by a facile solution cast technique. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) are employed to study the influence of ion-polymer interactions on the micro structural properties of blend electrolytes. Measurements of electrical conductivity of the blend polymer complexes have been performed by using complex impedance spectroscopy in the frequency range 1 Hz - 1 MHz and within the temperature range 303 K - 343 K.A study on electrical conductivity properties of GO doped ‘salt complexed electrolyte’ systems is presented.

  6. A quasi-direct methanol fuel cell system based on blend polymer membrane electrolytes

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, Hans Aage; Hasiotis, C.

    2002-01-01

    , compared to less than 100 ppm CO for the Nafion-based technology at 80degrees C. The high CO tolerance makes it possible to use the reformed hydrogen directly from a simple methanol reformer without further CO removal. That both the fuel cell and the methanol reformer operate at temperatures around 200......On the basis of blend polymer electrolytes of polybenzimidazole and sulfonated polysulfone, a polymer electrolyte membrane fuel cell was developed with an operational temperature up to 200degrees C. Due to the high operational temperature, the fuel cell can tolerate 1.0-3.0 vol % CO in the fuel...

  7. High ionic conductivity P(VDF-TrFE)/PEO blended polymer electrolytes for solid electrochromic devices.

    Science.gov (United States)

    Nguyen, Chien A; Xiong, Shanxin; Ma, Jan; Lu, Xuehong; Lee, Pooi See

    2011-08-07

    Solid polymer electrolytes with excellent ionic conductivity (above 10(-4) S cm(-1)), which result in high optical modulation for solid electrochromic (EC) devices are presented. The combination of a polar host matrix poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) and a solid plasticized of a low molecular weight poly(ethylene oxide) (PEO) (M(w)≤ 20,000) blended polymer electrolyte serves to enhance both the dissolution of lithium salt and the ionic transport. Calorimetric measurement shows a reduced crystallization due to a better intermixing of the polymers with small molecular weight PEO. Vibrational spectroscopy identifies the presence of free ions and ion pairs in the electrolytes with PEO of M(w)≤ 8000. The ionic dissolution is improved using PEO as a plasticizer when compared to liquid propylene carbonate, evidently shown in the transference number analysis. Ionic transport follows the Arrhenius equation with a low activation energy (0.16-0.2 eV), leading to high ionic conductivities. Solid electrochromic devices fabricated with the blended P(VDF-TrFE)/PEO electrolytes and polyaniline show good spectroelectrochemical performance in the visible (300-800 nm) and near-infrared (0.9-2.4 μm) regions with a modulation up to 60% and fast switching speed of below 20 seconds. The successful introduction of the solid polymer electrolytes with its best harnessed qualities helps to expedite the application of various electrochemical devices.

  8. Synthesis and characterization of nanocomposite polymer blend electrolyte thin films by spin-coating method

    Science.gov (United States)

    Chapi, Sharanappa; Niranjana, M.; Devendrappa, H.

    2016-05-01

    Solid Polymer blend electrolytes based on Polyethylene oxide (PEO) and poly vinyl pyrrolidone (PVP) complexed with zinc oxide nanoparticles (ZnO NPs; Synthesized by Co-precipitation method) thin films have prepared at a different weight percent using the spin-coating method. The complexation of the NPs with the polymer blend was confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR). The variation in film morphology was examined by polarized optical micrographs (POMs). The thermal behavior of blends was investigated under non-isothermal conditions by differential thermal analyses (DTA). A single glass transition temperature for each blend was observed, which supports the existence of compatibility of such system. The obtained results represent that the ternary based thin films are prominent materials for battery and optoelectronic device applications.

  9. Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Putri, Zufira; Arcana, I. Made

    2014-03-01

    Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO2 are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO2 compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO2 blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM).

  10. Biodegradation test of SPS-LS blends as polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Putri, Zufira, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: zufira.putri@gmail.com, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-03-24

    Sulfonated polystyrene (SPS) can be applied as a proton exchange membrane fuel cell due to its fairly good chemical stability. In order to be applied as polymer electrolyte membrane fuel cells (PEMFCs), membrane polymer should have a good ionic conductivity, high proton conductivity, and high mechanical strength. Lignosulfonate (LS) is a complex biopolymer which has crosslinks and sulfonate groups. SPS-LS blends with addition of SiO{sub 2} are used to increase the proton conductivity and to improve the mechanical properties and thermal stability. However, the biodegradation test of SPS-LS blends is required to determine whether the application of these membranes to be applied as an environmentally friendly membrane. In this study, had been done the synthesis of SPS, biodegradability test of SPS-LS blends with variations of LS and SiO{sub 2} compositions. The biodegradation test was carried out in solid medium of Luria Bertani (LB) with an activated sludge used as a source of microorganism at incubation temperature of 37°C. Based on the results obtained indicated that SPS-LS-SiO{sub 2} blends are more decomposed by microorganism than SPS-LS blends. This result is supported by analysis of weight reduction percentage, functional groups with Fourier Transform Infrared (FTIR) Spectroscopy, and morphological surface with Scanning Electron Microscopy (SEM)

  11. Zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends

    Science.gov (United States)

    Ye, Hui; Xu, Jun John

    Here we report novel zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends with or without the incorporation of a small amount of organic carbonates. Their thermal properties, ionic conductivity and electrochemical properties are characterized and the effect of different Zn salts and incorporation of a small amount of organic carbonates are investigated. These polymer electrolyte membranes exhibit essentially no or very low volatility, high thermal stability, high ionic conductivity, wide electrochemical stability window, acceptable interfacial resistance with zinc, and the capability for reversible Zn plating/stripping. Particularly promising are electrolyte systems based on the combination of low lattice energy zinc imide salt and a special co-solvent of oligomeric poly(ethylene glycol) dimethyl ether (PEGDME) mixed with a small amount of ethylene carbonate (EC), dimensionally stabilized with PVDF-HFP. Such novel polymer electrolyte membranes could lead to the development of new kinds of electrochemical energy storage devices based on zinc electrochemistry, including solid-state, thin-film rechargeable zinc/air cells envisaged.

  12. Zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Hui; Xu, Jun John [Department of Materials Science and Engineering, Rutgers, the State University of New Jersey, Piscataway, NJ 08854 (United States)

    2007-03-20

    Here we report novel zinc ion conducting polymer electrolytes based on oligomeric polyether/PVDF-HFP blends with or without the incorporation of a small amount of organic carbonates. Their thermal properties, ionic conductivity and electrochemical properties are characterized and the effect of different Zn salts and incorporation of a small amount of organic carbonates are investigated. These polymer electrolyte membranes exhibit essentially no or very low volatility, high thermal stability, high ionic conductivity, wide electrochemical stability window, acceptable interfacial resistance with zinc, and the capability for reversible Zn plating/stripping. Particularly promising are electrolyte systems based on the combination of low lattice energy zinc imide salt and a special co-solvent of oligomeric poly(ethylene glycol) dimethyl ether (PEGDME) mixed with a small amount of ethylene carbonate (EC), dimensionally stabilized with PVDF-HFP. Such novel polymer electrolyte membranes could lead to the development of new kinds of electrochemical energy storage devices based on zinc electrochemistry, including solid-state, thin-film rechargeable zinc/air cells envisaged. (author)

  13. Ion Transport and Discharge Characteristics of Polymer Blend (PVP/PVA) Electrolyte Films Doped with Potassium Iodide

    Science.gov (United States)

    Umadevi, C.; Mohan, K. R.; Achari, V. B. S.; Sharma, A. K.; Rao, V. V. R. N.

    2010-12-01

    Solid polymer blend electrolyte films based on PVP/PVA complexed with KI were prepared by the solution cast technique. Various experimental techniques such as electrical conductivity and transport number measurement were used to characterize the polymer electrolyte films. Electrochemical cells with the polymer electrolytes (PVP+PVA+KI) were fabricated in the configuration K/(PVP+PVA+KI)/ (I2+C+electrode). The discharge characteristics of the cells were studied under a constant load of 100 KΩ. The open-circuit voltage, short-circuit current and discharge time for the plateau region are measured. Several other cell parameters were evaluated and are reported.

  14. Structural and ionic conductivity studies of electrospun polymer blend P(VdF-co-HFP)/PMMA electrolyte membrane for lithium battery application

    Energy Technology Data Exchange (ETDEWEB)

    Padmaraj, O.; Satyanarayana, N., E-mail: nallanis2011@gmail.com [Department of Physics, Pondicherry University, Pondicherry 605 014 (India); Venkateswarlu, M. [R& D, Amara Raja Batteries Ltd., Karakambadi 517 520 (India)

    2015-06-24

    A novel fibrous polymer blend [(100-x) % P(VdF-co-HFP)/x % PMMA, x = 10, 20, 30, 40, 50] electrolyte membranes were prepared by electrospinning technique. Structural, thermal and surface morphology of all the compositions of electrospun polymer blend membranes were studied by using XRD, DSC & SEM. The newly developed five different compositions of polymer blend fibrous electrolyte membranes were obtained by soaking in an electrolyte solution contains 1M LiPF{sub 6} in EC: DEC (1:1,v/v). The wet-ability and conductivity of all the compositions of polymer blend electrolyte membranes are evaluated through electrolyte uptake and impedance measurements. The polymer blend [90% P(VdF-co-HFP)/10% PMMA] electrolyte membrane showed good wet-ability and high conductivity (1.788 × 10{sup −3} Scm{sup −1}) at room temperature.

  15. POLYMER ELECTROLYTE MEMBRANE FUEL CELLS

    DEFF Research Database (Denmark)

    2001-01-01

    A method for preparing polybenzimidazole or polybenzimidazole blend membranes and fabricating gas diffusion electrodes and membrane-electrode assemblies is provided for a high temperature polymer electrolyte membrane fuel cell. Blend polymer electrolyte membranes based on PBI and various...... thermoplastic polymers for high temperature polymer electrolyte fuel cells have also been developed. Miscible blends are used for solution casting of polymer membranes (solid electrolytes). High conductivity and enhanced mechanical strength were obtained for the blend polymer solid electrolytes...... electrolyte membrane by hot-press. The fuel cell can operate at temperatures up to at least 200 °C with hydrogen-rich fuel containing high ratios of carbon monoxide such as 3 vol% carbon monoxide or more, compared to the carbon monoxide tolerance of 10-20 ppm level for Nafion$m(3)-based polymer electrolyte...

  16. PREPARATION AND ELECTROCHEMICAL CHARACTERISTICS OF POLYMER ELECTROLYTE MEMBRANES BASED ON SAN/PVDF-HFP BLENDS

    Institute of Scientific and Technical Information of China (English)

    Ding-guo Tang; Lu Qi; Yun-xiang Ci

    2006-01-01

    A copolymer of poly(acrylonitrile-co-styrene) (SAN) was synthesized via an emulsion polymerization method.Novel polymer electrolyte membranes cast from the blends of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), SAN and fumed silica (SiO2) are microporous and can be used in polymer lithium-ion batteries. The membrane shows excellent characteristics such as high ionic conductivity and good mechanical strength when the mass ratio between SAN and PVDF-HFP and SiO2 is 3.5/31.5/5. The ionic conductivity of the membrane soaked in a liquid electrolyte of 1 mol/L LiPF6/EC/DMC/DEC is 4.9 × 10-3 Scm-1 at 25℃. The membrane is electrochemical stable up to 5.5 V versus Li+/Li in the liquid electrolyte. The influences of SiO2 content on the porosity and mechanical strength of the membranes were studied.Polymer lithium-ion batteries based on the membranes were assembled and their performances were also studied.

  17. Optimization of hybrid polymer electrolytes with the effect of lithium salt concentration in PEO/PVdF-HFP blends

    Energy Technology Data Exchange (ETDEWEB)

    Pradeepa, P.; Edwin raj, S.; Sowmya, G.; Kalaiselvimary, J.; Ramesh Prabhu, M., E-mail: mkram83@gmail.com

    2016-03-15

    Highlights: • Polymer blends based on PVdF-HFP/PEO were prepared for Li-ion battery applications. • Structural and electrochemical studies were carried out on prepared electrolytes. • The electrolytes can be used as electrolyte in the possible device fabrications. - Abstract: Poly(ethylene oxide) (PEO) 6.25 wt%/poly(vinylidene fluoride-co-hexafluoropropylene) [P(VdF-HFP)] 18.75 wt% blend based electrolyte films containing different concentrations (2–10) wt% of lithium salt were prepared. The miscibility studies have been performed by using X-ray diffraction and Fourier transform infrared spectroscopy. The role of interaction between polymer hosts on conductivity is discussed using the results of a.c. impedance studies. A room temperature conductivity of 2.3912 × 10{sup −4} S cm{sup −1} has been obtained for PEO (6.25)–PVdF-HFP (18.75)–LiClO{sub 4} (8)–PC (67) polymer complex. The temperature dependence of the conductivity of polymer electrolyte seems to obey VTF relation. Electrochemical stability (3.3 V) was observed in the prepared polymer electrolyte. Reduction process and oxidation process of the prepared electrolyte system have also been evaluated by means of cyclic voltammetry. Thermogravimetric analysis results indicate thermal stability of PEO/PVdF-HFP lithium salt complexes. Roughness parameter of the sample having maximum ionic conductivity was studied by AFM. The morphology of the polymer complex is investigated by using SEM.

  18. Optimized performance of quasi-solid-state DSSC with PEO-bismaleimide polymer blend electrolytes filled with a novel procedure.

    Science.gov (United States)

    Lee, Dong Ha; Sun, Kyung Chul; Qadir, Muhammad Bilal; Jeong, Sung Hoon

    2014-12-01

    Dye-sensitized solar cell (DSSC) is an attractive renewable energy technology currently under intense investigation. Electrolyte plays an important role in the photovoltaic performance of the DSSCs and many efforts have been contributed to study different kinds of electrolytes with various characteristics such as liquid electrolytes, polymer electrolytes and so on. In this study, DSSC is developed by using quasi-solid electrolyte and a novel procedure is adopted for filling this electrolyte. The quasi-solid-state electrolyte was prepared by mixing Poly ethylene oxide (PEO) and bismaleimide together and constitution was taken as PEO (15 wt%) at various bismaleimide concentrations (1, 3, 5 wt%). The novel procedure of filling electrolyte consists of three major steps (first step: filling liquid electrolyte, second step: vaporization of liquid electrolyte, third step: refilling quasi-solid-state electrolyte). The electrochemical and photovoltaic performances of DSSCs with these electrolytes were also investigated. The electrochemical impedance spectroscopy (EIS) indicated that TiO2/Dye/electrolyte impedance is reduced and electron lifetime is increased, and consequently efficiency of cell has been improved after using this novel procedure. The photovoltaic power conversion efficiency of 6.39% has been achieved under AM 1.5 simulated sunlight (100 W/cm2) through this novel procedure and by using specified blend of polymers.

  19. Compatibility and thermal stability studies on plasticized PVC/PMMA blend polymer electrolytes complexed with different lithium salts

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2005-03-01

    Full Text Available The lithium salt (x (X= LiAsF6, LiPF6, LiN(C2F5SO22 , LiN(CF3SO22, LiBF4 was complexed with a host of poly(vinyl chloride (PVC/ poly(methyl methacrylate (PMMA blend polymer and plasticized with a combination of ethylene carbonate (EC and propylene carbonate(PC. The polymer electrolyte films were prepared for constant PVC/PMMA blend ratio. The electrochemical stability and thermal stability of the solid polymer electrolytes were reported. The role of PMMA to the phenomena occurring at the interface between the electrolyte and the lithium metal electrode was explored.

  20. Influence of Al2O3 on the ionic conductivity of plasticized PVC-PEG blend polymer electrolytes

    Science.gov (United States)

    Ravindran, D.; Vickraman, P.

    2016-05-01

    Polymer electrolytes with PVC-PEG blend as host matrix and LiClO4 as dopant salt was prepared through conventional solution casting method. To enhance the conductivity propylene carbonate (PC) was used as plasticizer. The influence of ceramic filler Al2O3 on the conductivity of the electrolyte films were studied by varying the (PVC: Al2O3) ratio. The films were subjected to XRD, complex impedance analysis and SEM analysis. The XRD studies reveal a marginal increase in the amorphous phase of the electrolyte films due to the incorporation of filler. The AC impedance analysis shows the dependency of ionic conductivity on the content (wt %) of filler and exhibit a maximum at 4 wt% filler. The SEM analysis depicts the occurrence of phase separation in electrolyte which is attributed to the poor solubility of polymer PVC in the liquid electrolyte.

  1. Development and characterization of acid-doped polybenzimidazole/sulfonated polysulfone blend polymer electrolytes for fuel cells

    DEFF Research Database (Denmark)

    Hasiotis, C.; Li, Qingfeng; Deimede, V.

    2001-01-01

    Polymeric membranes from blends of sulfonated polysulfones (SPSF) and polybenzimidazole (PBI) doped with phosphoric acid were developed as potential high-temperature polymer electrolytes for fuel cells and other electrochemical applications. The water uptake and acid doping of these polymeric...... it was found to be higher than 10/sup -2/ S cm/sup -1/. Much improvement in the mechanical strength is observed for the blend polymer membranes, especially at higher temperatures. Preliminary work has demonstrated the feasibility of these polymeric membranes for fuel-cell applications...

  2. Improved electrical properties of Fe nanofiller impregnated PEO + PVP:Li+ blended polymer electrolytes for lithium battery applications

    Science.gov (United States)

    Naveen Kumar, K.; Saijyothi, K.; Kang, Misook; Ratnakaram, Y. C.; Hari Krishna, K.; Jin, Dahee; Lee, Yong Min

    2016-07-01

    Solid polymer-blended electrolyte films of polyethylene oxide (PEO) + polyvinyl pyrrolidone (PVP)/lithium perchlorate embedded with iron (Fe) nanofiller in different concentrations have been synthesized by a solution casting method. The semicrystalline nature of these polymer electrolyte films has been confirmed from their XRD profiles. Polymer complex formation and ion-polymer interactions are systematically studied by FTIR and laser Raman spectral analysis. Surface morphological studies are carried out from SEM analysis. Dispersed Fe nanofiller size evaluation study has been carried out using transmission electron microscopy (TEM). In order to evaluate the thermal stability, decomposition temperature, and thermogravimetric dynamics, we carried out the TG/DTA measurement. Upon addition of Fe nanofiller to the PEO + 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 × 10-4 Scm-1 at the optimized concentration of 4 wt% Fe nanofiller-embedded PEO + PVP/Li+ polymer electrolyte nanocomposite at an ambient temperature. PEO + PVP/Li+ + Fe nanofiller (4 wt%) cell exhibited better performance in terms of cell parameters. Based on the cell parameters, the 4 wt% Fe nanofiller-dispersed PEO + PVP/Li+ polymer electrolyte system could be suggested as a perspective candidate for solid-state battery applications.

  3. Effect of complexing salt on conductivity of PVC/PEO polymer blend electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; Ravi Shanker Babu; M Usha Rani

    2011-12-01

    Solid polymer electrolyte membrane comprising poly(vinyl chloride) (PVC), poly(ehylene oxide) (PEO) and different lithium salts (LiClO4, LiBF4 and LiCF3SO3) were prepared by the solution casting technique. The effect of complexing salt on the ionic conductivity of the PVC/PEO host polymer is discussed. Solid polymer electrolyte films were characterized by X-ray diffraction, FTIR spectroscopy, TG/DTA and ac impedance spectroscopic studies. The conductivity studies of these solid polymer electrolyte (SPE) films are carried out as a function of frequency at various temperatures ranging from 302 K to 353 K. The maximum room temperature ionic conductivity is found to be 0.079 × 10-4 S cm-1 for the film containing LiBF4 as the complexing salt. The temperature dependence of the conductivity of polymer electrolyte films seems to obey the Vogel–Tamman–Fulcher (VTF) relation.

  4. AC impedance and dielectric spectroscopic studies of Mg2+ ion conducting PVA–PEG blended polymer electrolytes

    Indian Academy of Sciences (India)

    Anji Reddy Polu; Ranveer Kumar

    2011-08-01

    Polyvinyl alcohol (PVA)–polyethylene glycol (PEG) based solid polymer blend electrolytes with magnesium nitrate have been prepared by the solution cast technique. Impedance spectroscopic technique has been used, to characterize these polymer electrolytes. Complex impedance analysis was used to calculate bulk resistance of the polymer electrolytes. The a.c.-impedance data reveal that the ionic conductivity of PVA–PEG–Mg(NO3)2 system is changed with the concentration of magnesium nitrate, maximum conductivity of 9.63 × 10-5 S/cm at room temperature was observed for the system of PVA–PEG–Mg(NO3)2 (35–35–30). However, ionic conductivity of the above system increased with the increase of temperature, and the highest conductivity of 1.71 × 10-3 S/cm was observed at 100°C. The effect of ionic conductivity of polymer blend electrolytes was measured by varying the temperature ranging from 303 to 373 K. The variation of imaginary and real parts of dielectric constant with frequency was studied.

  5. Properties of Polymer Electrolyte Membranes Prepared by Blending of Sulfonated Polystyrene-Lignosulfonate

    OpenAIRE

    Siang Tandi Gonggo; Cynthia L. Radiman; Bunbun Bundjali; I Made Arcana

    2012-01-01

    Electrolyte polymer membrane widely used in PEMFC and DMFC is a perfluorosulfonated membrane such as Nafion. This membrane material exhibits good chemical stability and proton conductivity, but it is very expensive and difficult to recycle. It has high cross-over methanol in DMFC that causes the decrease efficiency and performance of fuel cell, so that the electrolyte polymer membrane with low cross-over methanol has been needed to substitute Nafion membrane. One of the materials used as a po...

  6. Ionic relaxation in PEO/PVDF-HFP-LiClO4 blend polymer electrolytes: dependence on salt concentration

    Science.gov (United States)

    Das, S.; Ghosh, A.

    2016-06-01

    In this paper, we have studied the effect of LiClO4 salt concentration on the ionic conduction and relaxation in poly ethylene oxide (PEO) and poly (vinylidene fluoride hexafluoropropylene) (PVDF-HFP) blend polymer electrolytes, in which the molar ratio of ethylene oxide segments to lithium ions (R  =  EO: Li) has been varied between 3 and 35. We have observed two phases in the samples containing low salt concentrations (R  >  9) and single phase in the samples containing high salt concentrations (R  ⩽  9). The scanning electron microscopic images indicate that there exists no phase separation in the blend polymer electrolytes. The temperature dependence of the ionic conductivity shows two slopes corresponding to high and low temperatures and follows Arrhenius relation for the samples containing low salt concentrations (R  >  9). The conductivity relaxation as well as the structural relaxation has been clearly observed at around 104 Hz and 106 Hz for these concentrations of the blended electrolytes. However, a single conductivity relaxation peak has been observed for the compositions with R  ⩽  9. The scaling of the conductivity spectra shows that the relaxation mechanism is independent of temperature, but depends on salt concentration.

  7. Li Ion Conducting Polymer Gel Electrolytes Based on Ionic Liquid/PVDF-HFP Blends.

    Science.gov (United States)

    Ye, Hui; Huang, Jian; Xu, Jun John; Khalfan, Amish; Greenbaum, Steve G

    2007-09-21

    Ionic liquids thermodynamically compatible with Li metal are very promising for applications to rechargeable lithium batteries. 1-methyl-3-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P(13)TFSI) is screened out as a particularly promising ionic liquid in this study. Dimensionally stable, elastic, flexible, nonvolatile polymer gel electrolytes (PGEs) with high electrochemical stabilities, high ionic conductivities and other desirable properties have been synthesized by dissolving Li imide salt (LiTFSI) in P(13)TFSI ionic liquid and then mixing the electrolyte solution with poly(vinylidene-co-hexafluoropropylene) (PVDF-HFP) copolymer. Adding small amounts of ethylene carbonate to the polymer gel electrolytes dramatically improves the ionic conductivity, net Li ion transport concentration, and Li ion transport kinetics of these electrolytes. They are thus favorable and offer good prospects in the application to rechargeable Li batteries including open systems like Li/air batteries, as well as more "conventional" rechargeable lithium and lithium ion batteries.

  8. Li Ion Conducting Polymer Gel Electrolytes Based on Ionic Liquid/PVDF-HFP Blends

    Science.gov (United States)

    Ye, Hui; Huang, Jian; Xu, Jun John; Khalfan, Amish; Greenbaum, Steve G.

    2009-01-01

    Ionic liquids thermodynamically compatible with Li metal are very promising for applications to rechargeable lithium batteries. 1-methyl-3-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P13TFSI) is screened out as a particularly promising ionic liquid in this study. Dimensionally stable, elastic, flexible, nonvolatile polymer gel electrolytes (PGEs) with high electrochemical stabilities, high ionic conductivities and other desirable properties have been synthesized by dissolving Li imide salt (LiTFSI) in P13TFSI ionic liquid and then mixing the electrolyte solution with poly(vinylidene-co-hexafluoropropylene) (PVDF-HFP) copolymer. Adding small amounts of ethylene carbonate to the polymer gel electrolytes dramatically improves the ionic conductivity, net Li ion transport concentration, and Li ion transport kinetics of these electrolytes. They are thus favorable and offer good prospects in the application to rechargeable Li batteries including open systems like Li/air batteries, as well as more “conventional” rechargeable lithium and lithium ion batteries. PMID:20354587

  9. Effect of PVC on ionic conductivity, crystallographic structural, morphological and thermal characterizations in PMMA-PVC blend-based polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Ramesh, S., E-mail: rameshtsubra@gmail.com [Centre for Ionics University Malaya, Department of Physics, Faculty of Science, University of Malaya, Lembah Pantai, 50603 Kuala Lumpur (Malaysia); Liew, Chiam-Wen; Morris, Ezra; Durairaj, R. [Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, Setapak, 53300 Kuala Lumpur (Malaysia)

    2010-11-20

    In this paper, temperature dependence of ionic conductivity, crystallographic structural, morphological and thermal characteristics of polymer blends of PMMA and PVC with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) as a dopant salt are investigated. The study on the temperature dependence of ionic conductivity shows that these polymer blends exhibit Arrhenius behavior. The highest ionic conductivity was achieved when 70 wt% of PMMA was blended with 30 wt% of PVC. X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveal the amorphous nature and surface morphology of polymer electrolytes, respectively. In DSC analysis it was found that the glass transition temperature (T{sub g}) and melting temperature (T{sub m}) decreased, whereas the decomposition temperature (T{sub d}) increased. In contrast, the shift towards higher decomposition temperature and decrease in weight loss of polymer electrolytes, in TGA studies, indicates that the thermal stability of polymer electrolytes improved.

  10. Performance of polymer electrolyte based on chitosan blended with poly(ethylene oxide) for plasmonic dye-sensitized solar cell

    Science.gov (United States)

    Buraidah, M. H.; Teo, L. P.; Au Yong, C. M.; Shah, Shahan; Arof, A. K.

    2016-07-01

    Chitosan and poly(ethylene oxide) powders have been mixed in different weight ratios. To each mixture, a fixed amount of ammonium iodide has been added. All mixtures have been dissolved in 1% acetic acid solution to form polymer blend electrolyte films by the solution cast technique. X-ray diffraction indicates that the polymer blend electrolytes are amorphous. Fourier transform infrared spectroscopy shows shifting of the amine, carboxamide and Csbnd Osbnd C bands to lower wavenumbers indicating the occurrence of complexation. Electrochemical impedance spectroscopy has been used to study the electrical properties of the samples. The ionic conductivity for 55 wt.% chitosan-45 wt.% NH4I electrolyte system is 3.73 × 10-7 S cm-1 at room temperature and is increased to 3.66 × 10-6 S cm-1 for the blended film (16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I film. Dye-sensitized solar cells (DSSCs) have been fabricated by sandwiching the polymer electrolyte between the TiO2/dye photoelectrode and Pt counter electrode. DSSCs fabricated exhibits short-circuit current density (Jsc) of 2.71 mA cm-2, open circuit voltage (Voc) of 0.58 V and efficiency of 0.78% with configuration ITO/TiO2/N3 dye/(16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I(+I2)/Pt/ITO and Jsc of 2.84 mA cm-2, Voc of 0.58 V and efficiency of 1.13% with configuration ITO/TiO2 + Ag nanoparticles/N3 dye/(16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I(+I2)/Pt/ITO.

  11. Properties of Polymer Electrolyte Membranes Prepared by Blending of Sulfonated Polystyrene-Lignosulfonate

    Directory of Open Access Journals (Sweden)

    Siang Tandi Gonggo

    2012-11-01

    Full Text Available Electrolyte polymer membrane widely used in PEMFC and DMFC is a perfluorosulfonated membrane such as Nafion. This membrane material exhibits good chemical stability and proton conductivity, but it is very expensive and difficult to recycle. It has high cross-over methanol in DMFC that causes the decrease efficiency and performance of fuel cell, so that the electrolyte polymer membrane with low cross-over methanol has been needed to substitute Nafion membrane. One of the materials used as a polymer electrolyte membrane is polyblends of a sulfonated polystyrene-lignosulfonate (SPS-LS. These polyblends have been prepared by casting polymer solution and characterized as a polyelectrolyte membrane for DMFC. SPS was prepared by sulfonation of polystyrene with acetyl sulfate used as a sulfonating agent. The membranes of SPS-LS were characterized by analysis of functional groups, mechanical properties, and methanol permeability. The maximum mechanical properties of the SPS-LS membrane were observed in LS ratio of 7.5%. However, the methanol permeability of membrane increases as the increase of LS ratio in SPS-LS membranes. The properties of membranes, especially the mechanical property and methanol permeability close to that of Nafion® 117 membrane, so the SPS-LS membrane is highly potential used as the electrolyte membrane for direct methanol fuel cell.

  12. Studies on electrical conductivity and dielectric behaviour of PVdF–HFP–PMMA–NaI polymer blend electrolyte

    Indian Academy of Sciences (India)

    S K Tripathi; Ashish Gupta; Manju Kumari

    2012-11-01

    Polymer blend electrolytes composed of poly(vinylidene fluoride-co-hexafluoro-propylene), poly(methyl methacrylate) and 1.0 M NaI as salt have been synthesized using solution caste technique by varying the PVdF(HFP)–PMMA blend concentration ratio systematically. A.c. impedance studies were performed to evaluate the ionic conductivity of the polymer electrolyte films. The highest ionic conductivity at room temperature for [PVdF(HFP)–PMMA(4:1)](20 wt%) – [NaI(1.0M)](80 wt%) system is found to be 1.67 × 10-2 S cm-1. XRD studies reveal complete complexation of the salt in the polymeric blend systems. The temperature dependence conductivity has been performed in the range of 303–373 K and it is observed that it obeys the Arrhenius behaviour. It has been observed that the dielectric constant, r and dielectric loss, i, increases with temperature in the lower frequency region and is almost negligible in the higher frequency region. This behaviour can be explained on the basis of electrode polarization effects. Plot of real part, r and imaginary part, i vs frequency indicates that the systems are predominantly ionic conductors. The phenomenon suggests a plurality of relaxation mechanism.

  13. Effect of nano CuO on the ionic conductivity of PVC-PEG blend polymer electrolytes

    Science.gov (United States)

    Ravindran, Dhandapani; Vickraman, Palanichamy

    2013-06-01

    Nano CuO was prepared by co-precipitation method and it was incorporated as filler in PVC-PEG blend based solid polymer electrolytes with lithium perchlorate (LiClO4) as salt. The PVC: CuO ratio was systematically varied in order to study its effect on the ionic conductivity behavior of electrolyte membranes. The membranes were subjected to XRD and impedance analysis. The analysis shows that the conductivity profile was strongly influenced by the PVC: CuO ratio. The membrane with PVC/CuO: PEG: PC: LiClO4=23/2:15:50:10 exhibits higher conductivity of 4.0×10-6 S/cm at room temperature.

  14. Li Ion Conducting Polymer Gel Electrolytes Based on Ionic Liquid/PVDF-HFP Blends

    OpenAIRE

    Ye, Hui; Huang, Jian; Xu, Jun John; Khalfan, Amish; Greenbaum, Steve G.

    2007-01-01

    Ionic liquids thermodynamically compatible with Li metal are very promising for applications to rechargeable lithium batteries. 1-methyl-3-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide (P13TFSI) is screened out as a particularly promising ionic liquid in this study. Dimensionally stable, elastic, flexible, nonvolatile polymer gel electrolytes (PGEs) with high electrochemical stabilities, high ionic conductivities and other desirable properties have been synthesized by dissolving Li i...

  15. Dye-sensitized solar cells based on electrospun polymer blends as electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Hae; Choi, Hyung-Ju; Hwang, Won-Pil; Kim, Jung-Heon; Lee, Jin-Kook; Kim, Mi-Ra [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Won, Du-Hyun [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Solchem Co., Ltd., Busan 609-735 (Korea, Republic of); Jang, Sung-il [Solchem Co., Ltd., Busan 609-735 (Korea, Republic of); Jeong, Seong-Hoon; Kim, Ji-Un [EAGUN WINDOW and DOOR SYSTEMS Co., Ltd., Incheon 967-3 (Korea, Republic of)

    2011-01-15

    We prepared electrospun polymer nanofibers by the electrospinning method and investigated about their applications to dye-sensitized solar cells (DSSCs). Electrospun poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) and PVDF-HFP/polystyrene (PS) blend nanofibers were prepared and examined the uptake, the ionic conductivity, and the porosity by impedance measurement and Scanning Electron Microscope (SEM). The best results of V{sub oc}, J{sub sc}, FF, and efficiency of the DSSC devices using the electrospun PVDF-HFP/PS(3:1) blend nanofibers were 0.76 V, 11.8 mA/cm{sup 2}, 0.66, and 5.75% under AM 1.5. (author)

  16. Polymer Electrolytes Based on Electrospun PEO-P(VdF-HFP) Blends for Lithium-Polymer Batteries

    Institute of Scientific and Technical Information of China (English)

    P.Raghvan; J.Manuel; G.Cheruvally; J.H.Ahn

    2007-01-01

    1 Results Electrospinning has attracted immense attention recently as a versatile and easy method to prepare polymer membranes that are made up of thin fibers of micron and sub-micron diameters.Such membranes are particularly suitable as host matrices for polymer electrolytes (PEs) since the interlaying of fibers generate large porosity with fully interconnected pore structure facilitating the easy transport of ions.Characterization of PEs based on electrospun membranes of poly(vinylidene fluoride) (PVd...

  17. Highly Conductive Redox-Couple Solid Polymer Electrolyte System: Blend-KI-I2 for Dye-Sensitized Solar Cells

    Directory of Open Access Journals (Sweden)

    Ravindra Kumar Gupta

    2011-01-01

    Full Text Available Ionic conductivity of a redox-couple solid polymer electrolyte system, (1− blend: [0.9KI : 0.1I2] with =0−0.15 in weight fraction, is reported. A blend of poly(ethylene oxide (abbreviated as PEO and succinonitrile in equal weight fraction was used as a polymeric matrix instead of the PEO and succinonitrile because of its low-cost, electrical conductivity superior to the PEO, and thermal stability better than the succinonitrile. The electrolyte with =0.15 showed ionic conductivity of 7×10−4 S cm−1 and iodine ion diffusivity of nearly 4×10−7 cm2 s−1 at 25°C. The conductivity and diffusivity values were nearly two orders of magnitude higher than those of the PEO-KI-I2 due to the improved PEO crystallinity. It also exhibited dye-sensitized solar cell efficiency of 2.2% at 100 mW cm−2, which is twice of the cell prepared using the PEO-KI-I2 only.

  18. Preparation and characterization of lithium ion conducting polymer electrolytes based on a blend of poly(vinylidene fluoride-co-hexafluoropropylene and poly(methyl methacrylate

    Directory of Open Access Journals (Sweden)

    Merhawi Abreha Gebreyesus

    2016-07-01

    Full Text Available Ion conducting polymer electrolytes composed of poly(vinylidene fluoride-co-hexafluoropropylene (PVdF-HFP, poly(methyl methacrylate (PMMA and lithium triflate (LiTf were prepared using the solution casting method. Structural change and complex formation in the blend electrolyte systems were confirmed from the X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy and scanning electron microscopy (SEM studies. Thermal properties of the samples were investigated by the differential scanning calorimetry (DSC technique. The ionic conductivity of these polymer electrolytes was studied by impedance spectroscopy at various temperatures ranging from 303–393 K. The results reveal that the ionic conductivity of the polymer blend electrolytes depends on the PVdF-HFP:PMMA composition as well as the temperature. Maximum room temperature conductivity of 7.4×10−5 S cm−1 was achieved with 22.5 wt.% PMMA. The blending of PVdF-HFP with PMMA improved the thermal stability and ionic conductivity of the polymer electrolyte. Estimated transference numbers suggest the charge transport is predominantly ionic.

  19. Preparation and characterization of lithium ion conducting polymer electrolytes based on a blend of poly(vinylidene fluoride-co-hexafluoropropylene) and poly(methyl methacrylate).

    Science.gov (United States)

    Gebreyesus, Merhawi Abreha; Purushotham, Y; Kumar, J Siva

    2016-07-01

    Ion conducting polymer electrolytes composed of poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), poly(methyl methacrylate) (PMMA) and lithium triflate (LiTf) were prepared using the solution casting method. Structural change and complex formation in the blend electrolyte systems were confirmed from the X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) studies. Thermal properties of the samples were investigated by the differential scanning calorimetry (DSC) technique. The ionic conductivity of these polymer electrolytes was studied by impedance spectroscopy at various temperatures ranging from 303-393 K. The results reveal that the ionic conductivity of the polymer blend electrolytes depends on the PVdF-HFP:PMMA composition as well as the temperature. Maximum room temperature conductivity of [Formula: see text] S cm(-1) was achieved with 22.5 wt.% PMMA. The blending of PVdF-HFP with PMMA improved the thermal stability and ionic conductivity of the polymer electrolyte. Estimated transference numbers suggest the charge transport is predominantly ionic.

  20. [FTIR investigation of new polymer solid electrolytes].

    Science.gov (United States)

    Yang, Shu-ting; Chen, Hong-jun; Dong, Hong-yu; Jia, Jun-hua; Cao, Zhao-xia

    2004-04-01

    The conductivity of the porous polymer solid electrolyte blended with PVDF and PMMA, which was made by a micro-wave hot-cross-linking method, reached 2.05 x 10(-3) S x cm(-1) at room temperature. The polymer solid electrolyte was analyzed and investigated by FTIR. The results show that the PVDF, PMMA and LiClO4 in the polymer solid electrolyte were not simply blended, but certain kind of effect existed which was strengthened only when the polymer solid electrolyte came into being.

  1. Ionic conduction in poly(vinyl chloride)/poly(ethyl methacrylate)-based polymer blend electrolytes complexed with different lithium salts

    Energy Technology Data Exchange (ETDEWEB)

    Rajendran, S.; Prabhu, M. Ramesh; Rani, M. Usha [Department of Physics, Alagappa University, Karaikudi, 630 003 (India)

    2008-06-01

    Poly(vinyl chloride)/poly(ethyl methacrylate)-based polymer blend electrolytes comprising propylene carbonate as a plasticizer and a lithium salt LiX (X = BF{sub 4}{sup -}, ClO{sub 4}{sup -}, CF{sub 3}SO{sub 3}{sup -}) are prepared by a solvent casting technique. The electrolytes are subjected to characterization by ionic conductivity, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetic/differential thermal analysis. The electrolytes that contain LiBF{sub 4} exhibit maximum conductivity and are thermally stable up to 254 C. (author)

  2. Nanoporous polymer electrolyte

    Science.gov (United States)

    Elliott, Brian [Wheat Ridge, CO; Nguyen, Vinh [Wheat Ridge, CO

    2012-04-24

    A nanoporous polymer electrolyte and methods for making the polymer electrolyte are disclosed. The polymer electrolyte comprises a crosslinked self-assembly of a polymerizable salt surfactant, wherein the crosslinked self-assembly includes nanopores and wherein the crosslinked self-assembly has a conductivity of at least 1.0.times.10.sup.-6 S/cm at 25.degree. C. The method of making a polymer electrolyte comprises providing a polymerizable salt surfactant. The method further comprises crosslinking the polymerizable salt surfactant to form a nanoporous polymer electrolyte.

  3. Performance characteristics of guanine incorporated PVDF-HFP/PEO polymer blend electrolytes with binary iodide salts for dye-sensitized solar cells

    Science.gov (United States)

    Senthil, R. A.; Theerthagiri, J.; Madhavan, J.; Arof, A. K.

    2016-08-01

    In this work, we have investigated the influence of guanine as an organic dopant in dye-sensitized solar cell (DSSC) based on poly(vinylidinefluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) polymer blend electrolyte along with binary iodide salts (potassium iodide (KI) and tetrabutylammonium iodide (TBAI)) and iodine (I2). The PVDF-HFP/KI + TBAI/I2, PVDF-HFP/PEO/KI + TBAI/I2 and guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 electrolytes were prepared by solution casting technique using DMF as solvent. The PVDF-HFP/KI + TBAI/I2 electrolyte showed an ionic conductivity value of 9.99 × 10-5 Scm-1, whereas, it was found to be increased to 4.53 × 10-5 Scm-1 when PEO was blended with PVDF-HFP/KI + TBAI/I2 electrolyte. However, a maximum ionic conductivity value of 3.67 × 10-4 Scm-1 was obtained for guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 blend electrolyte. The photovoltaic properties of all these polymer electrolytes in DSSCs were characterized. As a consequence, the power conversion efficiency of the guanine incorporated PVDF-HFP/PEO/KI + TBAI/I2 electrolyte based DSSC was significantly improved to 4.98% compared with PVDF-HFP/PEO/KI + TBAI/I2 electrolyte based DSSC (2.46%). These results revealed that the guanine can be an effective organic dopant to enhance the performance of DSSCs.

  4. Preparation and characterization of PVC/PMMA blend polymer electrolytes complexed with LiN(C2F5SO22

    Directory of Open Access Journals (Sweden)

    R. Nimma Elizabeth

    2004-03-01

    Full Text Available Thin films of polymer blend electrolytes comprising Poly(vinyl chloride (PVC and Poly(methyl methacrylate(PMMA and plasticized with a combination of ethylene carbonate (EC and propylene carbonate (PC for different lithium imide salt, LiN(C2F5SO32 , concentrations were prepared using the solution casting technique. The films were subjected to a. c. impedance measurements as a function of temperature ranging from -30 °C to 70 °C. The variation of ionic conductivity as a function of temperature and PVC content in the blend was analysed. The role of PMMA in the phenomena occurring at the interface between the plasticized polymer electrolyte and lithium electrode was also studied. The cast films were also subjected to TG/DTA and FT-IR studies which are discussed.

  5. Highly conductive and electrochemically stable plasticized blend polymer electrolytes based on PVdF-HFP and triblock copolymer PPG-PEG-PPG diamine for Li-ion batteries

    Science.gov (United States)

    Saikia, Diganta; Wu, Hao-Yiang; Pan, Yu-Chi; Lin, Chi-Pin; Huang, Kai-Pin; Chen, Kan-Nan; Fey, George T. K.; Kao, Hsien-Ming

    2011-03-01

    A new plasticized poly(vinylidene fluoride-co-hexafluoropropylene (PVdF-HFP)/PPG-PEG-PPG diamine/organosilane blend-based polymer electrolyte system has been synthesized and characterized. The structural and electrochemical properties of the electrolytes thus obtained were systematically investigated by a variety of techniques including differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), tensile test, Fourier transform infrared spectroscopy (FTIR), 13C and 29Si solid-state NMR, AC impedance, linear sweep voltammetry (LSV) and charge-discharge measurements. The FTIR and NMR results provided the information about the interaction among the constituents in the blend polymer membrane. The present blend polymer electrolyte exhibits several advantageous electrochemical properties such as ionic conductivity up to 1.3 × 10-2 S cm-1 at room temperature, high value of Li+ transference number (t+ = 0.82), electrochemical stability up to 6.4 V vs. Li/Li+ with the platinum electrode, and stable charge-discharge cycles for lithium-ion batteries.

  6. Effects of TiO{sub 2} addition on ionic conductivity of PVC/PEMA blend based composite polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Subban, R. H. Y. [Institute of Science Universiti Teknologi MARA 40450 Shah Alam Selangor Malaysia (Malaysia); Facultyof Applied Sciences Universiti Teknologi MARA40450 Shah Alam Selangor Malaysia (Malaysia); Sukri, Nursyazwani [Facultyof Applied Sciences Universiti Teknologi MARA40450 Shah Alam Selangor Malaysia (Malaysia)

    2015-08-28

    PVC/PEMA blend based polymer electrolytes with lithium bistrifluoromethane sulfonimide (LiN(CF{sub 3}SO{sub 2}){sub 2}) and PVC/PEMA/(LiN(CF{sub 3}SO{sub 2}){sub 2}-TiO{sub 2} films were prepared by solution cast technique. The sample containing 35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} exhibited the highest conductivity of 1.75 × 10{sup −5} Scm{sup −1}. The conductivity of the sample increased to 2.12 × 10{sup −5} Scm{sup −1} and 4.61 × 10{sup −5} Scm{sup −1} when 4 wt. % and 10 wt. % of titanium dioxide (TiO{sub 2}) was added to the sample at 65 wt. % PVC/PEMA-35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} composition respectively. The low increase in conductivity is attributed to two competing factors: increase in crystallinity as accounted by X-Ray diffraction (XRD) and decrease in glass transition temperature as accounted by differential scanning calorimetry (DSC)

  7. Electrochemical performances of electric double layer capacitor with UV-cured gel polymer electrolyte based on poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride) blend

    Energy Technology Data Exchange (ETDEWEB)

    Chunmo Yang; Joongkee Lee; Wonil Cho; Byungwon Cho [Korea Inst. of Science and Technology, Eco-Nano Research Center, Seoul (Korea); Jehbeck Ju [Hongik Univ., Dept. of Chemical Engineering, Seoul (Korea)

    2005-03-01

    Poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride), a gel polymer blend with ethylene carbonate:dimethyl carbonate:ethylmethyl carbonate (EC:DMC:EMC, 1:1:1 volume ratio) and containing 1.0 M of lithium hexafluoro phosphate (LiPF{sub 6}) as liquid components, is employed as a gel polymer electrolyte for an electric double layer capacitor (EDLC). Its electrochemical characteristics is compared with that of liquid organic electrolyte mixture of ethylene carbonate, dimethyl carbonate and ethylmethyl carbonate in a 1:1:1 volume ratio containing 1.0 M LiPF{sub 6} salt. The specific surface area of the activated carbon powder as an active material is 1908 m{sup 2}/g. Liquid poly[(ethylene glycol)diacrylate] (PEGDA) oligomer with a high retention capability of liquid electrolytes is cured by UV irradiation and poly(vinylidene fluoride)-hexafluoropropylene (PVdF-HFP) copolymer with a porous structure endows polymer matrix with high mechanical strength. The specific capacitance of EDLC using the gel polymer electrolyte (GPE-EDLC) shows 120 F/g, which is better than the liquid organic electrolyte. Good cycling efficiency is observed for a GPE-EDLC with high retention capability of liquid components. The high specific capacitance and good cycling efficiency are most likely due to the polarization resistance of EDLC with the gel polymer electrolyte, which is lower than the liquid organic electrolyte. This may result from the distinguished adhesion between the activated carbon electrode and the gel polymer electrolyte, as well as high retention capability of liquid components. Power densities of GPE-EDLC and LOE-EDLC shows 1.88 kW/kg and 1.21 kW/kg, respectively. However, the energy densities are low in both electrolytes. The GPE-EDLC exhibits rectangular cyclic voltammogram similar to an ideal EDLC within operating voltage range of 0 V-2.5 V. It should be noted that a region of electric double layer means a wide voltage and a rapid formation. Redox currents of both

  8. Electrochemical performances of electric double layer capacitor with UV-cured gel polymer electrolyte based on poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride) blend

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Chun-Mo [Eco-Nano Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)]. E-mail: ycm@kist.re.kr; Ju, Jeh Beck [Department of Chemical Engineering, Hongik University, Seoul 121-791 (Korea, Republic of); Lee, Joong Kee [Eco-Nano Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Cho, Won Il [Eco-Nano Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of); Cho, Byung Won [Eco-Nano Research Center, Korea Institute of Science and Technology, Seoul 130-650 (Korea, Republic of)

    2005-03-01

    Poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride), a gel polymer blend with ethylene carbonate:dimethyl carbonate:ethylmethyl carbonate (EC:DMC:EMC, 1:1:1 volume ratio) and containing 1.0 M of lithium hexafluoro phosphate (LiPF{sub 6}) as liquid components, is employed as a gel polymer electrolyte for an electric double layer capacitor (EDLC). Its electrochemical characteristics is compared with that of liquid organic electrolyte mixture of ethylene carbonate, dimethyl carbonate and ethylmethyl carbonate in a 1:1:1 volume ratio containing 1.0 M LiPF{sub 6} salt. The specific surface area of the activated carbon powder as an active material is 1908 m{sup 2}/g. Liquid poly[(ethylene glycol)diacrylate] (PEGDA) oligomer with a high retention capability of liquid electrolytes is cured by UV irradiation and poly(vinylidene fluoride)-hexafluoropropylene (PVdF-HFP) copolymer with a porous structure endows polymer matrix with high mechanical strength. The specific capacitance of EDLC using the gel polymer electrolyte (GPE-EDLC) shows 120 F/g, which is better than the liquid organic electrolyte. Good cycling efficiency is observed for a GPE-EDLC with high retention capability of liquid components. The high specific capacitance and good cycling efficiency are most likely due to the polarization resistance of EDLC with the gel polymer electrolyte, which is lower than the liquid organic electrolyte. This may result from the distinguished adhesion between the activated carbon electrode and the gel polymer electrolyte, as well as high retention capability of liquid components. Power densities of GPE-EDLC and LOE-EDLC shows 1.88 kW/kg and 1.21 kW/kg, respectively. However, the energy densities are low in both electrolytes. The GPE-EDLC exhibits rectangular cyclic voltammogram similar to an ideal EDLC within operating voltage range of 0 V-2.5 V. It should be noted that a region of electric double layer means a wide voltage and a rapid formation. Redox currents of both

  9. Influence of 2,6 (N-pyrazolyl)isonicotinic acid on the photovoltaic properties of a dye-sensitized solar cell fabricated using poly(vinylidene fluoride) blended with poly(ethylene oxide) polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Ganesan, S.; Muthuraaman, B.; Mathew, Vinod; Vadivel, M. Kumara [Department of Energy, University of Madras, Maraimalai Campus, Guindy, Chennai 600 025 (India); Maruthamuthu, P., E-mail: pmaruthu@yahoo.com [Department of Energy, University of Madras, Maraimalai Campus, Guindy, Chennai 600 025 (India); Ashokkumar, M. [School of Chemistry, University of Melbourne, VIC 3010 (Australia); Suthanthiraraj, S. Austin [Department of Energy, University of Madras, Maraimalai Campus, Guindy, Chennai 600 025 (India)

    2011-10-01

    Highlights: > 2,6 (N-pyrazolyl)isonicotinic acid (BNIN) has been synthesized through a simple and cost-effective method to produce good yield. > For the first time, attempt is made to use the synthesized BNIN in PVdF-PEO based polymer electrolyte as a plasticizer. > This enhanced the conductivity of polymer and increased the efficiency of DSSCs. > The fabricated solar cell exhibited efficiency as high as 7.3%. > This is comparatively higher than those of the present day DSSCs fabricated with Poly (vinylidine fluoride) polymer electrolyte. - Abstract: A novel method of introducing a synthesized organic nitrogenous compound 2,6 (N-pyrazolyl)isonicotinic acid (BNIN) and its effect on the conduction behavior of poly(vinylidene fluoride) (PVdF)-poly(ethylene oxide) (PEO) polymer-blend electrolyte with potassium iodide (KI) and iodine (I{sub 2}) and the corresponding performance of the dye-sensitized solar cells (DSSCs) were studied. A systematic investigation of the blends using FTIR provides evidence of interaction of BNIN with the polymer. Differential scanning calorimetry (DSC) study proves the miscibility of these polymers. Due to the coordinating and plasticizing effects of BNIN, the ionic conductivity of polymer blend electrolytes is enhanced. The efficiency of DSSC using BNIN doped polymer blend electrolyte was 7.3% under an illumination of 60 mW cm{sup -2} were observed for the best performance of a solar cell in this work.

  10. Polymer electrolyte reviews. 1

    Energy Technology Data Exchange (ETDEWEB)

    Mac Callum, J.R.; Vincent, C.A.

    1987-01-01

    The development of polymer electrolytes which have potential applications in battery technology has resulted in an escalation of research into the synthesis of new macromolecular supports and the mechanisms of ionic transport within the solid matrix. Investigation of the properties of polymer electrolytes has brought together polymer chemists and electrochemists, and the understanding of the solubility and transport of electrolytes in organic polymers is now developing from this pooled experience. This book deals with experimental, theoretical and applied aspects of solid solutions of electrolytes used in coordinating polymer matrices. Attention is focused on the synthesis and properties of these new materials, the mechanisms of conduction processes and practical applications, especially with regard to battery technology.

  11. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Luciano T., E-mail: ltcosta@id.uff.br [Instituto de Química-Departamento de Físico-Química, Universidade Federal Fluminense, Outeiro de São João Batista s/n CEP, 24020-150 Niterói, Rio de Janeiro (Brazil); Sun, Bing; Jeschull, Fabian; Brandell, Daniel [Department of Chemistry—Ångström Laboratory, Uppsala University, P.O. Box 538, SE-751 21 Uppsala (Sweden)

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li{sup +} coordination and transportation were studied in the ternary electrolyte system, i.e., PEO{sub 16}LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  12. Polymer-ionic liquid ternary systems for Li-battery electrolytes: Molecular dynamics studies of LiTFSI in a EMIm-TFSI and PEO blend.

    Science.gov (United States)

    Costa, Luciano T; Sun, Bing; Jeschull, Fabian; Brandell, Daniel

    2015-07-14

    This paper presents atomistic molecular dynamics simulation studies of lithium bis(trifluoromethane)sulfonylimide (LiTFSI) in a blend of 1-ethyl-3-methylimidazolium (EMIm)-TFSI and poly(ethylene oxide) (PEO), which is a promising electrolyte material for Li- and Li-ion batteries. Simulations of 100 ns were performed for temperatures between 303 K and 423 K, for a Li:ether oxygen ratio of 1:16, and for PEO chains with 26 EO repeating units. Li(+) coordination and transportation were studied in the ternary electrolyte system, i.e., PEO16LiTFSI⋅1.0 EMImTFSI, by applying three different force field models and are here compared to relevant simulation and experimental data. The force fields generated significantly different results, where a scaled charge model displayed the most reasonable comparisons with previous work and overall consistency. It is generally seen that the Li cations are primarily coordinated to polymer chains and less coupled to TFSI anion. The addition of EMImTFSI in the electrolyte system enhances Li diffusion, associated to the enhanced TFSI dynamics observed when increasing the overall TFSI anion concentration in the polymer matrix.

  13. Polymer Blends. Volume 1

    Science.gov (United States)

    1992-05-01

    PBI/ ULTEM NEAT RESIN MOLDING EVALUATIONS 18 2.1.3 85/15 PBI/ ULTEM COMPOSITE EVALUATIONS 22 2.1.4 FIRST GENERATION SUMMARY 26 2.2 IMPROVED PBI/"BEST...PBI 37 2.2.4 85/15 eCPBI-2/ ULTEM NEAT RESIN EVALUATIONS 42 2.2.5 SECOND GENERATION SUMMARY 45 2.3 IMPROVED PBI/6F POLYIMIDE BLENDS: THIRD GENERATION...PYROMELLITIC DIANHYDRIDE 100 A1.2 REVIEW AND RISK ANALYSIS 105 iv FIGURES FIGURE PAGE # I HIGH PERFORMANCE POLYMER BLENDS PLAN 6 2 PBI/ ULTEM SEPARATION

  14. Gel polymer electrolytes for batteries

    Science.gov (United States)

    Balsara, Nitash Pervez; Eitouni, Hany Basam; Gur, Ilan; Singh, Mohit; Hudson, William

    2014-11-18

    Nanostructured gel polymer electrolytes that have both high ionic conductivity and high mechanical strength are disclosed. The electrolytes have at least two domains--one domain contains an ionically-conductive gel polymer and the other domain contains a rigid polymer that provides structure for the electrolyte. The domains are formed by block copolymers. The first block provides a polymer matrix that may or may not be conductive on by itself, but that can soak up a liquid electrolyte, thereby making a gel. An exemplary nanostructured gel polymer electrolyte has an ionic conductivity of at least 1.times.10.sup.-4 S cm.sup.-1 at 25.degree. C.

  15. Rheological studies of PMMA-PVC based polymer blend electrolytes with LiTFSI as doping salt.

    Directory of Open Access Journals (Sweden)

    Chiam-Wen Liew

    Full Text Available In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate (PMMA and poly (vinyl chloride (PVC is varied, whereas in the second system, the composition of PMMA-PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl imide (LiTFSI with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of G' and G'' is absent. Linear viscoelastic (LVE range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases.

  16. Electrochemical polymer electrolyte membranes

    CERN Document Server

    Fang, Jianhua; Wilkinson, David P

    2015-01-01

    Electrochemical Polymer Electrolyte Membranes covers PEMs from fundamentals to applications, describing their structure, properties, characterization, synthesis, and use in electrochemical energy storage and solar energy conversion technologies. Featuring chapters authored by leading experts from academia and industry, this authoritative text: Discusses cutting-edge methodologies in PEM material selection and fabricationPoints out important challenges in developing PEMs and recommends mitigation strategies to improve PEM performanceAnalyzes the cur

  17. Blends of POSS-PEO(n=4)(8) and high molecular weight poly(ethylene oxide) as solid polymer electrolytes for lithium batteries.

    Science.gov (United States)

    Zhang, Hanjun; Kulkarni, Sunil; Wunder, Stephanie L

    2007-04-12

    Solid polymer electrolyte blends were prepared with POSS-PEO(n=4)8 (3K), poly(ethylene oxide) (PEO(600K)), and LiClO4 at different salt concentrations (O/Li = 8/1, 12/1, and 16/1). POSS-PEO(n=4)8/LiClO4 is amorphous at all O/Li investigated, whereas PEO(600K) is amorphous only for O/Li = 8/1 and semicrystalline for O/Li = 12/1 and 16/1. The tendency of PEO(600K) to crystallize limited the amount of POSS-PEO(n=4)(8) that could be incorporated into the blends, so that the greatest incorporation of POSS-PEO(n=4)(8) occurred for O/Li = 8/1. Blends of POSS-PEO(n=4)(8)/PEO(600K)/LiClO4 (O/Li = 8/1 and 12/1) microphase separated into two amorphous phases, a low T(g) phase of composition 85% POSS-PEO(n=4)(8)/15% PEO(600K) and a high T(g) phase of composition 29% POSS-PEO(n=4)(8)/71% PEO(600K). For O/Li = 16/1, the blends contained crystalline (pure PEO(600K)), and two amorphous phases, one rich in POSS-PEO(n=4)(8) and one rich in PEO(600K). Microphase, rather than macrophase separation was believed to occur as a result of Li(+)/ether oxygen cross-link sites. The conductivity of the blends depended on their composition. As expected, crystallinity decreased the conductivity of the blends. For the amorphous blends, when the low T(g) (80/20) phase was the continuous phase, the conductivity was intermediate between that of pure PEO(600K) and POSS-PEO(n=4)(8). When the high T(g) (70/30, 50/50, 30/70, and 20/80) phase was the continuous phase, the conductivity of the blend and PEO(600K) were identical, and lower than that for the POSS-PEO(n=4)(8) over the whole temperature range (10-90 degrees C). This suggests that the motions of the POSS-PEO(n=4)(8) were slowed down by the dynamics of the long chain PEO(600K) and that the minor, low Tg phase was not interconnected and thus did not contribute to enhanced conductivity. At temperatures above T(m) of PEO(600K), addition of the POSS-PEO(n=4)(8) did not result in conductivity improvement. The highest RT conductivity, 8 x 10(-6) S

  18. Composite solid polymer electrolyte membranes

    Energy Technology Data Exchange (ETDEWEB)

    Formato, Richard M. (Shrewsbury, MA); Kovar, Robert F. (Wrentham, MA); Osenar, Paul (Watertown, MA); Landrau, Nelson (Marlborough, MA); Rubin, Leslie S. (Newton, MA)

    2001-06-19

    The present invention relates to composite solid polymer electrolyte membranes (SPEMs) which include a porous polymer substrate interpenetrated with an ion-conducting material. SPEMs of the present invention are useful in electrochemical applications, including fuel cells and electrodialysis.

  19. Enhanced performance of dye-sensitized solar cells based on organic dopant incorporated PVDF-HFP/PEO polymer blend electrolyte with g-C3N4/TiO2 photoanode

    Science.gov (United States)

    Senthil, R. A.; Theerthagiri, J.; Madhavan, J.; Murugan, K.; Arunachalam, Prabhakarn; Arof, A. K.

    2016-10-01

    This work describes the effect of 2-aminopyrimidine (2-APY) on poly(vinylidinefluoride-co-hexafluoropropylene) (PVDF-HFP)/polyethylene oxide (PEO) blend polymer electrolyte along with binary iodide salts (tetrabutylammonium iodide (TBAI) and potassium iodide (KI)) and iodine (I2) were studied for enhancing the efficiency of the dye-sensitized solar cells (DSSCs) consisting of g-C3N4/TiO2 composite as photoanode. The g-C3N4 was synthesized from low cost urea by thermal condensation method. It was used as a precursor to synthesize the various weight percentage ratios (5%, 10% and 15%) of g-C3N4/TiO2 composites by wet-impregnation method. The pure and 2-APY incorporated PVDF-HFP/PEO polymer blend electrolytes were arranged by wet chemical process (casting method) using DMF as a solvent. The synthesized g-C3N4/TiO2 composites and polymer blend electrolytes were studied and analyzed by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The ionic conductivity values of the pure and 2-APY incorporated PVDF-HFP/PEO blend electrolytes were estimated to be 4.53×10-5 and 1.87×10-4 Scm-1 respectively. The UV-vis absorption spectroscopy was carried out for the pure and different wt% of g-C3N4/TiO2 composites coated FTO films after N3 dye-sensitization. The 10 wt% g-C3N4/TiO2 composite film showed a maximum absorption compared to the others. The DSSC assembled with 10 wt% g-C3N4/TiO2 as photoanode using the pure polymer blend electrolyte exhibited a power conversion efficiency (PCE) of 3.17% , which was superior than that of DSSC based pure TiO2 (2.46%). However, the PCE was increased to 4.73% for the DSSC assembled using 10 wt% g-C3N4/TiO2 as photoanode with 2-APY incorporated polymer blend electrolyte. Hence, the present study is a successful attempt to provide a new pathway to enhance the performance of DSSCs.

  20. Bimodal porous TiO2 structures templated by graft copolymer/homopolymer blend for dye-sensitized solar cells with polymer electrolyte

    Science.gov (United States)

    Kim, Jin Kyu; Lee, Chang Soo; Lee, Sang-Yup; Cho, Hyung Hee; Kim, Jong Hak

    2016-12-01

    Bimodal porous TiO2 (BP-TiO2) with large surface area, high porosity, good interconnectivity, and excellent light-scattering ability are synthesized via a facile one-step method using a self-assembled blend template consisting of an amphiphilic poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer and a hydrophobic poly(vinyl chloride) (PVC) homopolymer. The hydrophilically surface-modified TiO2 nanoparticles selectively interact with the hydrophilic POEM chains, while the addition of the PVC homopolymer increases the hydrophobic domain size, resulting in the formation of dual pores (i.e., macropores and mesopores). The sizes and numbers of macropores can easily be controlled by changing the molecular weight and amount of the PVC homopolymer. The polymer electrolyte dye-sensitized solar cells (DSSCs) fabricated with BP-TiO2 photoanodes exhibited energy conversion efficiencies of up to 7.6% at 100 mW cm-2, which is much higher than those of mesoporous TiO2 (5.8%) with PVC-g-POEM only and conventional nanocrystalline TiO2 (4.9%) with commercial Dyesol paste. The enhanced energy conversion efficiencies mostly resulted from the light-scattering effects of the macropores, which increased the light-harvesting efficiencies. The improved light-harvesting and photovoltaic performances of the DSSCs were characterized by UV-vis spectroscopy, incident photon-to-current conversion efficiency analysis, electrochemical impedance spectroscopy, intensity-modulated photocurrent spectroscopy, and intensity-modulated photovoltage spectroscopy.

  1. Anion exchange polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung; Kim, Dae Sik; Lee, Kwan-Soo

    2013-07-23

    Solid anion exchange polymer electrolytes and compositions comprising chemical compounds comprising a polymeric core, a spacer A, and a guanidine base, wherein said chemical compound is uniformly dispersed in a suitable solvent and has the structure: ##STR00001## wherein: i) A is a spacer having the structure O, S, SO.sub.2, --NH--, --N(CH.sub.2).sub.n, wherein n=1-10, --(CH.sub.2).sub.n--CH.sub.3--, wherein n=1-10, SO.sub.2-Ph, CO-Ph, ##STR00002## wherein R.sub.5, R.sub.6, R.sub.7 and R.sub.8 each are independently --H, --NH.sub.2, F, Cl, Br, CN, or a C.sub.1-C.sub.6 alkyl group, or any combination of thereof; ii) R.sub.9, R.sub.10, R.sub.11, R.sub.12, or R.sub.13 each independently are --H, --CH.sub.3, --NH.sub.2, --NO, --CH.sub.nCH.sub.3 where n=1-6, HC.dbd.O--, NH.sub.2C.dbd.O--, --CH.sub.nCOOH where n=1-6, --(CH.sub.2).sub.n--C(NH.sub.2)--COOH where n=1-6, --CH--(COOH)--CH.sub.2--COOH, --CH.sub.2--CH(O--CH.sub.2CH.sub.3).sub.2, --(C.dbd.S)--NH.sub.2, --(C.dbd.NH)--N--(CH.sub.2).sub.nCH.sub.3, where n=0-6, --NH--(C.dbd.S)--SH, --CH.sub.2--(C.dbd.O)--O--C(CH.sub.3).sub.3, --O--(CH.sub.2).sub.n--CH--(NH.sub.2)--COOH, where n=1-6, --(CH.sub.2).sub.n--CH.dbd.CH wherein n=1-6, --(CH.sub.2).sub.n--CH--CN wherein n=1-6, an aromatic group such as a phenyl, benzyl, phenoxy, methylbenzyl, nitrogen-substituted benzyl or phenyl groups, a halide, or halide-substituted methyl groups; and iii) wherein the composition is suitable for use in a membrane electrode assembly.

  2. SCATTERING FUNCTION OF POLYMER BLENDS

    Institute of Scientific and Technical Information of China (English)

    Lin-ping Ke; Mei-li Guo; De-lu Zhao

    2004-01-01

    For a system of flexible polymer molecules, the concepts of two concentrations, namely the segmental and the molecular concentrations, have been proposed in this paper. The former is equivalent to the volume fraction. The latter can be defined as the number of the gravity centers of macromolecules in a unit volume. The two concentrations should be correlated with each other by the conformational function of the polymer chain and should be discussed in different thermodynamic equations. On the basis of these concepts it has been proved that the Flory-Huggins entropy of mixing should be the result of the mixing "ideal gases of the gravity centers of macromolecules". The general correlation between the free energy of mixing and the scattering function (structural factor) of polymer blends has been studied based on the general fluctuation theory. When the Flory-Huggins free energy of mixing is adopted, the de Gennes scattering function of a polymer blend can be derived.

  3. Polymer Electrolytes for Lithium/Sulfur Batteries

    Directory of Open Access Journals (Sweden)

    The Nam Long Doan

    2012-08-01

    Full Text Available This review evaluates the characteristics and advantages of employing polymer electrolytes in lithium/sulfur (Li/S batteries. The main highlights of this study constitute detailed information on the advanced developments for solid polymer electrolytes and gel polymer electrolytes, used in the lithium/sulfur battery. This includes an in-depth analysis conducted on the preparation and electrochemical characteristics of the Li/S batteries based on these polymer electrolytes.

  4. Role of salt concentration in blend polymer for energy storage conversion devices

    Science.gov (United States)

    Arya, Anil; Sadiq, M.; Sharma, A. L.

    2016-05-01

    Solid Polymer Electrolytes (SPE) are materials of considerable interest worldwide, which serves dual purpose of electrolyte and separator between electrode compartments in renewable energy conversion/storage devices such as; high energy density batteries, electrochromic display devices, and supercapacitors. Polymer blend electrolytes are prepared for various concentration of salt (Ö/Li) with the constant ratio (0.5 gm) of each PEO and PAN polymers (blend polymer) using solution casting technique. Solid polymeric ionic conductor as a separator is the ultimate substitute to eliminate the drawback related to liquid and gel polymer ionic conductors. In the present work, solid polymer electrolyte film consisting of PEO, PAN and LiPF6 are examined for various concentration of lithium salt by keeping PEO/PAN blend ratio as a constant with a view to optimize the dominant salt concentration which could give the maximum conductivity at ambient temperature.

  5. Interfacial behavior of polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, John; Kerr, John B.; Han, Yong Bong; Liu, Gao; Reeder, Craig; Xie, Jiangbing; Sun, Xiaoguang

    2003-06-03

    Evidence is presented concerning the effect of surfaces on the segmental motion of PEO-based polymer electrolytes in lithium batteries. For dry systems with no moisture the effect of surfaces of nano-particle fillers is to inhibit the segmental motion and to reduce the lithium ion transport. These effects also occur at the surfaces in composite electrodes that contain considerable quantities of carbon black nano-particles for electronic connection. The problem of reduced polymer mobility is compounded by the generation of salt concentration gradients within the composite electrode. Highly concentrated polymer electrolytes have reduced transport properties due to the increased ionic cross-linking. Combined with the interfacial interactions this leads to the generation of low mobility electrolyte layers within the electrode and to loss of capacity and power capability. It is shown that even with planar lithium metal electrodes the concentration gradients can significantly impact the interfacial impedance. The interfacial impedance of lithium/PEO-LiTFSI cells varies depending upon the time elapsed since current was turned off after polarization. The behavior is consistent with relaxation of the salt concentration gradients and indicates that a portion of the interfacial impedance usually attributed to the SEI layer is due to concentrated salt solutions next to the electrode surfaces that are very resistive. These resistive layers may undergo actual phase changes in a non-uniform manner and the possible role of the reduced mobility polymer layers in dendrite initiation and growth is also explored. It is concluded that PEO and ethylene oxide-based polymers are less than ideal with respect to this interfacial behavior.

  6. Norbornene-Based Polymer Electrolytes for Lithium Cells

    Science.gov (United States)

    Cheung, Iris; Smart, Marshall; Prakash, Surya; Miyazawa, Akira; Hu, Jinbo

    2007-01-01

    Norbornene-based polymers have shown promise as solid electrolytes for lithium-based rechargeable electrochemical cells. These polymers are characterized as single-ion conductors. Single-ion-conducting polymers that can be used in lithium cells have long been sought. Single-ion conductors are preferred to multiple-ion conductors as solid electrolytes because concentration gradients associated with multiple-ion conduction lead to concentration polarization. By minimizing concentration polarization, one can enhance charge and discharge rates. Norbornene sulfonic acid esters have been synthesized by a ring-opening metathesis polymerization technique, using ruthenium-based catalysts. The resulting polymer structures (see figure) include sulfonate ionomers attached to the backbones of the polymer molecules. These molecules are single-ion conductors in that they conduct mobile Li+ ions only; the SO3 anions in these polymers, being tethered to the backbones, do not contribute to ionic conduction. This molecular system is especially attractive in that it is highly amenable to modification through functionalization of the backbone or copolymerization with various monomers. Polymers of this type have been blended with poly(ethylene oxide) to lend mechanical integrity to free-standing films, and the films have been fabricated into solid polymer electrolytes. These electrolytes have been demonstrated to exhibit conductivity of 2 10(exp -5)S/cm (which is high, relative to the conductivities of other solid electrolytes) at ambient temperature, plus acceptably high stability. This type of norbornene-based polymeric solid electrolyte is in the early stages of development. Inasmuch as the method of synthesis of these polymers is inherently flexible and techniques for the fabrication of the polymers into solid electrolytes are amenable to optimization, there is reason to anticipate further improvements.

  7. Conductivity behaviour of polymer gel electrolytes: Role of polymer

    Indian Academy of Sciences (India)

    S S Sekhon

    2003-04-01

    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.

  8. New Polymer Electrolyte Cell Systems

    Science.gov (United States)

    Smyrl, William H.; Owens, Boone B.; Mann, Kent; Pappenfus, T.; Henderson, W.

    2004-01-01

    PAPERS PUBLISHED: 1. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Complexes of Lithium Imide Salts with Tetraglyme and Their Polyelectrolyte Composite Materials. Journal of the Electrochemical Society (2004), 15 1 (2), A209-A2 15. 2. Pappenfus, Ted M.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; Smyrl, William H. Ionic-liquidlpolymer electrolyte composite materials for electrochemical device applications. Polymeric Materials Science and Engineering (2003), 88 302. 3. Pappenfus, Ted R.; Henderson, Wesley A.; Owens, Boone B.; Mann, Kent R.; and Smyrl, William H. Ionic Conductivity of a poly(vinylpyridinium)/Silver Iodide Solid Polymer Electrolyte System. Solid State Ionics (in press 2004). 4. Pappenfus Ted M.; Mann, Kent R; Smyrl, William H. Polyelectrolyte Composite Materials with LiPFs and Tetraglyme. Electrochemical and Solid State Letters, (2004), 7(8), A254.

  9. Electrochromic Device with Polymer Electrolyte

    Science.gov (United States)

    Solovyev, Andrey A.; Zakharov, Alexander N.; Rabotkin, Sergey V.; Kovsharov, Nikolay F.

    2016-08-01

    In this study a solid-state electrochromic device (ECD) comprised of a WO3 and Prussian blue (Fe4[Fe(CN)6]3) thin film couple with a Li+-conducting solid polymer electrolyte is discussed. WO3 was deposited on K-Glass substrate by magnetron sputtering method, while Prussian blue layer was formed on the same substrate by electrodeposition method. The parameters of the electrochromic device K-Glass/WO3/Li+-electrolyte/PB/K-Glass, such as change of transmittance, response time and stability were successfully tested using coupled optoelectrochemical methods. The device was colored or bleached by the application of +2 V or -2 V, respectively. Light modulation with transmittance variation of up to 59% and coloration efficiency of 43 cm2/C at a wavelength of 550 nm were obtained. Numerous switching of the ECD over 1200 cycles without the observation of significant degradation has been demonstrated.

  10. Polyvinyl alcohol-polystyrene sulphonic acid blend electrolyte for supercapacitor application

    Energy Technology Data Exchange (ETDEWEB)

    Selva Kumar, M. [Department of Chemistry, National Institute of Technology Karnataka Surathkal, Srinivasnagar 575025 (India); Bhat, D. Krishna, E-mail: denthaje@gmail.co [Department of Chemistry, National Institute of Technology Karnataka Surathkal, Srinivasnagar 575025 (India)

    2009-05-01

    A new polymer blend electrolyte based on poly vinyl alcohol and poly styrene sulphonic acid has been studied as an electrolyte for supercapcitors. A carbon-carbon supercapacitor has been fabricated using this electrolyte and its electrochemical characteristics and performance have been studied. The conductivity has been calculated using the bulk impedance obtained through impedance spectroscopy. The real and imaginary parts of the electrical modulus of samples show a long tail feature, which can be attributed to high capacitance of the material. The super capacitor showed a fairly good specific capacitance of 40Fg{sup -1} and a time constant of 5 s.

  11. Nanocomposite polymer electrolyte for rechargeable magnesium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Shao, Yuyan; Rajput, Nav Nidhi; Hu, Jian Z.; Hu, Mary Y.; Liu, Tianbiao L.; Wei, Zhehao; Gu, Meng; Deng, Xuchu; Xu, Suochang; Han, Kee Sung; Wang, Jiulin; Nie, Zimin; Li, Guosheng; Zavadil, K.; Xiao, Jie; Wang, Chong M.; Henderson, Wesley A.; Zhang, Jiguang; Wang, Yong; Mueller, Karl T.; Persson, Kristin A.; Liu, Jun

    2014-12-28

    Nanocomposite polymer electrolytes present new opportunities for rechargeable magnesium batteries. However, few polymer electrolytes have demonstrated reversible Mg deposition/dissolution and those that have still contain volatile liquids such as tetrahydrofuran (THF). In this work, we report a nanocomposite polymer electrolyte based on poly(ethylene oxide) (PEO), Mg(BH4)2 and MgO nanoparticles for rechargeable Mg batteries. Cells with this electrolyte have a high coulombic efficiency of 98% for Mg plating/stripping and a high cycling stability. Through combined experiment-modeling investigations, a correlation between improved solvation of the salt and solvent chain length, chelation and oxygen denticity is established. Following the same trend, the nanocomposite polymer electrolyte is inferred to enhance the dissociation of the salt Mg(BH4)2 and thus improve the electrochemical performance. The insights and design metrics thus obtained may be used in nanocomposite electrolytes for other multivalent systems.

  12. Organic/inorganic nanocomposite polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    Li Qi; Shao Jun Dong

    2007-01-01

    The organic/inorganic nanocomposites polymer electrolytes were designed and synthesized. The organic/inorganic nanocom posites membrane materials and their lithium salt complexes have been found thermally stable below 200 ℃. The conductivity of the organic/inorganic nanocomposites polymer electrolytes prepared at room temperature was at magnitude range of 10-6 S/cm.

  13. Hyperbranched Polymer-Based Electrolyte for Lithium Polymer Batteries

    Institute of Scientific and Technical Information of China (English)

    Takahito Itoh

    2005-01-01

    @@ 1Introduction Solid polymer electrolytes have attracted much attention as electrolyte materials for all solid-state recharge able lithium batteries, and poly ( ethylene oxide) ( PEO)-based polymer electrolytes are among the most intensively studied systems[1-3]. Hyperbranched polymers have unique properties such as completely amorphous, highly soluble in common organic solvent and processible because of the highly branched nature[4,5].

  14. Novel, Solvent-Free, Single Ion-Conducting Polymer Electrolytes

    Science.gov (United States)

    2007-10-31

    the selected polymer electrolyte membrane and a LiFePO4 -based composite cathode film. The latter was prepared by blending the LiFePO4 active...following: charge Li+ + FePO4 + e LiFePO4 [1] discharge to which is associate a maximum...as separator in a Li/ LiFePO4 battery. . 1.Experimental. Calixpyrrole (CP, provided by the University of Warsaw), LiBOB (Libby) and PEO

  15. CS-PVA-NH_4Cl共混固态聚合物电解质膜的制备与性能%Synthesis and Properties of CS-PVA-NH_4Cl Blend Solid Polymer Electrolyte Membranes

    Institute of Scientific and Technical Information of China (English)

    杨丞; 闫康平

    2012-01-01

    以壳聚糖(CS),聚乙烯醇(PVA)为基体掺杂不同比例NH4Cl进行共混,使用溶液浇铸法制备了CS-PVA-NH4Cl共混固态聚合物电解质膜,溶胀度均在1 000%左右。使用交流阻抗,直流极化,循环伏安对其电导率、离子迁移率及电化学稳定窗口进行测量,使用Zview软件对交流阻抗谱进行拟合。结果表明在40%NH4Cl掺杂时电导率为1.4×10-3S.cm-1,离子迁移率为0.93,电化学稳定窗口为2.0V。%In this paper,CS-PVA-NH4Cl blend solid polymer electrolyte membrane is prepared via solution casting method by using chitosan(CS) and polyvinyl alcohol(PVA) as matrix blended with different amount of NH4Cl,the swelling rates of every sample are all around 1 000%.The conductivity,ion mobility and electrochemical stability of the SPE membranes are investigated by using AC impedance and DC polarization,cyclic voltammetry,and Zview software is used to fit the AC impedance spectroscopy.The results show that with 40% NH4Cl blending,the conductivity was 1.4 × 10-3S·cm-1,the ion mobility was 0.93,the electrochemical stability window is 2.0 V.

  16. Microporous polymer electrolyte based on PVDF-PEO

    Institute of Scientific and Technical Information of China (English)

    LI Jian; XI Jingyu; SONG Qing; TANG Xiaozhen

    2005-01-01

    @@ Since Wright et al.[1] found that the complex of PEO/alkali metals salt had the ability of ionic conductivity in 1973, in-depth studies have been carried out about various polymer electrolytes, which were applied to replacing the liquid electrolytes in lithium ion battery[2,3]. At present, polymer electrolytes mainly include three kinds: dry polymer electrolytes, gel polymer electrolytes and microporous polymer electrolytes.

  17. Proton Conducting Polymer Electrolytes and Its Applications

    Institute of Scientific and Technical Information of China (English)

    S. Selvasekarapandian; G. Hirankumar; R. Baskaran; M.S. Bhuvaneswari

    2005-01-01

    @@ 1Introduction Proton conducting solid polymer electrolytes have been extensively studied due to their potential applications in electrochemical devices such as batteries, super capacitors, electrochromic windows, sensors etc[1,2]Many researchers have studied the behaviour of inorganic based polymer electrolytes as proton conductors and their applications in solid state devices at room temperature[3]. But, inorganic acid doped electrolytes have some serious disadvantages like corrosion towards the electrode and hazardous. Hence, there is need for searching new electrolyte which is stable towards the electrode. It has been reported that the ammonium salts which behaves like alkali metal salt are good dopant to the polymer matrix[4, 5] for the development of proton conducting polymer electrolyte. The proton conductors based on poly (ethylene oxide)[6], poly (ethylene succinate)[7], poly (ethylene glycol)[8], as host matrix doped with ammonium salt have already been reported.

  18. Conductivity and Dielectric Studies of Lithium Trifluoromethanesulfonate Doped Polyethylene Oxide-Graphene Oxide Blend Based Electrolytes

    Directory of Open Access Journals (Sweden)

    A. A. Azli

    2015-01-01

    Full Text Available Series of polymer blend consisting of polyethylene oxide (PEO and graphene oxide (GO as co-host polymer were prepared using solution cast method. The most amorphous PEO-GO blend was obtained using 90 wt.% of PEO and 10 wt.% of GO as recorded by X-ray diffraction (XRD. Fourier transform infrared spectroscopy (FTIR analysis proved the interaction between PEO, GO, lithium trifluoromethanesulfonate (LiCF3SO3, and ethylene sulfite (ES. Incorporation of 25 wt.% LiCF3SO3 into the PEO-GO blend increases the conductivity to 3.84±0.83×10-6 S cm−1. The conductivity starts to decrease when more than 25 wt.% salt is doped into the polymer blend. The addition of 1 wt.% ES into the polymer electrolyte has increased the conductivity to 1.73±0.05×10-5 S cm−1. Dielectric studies show that all the electrolytes obey non-Debye behavior.

  19. Solid polymer electrolyte from phosphorylated chitosan

    Energy Technology Data Exchange (ETDEWEB)

    Fauzi, Iqbal, E-mail: arcana@chem.itb.ac.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Groups, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Recently, the need of secondary battery application continues to increase. The secondary battery which using a liquid electrolyte was indicated had some weakness. A solid polymer electrolyte is an alternative electrolytes membrane which developed in order to replace the liquid electrolyte type. In the present study, the effect of phosphorylation on to polymer electrolyte membrane which synthesized from chitosan and lithium perchlorate salts was investigated. The effect of the component’s composition respectively on the properties of polymer electrolyte, was carried out by analyzed of it’s characterization such as functional groups, ion conductivity, and thermal properties. The mechanical properties i.e tensile resistance and the morphology structure of membrane surface were determined. The phosphorylation processing of polymer electrolyte membrane of chitosan and lithium perchlorate was conducted by immersing with phosphoric acid for 2 hours, and then irradiated on a microwave for 60 seconds. The degree of deacetylation of chitosan derived from shrimp shells was obtained around 75.4%. Relative molecular mass of chitosan was obtained by viscometry method is 796,792 g/mol. The ionic conductivity of chitosan membrane was increase from 6.33 × 10{sup −6} S/cm up to 6.01 × 10{sup −4} S/cm after adding by 15 % solution of lithium perchlorate. After phosphorylation, the ionic conductivity of phosphorylated lithium chitosan membrane was observed 1.37 × 10{sup −3} S/cm, while the tensile resistance of 40.2 MPa with a better thermal resistance. On the strength of electrolyte membrane properties, this polymer electrolyte membrane was suggested had one potential used for polymer electrolyte in field of lithium battery applications.

  20. Ultrafiltration of a polymer-electrolyte mixture

    NARCIS (Netherlands)

    Vonk, P; Noordman, T.R; Schippers, D; Tilstra, B; Wesselingh, J.A

    1997-01-01

    We present a mathematical model to describe the ultrafiltration behaviour of polymer-electrolyte mixtures. The model combines the proper thermodynamic forces (pressure, chemical potential and electrical potential differences) with multicomponent diffusion theory. The model is verified with experimen

  1. Polymer blend compositions and methods of preparation

    Science.gov (United States)

    Naskar, Amit K.

    2016-09-27

    A polymer blend material comprising: (i) a first polymer containing hydrogen bond donating groups having at least one hydrogen atom bound to a heteroatom selected from oxygen, nitrogen, and sulfur, or an anionic version of said first polymer wherein at least a portion of hydrogen atoms bound to a heteroatom is absent and replaced with at least one electron pair; (ii) a second polymer containing hydrogen bond accepting groups selected from nitrile, halogen, and ether functional groups; and (iii) at least one modifying agent selected from carbon particles, ether-containing polymers, and Lewis acid compounds; wherein, if said second polymer contains ether functional groups, then said at least one modifying agent is selected from carbon particles and Lewis acid compounds. Methods for producing the polymer blend, molded forms thereof, and articles thereof, are also described.

  2. Investigation of Ionic Conductivity of Nanocomposite Polymer Electrolytes Based On PVDF-HFP/PVC Blend, LiClO4 and TiO2 Nanofiller

    Science.gov (United States)

    Basri, N. H.; Mohamed, N. S.

    2010-07-01

    The effects of nanosized TiO2 on the conductivity of PVDF-HFP/PVC-LiClO4 was studied by means of impedance spectroscopy and x-ray diffraction (XRD). The addition of TiO2 nanofiller increases the crystalline phase fraction but slightly increases the conductivity of the PVDF-HFP/PVC-LiClO4 complex. The increase in conductivity is attributed to the formation of highly conducting layer at the electrolyte/filler interface. The temperature dependence of conductivity obeys the VTF type behaviour while the transference number confirms that the electrolyte containing 6 wt.% TiO2 is an ionic conductor are ionic conductors.

  3. Electrochemical behaviors of novel composite polymer electrolytes for lithium batteries

    Institute of Scientific and Technical Information of China (English)

    Guorong Chen; Pengfei Shi; Yongping Bai; Taibing Fan

    2004-01-01

    A novel composite polymer electrolyte was prepared by blending an appropriate amount of LiClO4 and 10% (mass fraction)fumed SiO2 with the block copolymer of poly (ethylene oxide) (PEO) synthesized by poly (ethylene glycol) (PEG) 400 and CH2Cl2.The ionic conductivity, electrochemical stability, interfacial characteristic and thermal behavior of the composite polymer electrolytewere studied by the measurements of AC impedance spectroscopy, linear sweep voltammetry and differential scanning calorimetry(DSC), respectively. The glass transition temperature acts as a function of salt concentration, which increases with the LiClO4 content.Lewis acid-base model interaction mechanism was introduced to interpret the interactive relation between the filled fumed SiO2 andthe lithium salt in the composite polymer electrolyte. Over the salt concentration range and the measured temperature, the maximumionic conductivity of the composite polymer electrolyte (10-4.41 S/cm) appeared at EO/Li=25 (mole ratio) and 30℃, and the begin-ning oxidative degradation potential versus Li beyond 5 V.

  4. Compatibilizing Bulk Polymer Blends by Using Organoclays

    Science.gov (United States)

    Si, Mayu; Gersappe, Dilip; Zhang, Wenhua; Ade, Harald; Rafailovich, Miriam; Sokolov, Jonathan; Rudomen, Gregory; Schwartz, Bradley; Fisher, Robert

    2004-03-01

    We investigated the compatiblizing performance of organoclays on melt mixed binary and tertiary polymer blends, such as, PS/PMMA, PC/SAN, PS/PMMA/PVC and PS/PMMA/PE. These polymer blends were characterized by TEM, STXM, DSC and DMA. TEM and STXM photographs show that the addition of organoclays into polymer blends drastically reduces the average domain size of the component phases. And the organoclay goes to the interfacial region between the different polymers and effectively slows down the domain size increasing during high temperature annealing. DMA and DSC results show the effect of organoclays on the mechanical properties and glass transitions temperature, which indicates the compatibilization on the molecular level. The generalized compatibilization induced by the nanoscale fillers for blends can be explained in terms of mean field models where the reduction of interfacial tension induced by in-situ grafting is counterbalanced by the increased bending energy due to the rigidity of the filler. This in turn can be shown to be a function of the degree of exfoliation, aspect ratio, and polymer filler interactions. Supported by NSF funded MRSEC at Stony Brook

  5. Mechanisms of Morphology Development and Control in Polymer- Polymer Blends

    Science.gov (United States)

    Macosko, Christopher W.

    1998-03-01

    Polymer-polymer blends continue to be the most important method for achieving optimization of properties in plastics products. Over 30 percent of all plastics are blends. While miscible blends generally give average properties between the components, immiscible blends offer synergistic possibilities such as high modulus with high toughness; high flow with high impact strength or diffusion barriers with good mechanical properties and low cost. The key to performance of these immiscible blends is their morphology. There are several important types of morphology which can lead to valuable property improvement: emulsion - small polymer spheres well dispersed in a polymer matrix. double emulsion - spheres inside spheres which are dispersed in another matrix. microlayer - thin, parallel layers of one polymer in a matrix. cocontinuous - two (or more) continuous, interpenetrating polymer phases. To be economical it is desirable to create these morphologies via melt mixing of powder or pellets in conventional compounding equipment. The melting stage during compounding is very important for morphology development. This presentation will demonstrate the role of melting or softening of each phase as well as their viscosity, elasticity and interfacial tension in morphology development. Interfacial modification with premade block copolymers or reactively formed copolymers can greatly alter morphology formation and stability. Experimental results will be presented which quantify the role of these additives. References to recent work in this area by our group are listed below: DeBrule, M. B., L. Levitt and C.W. Macosko, "The Rheology and Morphology of Layered Polymer Melts in Shear," Soc. Plastics Eng. Tech Papers (ANTEC), 84-89 (1996). Guegan, P., C. W. Macosko, T. Ishizone, A. Hirao and S. Nakahama, "Kinetics of Chain Coupling at Melt Interfaces, Macromol. 27, 4993-4997 (1994). Lee, M. S., T.P. Lodge, and C. W. Macosko, "Can Random Copolymers Serve as Effective Polymeric

  6. Porous Polyolefin Films via Polymer Blends

    Science.gov (United States)

    Macosko, Chris

    Porous polymer films have broad application including battery separators, membrane supports and filters. Polyolefins are attractive for these applications because of their solvent resistance, low electrical and thermal conductivity, easy fabrication and cost. We will describe fabrication of porous films using cocontinuous blends of a polyolefin with another polymer which can be readily removed with a solvent. Methods to image and control the cocontinuous morphology will be presented.Bell, J. R., K. Chang, C. R. Lopez-Barron, C. W. Macosko, and D. C. Morse, ''Annealing of cocontinuous polymer blends: effect of block copolymer molecular weight and architecture,'' Macromolecules 43, 5024-5032 (2010).Lopez-Barron, C. R., and C. W. Macosko, ''Direct measurement of interface anisotropy of bicontinuous structures via 3D image analysis,'' Langmuir 26, 14284-14293 (2010).Trifkovic, M., A. T. Hedegaard, K. Huston, M. Sheikhzadeh, and C. W. Macosko, ''Porous films via PE/PEO cocontinuous blends,'' Macromolecules 45, 6036-6044 (2012).Hedegaard, A.T., L.L. Gu and C. W. Macosko, ``Effect of Extensional Viscosity on Cocontinuity of Immiscible Polymer Blends'' J. Rheol. 59, 1397-1417 (2015).

  7. Miscibility of polymer blends with engineering models

    DEFF Research Database (Denmark)

    Vassilis, Harismiadis; van Bergen, A. R. D.; Goncalves, Ana Saraiva;

    1996-01-01

    The miscibility behavior of polymer blends that do not exhibit strong specific interactions is examined. Phase equilibrium calculations are presented with the van der Waals equation of state and three group-contribution models (UNIFAC, Entropic-FV, and GC-Flory). Performance of these models is al...

  8. Thin films of photoactive polymer blends.

    Science.gov (United States)

    Ruderer, Matthias A; Metwalli, Ezzeldin; Wang, Weinan; Kaune, Gunar; Roth, Stephan V; Müller-Buschbaum, Peter

    2009-03-09

    The morphology inside photoactive blended films of two conjugated homopolymers poly [(1-methoxy)-4-(2-ethylhexyloxy)-p-phenylene-vinylene] (MEH-PPV) and poly(3-hexylthiophene-2,5-diyl) (P3HT) is investigated. For both homopolymers a linear dependence of the installed film thickness from the concentration of the polymer solution used in spin coating is probed. This dependence allows preparation of an efficient series of blended films with constant thickness and different blending ratios. Information about the lateral structure inside the films is gained from grazing incidence small angle X-ray scattering. At the calculated critical blending ratio the smallest lateral separation between adjacent domains is found representing the highest surface contact between both homopolymers in the films. The presence of wetting layers at both interfaces as detected with X-ray reflectivity and atomic force microscopy is promising for photovoltaic applications. UV/Vis spectroscopy complements the structural investigation.

  9. Macroscopic Modeling of Polymer-Electrolyte Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Weber, A.Z.; Newman, J.

    2007-04-01

    In this chapter, the various approaches for the macroscopic modeling of transport phenomena in polymer-electrolyte membranes are discussed. This includes general background and modeling methodologies, as well as exploration of the governing equations and some membrane-related topic of interest.

  10. Engineering thermal conductivity in polymer blends

    Science.gov (United States)

    Rashidi, Vahid; Coyle, Eleanor; Kieffer, John; Pipe, Kevin

    Weak inter-chain bonding in polymers is believed to be a bottleneck for both thermal conductivity and mechanical strength. Most polymers have low thermal conductivity (~0.1 W/mK), hindering their performance in applications for which thermal management is critical (e.g., electronics packaging). In this work, we use computational methods to study how hydrogen bonding between polymer chains as well as water content can be used to engineer thermal transport in bulk polymers. We examine how changes in the number of hydrogen bonds, chain elongation, density, and vibrational density of states correlate with changes in thermal conductivity for polymer blends composed of different relative constituent fractions. We also consider the effects of bond strength, tacticity, and polymer chain mass. For certain blend fractions, we observe large increases in thermal conductivity, and we analyze these increases in terms of modifications to chain chemistry (e.g., inter-chain bonding) and chain morphology (e.g., chain alignment and radius of gyration). We observe that increasing the number of hydrogen bonds in the system results in better packing as well as better chain alignment and elongation that contribute to enhanced thermal conductivity. The Air Force Office of Scientific Research, Grant No. FA9550-14-1-0010.

  11. Lithium Polymer Electrolytes and Solid State NMR

    Science.gov (United States)

    Berkeley, Emily R.

    2004-01-01

    Research is being done at the Glenn Research Center (GRC) developing new kinds of batteries that do not depend on a solution. Currently, batteries use liquid electrolytes containing lithium. Problems with the liquid electrolyte are (1) solvents used can leak out of the battery, so larger, more restrictive, packages have to be made, inhibiting the diversity of application and decreasing the power density; (2) the liquid is incompatible with the lithium metal anode, so alternative, less efficient, anodes are required. The Materials Department at GRC has been working to synthesize polymer electrolytes that can replace the liquid electrolytes. The advantages are that polymer electrolytes do not have the potential to leak so they can be used for a variety of tasks, small or large, including in the space rover or in space suits. The polymers generated by Dr. Mary Ann Meador's group are in the form of rod -coil structures. The rod aspect gives the polymer structural integrity, while the coil makes it flexible. Lithium ions are used in these polymers because of their high mobility. The coils have repeating units of oxygen which stabilize the positive lithium by donating electron density. This aids in the movement of the lithium within the polymer, which contributes to higher conductivity. In addition to conductivity testing, these polymers are characterized using DSC, TGA, FTIR, and solid state NMR. Solid state NMR is used in classifying materials that are not soluble in solvents, such as polymers. The NMR spins the sample at a magic angle (54.7') allowing the significant peaks to emerge. Although solid state NMR is a helpful technique in determining bonding, the process of preparing the sample and tuning it properly are intricate jobs that require patience; especially since each run takes about six hours. The NMR allows for the advancement of polymer synthesis by showing if the expected results were achieved. Using the NMR, in addition to looking at polymers, allows for

  12. High temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    This book is a comprehensive review of high-temperature polymer electrolyte membrane fuel cells (PEMFCs). PEMFCs are the preferred fuel cells for a variety of applications such as automobiles, cogeneration of heat and power units, emergency power and portable electronics. The first 5 chapters...... of the book describe rationalization and illustration of approaches to high temperature PEM systems. Chapters 6 - 13 are devoted to fabrication, optimization and characterization of phosphoric acid-doped polybenzimidazole membranes, the very first electrolyte system that has demonstrated the concept...

  13. Rechargeable lithium battery employing a new ambient temperature hybrid polymer electrolyte based on PVK+PVdF-HFP (copolymer)

    Science.gov (United States)

    Michael, M. S.; Prabaharan, S. R. S.

    We describe here for the first time, our recent success in developing an ambient temperature Li + conducting solid polymer electrolyte (SPE) using the concept of polymer alloying upon blending two thermoplastic polymers such as poly(vinylidene) fluoride-hexafluoropropylene (PVdF-HFP-copolymer) and poly( N-vinylcarbazole), PVK and achieved the room temperature electrolytic conductivity ( σi) of 0.7×10 -3 S/cm for a typical composition of PVdF-HFP copolymer/PVK blend mixed with EC/LiBF 4 molar composition. The ionic transference number of 0.49 was deduced from combined ac-impedance and dc polarization method. High-resolution optical microscopic examination revealed the disappearance of characteristic highly porous surface structure of PVdF-HFP matrix upon blending with PVK leading to the formation of resultant PVdF-HFP/PVK blend polymer alloy. The electrochemical stability of the polymer electrolyte membrane thus obtained was found to be stable up to ˜4.7 V versus Li/Li +. The new hybrid alloy polymer electrolyte membrane was found to exhibit good interfacial properties against lithium metal and thus, it was found to aid the room temperature operation as electrolytic membrane cum separator in all-solid state rechargeable lithium polymer test cell, LiCo 0.8Ni 0.2O 2/SPE/Li.

  14. Can Nanorods Emulsify Immiscible Polymer Blends?

    Science.gov (United States)

    Hore, Michael J. A.

    2005-03-01

    The addition of nanoscale rods to immiscible binary polymer blends has a pronounced effect on the dynamics of phase separation. The results of computer simulations of the Dissipative Particle Dynamics (DPD) model in three dimensions (3D) indicate that when nanorods prefer one of two components in an immiscible binary polymer blend, the rate of phase separation decreases when the volume fraction of nanorods is increased, or as the aspect ratio (L/D) of the rods is increased. Interestingly, anisotropic nanoparticles have a much more pronounced effect on phase separation dynamics in the system when compared to the effects of spherical nanoparticles, which, generically, do not alter the characteristics of the kinetics in the system. In particular, it may be the case that at high volume fractions -- or alternatively, low volume fractions and large aspect ratio of nanorods -- the system may undergo micro-phase separation only, indicating that the nanorods may be excellent emulsifying agents.

  15. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Science.gov (United States)

    Titterington, W. A.; Fickett, A. P.

    1973-01-01

    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.

  16. On electrochemical devices using alkaline polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, L. [Wuhan Univ., Wuhan (China). Dept. of Chemistry

    2010-07-01

    Solid polymer electrolytes (SPEs) enable a compact assembly of fuel cells and electrolyzers, thereby increasing the space-specific conversion efficiency and avoiding electrolyte leakage. The most widely used SPE in proton exchange membrane fuel cells (PEMFC) and chloro-alkali electrolyzers is Nafion. However, this strongly acidic polyelectrolyte allows only noble metals to be used as the catalysts in the electrochemical devices, which poses a problem in terms of price and resource limits. In principle, alkaline polymer electrolytes (APEs) should be used to eliminate the dependence on noble metal catalysts. The general structure of alkaline polymer electrolytes is a positively charged polymer, notably, a polymer chain attached with fixed cations such as quaternary ammonia group, and dissociated anion, OH-, to act as the charge carrier. This presentation described the challenges of developing APEs in terms of the chemical stability of quaternary ammonia group, the mobility of OH-, and high ionic concentration. The authors have been working on developing high-performance APEs since 2001. The most recent APEs were quaternary ammonia polysulfone (QAPS), which were found to be suitable for fuel cell and electrolyzer applications. The ionic conductivity was high and the crosslinked membrane had excellent mechanical strength, enabling operation at 90 degrees C. Non-precious metal catalysts were used in the APEs. For APE-based fuel cells (APEFC), chromium decorated nickel was used as the anode catalyst for hydrogen oxidation, and silver was used as the cathode catalyst for oxygen reduction. The preliminary performance of such an APEFC with non-Pt catalysts was found to be much better than that of traditional water electrolyzers using KOH solutions. 2 refs.

  17. Segmental dynamics in polymer electrolytes

    CERN Document Server

    Triolo, A; Lo Celso, F; Triolo, R; Passerini, S; Arrighi, V; Frick, B

    2002-01-01

    Polymer dynamics in poly(ethylene oxide) (PEO)-salt mixtures is investigated by means of quasi-elastic neutron scattering (QENS). In a previous study, we reported QENS data from the NEAT spectrometer (BENSC) that evidenced, for the first time, a dynamic heterogeneity in PEO-salt mixtures induced by salt addition. This finding is supported by molecular dynamics (MD) simulations carried out by Borodin et al. In agreement with MD simulations, our QENS data revealed two distinct processes: a fast motion corresponding to the bulk polymer and a slower relaxation, which we attribute to formation of PEO-cation complexes. In this paper we present new QENS data from the high-resolution spectrometer IN16 that further support MD simulations as well as our previous data interpretation. (orig.)

  18. Segmental dynamics in polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Triolo, A.; Lechner, R.E. [CNR - Instituto per i Processi Chimico-Fisici, sez. Messina, Via La Farina 237, 98123 Messina (Italy); Lo Celso, F.; Triolo, R. [Dip. Chimica Fisica, V.le delle Scienze, Parco d' Orleans, Padiglione 17, Universita di Palermo, 90128 Palermo (Italy); Passerini, S. [ENEA, Rome (Italy); Arrighi, V. [Chemistry School of Engeneering and Physical Sciences, Heriot-Watt University, EH14 4AS Edinburgh (United Kingdom); Frick, B. [Institute Laue-Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble, Cedex 9 (France)

    2002-07-01

    Polymer dynamics in poly(ethylene oxide) (PEO)-salt mixtures is investigated by means of quasi-elastic neutron scattering (QENS). In a previous study, we reported QENS data from the NEAT spectrometer (BENSC) that evidenced, for the first time, a dynamic heterogeneity in PEO-salt mixtures induced by salt addition. This finding is supported by molecular dynamics (MD) simulations carried out by Borodin et al. In agreement with MD simulations, our QENS data revealed two distinct processes: a fast motion corresponding to the bulk polymer and a slower relaxation, which we attribute to formation of PEO-cation complexes. In this paper we present new QENS data from the high-resolution spectrometer IN16 that further support MD simulations as well as our previous data interpretation. (orig.)

  19. Improved electrical properties of free standing blend polymer for renewable energy resources

    Science.gov (United States)

    Arya, Anil; Sharma, Sweety; Sharma, A. L.

    2016-05-01

    Blend polymer electrolytes are prepared for salt concentration (Ö/Li = 4) with the constant ratio (0.5 gm) of PEO and PAN using solution casting technique. The prepared free standing solid polymeric film is characterized by Field Emission Scanning Electron Microscopy (FESEM) which confirms the homogeneous distribution of dissociated salt in blend polymer matrix. After addition of salt the ionic conductivity value is found to be of the order of 7.13 × 10-5 Scm-1 which is three orders higher when compared with pure blend polymer films. The microscopic interaction among the polymer-ion, ion-ion has been confirmed by the Fourier Transform Infrared (FTIR) Spectroscopy. A very fine correlation has been built in the electrical conductivity and FTIR result. On the basis of above finding, a prepared free standing solid polymeric film appears to be appropriate for the energy storage/conversion device applications.

  20. Electrostatic contributions in the increased compatibility of polymer blends.

    Science.gov (United States)

    Linares, Elisângela M; Jannuzzi, Sergio A V; Galembeck, Fernando

    2011-12-20

    Successful blending of different polymers to make a structural or functional material requires overcoming limitations due to immiscibility and/or incompatibility that arise from large polymer-polymer interfacial tensions. In the case of latex blends, the combination of capillary adhesion during the blended dispersion drying stage with electrostatic adhesion in the final product is an effective strategy to avoid these limitations, which has been extended to a number of polymer blends and composites. This work shows that adhesion of polymer domains in blends made with natural rubber and synthetic latexes is enhanced by electrostatic adhesion that is in turn enhanced by ion migration, according to the results from scanning electric potential microscopy. The additional attractive force between domains improves blend stability and mechanical properties, broadening the possibilities and scope of latex blends, in consonance with the "green chemistry" paradigm. This novel approach based on electrostatic adhesion can be easily extended to multicomponent systems, including nonpolymers.

  1. Superacid-Based Lithium Salts For Polymer Electrolytes

    Science.gov (United States)

    Nagasubramanian, Ganesan; Prakash, Surya; Shen, David H.; Surampudi, Subbarao; Olah, George

    1995-01-01

    Solid polymer electrolytes exhibiting high lithium-ion conductivities made by incorporating salts of superacids into thin films of polyethylene oxide (PEO). These and other solid-polymer electrolytes candidates for use in rechargeable lithium-based electrochemical cells. Increases in room-temperature lithium-ion conductivities of solid electrolytes desirable because they increase achievable power and energy densities.

  2. Phase Behavior of Polymer Blends for Organic Photovoltaic Applications

    Science.gov (United States)

    Emerson, Jillian; Furst, Eric; Epps, Thomas, III

    2014-03-01

    Polymer blends offer a promising and economically-viable route to creating organic photovoltaic (OPV) devices, as blends can form bicontinuous domains via spinodal decomposition. Understanding the phase behavior of conjugated polymer blends commonly used in OPVs is vital to producing more efficient devices. In this work, we determined the Flory-Huggins solvent-polymer and polymer-polymer interaction parameters for a model system of poly(3-hexylthiophene) (P3HT) and polystyrene (PS) through solvent vapor swelling of thin polymer films. From these interaction parameters, we constructed a polymer/polymer/solvent phase diagram. The phase diagram was validated experimentally with solution-based transmission measurements of PS/P3HT. This work highlights a method to determine the phase behavior in polymer/polymer/solvent blends that can be extended to other combinations of macromolecules relevant to organic photovoltaics, composites, and other materials systems.

  3. High temperature polymer electrolyte membrane fuel cell

    Institute of Scientific and Technical Information of China (English)

    K.Scott; M. Mamlouk

    2006-01-01

    One of the major issues limiting the introduction of polymer electrolyte membrane fuel cells (PEMFCs) is the low temperature of operation which makes platinum-based anode catalysts susceptible to poisoning by the trace amount of CO, inevitably present in reformed fuel. In order to alleviate the problem of CO poisoning and improve the power density of the cell, operating at temperature above 100 ℃ is preferred. Nafion(R) -type perfluorosulfonated polymers have been typically used for PEMFC. However, the conductivity of Nafion(R) -type polymers is not high enough to be used for fuel cell operations at higher temperature ( > 90 ℃) and atmospheric pressure because they dehydrate under these condition.An additional problem which faces the introduction of PEMFC technology is that of supplying or storing hydrogen for cell operation,especially for vehicular applications. Consequently the use of alternative fuels such as methanol and ethanol is of interest, especially if this can be used directly in the fuel cell, without reformation to hydrogen. A limitation of the direct use of alcohol is the lower activity of oxidation in comparison to hydrogen, which means that power densities are considerably lower. Hence to improve activity and power output higher temperatures of operation are preferable. To achieve this goal, requires a new polymer electrolyte membrane which exhibits stability and high conductivity in the absence of liquid water.Experimental data on a polybenzimidazole based PEMFC were presented. A simple steady-state isothermal model of the fuel cell is also used to aid in fuel cell performance optimisation. The governing equations involve the coupling of kinetic, ohmic and mass transport. This paper also considers the advances made in the performance of direct methanol and solid polymer electrolyte fuel cells and considers their limitations in relation to the source and type of fuels to be used.

  4. Engineering Polymer Blends for Impact Damage Mitigation

    Science.gov (United States)

    Gordon, Keith L.; Smith, Russell W.; Working, Dennis C.; Siochi, Emilie J.

    2016-01-01

    Structures containing polymers such as DuPont's Surlyn® 8940, demonstrate puncture healing when impacted by a 9 millimeter projectile traveling from speeds near 300 meters per second (1,100 feet per second) to hypervelocity impacts in the micrometeoroid velocity range of 5 kilometers per second (16,000 feet per second). Surlyn® 8940 puncture heals over a temperature range of minus 30 degrees Centigrade to plus 70 degrees Centigrade and shows potential for use in pressurized vessels subject to impact damage. However, such polymers are difficult to process and limited in applicability due to their low thermal stability, poor chemical resistance and overall poor mechanical properties. In this work, several puncture healing engineered melt formulations were developed. Moldings of melt blend formulations were impacted with a 5.56 millimeter projectile with a nominal velocity of 945 meters per second (3,100 feet per second) at about 25 degrees Centigrade, 50 degrees Centigrade and 100 degrees Centigrade, depending upon the specific blend being investigated. Self-healing tendencies were determined using surface vacuum pressure tests and tensile tests after penetration using tensile dog-bone specimens (ASTM D 638-10). For the characterization of tensile properties both pristine and impacted specimens were tested to obtain tensile modulus, yield stress and tensile strength, where possible. Experimental results demonstrate a range of new puncture healing blends which mitigate damage in the ballistic velocity regime.

  5. Supramolecular assembly in telechelic polymer blends

    Science.gov (United States)

    Elliott, R.; Fredrickson, Glenn H.

    2009-10-01

    Equilibrium, supramolecular assembly in melt blends of two species of telechelic polymers with reversible bonding sites at both ends is theoretically investigated. The bonding between polymers, whether between like or dislike chains, is controlled by affinities of chain bonding set by specified bond energies. Low affinities, or low overall bond strength, results in a monodisperse population of unlinked chains while larger affinities cause longer chains to assemble, forming a polydisperse blend. We investigate sequentially blends with only homobonding (like chain), only heterobonding (dislike chain), and finally a mixed homo- and heterobonding melt. In the first case, the effects of longer chain assembly and polydispersity in a homogeneous melt and its bulk demixing transition are explored. In contrast with the homobonding case, large heterobonding affinities cause alternating blocks to assemble into multiblock copolymers, which can lead to mesophases. The weak bonding region between bulk phase separation and mesophase stability is investigated and a novel Lifshitz point is found indicating a region prone to emulsify. Mixed homo- and heterobonding systems are also examined. Polymeric segments of both species are modeled as flexible Gaussian threads and nonspecific interactions between dissimilar blocks are contactlike Flory-Huggins repulsions. The melts are assumed to be incompressible and all calculations are carried out within mean-field theory. A new integral equation formalism is developed for enumerating all linear species in these complex supramolecular systems, and the random phase approximation and numerical self-consistent field theory are invoked in this context to map out a variety of phase diagrams.

  6. Development of structured polymer electrolyte membranes for fuel cell applications

    Science.gov (United States)

    Gasa, Jeffrey

    The objective of this research was to explore structure-property relationships to develop the understanding needed for introduction of superior PEM materials. Polymer electrolyte membranes based on sulfonated poly(ether ketone ketone) (SPEKK) were fabricated using N-methyl pyrrolidone as casting solvent. The membranes were characterized in terms of properties that were relevant to fuel cell applications, such as proton conductivity, methanol permeability, and swelling properties, among others. It was found in this study that the proton conductivity of neat SPEKK membranes could reach the conductivity of commercial membranes such as NafionRTM. However, when the conductivity of SPEKK was comparable to NafionRTM, the swelling of SPEKK in water was quite excessive. The swelling problem was remedied by modifying the microstructure of SPEKK using different techniques. One of them involved blending of lightly sulfonated PEKK with highly acidic particles (sulfonated crosslinked polystyrene-SXLPS). Low sulfonation level of SPEKK was used to reduce the swelling of the membrane in water and the role of the highly acidic particles was to enhance the proton conductivity of the membrane. Because of the residual crystallinity in SPEKK with low sulfonation levels (IEC sulfone)) to act as mechanical reinforcement. It was found that miscibility behavior of the blends had a significant impact on the transport and swelling properties of these blends, which could be explained by the blend microstructure. The miscibility behavior was found to be strongly dependent on the sulfonation level of SPEKK. The conductivities of the blends were enhanced by as much as two orders of magnitude when the morphology was modified by electric field. The last approach was ionic crosslinking of the sulfonate groups in SPEKK using divalent cations, specifically barium ions. The crosslinking treatment has greatly improved the thermal stability of the membranes in both dry and wet conditions.

  7. How Pure Components Control Polymer Blend Miscibility

    Science.gov (United States)

    White, Ronald; Lipson, Jane; Higgins, Julia

    2012-02-01

    We present insight into some intriguing relationships revealed by our recent studies of polymer mixture miscibility. Applying our simple lattice-based equation of state, we discuss some of the patterns observed over a sample of experimental blends. We focus on the question of how much key information can one determine from a knowledge of just the pure components only, and further, on the role of separate enthalpic and entropic contributions to the miscibility behavior. One interesting correlation connects the value of the difference in pure component energetic parameters with that of the mixed segment interactions, suggesting new possibilities for predictive modeling. We also show how in some cases these two parameter groupings act as separate controls determining the entropy and enthalpy of mixing. Also discussed are the different patterns exhibited for UCST-type and LCST-type blends, these being revealed in some cases by simple examination of the underlying microscopic parameters.

  8. Preparation and Characterization of Lithium Ion Conducting Solid Polymer Electrolytes from Biodegradable Polymers Starch And PVA

    Directory of Open Access Journals (Sweden)

    B. Chatterjee,

    2015-06-01

    Full Text Available Solid Polymer electrolyte films have been prepared from Starch-Poly vinyl alcohol (PVA blend a well acknowledged biodegradable material. Solution cast technique was employed for the preparation of solid polymer electrolyte films added with Lithium Bromide (LiBr salt. X-ray diffraction (XRD studies of the prepared films portrayed the evolution of an amorphous structure with increasing content of salt which is an important factor that leads to the augmentation of conductivity. Electrochemical impedance spectroscopic analysis revealed noticeable ionic conductivity ~ 5x 10-3 S/cm for 20 wt% of salt at ambient conditions. Ionic conductivity showed an increasing trend with salt content at ambient conditions. Transference number measurements confirmed the ionic nature of the prepared solid polymer electrolyte films. Dielectric studies revealed a sharp increase in the number of charge carriers which contributed to enhancement in conductivity. Low values of activation energy extracted from temperature dependent conductivity measurements could be favorable for device applications. For the composition with highest conductivity a temperature independent relaxation mechanism was confirmed by electric modulus scaling.

  9. Ionic-Liquid-Based Polymer Electrolytes for Battery Applications.

    Science.gov (United States)

    Osada, Irene; de Vries, Henrik; Scrosati, Bruno; Passerini, Stefano

    2016-01-11

    The advent of solid-state polymer electrolytes for application in lithium batteries took place more than four decades ago when the ability of polyethylene oxide (PEO) to dissolve suitable lithium salts was demonstrated. Since then, many modifications of this basic system have been proposed and tested, involving the addition of conventional, carbonate-based electrolytes, low molecular weight polymers, ceramic fillers, and others. This Review focuses on ternary polymer electrolytes, that is, ion-conducting systems consisting of a polymer incorporating two salts, one bearing the lithium cation and the other introducing additional anions capable of plasticizing the polymer chains. Assessing the state of the research field of solid-state, ternary polymer electrolytes, while giving background on the whole field of polymer electrolytes, this Review is expected to stimulate new thoughts and ideas on the challenges and opportunities of lithium-metal batteries.

  10. Preliminary Evaluations of Polymer-based Lithium Battery Electrolytes Under Development for the Polymer Electrolyte Rechargeable Systems Program

    Science.gov (United States)

    Manzo, Michelle A.; Bennett, William R.

    2003-01-01

    A component screening facility has been established at The NASA Glenn Research Center (GRC) to evaluate candidate materials for next generation, lithium-based, polymer electrolyte batteries for aerospace applications. Procedures have been implemented to provide standardized measurements of critical electrolyte properties. These include ionic conductivity, electronic resistivity, electrochemical stability window, cation transference number, salt diffusion coefficient and lithium plating efficiency. Preliminary results for poly(ethy1ene oxide)-based polymer electrolyte and commercial liquid electrolyte are presented.

  11. Critical crossover phenomena in compatible polymer blends studied with SANS

    DEFF Research Database (Denmark)

    Schwahn, D.; Janssen, S.; Willner, L.;

    1995-01-01

    Polymer blends show a much larger 3d-Ising regime, e.g. a much larger Ginzburg number Gi than predicted by the Ginzburg criterion. This discrepancy is supposed to be explained by the compressibility or the free volume of the blend. In this paper we present and discuss the Gi number of polymer...

  12. Solid polymer electrolyte composite membrane comprising laser micromachined porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.; Mittelsteadt, Cortney K.; McCallum, Thomas J.

    2011-01-11

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 5 microns, are made by laser micromachining and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  13. Molecular composites and polymer blends containing ionic polymers

    Science.gov (United States)

    Tsou, Li-Chun

    1997-11-01

    Polymer blends are generally immiscible due to the unfavorable thermodynamics of mixing. By the introduction of ion-dipole interaction, mechanical properties of the PPTA anion/polar polymers (such as PVP, PEO and PPrO) molecular composites have been investigated in relation to their miscibility and microstructural morphology. Optical clarity observed in the glassy PPTA anion/PVP system suggest the presence of miscibility, since the refractive indices between the two components are quite different, nsb{PVP} = 1.509 and nsb{PPTA} = 1.644. In general, the difference greater than 0.01 is sufficient to make blends opaque. DSC measurements, showing a composition dependent Tsb{g} and a melting temperature depression, also indicate the miscibility achieved at the molecular level, about 50-100 A. By using the Hoffman-Weeks plot, a negative Flory-Huggins interaction parameter, chi = -1.10, is obtained for the PPTA anion/PEO molecular composites. An irregular spherulitic pattern and a reduced crystal size suggest that PPTA anion is intimately mixed with the amorphous PEO, both inter- and intra-spherulitically. Molecular composites exhibit not only an enhanced tensile strength and modulus, but also a greater fracture toughness, Ksb{IC}, e.g., an 80% increase at a 2 wt% PPTA anion addition. An enhanced tensile strength associated with a reduced crystallinity suggests that PPTA anion is the major contributor to the superior tensile properties instead of the crystalline phase. Upon addition of PPTA anion to PPrO, a slower relaxation rate and a better thermal stability are observed. Significant enhancement is found when the monovalent K salt is replaced with a divalent Ca salt. The molecular reinforcement achieved via ion-dipole interactions is more effective than the rigid filler effect obtained in the non-ionic PPTA/PPrO blend: e.g., a modulus enhancement of 814% vs. 286%, as compared with the value for PPrO. Two phase systems with microphase separation are developed since many

  14. Synthesis of polymer electrolyte membranes from cellulose acetate/poly(ethylene oxide)/LiClO{sub 4} for lithium ion battery application

    Energy Technology Data Exchange (ETDEWEB)

    Nurhadini,, E-mail: nur-chem@yahoo.co.id; Arcana, I Made, E-mail: arcana@chem.itb.ac.id [Inorganic and Physical Chemistry Research Division, Faculty of Mathematics and Natural Sciences, Institiut Teknologi Bandung, Jalan Ganesha 10, Bandung 40132 (Indonesia)

    2015-09-30

    This study was conducted to determine the effect of cellulose acetate on poly(ethylene oxide)-LiClO{sub 4} membranes as the polymer electrolyte. Cellulose acetate is used as an additive to increase ionic conductivity and mechanical property of polymer electrolyte membranes. The increase the percentage of cellulose acetate in membranes do not directly effect on the ionic conductivity, and the highest ionic conductivity of membranes about 5,7 × 10{sup −4} S/cm was observed in SA/PEO/LiClO{sub 4} membrane with cellulose ratio of 10-25% (w/w). Cellulose acetate in membranes increases mechanical strength of polymer electrolyte membranes. Based on TGA analysis, this polymer electrolyte thermally is stable until 270 °C. The polymer electrolyte membrane prepared by blending the cellulose acetate, poly(ethylene oxide), and lithium chlorate could be potentially used as a polymer electrolyte for lithium ion battery application.

  15. Alternative membranes for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, A.K.; Pitchumani, S.; Sridhar, P.; Shukla, A.K. [Central Electrochemical Research Inst., Karaikudi (India)

    2009-07-01

    Nafion, a perfluoro-sulfonated membrane, is utilized as a membrane electrolyte in polymer electrolyte fuel cells (PEFCs). However, to realize optimum PEFC performance, the Nafion membrane needs to be fully humidified, making the system quite costly. Therefore, in order to solve this problem, alternative membrane electrolytes that could operate under low humidity conditions are needed. This paper reported on composite Nafion membranes with ceramic/inorganic fillers such as silica and mesoporous zirconium phosphate (MZP). Silica was impregnated to the Nafion matrix by a unique water hydrolysis sol-gel route and casted as a composite membrane while MZP, a solid-super-acid-proton-conducting medium as well as water absorbing material was synthesized by a co-assembly technique and impregnated to the Nafion matrix to form a composite membrane. The performance of the PEFCs with Nafion membrane and composite membranes was tested with hydrogen/oxygen gas and hydrogen/air feeds at varying relative humidity (RH) values under ambient conditions. It was concluded that under RH value as low as 18 per cent, the PEFC with Nafion membrane delivers a peak-power density of only 130 mW/square centimeter.

  16. Mathematical modeling of polymer electrolyte fuel cells

    Science.gov (United States)

    Sousa, Ruy; Gonzalez, Ernesto R.

    Fuel cells with a polymer electrolyte membrane have been receiving more and more attention. Modeling plays an important role in the development of fuel cells. In this paper, the state-of-the-art regarding modeling of fuel cells with a polymer electrolyte membrane is reviewed. Modeling has allowed detailed studies concerning the development of these cells, e.g. in discussing the electrocatalysis of the reactions and the design of water-management schemes to cope with membrane dehydration. Two-dimensional models have been used to represent reality, but three-dimensional models can cope with some important additional aspects. Consideration of two-phase transport in the air cathode of a proton exchange membrane fuel cell seems to be very appropriate. Most fuel cells use hydrogen as a fuel. Besides safety concerns, there are problems associated with production, storage and distribution of this fuel. Methanol, as a liquid fuel, can be the solution to these problems and direct methanol fuel cells (DMFCs) are attractive for several applications. Mass transport is a factor that may limit the performance of the cell. Adsorption steps may be coupled to Tafel kinetics to describe methanol oxidation and methanol crossover must also be taken into account. Extending the two-phase approach to the DMFC modeling is a recent, important point.

  17. New Solid Polymer Electrolytes for Improved Lithium Batteries

    Science.gov (United States)

    Hehemann, David G.

    2002-01-01

    The objective of this work was to identify, synthesize and incorporate into a working prototype, next-generation solid polymer electrolytes, that allow our pre-existing solid-state lithium battery to function better under extreme conditions. We have synthesized polymer electrolytes in which emphasis was placed on the temperature-dependent performance of these candidate electrolytes. This project was designed to produce and integrate novel polymer electrolytes into a lightweight thin-film battery that could easily be scaled up for mass production and adapted to different applications.

  18. Novel All Solid-state Polymer Electrolytes for Lithium Battery

    Institute of Scientific and Technical Information of China (English)

    Hui Jiang; Shibi Fang

    2005-01-01

    @@ 1Introduction All solid-state polymer electrolytes for lithium battery was proved to be an attractive direction. Compared with prevenient polymer electrolytes all solid-state polymer electrolytes were superiority in more broad electrochemical window, more stable/low interfacial resistance especially when situ-polymerization utilized, excellent mechanical properties and dissepiment free. A lithium secondary battery using all solid-state polymer electrolyte meet the challenge of energy source for both portable electronic devices and electric vehicles (EV) or engine/battery hybrid vehicles (HEV). All solid-state comb-like network polymer electrolytes (CNPE) based on polysiloxane with internal plasticizing chain (IPC) has been designed and synthesized. See Fig. 1.

  19. A microporous gel electrolyte based on poly(vinylidene fluoride-co-hexafluoropropylene)/fully cyanoethylated cellulose derivative blend for lithium-ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Ren Zhong [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Liu Yuyan [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)], E-mail: liuyy@hit.edu.cn; Sun Kening; Zhou Xiaoliang; Zhang Naiqing [Science Reseach Center, Harbin Institute of Technology, Harbin 150001 (China)

    2009-02-15

    A gel polymer electrolyte based on the blend of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and fully cyanoethylated cellulose derivative (DH-4-CN) was prepared and characterized. Thermal, mechanical, swelling, liquid electrolyte retention and electrochemical properties, as well as microstructures of the prepared polymer electrolytes, were investigated using thermogravimetric analysis, electrochemical impedance spectroscopy, linear sweep voltammetry, and scanning electron microscopy. The results showed that the addition of DH-4-CN could obviously improve the conductivity of PVDF-HFP based electrolyte. The maximum ionic conductivity of 4.36 mS cm{sup -1} at 20 deg. C can be obtained for PVDF-HFP/DH-4-CN 14:1 in the presence of 1 M LiPF{sub 6} in EC and DMC (1:1, w/w). The dry blend membranes exhibit excellent thermal behavior. All the blend electrolytes are electrochemically stable up to about 4.8 V vs. Li/Li{sup +} for all compositions. The results reveal that the composite polymer electrolyte qualifies as a potential application in lithium-ion battery.

  20. PMMA-based Gel Polymer Electrolytes with Crosslinking Network

    Institute of Scientific and Technical Information of China (English)

    H.P. Zhang; Y. P. Wu; H. Q. Wu; M. Sun

    2005-01-01

    @@ 1Introduction The lithium-ion battery has a good rate capability and low-temperature performance, but its safety is relatively low due to the possibility of leakage of liquid electrolyte. The use of a solid or gel type electrolyte can lower the probability of leakage liquid electrolyte, and the electrochemical performance of gel electrolyte doesn't decrease so markedly as the solid electrolyte. Now, new types of advanced lithium-ion battery with gel polymer electrolytes are under developing which can be used in the future.

  1. High ion conducting polymer nanocomposite electrolytes using hybrid nanofillers.

    Science.gov (United States)

    Tang, Changyu; Hackenberg, Ken; Fu, Qiang; Ajayan, Pulickel M; Ardebili, Haleh

    2012-03-14

    There is a growing shift from liquid electrolytes toward solid polymer electrolytes, in energy storage devices, due to the many advantages of the latter such as enhanced safety, flexibility, and manufacturability. The main issue with polymer electrolytes is their lower ionic conductivity compared to that of liquid electrolytes. Nanoscale fillers such as silica and alumina nanoparticles are known to enhance the ionic conductivity of polymer electrolytes. Although carbon nanotubes have been used as fillers for polymers in various applications, they have not yet been used in polymer electrolytes as they are conductive and can pose the risk of electrical shorting. In this study, we show that nanotubes can be packaged within insulating clay layers to form effective 3D nanofillers. We show that such hybrid nanofillers increase the lithium ion conductivity of PEO electrolyte by almost 2 orders of magnitude. Furthermore, significant improvement in mechanical properties were observed where only 5 wt % addition of the filler led to 160% increase in the tensile strength of the polymer. This new approach of embedding conducting-insulating hybrid nanofillers could lead to the development of a new generation of polymer nanocomposite electrolytes with high ion conductivity and improved mechanical properties.

  2. Solid electrolyte material manufacturable by polymer processing methods

    Science.gov (United States)

    Singh, Mohit; Gur, Ilan; Eitouni, Hany Basam; Balsara, Nitash Pervez

    2012-09-18

    The present invention relates generally to electrolyte materials. According to an embodiment, the present invention provides for a solid polymer electrolyte material that is ionically conductive, mechanically robust, and can be formed into desirable shapes using conventional polymer processing methods. An exemplary polymer electrolyte material has an elastic modulus in excess of 1.times.10.sup.6 Pa at 90 degrees C. and is characterized by an ionic conductivity of at least 1.times.10.sup.-5 Scm-1 at 90 degrees C. An exemplary material can be characterized by a two domain or three domain material system. An exemplary material can include material components made of diblock polymers or triblock polymers. Many uses are contemplated for the solid polymer electrolyte materials. For example, the present invention can be applied to improve Li-based batteries by means of enabling higher energy density, better thermal and environmental stability, lower rates of self-discharge, enhanced safety, lower manufacturing costs, and novel form factors.

  3. Migration of Cations and Anions in Amorphous Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    N.A.Stolwijk; S.H.Obeidi; M.Wiencierz

    2007-01-01

    1 Results Polymer electrolytes are used as ion conductors in batteries and fuel cells.Simple systems consist of a polymer matrix complexing an inorganic salt and are fully amorphous at the temperatures of interest.Both cations and anions are mobile and contribute to charge transport.Most studies on polymer electrolytes use the electrical conductivity to characterize the ion mobility.However,conductivity measurements cannot discriminate between cations and anions.This paper reports some recent results fr...

  4. Phase equilibria in polymer blend thin films: a Hamiltonian approach.

    Science.gov (United States)

    Souche, M; Clarke, N

    2009-12-28

    We propose a Hamiltonian formulation of the Flory-Huggins-de Gennes theory describing a polymer blend thin film. We then focus on the case of 50:50 polymer blends confined between antisymmetric walls. The different phases of the system and the transitions between them, including finite-size effects, are systematically studied through their relation with the geometry of the Hamiltonian flow in phase space. This method provides an easy and efficient way, with strong graphical insight, to infer the qualitative physical behavior of polymer blend thin films.

  5. High Temperature Polymer Electrolyte Fuel Cells

    DEFF Research Database (Denmark)

    Fleige, Michael

    This thesis presents the development and application of electrochemical half-cell setups to study the catalytic reactions taking place in High Temperature Polymer Electrolyte Fuel Cells (HTPEM-FCs): (i) a pressurized electrochemical cell with integrated magnetically coupled rotating disk electrode...... (RDE) and (ii) a gas diffusion electrode (GDE) setup designed for experiments in conc. H3PO4. The pressurized cell is demonstrated by tests on polycrystalline platinum electrodes up to 150 ºC. Functionality of the RDE system is proved studying the oxygen reduction reaction (ORR) at temperatures up...... to 140 ºC and oxygen pressures up to ~100 bar at room temperature. The GDE cell is successfully tested at 130 ºC by means of direct oxidation of methanol and ethanol, respectively. In the second part of the thesis, the emphasis is put on the ORR in H3PO4 with particular focus on the mass transport...

  6. CO tolerance of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gubler, L.; Scherer, G.G.; Wokaun, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Reformed methanol can be used as a fuel for polymer electrolyte fuel cells instead of pure hydrogen. The reformate gas contains mainly H{sub 2}, CO{sub 2} in the order of 20% and low levels of CO in the order of 100 ppm. CO causes severe voltage losses due to poisoning of the anode catalyst. The effect of CO on cell performance was investigated at different CO levels up to 100 ppm. Various options to improve the CO tolerance of the fuel cell were assessed thereafter, of which the injection of a few percents of oxygen into the fuel feed stream proved to be most effective. By mixing 1% of oxygen with hydrogen containing 100 ppm CO, complete recovery of the cell performance could be attained. (author) 2 figs., 2 tabs., 3 refs.

  7. Advanced composite polymer electrolyte fuel cell membranes

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, M.S.; Zawodzinski, T.A.; Gottesfeld, S.; Kolde, J.A.; Bahar, B.

    1995-09-01

    A new type of reinforced composite perfluorinated polymer electrolyte membrane, GORE-SELECT{trademark} (W.L. Gore & Assoc.), is characterized and tested for fuel cell applications. Very thin membranes (5-20 {mu}m thick) are available. The combination of reinforcement and thinness provides high membrane, conductances (80 S/cm{sup 2} for a 12 {mu}m thick membrane at 25{degrees}C) and improved water distribution in the operating fuel cell without sacrificing longevity or durability. In contrast to nonreinforced perfluorinated membranes, the x-y dimensions of the GORE-SELECT membranes are relatively unaffected by the hydration state. This feature may be important from the viewpoints of membrane/electrode interface stability and fuel cell manufacturability.

  8. Solid Polymer Electrolyte Fuel Cell Technology Program

    Science.gov (United States)

    1980-01-01

    Work is reported on phase 5 of the Solid Polymer Electrolyte (SPE) Fuel Cell Technology Development program. The SPE fuel cell life and performance was established at temperatures, pressures, and current densities significantly higher than those previously demonstrated in sub-scale hardware. Operation of single-cell Buildup No. 1 to establish life capabilities of the full-scale hardware was continued. A multi-cell full-scale unit (Buildup No. 2) was designed, fabricated, and test evaluated laying the groundwork for the construction of a reactor stack. A reactor stack was then designed, fabricated, and successfully test-evaluated to demonstrate the readiness of SPE fuel cell technology for future space applications.

  9. Electrospun nanocomposite fibrous polymer electrolyte for secondary lithium battery applications

    Science.gov (United States)

    Padmaraj, O.; Rao, B. Nageswara; Jena, Paramananda; Venkateswarlu, M.; Satyanarayana, N.

    2014-04-01

    Hybrid nanocomposite [poly(vinylidene fluoride -co- hexafluoropropylene) (PVdF-co-HFP)/magnesium aluminate (MgAl2O4)] fibrous polymer membranes were prepared by electrospinning method. The prepared pure and nanocomposite fibrous polymer electrolyte membranes were soaked into the liquid electrolyte 1M LiPF6 in EC: DEC (1:1,v/v). XRD and SEM are used to study the structural and morphological studies of nanocomposite electrospun fibrous polymer membranes. The nanocomposite fibrous polymer electrolyte membrane with 5 wt.% of MgAl2O4 exhibits high ionic conductivity of 2.80 × 10-3 S/cm at room temperature. The charge-discharge capacity of Li/LiCoO2 coin cells composed of the newly prepared nanocomposite [(16 wt.%) PVdF-co-HFP+(5 wt.%) MgAl2O4] fibrous polymer electrolyte membrane was also studied and compared with commercial Celgard separator.

  10. Predicting morphologies of solution processed polymer: Fullerene blends

    NARCIS (Netherlands)

    Kouijzer, S.; Michels, J.J.; Berg, M. van den; Gevaerts, V.S.; Turbiez, M.; Wienk, M.M.; Janssen, R.A.J.

    2013-01-01

    The performance of solution processed polymer:fullerene thin film photovoltaic cells is largely determined by the nanoscopic and mesoscopic morphology of these blends that is formed during the drying of the layer. Although blend morphologies have been studied in detail using a variety of microscopic

  11. Shearing of particles during crack growth in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, K.G.W.; Steenbrink, A.C.; Giessen, E.V.D.

    1999-01-01

    Microstructural investigations below the fracture surface have revealed that the rubber particles in a number of polymer-rubber blends were deformed into remarkable S-like shapes. These shapes seem to have been largely ignored in previous microstructural studies of blends, but in fact cannot be expl

  12. Fuel cells with solid polymer electrolyte and their application on vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

  13. Unraveling Structure-Property Relationships in Polymer Blends for Intelligent Materials Design

    Science.gov (United States)

    Irwin, Matthew Tyler

    Block polymers provide an accessible route to structured, composite materials by combining two or more components with disparate mechanical, chemical, and electrical properties into a single bulk material with nanoscale domains. However, the characteristic lengthscale of these systems is limited, and the choice of components is restricted to those that are able to undergo microstructural ordering at accessible temperatures. This thesis details routes to overcoming these limitations through the addition of a lithium salt, a blend of homopolymers, or both. Chapter 2 describes a study wherein complex sphere phases such as the Frank-Kasper sigma phase can be observed in otherwise disordered asymmetric block polymers through the addition of a lithium salt. Chapter 3 discusses the development and characterization of a ternary polymer blend of an AB diblock copolymer and A and B homopolymers doped with a lithium salt. Detailed characterization showed that doping blends that are otherwise disordered with lithium salt induced microstructural ordering and largely recovers the phase behavior of traditional ternary polymer blends. A systematic study of the ionic conductivity of the blends at a fixed salt concentration demonstrates that, at a given composition, disordered, yet highly structured blends consistently exhibit better conductivity than polycrystalline morphologies with long range order. Chapter 4 extends the methodology of Chapter 3 and details a systematic study of the effects of cross-linker concentration on the performance of polymer electrolyte membranes produced via polymerization-induced microphase separation that exhibit a highly structured, globally disordered microstructure. Finally, Chapter 5 details efforts to develop a water filtration membrane using a polyethylene template derived from a polymeric bicontinuous microemulsion. Throughout all of this work, the goal is to better understand structure-property relationships at the molecular level in order to

  14. Lithium carbon batteries with solid polymer electrolyte; Accumulateur lithium carbone a electrolyte solide polymere

    Energy Technology Data Exchange (ETDEWEB)

    Andrieu, X.; Boudin, F. [Alcatel Alsthom Recherche, 91 - Marcoussis (France)

    1996-12-31

    The lithium carbon batteries studied in this paper use plasticized polymer electrolytes made with passive polymer matrix swollen by a liquid electrolyte with a high ionic conductivity (> 10{sup -3} S/cm at 25 deg. C). The polymers used to prepare the gels are polyacrylonitrile (PAN) and vinylidene poly-fluoride (PVdF). The electrochemical and physical properties of these materials are analyzed according to their composition. The behaviour of solid electrolytes with different materials of lithium ion insertion (graphite and LiNiO{sub 2}) are studied and compared to liquid electrolytes. The parameters taken into account are the reversible and irreversible capacities, the cycling performance and the admissible current densities. Finally, complete lithium ion batteries with gelled electrolytes were manufactured and tested. (J.S.) 2 refs.

  15. Can Biochemistry Usefully Guide the Search for Better Polymer Electrolytes?

    Directory of Open Access Journals (Sweden)

    J. Woods Halley

    2013-09-01

    Full Text Available I review some considerations that suggest that the biochemical products of evolution may provide hints concerning the way forward for the development of better electrolytes for lithium polymer batteries.

  16. Can Biochemistry Usefully Guide the Search for Better Polymer Electrolytes?

    Science.gov (United States)

    Halley, J. Woods

    2013-01-01

    I review some considerations that suggest that the biochemical products of evolution may provide hints concerning the way forward for the development of better electrolytes for lithium polymer batteries. PMID:24956948

  17. Exciton and Hole-Transfer Dynamics in Polymer: Fullerene Blends

    Directory of Open Access Journals (Sweden)

    van Loosdrecht P. H. M.

    2013-03-01

    Full Text Available Ultrafast hole transfer dynamics from fullerene derivative to polymer in bulk heterojunction blends are studied with visible-pump - IR-probe spectroscopy. The hole transfer process is found to occur in 50/300 fs next to the interface, while a longer 15-ps time is attributed to exciton diffusion towards interface in PC71BM domains. High polaron generation efficiency in P3HT blends indicates excellent intercalation between the polymer and the fullerene even at highest PC71BM concentration thereby yielding a valuable information on the blend morphology.

  18. Nanostructure enhanced ionic transport in fullerene reinforced solid polymer electrolytes.

    Science.gov (United States)

    Sun, Che-Nan; Zawodzinski, Thomas A; Tenhaeff, Wyatt E; Ren, Fei; Keum, Jong Kahk; Bi, Sheng; Li, Dawen; Ahn, Suk-Kyun; Hong, Kunlun; Rondinone, Adam J; Carrillo, Jan-Michael Y; Do, Changwoo; Sumpter, Bobby G; Chen, Jihua

    2015-03-28

    Solid polymer electrolytes, such as polyethylene oxide (PEO) based systems, have the potential to replace liquid electrolytes in secondary lithium batteries with flexible, safe, and mechanically robust designs. Previously reported PEO nanocomposite electrolytes routinely use metal oxide nanoparticles that are often 5-10 nm in diameter or larger. The mechanism of those oxide particle-based polymer nanocomposite electrolytes is under debate and the ion transport performance of these systems is still to be improved. Herein we report a 6-fold ion conductivity enhancement in PEO/lithium bis(trifluoromethanesulfonyl) imide (LiTFSI)-based solid electrolytes upon the addition of fullerene derivatives. The observed conductivity improvement correlates with nanometer-scale fullerene crystallite formation, reduced crystallinities of both the (PEO)6:LiTFSI phase and pure PEO, as well as a significantly larger PEO free volume. This improved performance is further interpreted by enhanced decoupling between ion transport and polymer segmental motion, as well as optimized permittivity and conductivity in bulk and grain boundaries. This study suggests that nanoparticle induced morphological changes, in a system with fullerene nanoparticles and no Lewis acidic sites, play critical roles in their ion conductivity enhancement. The marriage of fullerene derivatives and solid polymer electrolytes opens up significant opportunities in designing next-generation solid polymer electrolytes with improved performance.

  19. Molecular Modeling of Interfacial Proton Transport in Polymer Electrolyte Membranes

    OpenAIRE

    2014-01-01

    The proton conductivity of polymer electrolyte membranes (PEMs) plays a crucial role for the performance of polymer electrolyte fuel cells (PEFCs). High hydration of Nafion-like membranes is crucial to high proton conduction across the PEM, which limits the operation temperature of PEFCs to <100o C. At elevated temperatures (>100o C) and minimal hydration, interfacial proton transport becomes vital for membrane operation. Along with fuel cell systems, interfacial proton conduction is of...

  20. Controlled release of tocopherols from polymer blend films

    Science.gov (United States)

    Obinata, Noe

    Controlled release packaging has great potential to increase storage stability of foods by releasing active compounds into foods continuously over time. However, a major limitation in development of this technology is the inability to control the release and provide rates useful for long term storage of foods. Better understanding of the factors affecting active compound release is needed to overcome this limitation. The objective of this research was to investigate the relationship between polymer composition, polymer processing method, polymer morphology, and release properties of active compounds, and to provide proof of principle that compound release is controlled by film morphology. A natural antioxidant, tocopherol was used as a model active compound because it is natural, effective, heat stable, and soluble in most packaging polymers. Polymer blend films were produced from combination of linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), polypropylene (PP), or polystyrene (PS) with 3000 ppm mixed tocopherols using conventional blending method and innovative blending method, smart blending with a novel mixer using chaotic advection. Film morphologies were visualized with scanning electron microscopy (SEM). Release of tocopherols into 95% ethanol as a food simulant was measured by UV/Visible spectrophotometry or HPLC, and diffusivity of tocopherols in the polymers was estimated from this data. Polymer composition (blend proportions) and processing methods have major effects on film morphology. Four different types of morphologies, dispersed, co-continuous, fiber, and multilayer structures were developed by either conventional extrusion or smart blending. With smart blending of fixed polymer compositions, different morphologies were progressively developed with fixed polymer composition as the number of rod rotations increased, providing a way to separate effects of polymer composition and morphology. The different morphologies

  1. Poly(hydroxyethyl methacrylate) based networked solid polymer electrolyte.

    Science.gov (United States)

    Lee, A-Ran; Kim, Young-Deok; Lee, Sang-Keol; Jo, Nam-Ju

    2013-10-01

    Solid polymer electrolytes (SPEs) have good safety for lithium battery compared to liquid electrolytes, but they have low ionic conductivity. To solve the problem, the polymer-in-salt system was introduced which has higher ionic conductivity than salt-in-polymer system. However, polymer-in-salt system has disadvantages that are poor mechanical properties with increasing salt concentration. In this study, networked polymer electrolytes consisting of poly(hydroxyethyl methacrylate) (P(HEMA)), lithium triflate (LiCF3SO3, LiTf) and hydrochloric acid (HCl) were prepared. And the electrochemical and mechanical properties of P(HEMA) based SPEs were investigated by using ac impedance analyzer and universal testing machine, respectively.

  2. Successively refined models for crack tip plasticity in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, KGW; Seelig, T; van der Giessen, E

    2005-01-01

    This paper is concerned with a comparative study of different, partly complementary micromechanical models for crack tip plasticity in polymer-rubber blends. It is experimentally well established that interspersion of micron-scale rubber particles into a polymer matrix can lead to a significantly en

  3. Photoluminescence of conjugated polymer blends at the nanoscale

    NARCIS (Netherlands)

    Jarzab, D.; Lu, M.; Nicolai, H.T.; Blom, P.W.M.; Loi, M.A.

    2011-01-01

    Here we report on a combined photoluminescence and morphological study of a polymer-polymer blend composed of a copolymer of derivatives of polyspirobifluorene and polyfluorene (PBFF) and a derivative of polyphenylene vinylene (MDMO-PPV). Evidence of partial Förster energy transfer from PBFF to MDMO

  4. Ionic conductivity enhancement of polymer electrolytes with ceramic nanowire fillers.

    Science.gov (United States)

    Liu, Wei; Liu, Nian; Sun, Jie; Hsu, Po-Chun; Li, Yuzhang; Lee, Hyun-Wook; Cui, Yi

    2015-04-08

    Solid-state electrolytes provide substantial improvements to safety and electrochemical stability in lithium-ion batteries when compared with conventional liquid electrolytes, which makes them a promising alternative technology for next-generation high-energy batteries. Currently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few decades on dispersing of ceramic nanoparticles into polymer matrix has been proved effective to enhance ionic conductivity although it is challenging to form the efficiency networks of ionic conduction with nanoparticles. In this work, we first report that ceramic nanowire fillers can facilitate formation of such ionic conduction networks in polymer-based solid electrolyte to enhance its ionic conductivity by three orders of magnitude. Polyacrylonitrile-LiClO4 incorporated with 15 wt % Li0.33La0.557TiO3 nanowire composite electrolyte exhibits an unprecedented ionic conductivity of 2.4 × 10(-4) S cm(-1) at room temperature, which is attributed to the fast ion transport on the surfaces of ceramic nanowires acting as conductive network in the polymer matrix. In addition, the ceramic-nanowire filled composite polymer electrolyte shows an enlarged electrochemical stability window in comparison to the one without fillers. The discovery in the present work paves the way for the design of solid ion electrolytes with superior performance.

  5. Impedance Spectroscopy and FTIR Studies of PEG - Based Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Anji Reddy Polu

    2011-01-01

    Full Text Available Ionic conductivity of poly(ethylene glycol (PEG - ammonium chloride (NH4Cl based polymer electrolytes can be enhanced by incorporating ceramic filler TiO2 into PEG-NH4Cl matrix. The electrolyte samples were prepared by solution casting technique. FTIR studies indicates that the complex formation between the polymer, salt and ceramic filler. The ionic conductivity was measured using impedance spectroscopy technique. It was observed that the conductivity of the electrolyte varies with TiO2 concentration and temperature. The highest room temperature conductivity of the electrolyte of 7.72×10−6 S cm-1 was obtained at 15% by weight of TiO2 and that without TiO2 filler was found to be 9.58×10−7 S cm−1. The conductivity has been improved by 8 times when the TiO2 filler was introduced into the PEG–NH4Cl electrolyte system. The conductance spectra shows two distinct regions: a dc plateau and a dispersive region. The temperature dependence of the conductivity of the polymer electrolytes seems to obey the VTF relation. The conductivity values of the polymer electrolytes were reported and the results were discussed. The imaginary part of dielectric constant (εi decreases with increase in frequency in the low frequency region whereas frequency independent behavior is observed in the high frequency region.

  6. Studies on AC Electrical Conductivity of CdCl2 Doped PVA Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    M. B. Nanda Prakash

    2013-01-01

    Full Text Available PVA-based polymer electrolytes were prepared with various concentrations of CdCl2 using solvent casting method. Prepared polymer films were investigated using line profile analysis employing X-ray diffraction (XRD data. XRD results show that the crystallite size decreases and then increases with increase in CdCl2. AC conductivity in these polymer increases films first and then decreases. These observations are in agreement with XRD results. The highest ionic conductivity of 1.68E − 08 Scm−1 was observed in 4% of CdCl2 in PVA polymer blend. Crystallite ellipsoids for different concentrations of CdCl2 are computed here using whole pattern powder fitting (WPPF indicating that crystallite area decreases with increase in the ionic conductivity.

  7. Composite polymer electrolyte based on PEO/Pvdf-HFP with MWCNT for lithium battery applications

    Science.gov (United States)

    Pradeepa, P.; Edwinraj, S.; Sowmya, G.; Kalaiselvimary, J.; Selvakumar, K.; Prabhu, M. Ramesh

    2016-05-01

    In the present study PEO and PVdF-HFP blend based composite polymer electrolytes (CPEs) has been prepared by using Multi Walled Carbon Nanotube (MWCNT), in order to examine the filler addition effect on the electrochemical properties. The complexed nanocomposite polymer electrolytes were obtained in the form of dimensionally stable and free standing films by using solution casting technique. The electrochemical properties of CPEs were measured by the AC impedance method. From the ionic conductivity results, the CPE containing MWCNT 2wt% showed the highest ionic conductivity with an excellent thermal stability at room temperature. The dielectric loss curve s for the sample 6.25wt% PEO: 18.75 wt% PVdF-HFP: 2wt% MWCNT reveal the low frequency β relaxation peak pronounced at high temperature, and it may caused by side group dipoles.

  8. Temperature dependent dielectric properties and ion transportation in solid polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Sengwa, R. J.; Dhatarwal, Priyanka; Choudhary, Shobhna

    2016-05-01

    Solid polymer electrolyte (SPE) film consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blend matrix with lithium tetrafluroborate (LiBF4) as dopant ionic salt and poly(ethylene glycol) (PEG) as plasticizer has been prepared by solution casting method followed by melt pressing. Dielectric properties and ionic conductivity of the SPE film at different temperatures have been determined by dielectric relaxation spectroscopy. It has been observed that the dc ionic conductivity of the SPE film increases with increase of temperature and also the decrease of relaxation time. The temperature dependent relaxation time and ionic conductivity values of the electrolyte are governed by the Arrhenius relation. Correlation observed between dc conductivity and relaxation time confirms that ion transportation occurs with polymer chain segmental dynamics through hopping mechanism. The room temperature ionic conductivity is found to be 4 × 10-6 S cm-1 which suggests the suitability of the SPE film for rechargeable lithium batteries.

  9. New polysaccharide-based polymer electrolytes; Nouveaux electrolytes polymeres a base de polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Velasquez-Morales, P.; Le Nest, J.F.; Gandini, A. [Ecole Francaise de Papeterie et des Industries Graphique, 38 - Saint Martin d`Heres (France)

    1996-12-31

    Polysaccharides like cellulose and chitosan are known for their filmic properties. This paper concerns the synthesis and the study of chitosan-based polymer electrolytes. A preliminary work concerns the study of glucosamine reactivity. The poly-condensation of chitosan ethers (obtained by reaction with ethylene oxide or propylene oxide) with bifunctional and monofunctional oligo-ethers leads to the formation of thin lattices (10 {mu}m) having excellent mechanical properties. The presence of grafted polyether chains along the polysaccharide skeleton allows to modify the vitreous transition temperature and the molecular disorder of the system. Two type of polymer electrolytes have been synthesized: electrolytes carrying a dissolved alkaline metal salt and ionomers. The analysis of their thermal, dynamical mechanical, nuclear magnetic relaxation, electrical, and electrochemical properties shows that this new class of polymer electrolytes has the same performances as ethylene poly-oxide based amorphous lattices plus the advantage of having good filmic properties. Abstract only. (J.S.)

  10. Structuring of Interface-Modified Polymer Blends

    DEFF Research Database (Denmark)

    Lyngaae-Jørgensen, Jørgen

    1999-01-01

    The paper treats the case where blends of polystyrene (PS), poly (dimethylsiloxane) (PDMS) and a diblock copolymer of PS and PDMS are used as model materials. This modelsystem is predicted to be "stable" in discrete blends in simple shear flow. Stable in the sence that the block copolymer can not...

  11. Solid polymer electrolyte composite membrane comprising plasma etched porous support

    Science.gov (United States)

    Liu, Han; LaConti, Anthony B.

    2010-10-05

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a rigid, non-electrically-conducting support, the support preferably being a sheet of polyimide having a thickness of about 7.5 to 15 microns. The support has a plurality of cylindrical pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores, which preferably have a diameter of about 0.1 to 5 microns, are made by plasma etching and preferably are arranged in a defined pattern, for example, with fewer pores located in areas of high membrane stress and more pores located in areas of low membrane stress. The pores are filled with a first solid polymer electrolyte, such as a perfluorosulfonic acid (PFSA) polymer. A second solid polymer electrolyte, which may be the same as or different than the first solid polymer electrolyte, may be deposited over the top and/or bottom of the first solid polymer electrolyte.

  12. Compatibilizing Bulk Polymer Blends by using Organoclays

    Energy Technology Data Exchange (ETDEWEB)

    Si, Mayu; Araki, Tohru; Ade, Harald; Kilcoyne, A.L.D.; Fischer,Robert; Sokolov, Jonathan C.; Rafailovich, Miriam H.

    2006-03-28

    We have studied the morphology of blends of PS/PMMA,PC/SAN24, and PMMA/EVA and compared the morphologies with and withoutmodified organoclay Cloisite 20A or Cloisite 6A clays. In each case wefound a large reduction in domains size and the localization of the clayplatelets along the interfaces of the components. The increasedmiscibility was accompanied in some cases, with the reduction of thesystem from multiple values of the glass transition temperatures to one.In addition, the modulus of all the systems increased significantly. Amodel was proposed where it was proposed that in-situ grafts were formingon the clay surfaces during blending and the grafts then had to belocalized at the interfaces. This blending mechanism reflects thecomposition of the blend and is fairly nonspecific. As a result, this maybe a promising technology for use in processing recycled blends where thecomposition is often uncertain and price is of generalconcern.

  13. Development and Characterization of Temperature-resistant Polymer Electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Hjuler, Hans Aage; Bjerrum, Niels

    1999-01-01

    Acid-doped PBI polymer electrolyte membranes have been developed and characterized for fuel cell applications at temperatures up to 200°C. Electric conductivity as high as 0.13 S/cm is obtained at 160°C at high doping levels. The water osmotic drag coefficient of the polymer electrolyte is found...... to be virtually zero, which allows a fuel cell to operate with no external humidification. At operational temperatures up to 200°C, a fuel cell based on this polymer membrane exhibits promising performance....

  14. Modeling of ionic transport in solid polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Cheang, P L; Teo, L L; Lim, T L, E-mail: plcheang@mmu.edu.my [Centre for Foundation Studies and Extension Education, Multimedia University, Jln Ayer Keroh Lama, 75450 Melaka (Malaysia)

    2010-05-15

    A Monte Carlo model describing the ionic trans port in solid polyme relectrolyte is developed. Single cation simulation is carried out using hopping rate to study the transport mechanism of a thermally activated ion in solid polymer electrolyte. In our model, the ion is able to hop along a polymer chain and to jump between different chains, surmounting energy barriers that consist of polymer's activation energy and the externally applied electric field. The model is able to trace the motion of ion across polymer electrolyte. The mean hopping distance is calculated based on the available open bond in the next nearest side. Random numbers are used to determine the hopping distances, free flight times, final energy and direction of the cation after successful hop. Drift velocity and energy of cation are simulated in our work. The model is expected to be able to simulate the lithium-polymer battery in future.

  15. A novel high-performance gel polymer electrolyte membrane basing on electrospinning technique for lithium rechargeable batteries

    Science.gov (United States)

    Wu, Na; Cao, Qi; Wang, Xianyou; Li, Xiaoyun; Deng, Huayang

    2011-10-01

    Nonwoven films of composites of thermoplastic polyurethane (TPU) with different proportion of poly(vinylidene fluoride) (PVdF) (80, 50 and 20%, w/w) are prepared by electrospinning 9 wt% polymer solution at room temperature. Then the gel polymer electrolytes (GPEs) are prepared by soaking the electrospun TPU-PVdF blending membranes in 1 M LiClO4/ethylene carbonate (EC)/propylene carbonate (PC) for 1 h. The gel polymer electrolyte (GPE) shows a maximum ionic conductivity of 3.2 × 10-3 S cm-1 at room temperature and electrochemical stability up to 5.0 V versus Li+/Li for the 50:50 blend ratio of TPU:PVdF system. At the first cycle, it shows a first charge-discharge capacity of 168.9 mAh g-1 when the gel polymer electrolyte (GPE) is evaluated in a Li/PE/lithium iron phosphate (LiFePO4) cell at 0.1 C-rate at 25 °C. TPU-PVdF (50:50, w/w) based gel polymer electrolyte is observed much more suitable than the composite films with other ratios for high-performance lithium rechargeable batteries.

  16. Molecular motion in polymer electrolytes. An investigation of methods for improving the conductivity of solid polymer electrolytes

    CERN Document Server

    Webster, M I

    2002-01-01

    Three methods were explored with a view to enhancing the ionic conductivity of polymer electrolytes; namely the addition of an inert, inorganic filler, the addition of a plasticizer and the incorporation of the electrolyte in the pores of silica matrices. There have been a number of reports, which suggest the addition of nanocrystalline oxides to polymer electrolytes increases the ionic conductivities by about a factor of two. In this thesis studies of the polymer electrolyte NaSCN.P(EO) sub 8 with added nanocrystalline alumina powder are reported which show no evidence of enhanced conductivity. The addition of a plasticizer to polymer electrolytes will increase the ionic conductivity. A detailed study was made of the polymer electrolytes LiT.P(EO) sub 1 sub 0 and LiClO sub 4.P(EO) sub 1 sub 0 with added ethylene carbonate plasticizer. The conductivities showed an enhancement, however this disappeared on heating under vacuum. The present work suggests that the plasticised system is not thermodynamically stabl...

  17. Comparing proton conductivity of polymer electrolytes by percent conducting volume

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yu Seung [Los Alamos National Laboratory; Pivovar, Bryan [NREL

    2009-01-01

    Proton conductivity of sulfonated polymers plays a key role in polymer electrolyte membrane fuel cells. Mass based water uptake and ion exchange capacity of sulfonated polymers have been failed to correlating their proton conductivity. In this paper, we report a length scale parameter, percent conductivity volume, which is rather simply obtained from the chemical structure of polymer to compare proton conductivity of wholly aromatic sulfonated polymer perflurosulfonic acid. Morphology effect on proton conductivity at lower RH conditions is discussed using the percent conductivity volume parameter.

  18. Electrospinning polymer blends for biomimetic scaffolds for ACL tissue engineering

    Science.gov (United States)

    Garcia, Vanessa Lizeth

    The anterior cruciate ligament (ACL) rupture is one of the most common knee injuries. Current ACL reconstructive strategies consist of using an autograft or an allograft to replace the ligament. However, limitations have led researchers to create tissue engineered grafts, known as scaffolds, through electrospinning. Scaffolds made of natural and synthetic polymer blends have the potential to promote cell adhesion while having strong mechanical properties. However, enzymes found in the knee are known to degrade tissues and affect the healing of intra-articular injuries. Results suggest that the natural polymers used in this study modify the thermal properties and tensile strength of the synthetic polymers when blended. Scanning electron microscopy display bead-free and enzyme biodegradability of the fibers. Raman spectroscopy confirms the presence of the natural and synthetic polymers in the scaffolds while, amino acid analysis present the types of amino acids and their concentrations found in the natural polymers.

  19. Clay platelet partition within polymer blend nanocomposite films by EFTEM.

    Science.gov (United States)

    Linares, Elisângela M; Rippel, Márcia M; Galembeck, Fernando

    2010-12-01

    Transmission electron microscopy (TEM) is the main technique used to investigate the spatial distribution of clay platelets in polymer nanocomposites, but it has not often been successfully used in polymer blend nanocomposites because the high contrast between polymer phases impairs the observation of clay platelets. This work shows that electron spectral imaging in energy-filtered TEM (EFTEM) in the low-energy-loss spectral crossover region allows the observation of platelets on a clear background. Separate polymer domains are discerned by imaging at different energy losses, above and below the crossover energy, revealing the material morphology. Three blends (natural rubber [NR]/poly(styrene-butyl acrylate) [P(S-BA)], P(S-BA)/poly(vinyl chloride) [PVC], and NR/starch) were studied in this work, showing low contrast between the polymer phases in the 40-60 eV range. In the NR/P(S-BA) and P(S-BA)/PVC blend nanocomposites, the clay platelets accumulate in the P(S-BA) phase, while in the P(S-BA)/PVC nanocomposites, clay is also found at the interfaces. In the NR/starch blend, clay concentrates at the interface, but it also penetrates the two polymer phases. These observations reveal that nanostructured soft materials can display complex morphochemical patterns that are discerned thanks to the ability of EFTEM to produce many contrast patterns for the same sample.

  20. A rheological study of behavior of polymer-bitumen blends

    Energy Technology Data Exchange (ETDEWEB)

    Djonlagic, J. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy; Dunjic, B. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy; Javanovic, J.A. [Belgrade Univ. (Yugoslavia). Faculty of Technology and Metallurgy

    1996-12-01

    The influence of the elastomer such as SBS and SBR and their mixtures on the structure and rheological properties of blown bitumen B 65 blends, was studied. The crude oil denoted as SEB (Soviet Export Blend) was used to obtain the B 65 sample. (orig./HS) [Deutsch] Es wurde die Wirkung der SBR- und SBS-Elastomere und ihrer Mischungen, auf die Struktur und die rheologischen Eigenschaften des aus geblasenem Bitumen B 65 hergestellten Polymer-Bitumens (PmB), untersucht. Die B 65 Probe stammte aus dem Erdoel SEB (Soviet Export Blend). (orig./HS)

  1. Alkaline polymer electrolyte fuel cells: Principle, challenges, and recent progress

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Polymer electrolyte membrane fuel cells (PEMFC) have been recognized as a significant power source in future energy systems based on hydrogen. The current PEMFC technology features the employment of acidic polymer electrolytes which, albeit superior to electrolyte solutions, have intrinsically limited the catalysts to noble metals, fundamentally preventing PEMFC from widespread deployment. An effective solution to this problem is to develop fuel cells based on alkaline polymer electrolytes (APEFC), which not only enable the use of non-precious metal catalysts but also avoid the carbonate-precipitate issue which has been troubling the conventional alkaline fuel cells (AFC). This feature article introduces the principle of APEFC, the challenges, and our research progress, and focuses on strategies for developing key materials, including high-performance alkaline polyelectrolytes and stable non-precious metal catalysts. For alkaline polymer electrolytes, high ionic conductivity and satisfactory mechanical property are difficult to be balanced, therefore polymer cross-linking is an ultimate strategy. For non-precious metal catalysts, it is urgent to improve the catalytic activity and stability. New materials, such as transition-metal complexes, nitrogen-doped carbon nanotubes, and metal carbides, would become applicable in APEFC.

  2. Advanced Polymer Electrolytes for High-energy-density Power Sources

    Institute of Scientific and Technical Information of China (English)

    D. Golodnitsky; E. Livshits; R. Kovarsky; E. Peled

    2005-01-01

    @@ 1Introduction The preparation of highly controlled thin films of lithium ion conducting organic materials is becoming a challenging but rewarding goal in view of obtaining high-performance technological devices like solid-state polymer batteries and capacitors. The classical polymer electrolyte consists of organic macromolecules (usually polyether polymer) that are doped with inorganic (typically lithium) salts. Poly(ethylene oxide) (PEO) is the most commonly employed polymer in PEs because of the peculiar array in the (-CH2-CH2-O-)n chain providing the ability to solvate low-lattice-energy lithium salts. For three decades the major research attention was focused on amorphous polymer electrolytes in the belief that ionic conductivity occurs in a manner somewhat analogous to gas diffusion through polymer membranes. Segmental motion of the polymer chains continuously creates free volume, into which the ions migrate, and this process allows ions to progress across the electrolyte. Such a view was established by a number of experiments, and denied the possibility of ionic conductivity in crystalline polymer phases. This concept has been recently overturned by our group, demonstrating that conductivity comes about as a result of permanent conducting pathways for the movement of ions.

  3. Composite Polymer Electrolytes: Nanoparticles Affect Structure and Properties

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-11-01

    Full Text Available Composite polymer electrolytes (CPEs can significantly improve the performance in electrochemical devices such as lithium-ion batteries. This review summarizes property/performance relationships in the case where nanoparticles are introduced to polymer electrolytes. It is the aim of this review to provide a knowledge network that elucidates the role of nano-additives in the CPEs. Central to the discussion is the impact on the CPE performance of properties such as crystalline/amorphous structure, dielectric behavior, and interactions within the CPE. The amorphous domains of semi-crystalline polymer facilitate the ion transport, while an enhanced mobility of polymer chains contributes to high ionic conductivity. Dielectric properties reflect the relaxation behavior of polymer chains as an important factor in ion conduction. Further, the dielectric constant (ε determines the capability of the polymer to dissolve salt. The atom/ion/nanoparticle interactions within CPEs suggest ways to enhance the CPE conductivity by generating more free lithium ions. Certain properties can be improved simultaneously by nanoparticle addition in order to optimize the overall performance of the electrolyte. The effects of nano-additives on thermal and mechanical properties of CPEs are also presented in order to evaluate the electrolyte competence for lithium-ion battery applications.

  4. Compatibilization of All-Conjugated Polymer Blends for Organic Photovoltaics.

    Science.gov (United States)

    Lombeck, Florian; Sepe, Alessandro; Thomann, Ralf; Friend, Richard H; Sommer, Michael

    2016-08-23

    Compatibilization of an immiscible binary blend comprising a conjugated electron donor and a conjugated electron acceptor polymer with suitable electronic properties upon addition of a block copolymer (BCP) composed of the same building blocks is demonstrated. Efficient compatibilization during melt-annealing is feasible when the two polymers are immiscible in the melt, i.e. above the melting point of ∼250 °C of the semicrystalline donor polymer P3HT. To generate immiscibility at these high temperatures, the acceptor polymer PCDTBT is equipped with fluorinated side chains leading to an increased Flory-Huggins interaction parameter. Compatibilization in bulk and thin films is demonstrated, showing that the photovoltaic performance of pristine microphase separated and nanostructured BCPs can also be obtained for compatibilized blend films containing low contents of 10-20 wt % BCP. Thermodynamically stable domain sizes range between several tens of microns for pure blends and ∼10 nm for pure block copolymers. In addition to controlling domain size, the amount of block copolymer added dictates the ratio of edge-on and face-on P3HT crystals, with compatibilized films showing an increasing amount of face-on P3HT crystals with increasing amount of compatibilizer. This study demonstrates the prerequisites and benefits of compatibilizing all-conjugated semicrystalline polymer blends for organic photovoltaics.

  5. Hybrid materials and polymer electrolytes for electrochromic device applications.

    Science.gov (United States)

    Thakur, Vijay Kumar; Ding, Guoqiang; Ma, Jan; Lee, Pooi See; Lu, Xuehong

    2012-08-08

    Electrochromic (EC) materials and polymer electrolytes are the most imperative and active components in an electrochromic device (ECD). EC materials are able to reversibly change their light absorption properties in a certain wavelength range via redox reactions stimulated by low direct current (dc) potentials of the order of a fraction of volts to a few volts. The redox switching may result in a change in color of the EC materials owing to the generation of new or changes in absorption band in visible region, infrared or even microwave region. In ECDs the electrochromic layers need to be incorporated with supportive components such as electrical contacts and ion conducting electrolytes. The electrolytes play an indispensable role as the prime ionic conduction medium between the electrodes of the EC materials. The expected applications of the electrochromism in numerous fields such as reflective-type display and smart windows/mirrors make these materials of prime importance. In this article we have reviewed several examples from our research work as well as from other researchers' work, describing the recent advancements on the materials that exhibit visible electrochromism and polymer electrolytes for electrochromic devices. The first part of the review is centered on nanostructured inorganic and conjugated polymer-based organic-inorganic hybrid EC materials. The emphasis has been to correlate the structures, morphologies and interfacial interactions of the EC materials to their electronic and ionic properties that influence the EC properties with unique advantages. The second part illustrates the perspectives of polymer electrolytes in electrochromic applications with emphasis on poly (ethylene oxide) (PEO), poly (methyl methacrylate) (PMMA) and polyvinylidene difluoride (PVDF) based polymer electrolytes. The requirements and approaches to optimize the formulation of electrolytes for feasible electrochromic devices have been delineated.

  6. Conductivity and Dielectric Studies of Lithium Trifluoromethanesulfonate Doped Polyethylene Oxide-Graphene Oxide Blend Based Electrolytes

    OpenAIRE

    Azli, A. A.; N. S. A. Manan; M. F. Z. Kadir

    2015-01-01

    Series of polymer blend consisting of polyethylene oxide (PEO) and graphene oxide (GO) as co-host polymer were prepared using solution cast method. The most amorphous PEO-GO blend was obtained using 90 wt.% of PEO and 10 wt.% of GO as recorded by X-ray diffraction (XRD). Fourier transform infrared spectroscopy (FTIR) analysis proved the interaction between PEO, GO, lithium trifluoromethanesulfonate (LiCF3SO3), and ethylene sulfite (ES). Incorporation of 25 wt.% LiCF3SO3 into the PEO-GO blend ...

  7. Interdiffusion and Spinodal Decomposition in Electrically Conducting Polymer Blends

    Directory of Open Access Journals (Sweden)

    Antti Takala

    2015-08-01

    Full Text Available The impact of phase morphology in electrically conducting polymer composites has become essential for the efficiency of the various functional applications, in which the continuity of the electroactive paths in multicomponent systems is essential. For instance in bulk heterojunction organic solar cells, where the light-induced electron transfer through photon absorption creating excitons (electron-hole pairs, the control of diffusion of the spatially localized excitons and their dissociation at the interface and the effective collection of holes and electrons, all depend on the surface area, domain sizes, and connectivity in these organic semiconductor blends. We have used a model semiconductor polymer blend with defined miscibility to investigate the phase separation kinetics and the formation of connected pathways. Temperature jump experiments were applied from a miscible region of semiconducting poly(alkylthiophene (PAT blends with ethylenevinylacetate-elastomers (EVA and the kinetics at the early stages of phase separation were evaluated in order to establish bicontinuous phase morphology via spinodal decomposition. The diffusion in the blend was followed by two methods: first during a miscible phase separating into two phases: from the measurement of the spinodal decomposition. Secondly the diffusion was measured by monitoring the interdiffusion of PAT film into the EVA film at elected temperatures and eventually compared the temperature dependent diffusion characteristics. With this first quantitative evaluation of the spinodal decomposition as well as the interdiffusion in conducting polymer blends, we show that a systematic control of the phase separation kinetics in a polymer blend with one of the components being electrically conducting polymer can be used to optimize the morphology.

  8. PEO nanocomposite polymer electrolyte for solid state symmetric capacitors

    Indian Academy of Sciences (India)

    Nirbhay K Singh; Mohan L Verma; Manickam Minakshi

    2015-10-01

    Physical and electrochemical properties of polyethylene oxide (PEO)-based nanocomposite solid polymer electrolytes (NPEs) were investigated for symmetric capacitor applications. Nanosize fillers, i.e., Al2O3 and SiO2 incorporated polymer electrolyte exhibited higher ionic conductivity than those with filler-free composites. The composites have been synthesized by the completely dry (solution-free) hot-press method. The addition of filler in fractional amount to the solid polymer matrix at room temperature further enhances the ionic conductivity. Nature of the NPEs were studied using X-ray diffraction and energy-dispersive spectra analyses. Thermal stability of the resulting electrolyte was analysed by thermogravimetric analysis and differential scanning calorimetric studies. Morphology changes occurred during the addition of fillers was evidenced by scanning electronic microscope images. Solid polymer electrolytes exhibiting these parameters was found to be suitable for solid state capacitors. The results obtained from the electrolytes with an optimum compositions (PEO70AgI30)93 (Al2O3)7 and (PEO70AgI30)95 (SiO2)5 used in the (PEO70AgI30)70 (AC)30 electrodes for symmetric capacitor applications and their performances were analysed by impedance spectroscopic, Bode plot, cyclic voltammetry, discharge characteristics and leakage current profile.

  9. Mechanisms of proton conductance in polymer electrolyte membranes

    DEFF Research Database (Denmark)

    Eikerling, M.; Kornyshev, A. A.; Kuznetsov, A. M.

    2001-01-01

    We provide a phenomenological description of proton conductance in polymer electrolyte membranes, based on contemporary views of proton transfer processes in condensed media and a model for heterogeneous polymer electrolyte membrane structure. The description combines the proton transfer events...... in a single pore with the total pore-network performance and, thereby, relates structural and kinetic characteristics of the membrane. The theory addresses specific experimentally studied issues such as the effect of the density of proton localization sites (equivalent weight) of the membrane material...

  10. Morphology of Polyvinylidene Fluoride Based Gel Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    田立颖; 黄小彬; 唐小真

    2004-01-01

    Two series of polyvinylidene fluoride (PVDF) based gel polymer electrolytes, with different LiClO4 or propylene carbonate (PC) content, were prepared and analyzed by infrared spectrometer, differential scanning calorimetry, scanning electron microscope and complex impedance spectrometer. The results show that there are great interactions between PVDF, PC and lithium cations. Both LiClO4 and PC content lead to evident change of the morphology of the gel polymer electrolytes. The content of LiClO4 and PC also influences the ionic conductivity of the samples,and an ionic conductivity of above 10-3S·cm-1 can be reached at room temperature.

  11. Solid Polymer Electrolyte (SPE) fuel cell technology program

    Science.gov (United States)

    1979-01-01

    The overall objectives of the Phase IV Solid Polymer Electrolyte Fuel Cell Technology Program were to: (1) establish fuel cell life and performance at temperatures, pressures and current densities significantly higher than those previously demonstrated; (2) provide the ground work for a space energy storage system based on the solid polymer electrolyte technology (i.e., regenerative H2/O2 fuel cell); (3) design, fabricate and test evaluate a full-scale single cell unit. During this phase, significant progress was made toward the accomplishment of these objectives.

  12. High temperature lithium cells with solid polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jin; Eitouni, Hany Basam; Singh, Mohit

    2017-03-07

    Electrochemical cells that use electrolytes made from new polymer compositions based on poly(2,6-dimethyl-1,4-phenylene oxide) and other high-softening-temperature polymers are disclosed. These materials have a microphase domain structure that has an ionically-conductive phase and a phase with good mechanical strength and a high softening temperature. In one arrangement, the structural block has a softening temperature of about 210.degree. C. These materials can be made with either homopolymers or with block copolymers. Such electrochemical cells can operate safely at higher temperatures than have been possible before, especially in lithium cells. The ionic conductivity of the electrolytes increases with increasing temperature.

  13. Investigation on poly (vinylidene fluoride) based gel polymer electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; P Sivakumar; Ravi Shanker Babu

    2006-12-01

    An investigation is carried out on gel polymer electrolytes consisting of poly (vinylidene fluoride) (PVdF) as a host polymer, lithium perchlorate (LiClO4), lithium triflate (LiCF3SO3) as salts and mixture of ethylene carbonate (EC) and propylene carbonate (PC) as plasticizers. Polymer thin films were prepared by solvent casting technique and the obtained films were subjected to different characterizations, to confirm their structure, complexation and thermal changes. X-ray diffraction revealed that the salts and plasticizers disrupted the crystalline nature of PVdF based polymer electrolytes and converted them into an amorphous phase. TG/DTA studies showed the thermal stability of the polymer electrolytes. The role of interaction between polymer hosts on conductivity is discussed using the results of a.c. impedance studies. Room temperature (28°C) conductivity of 2.786 × 10-3 Scm-1 was observed in PVdF (24)–EC/PC (68)–LiCF3SO3 (2)/LiClO4 (6) polymer system.

  14. Electrospun nanocomposite fibrous polymer electrolyte for secondary lithium battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Padmaraj, O.; Rao, B. Nageswara; Jena, Paramananda; Satyanarayana, N., E-mail: nallanis2011@gmail.com [Department of Physics, Pondicherry University, Pondicherry-605014 (India); Venkateswarlu, M. [R and D, Amaraja batteries, Thirupathi-517501 (India)

    2014-04-24

    Hybrid nanocomposite [poly(vinylidene fluoride -co- hexafluoropropylene) (PVdF-co-HFP)/magnesium aluminate (MgAl{sub 2}O{sub 4})] fibrous polymer membranes were prepared by electrospinning method. The prepared pure and nanocomposite fibrous polymer electrolyte membranes were soaked into the liquid electrolyte 1M LiPF{sub 6} in EC: DEC (1:1,v/v). XRD and SEM are used to study the structural and morphological studies of nanocomposite electrospun fibrous polymer membranes. The nanocomposite fibrous polymer electrolyte membrane with 5 wt.% of MgAl{sub 2}O{sub 4} exhibits high ionic conductivity of 2.80 × 10{sup −3} S/cm at room temperature. The charge-discharge capacity of Li/LiCoO{sub 2} coin cells composed of the newly prepared nanocomposite [(16 wt.%) PVdF-co-HFP+(5 wt.%) MgAl{sub 2}O{sub 4}] fibrous polymer electrolyte membrane was also studied and compared with commercial Celgard separator.

  15. PREPARATION OF CARBON NANOFIBERS BY POLYMER BLEND TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.

  16. Novel Elastomeric Membranes Developed for Polymer Electrolytes in Lithium Batteries

    Science.gov (United States)

    Tigelaar, Dean M.; Meador, Maryann B.; Kinder, James D.; Bennett, William R.

    2005-01-01

    Lithium-based polymer batteries for aerospace applications need to be highly conductive from -70 to 70 C. State-of-the-art polymer electrolytes are based on polyethylene oxide (PEO) because of the ability of its ether linkages to solvate lithium ions. Unfortunately, PEO has a tendency to form crystalline regions below 60 C, dramatically lowering conductivity below this temperature. PEO has acceptable ionic conductivities (10(exp -4) to 10(exp -3) S/cm) above 60 C, but it is not mechanically strong. The room-temperature conductivity of PEO can be increased by adding solvent or plasticizers, but this comes at the expense of thermal and mechanical stability. One of NASA Glenn Research Center s objectives in the Polymer Rechargeable System program (PERS) is to develop novel polymer electrolytes that are highly conductive at and below room temperature without added solvents or plasticizers.

  17. Ionic conductivity in the polymer electrolytes PEO/CF{sub 3}COONa

    Energy Technology Data Exchange (ETDEWEB)

    Delgado, I.; Chacon, M.; Vargas, R.A. [Valle Univ., Cali (Colombia). Dept. de Fisica; Castillo, J. [Ingenieria Electronica, Univ. del Quindio, Armenia (Colombia)

    2000-07-01

    In the present work, the electrical and thermal characterization of polymer electrolytes based on PEO/CF{sub 3}COONa are reported, which turn out to be good ionic conductors near room temperature (of the order 10{sup -4} {omega}{sup -1} cm{sup -1} for high salt concentrations). The variation of conductivity with temperature (plotted as ln {sigma} versus 1/T) and salt concentration suggests a complex formation. This is confirmed by differential scanning calorimetry (DSC), which also indicates that the blends are thermally stable up to approximately 480 K. The high conductivity and the single-phase behavior of the blends are explained in terms of the plastification effect of the organic salt on the PEO. (orig.)

  18. Novel bio-based and biodegradable polymer blends

    Science.gov (United States)

    Yang, Shengzhe

    Most plastic materials, including high performance thermoplastics and thermosets are produced entirely from petroleum-based products. The volatility of the natural oil markets and the increasing cost of petroleum have led to a push to reduce the dependence on petroleum products. Together with an increase in environmental awareness, this has promoted the use of alternative, biorenewable, environmentally-friendly products, such as biomass. The growing interest in replacing petroleum-based products by inexpensive, renewable, natural materials is important for sustainable development into the future and will have a significant impact on the polymer industry and the environment. This thesis involved characterization and development of two series of novel bio-based polymer blends, namely polyhydroxyalkanoate (PHA)/polyamide (PA) and poly(lactic acid) (PLA)/soy protein. Blends with different concentrations and compatible microstructures were prepared using twin-screw extruder. For PHA/PA blends, the poor mechanical properties of PHA improved significantly with an excellent combination of strength, stiffness and toughness by adding PA. Furthermore, the effect of blending on the viscoelastic properties has been investigated using small-amplitude oscillatory shear flow experiments as a function of blend composition and angular frequency. The elastic shear modulus (G‧) and complex viscosity of the blends increased significantly with increasing the concentration of PHA. Blending PLA with soy protein aims at reducing production cost, as well as accelerating the biodegradation rate in soil medium. In this work, the mechanical, thermal and morphological properties of the blends were investigated using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and tensile tests.

  19. Electrostatic model of semiconductor nanoparticles trapped in polymer electrolytes

    Indian Academy of Sciences (India)

    Divya Singh; Pramod K Singh; Nitin A Jadhav; Bhaskar Bhattacharya

    2013-11-01

    A simple electrostatic model is applied to study the solvation energy and localization energy to inorganic semiconductor nanocrystallites trapped in polymer and ion conducting polymer electrolytes. The effective mass approximation has been applied to the system. In the single charge configuration, the dielectric constant of the medium has been identified as the selection criteria for hosting the nanoparticles. Solvation energy has been shown to depend on the host medium and the size of the crystallite.

  20. Ionic transport in P(VdF–HFP)–PEO based novel microporous polymer electrolytes

    Indian Academy of Sciences (India)

    M Deka; A Kumar

    2009-12-01

    A novel microporous polymer electrolyte (MPE) comprising blends of poly(vinylidene fluoride-cohexafluoropropylene) [P(VdF–HFP)] and polyethylene oxide (PEO) was prepared by phase inversion technique. It was observed that addition of PEO improved the pore configuration, such as pore size, pore connectivity and porosity of P(VdF–HFP) based membranes. The room temperature ionic conductivity was significantly enhanced. The highest porosity of about 65% and ionic conductivity of about 7 × 10-4 S cm-1 was obtained when the weight ratio of PEO was 40%. The liquid electrolyte uptake was found to increase with increase in porosity and pore size. However, at higher weight ratio of PEO (> 40%) porosity, pore size and ionic conductivity was decreased. This descending trend with further increase of PEO weight ratio was attributed to conglomeration effect of PEO at the pores.

  1. Electrospun PVDF nanofiber web as polymer electrolyte or separator

    Energy Technology Data Exchange (ETDEWEB)

    Sung-Seen Choi [Sejong University, Seoul (Korea). College of Natural Sciences, Department of Applied Chemistry; Young Soo Lee; Chang Whan Joo; Seung Goo Lee [Chungnam National University, Daejeon (Korea). Department of Textile Engineering; Jong Kyoo Park; Kyoo-Seung Han [Chungnam National University, Daejeon (Korea). Department of Fine Chemicals Engineering and Chemistry

    2004-11-30

    Electrospinning is an useful technique to produce nanofiber webs. Since electrospun nanofiber webs have a nanoporous structure, they have a potential application for a polymer electrolyte or a separator. Poly(vinylidene fluoride) (PVDF) is used as one of polymer electrolyte binders. We studied application of electrospun PVDF nanofiber webs as an electrolyte binder or a separator for a battery. Diameters of the electrospun PVDF nanofibers were 100-800 nm. The electrospun PVDF nanofiber web was thermally treated at 150-160 {sup o}C to improve the physical property and dimensional stability. The tensile strength and elongation at break as well as the tensile modulus were notably improved by the thermal treatment. Level of crystallinity of the electrospun PVDF nanofiber was increased by the thermal treatment. The ion conductivity of the polymer electrolyte formed from the electrospun PVDF nanofiber web and 1 M LiN(CF{sub 3}SO{sub 2}){sub 2} electrolyte solution was 1.6-2.0 x 10{sup -3} S/cm. The electrospun PVDF nanofiber mat was treated with ethylene plasma to use as a separator. The ethylene plasma-treated mat showed a role of shutter by melting the polyethylene (PE) layer grafted on the PVDF nanofibers. (author)

  2. Inkjet printed organic electrochemical transistors with highly conducting polymer electrolytes

    Science.gov (United States)

    Afonso, Mónica; Morgado, Jorge; Alcácer, Luís

    2016-10-01

    Organic Electrochemical Transistors (OECTs) were fabricated with two kinds of highly conducting polymer electrolytes, one with cations of small dimensions (Li+) and the other with cations of large dimensions (1-ethyl-3-methylimidazolium, EMI+). All OECTs exhibit transconductance values in the millisiemens range. Those with the larger EMI+ cations reach higher transconductance values and the saturated region of their I(V) characteristics extends to drain negative voltages of the order of -2 V without breakdown. These OECTs aim at potential applications for which it is relevant to use a solid polymer electrolyte instead of an aqueous electrolyte, namely, for integration in complex devices or in sensors and transducers where the electrolyte film may act as a membrane to prevent direct contact of the active material (PEDOT:PSS) with the biological media. The choice of electrolytes with cations of disparate sizes aims at assessing the nature (Faradaic or capacitive) of the processes occurring at the electrolyte/channel interface. The results obtained are consistent with a Faradaic-based operation mechanism.

  3. Genistein Modified Polymer Blends for Hemodialysis Membranes

    Science.gov (United States)

    Chang, Teng; Kyu, Thein; Define, Linda; Alexander, Thomas

    2012-02-01

    A soybean-derived phytochemical called genistein was used as a modifying agent to polyether sulfone/polyvinyl pyrrolidone (PES/PVP) blends to produce multi-functional hemodialysis membranes. With the aid of phase diagrams of PES/PVP/genistein blends, asymmetric porous membranes were fabricated by coagulating in non-solvent. Both unmodified and genistein modified PES/PVP membranes were shown to be non-cytotoxic to the blood cells. Unmodified PES/PVP membranes were found to reduce reactive oxygen species (ROS) levels, whereas the genistein modified membranes exhibited suppression for ˜60% of the ROS levels. Also, the genistein modified membranes revealed significant suppression of pro-inflammatory cytokines: IL-1β, IL-6, and TNF-α. Moreover, addition of PVP to PES showed the reduced trend of platelet adhesion and then leveled off. However, the modified membranes exhibited suppression of platelet adhesion at low genistein loading, but beyond 15 wt%, the platelet adhesion level rised up.

  4. Toughness of membranes applied in polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kiefer, J.; Brack, H.P.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

  5. Design of Hybrid Solid Polymer Electrolytes: Structure and Properties

    Science.gov (United States)

    Bronstein, Lyudmila M.; Karlinsey, Robert L.; Ritter, Kyle; Joo, Chan Gyu; Stein, Barry; Zwanziger, Josef W.

    2003-01-01

    This paper reports synthesis, structure, and properties of novel hybrid solid polymer electrolytes (SPE's) consisting of organically modified aluminosilica (OM-ALSi), formed within a poly(ethylene oxide)-in-salt (Li triflate) phase. To alter the structure and properties we fused functionalized silanes containing poly(ethylene oxide) (PEO) tails or CN groups.

  6. Novel Ceramic Materials for Polymer Electrolyte Membrane Water Electrolysers' Anodes

    DEFF Research Database (Denmark)

    Polonsky, J.; Bouzek, K.; Prag, Carsten Brorson

    2012-01-01

    Tantalum carbide was evaluated as a possible new support for the IrO2 for use in anodes of polymer electrolyte membrane water electrolysers. A series of supported electrocatalysts varying in mass content of iridium oxide was prepared. XRD, powder conductivity measurements and cyclic and linear sw...

  7. Synthesis and properties of aromatic polyethers containing poly(ethylene oxide) side chains as polymer electrolytes for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Vöge, Andrea, E-mail: andreavoege@online.de [Department of Chemistry, University of Patras, 26500 Patras (Greece); Deimede, Valadoula, E-mail: deimede@upatras.gr [Department of Chemistry, University of Patras, 26500 Patras (Greece); Paloukis, Fotis; Neophytides, Stylianos G. [Foundation of Research and Technology – Hellas, Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Patras 26504 (Greece); Kallitsis, Joannis K. [Department of Chemistry, University of Patras, 26500 Patras (Greece)

    2014-11-14

    Polymer electrolytes consisting of polar pyridine units in the backbone and poly(ethylene oxide) (PEO) side chains are designed for possible application in lithium ion batteries. In particular, aromatic polyethers bearing PEO side chains with varying length are synthesized either by copolymerization of the corresponding PEO based diols with different arylfluorides or by modification of dihydroxyl functionalized precursor polymers with poly(ethylene oxide) methyl ether tosylate. The formation of free standing films is dependent on the PEO content, polymers' composition as well as on the different monomers used. The mechanical properties study shows that the glass transition temperature can be controlled by varying the PEO content. Thermal stability is also influenced by the PEO length: the shorter the PEO side chain, the higher the stability. XRD analysis gives information about the desired amorphous character of these polymers, which is independent of the PEO content. Solid polymer electrolytes prepared by blending the PEO-based polymers with lithium salt and PEO 2000 (used as plasticizer) show ambient temperature conductivities in the range of 10{sup −6} S/cm. To further improve conductivity doping of PEO-based polymers in liquid electrolyte (1 M LiPF{sub 6} in EC/DMC 1/1) in some cases results in high conductivities in the range of 10{sup −3} S cm{sup −1} at 80 °C. - Highlights: • Polymer electrolytes bearing PEO side chains of varying lengths were designed. • DMA and TGA show that T{sub g} and T{sub d} can be controlled by varying the PEO content. • XRD confirms polymers amorphous character, independent of the PEO content. • Membranes doped in liquid electrolyte have high conductivities (10{sup −3} S cm{sup −1}, 80 °C)

  8. A new nanocomposite polymer electrolyte based on poly(vinyl alcohol) incorporating hypergrafted nano-silica

    KAUST Repository

    Hu, Xian-Lei

    2012-01-01

    Solid-state nanocomposite polymer electrolytes based on poly(vinyl alcohol)(PVA) incorporating hyperbranched poly(amine-ester) (HBPAE) grafted nano-silica (denoted as SiO2-g-HBPAE) have been prepared and investigated. Through surface pretreatment of nanoparticles, followed by Michael-addition and a self-condensation process, hyperbranched poly(amine-ester) was directly polymerized from the surface of nano-silica. Then the hypergrafted nanoparticles were added to PVA matrix, and blended with lithium perchlorate via mold casting method to fabricate nanocomposite polymer electrolytes. By introducing hypergrafted nanoparticles, ionic conductivity of solid composite is improved significantly at the testing temperature. Hypergrafted nano-silica may act as solid plasticizer, promoting lithium salt dissociation in the matrix as well as improving segmental motion of matrix. In addition, tensile testing shows that such materials are soft and tough even at room temperature. From the dielectric spectra of nanocomposite polymer electrolyte as the function of temperature, it can be deduced that Arrhenius behavior appears depending on the content of hypergrafted nano-silica and concentration of lithium perchlorate. At a loading of 15 wt% hypergrafted nano-silica and 54 wt% lithium perchlorate, promising ionic conductivities of PVA nanocomposite polymer electrolyte are achieved, about 1.51 × 10 -4 S cm-1 at 25 °C and 1.36 × 10-3 S cm-1 at 100 °C. © The Royal Society of Chemistry.

  9. Status and applicability of solid polymer electrolyte technology to electrolytic hydrogen and oxygen production

    Science.gov (United States)

    Titterington, W. A.

    1973-01-01

    The solid polymer electrolyte (SPE) water electrolysis technology is presented as a potential energy conversion method for wind driven generator systems. Electrolysis life and performance data are presented from laboratory sized single cells (7.2 sq in active area) with high cell current density selected (1000 ASF) for normal operation.

  10. Preparation of porous, chemically cross-linked, PVdF-based gel polymer electrolytes for rechargeable lithium batteries

    Science.gov (United States)

    Cheng, C. L.; Wan, C. C.; Wang, Y. Y.

    This study reports the development of a new system of porous, chemically cross-linked, gel polymer electrolytes based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) copolymer as a polymer matrix, polyethylene glycol (PEG) as a plasticizer, and polyethylene glycol dimethacrylate (PEGDMA) as a chemical cross-linking oligomer. The electrolytes are prepared by a combination of controlled evaporation and thermal polymerization of PEGDMA. PVdF-HFP/PEG/PEGDMA gel polymer electrolytes with a composition of 5/3/2 exhibit both high ambient ionic conductivity, viz., >1 mS cm -1, and a high tensile modulus of 52 MPa, because of their porous and network structures. All the blends of electrolytes are electrochemically stable up to 5 V versus Li/Li + in the presence of 1 M LiPF 6/ethylene carbonate-diethyl carbonate (EC-DEC). With these polymer electrolytes, rechargeable lithium batteries composed of carbon anode and LiCoO 2 cathode have acceptable cycleability and a good rate capability.

  11. Predicting morphologies of solution processed polymer:fullerene blends.

    Science.gov (United States)

    Kouijzer, Sandra; Michels, Jasper J; van den Berg, Mauricio; Gevaerts, Veronique S; Turbiez, Mathieu; Wienk, Martijn M; Janssen, René A J

    2013-08-14

    The performance of solution processed polymer:fullerene thin film photovoltaic cells is largely determined by the nanoscopic and mesoscopic morphology of these blends that is formed during the drying of the layer. Although blend morphologies have been studied in detail using a variety of microscopic, spectroscopic, and scattering techniques and a large degree of control has been obtained, the current understanding of the processes involved is limited. Hence, predicting the optimized processing conditions and the corresponding device performance remains a challenge. We present an experimental and modeling study on blends of a small band gap diketopyrrolopyrrole-quinquethiophene alternating copolymer (PDPP5T) and [6,6]-phenyl-C71-butyric acid methyl ester ([70]PCBM) cast from chloroform solution. The model uses the homogeneous Flory-Huggins free energy of the multicomponent blend and accounts for interfacial interactions between (locally) separated phases, based on physical properties of the polymer, fullerene, and solvent. We show that the spinodal liquid-liquid demixing that occurs during drying is responsible for the observed morphologies. The model predicts an increasing feature size and decreasing fullerene concentration in the polymer matrix with increasing drying time in accordance with experimental observations and device performance. The results represent a first step toward a predictive model for morphology formation.

  12. Cocontinuous polymer blends: The role of block copolymer in blend morphology evolution

    Science.gov (United States)

    Bell, Joel Richard

    Cocontinuous morphologies are distinguished by the mutual interpenetration of two polymer phases and allow for enhanced mechanical properties, static charge dissipation, and barrier properties. Cocontinuous morphologies form over a range of compositions, depending largely on mixing history and the relative polymer viscosities, elasticities, and interfacial tension. Because cocontinuous morphologies are thermodynamically unstable, they will coarsen when held above their glass or melt transition temperature. Since the unique properties of these blends depend directly on the continuous nature of the microstructure and its phase size, stabilization of the cocontinuous morphology is extremely important. To address this challenge, compatibilizers, e.g. block copolymers (bcp), are often added to hinder phase coarsening in blends of immiscible polymers and can improve bonding at interfaces. The effects of bcp on the cocontinuous morphology of polystyrene (PS)/polyethylene (PE) and PS/poly(methyl methacrylate) (PMMA) blends were studied using scanning electron microscopy (SEM) with image analysis, 3D imaging, mercury porosimetry, solvent extraction, and rheology. It was shown that diblock copolymers were able to suppress coarsening during annealing in cocontinuous PS/PE and PS/PMMA blends. Bcp effectiveness was dependent on molecular weight, concentration, and architecture. Self consistent mean field theory and bending elasticity theory were used to estimate the proper bcp architecture for maximum reduction in interfacial tension; experimental results agreed well with the theory. In addition to slowing coarsening, bcp was shown to widen the range of cocontinuity for both the PS/PE and PS/PMMA systems. To aid determination of the range of cocontinuity, a new technique for analyzing SEM micrographs was developed. The new technique classifies blend morphology according to the normalized fraction of drops present in the 2D microstructure. It was found that a blend becomes

  13. Electrospun PVdF-based fibrous polymer electrolytes for lithium ion polymer batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jeong Rae Kim [Hanyang University, Seoul (France). Applied Chemical Engineering Division; Korea Institute of Science and Technology, Seoul (Korea). Polymer Hybrid Research Center; Sung Won Choi [Yonsei University, Seoul (Korea). Department of Chemistry; Seong Mu Jo; Wha Seop Lee [Korea Institute of Science and Technology, Seoul (Korea). Polymer Hybrid Research Center; Byung Chul Kim [Hanyang University, Seoul (France). Applied Chemical Engineering Division

    2004-11-15

    This paper discusses the preparation of microporous fibrous membranes from PVdF solutions with different polymer contents, using the electrospinning technique. Electrospun PVdF-based fibrous membranes with average fiber diameters (AFD's) of 0.45-1.38 {mu}m have an apparent porosity and a mean pore size (MPS) of 80-89% and 1.1-4.3 {mu}m, respectively. They exhibited a high uptake of the electrolyte solution (320-350%) and a high ionic conductivity of above 1 x 10{sup -3} s/cm at room temperature. Their ionic conductivity increased with the decrease in the AFD of the fibrous membrane due to its high electrolyte uptake. The interaction between the electrolyte molecules and the PVdF with a high crystalline content may have had a minor effect on the lithium ion transfer in the fibrous polymer electrolyte, unlike in a nanoporous gel polymer electrolyte. The fibrous polymer electrolyte that contained a 1 M LiPF{sub 6}-EC/DMC/DEC (1/1/1 by weight) solution showed a high electrochemical stability of above 5.0 V, which increased with the decrease in the AFD. The interfacial resistance (R{sub i}) between the polymer electrolyte and the lithium electrode slightly increased with the storage time, compared with the higher increase in the interfacial resistance of other gel polymer electrolytes. The prototype cell (MCMB/PVdF-based fibrous electrolyte/LiCoO{sub 2}) showed a very stable charge-discharge behavior with a slight capacity loss under constant current and voltage conditions at the C/2-rate of 20 and 60 {sup o}C. (author)

  14. Electrospun PVdF-based fibrous polymer electrolytes for lithium ion polymer batteries

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Rae [Applied Chemical Engineering Division, Hanyang University, 17, Haengdang-dong, Seongdong-Ku, Seoul 133-791 (Korea, Republic of); Polymer Hybrid Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Choi, Sung Won [Department of Chemistry, Yonsei University, 134, Sinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Polymer Hybrid Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Jo, Seong Mu [Polymer Hybrid Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)]. E-mail: smjo@kist.re.kr; Lee, Wha Seop [Polymer Hybrid Research Center, Korea Institute of Science and Technology, 39-1, Hawolgok-dong, Seongbuk-gu, Seoul 136-791 (Korea, Republic of); Kim, Byung Chul [Applied Chemical Engineering Division, Hanyang University, 17, Haengdang-dong, Seongdong-Ku, Seoul 133-791 (Korea, Republic of)

    2004-11-15

    This paper discusses the preparation of microporous fibrous membranes from PVdF solutions with different polymer contents, using the electrospinning technique. Electrospun PVdF-based fibrous membranes with average fiber diameters (AFD's) of 0.45-1.38 {mu}m have an apparent porosity and a mean pore size (MPS) of 80-89% and 1.1-4.3 {mu}m, respectively. They exhibited a high uptake of the electrolyte solution (320-350%) and a high ionic conductivity of above 1 x 10{sup -3} s/cm at room temperature. Their ionic conductivity increased with the decrease in the AFD of the fibrous membrane due to its high electrolyte uptake. The interaction between the electrolyte molecules and the PVdF with a high crystalline content may have had a minor effect on the lithium ion transfer in the fibrous polymer electrolyte, unlike in a nanoporous gel polymer electrolyte. The fibrous polymer electrolyte that contained a 1 M LiPF{sub 6}-EC/DMC/DEC (1/1/1 by weight) solution showed a high electrochemical stability of above 5.0 V, which increased with the decrease in the AFD The interfacial resistance (R{sub i}) between the polymer electrolyte and the lithium electrode slightly increased with the storage time, compared with the higher increase in the interfacial resistance of other gel polymer electrolytes. The prototype cell (MCMB/PVdF-based fibrous electrolyte/LiCoO{sub 2}) showed a very stable charge-discharge behavior with a slight capacity loss under constant current and voltage conditions at the C/2-rate of 20 and 60 deg. C.

  15. International Symposium on Polymer Electrolytes (1st)

    Science.gov (United States)

    1987-06-01

    been attributed to the greater stability of the trifluoromethane sulphonate anion and a lower degree of ion-pairing, trifluoromethane sulphonic acid ...Electrolytes’. 31. R. TANAKA, T. IWASE, T. HORI and S. SAITO, ’Proton Conduction In Linear Poly(ethyleneimine)-Sulphuric Acid and Phosphoric Acid Systems’. 32...relaxation time requires some thought since the macroscopic viscosity in high molecular weight systems may not reflect at all the relaxation time for

  16. Performance of Lithium Polymer Cells with Polyacrylonitrile based Electrolyte

    DEFF Research Database (Denmark)

    Perera, Kumudu; Skaarup, Steen; West, Keld

    2006-01-01

    The performance of lithium polymer cells fabricated with Polyacrylonitrile (PAN) based electrolytes was studied using cycling voltammetry and continuous charge discharge cycling. The electrolytes consisted of PAN, ethylene carbonate (EC), propylene carbonate (PC) and lithium...... trifluoromethanesulfonate (LiCF3SO3 – LiTF). The polymer electrode material was polypyrrole (PPy) doped with dodecyl benzene sulfonate (DBS). The cells were of the form, Li / PAN : EC : PC : LiCF3SO3 / PPy : DBS. Polymer electrodes of three different thicknesses were studied using cycling at different scan rates. All cells...... voltammetry at slow scan rates were similar. The charge factor remained close to unity. These results show the fact that satisfactory cell performance can be achieved with thin electrode films and cycling at slow scan rates....

  17. STUDY ON THE PREPARATION AND PERFORMANCES OF P(VAc-MMA) POLYMER ELECTROLYTES FOR LITHIUM ION BATTERY

    Institute of Scientific and Technical Information of China (English)

    Dao-jun Yang; Xiang-kai Fu; Yong-feng Gong

    2008-01-01

    A random copolymer P(VAc-MMA) was synthesized via seeded emulsion copolymerization with vinyl acetate (VAc) and methyl methacrylate (MMA) as monomers, and the polymer electrolytes comprising blend of corresponding copolymer P(VAc-MMA) as a host polymer and LiC104 as a dopant were prepared by solution casting technique. Performances of the synthesized copolymer and prepared polymer membrane and electrolyte were studied by FTIR, XRD, TG, DSC, mechanical testing and AC impedance. According to the study of FTIR and DSC, it was found that P(VAc-MMA) had been formed. XRD indicates that the amorphous nature in copolymer increased with increasing the ratio of VAc in monomers, resulting in expedite migration of ions. The polymer electrolytes based on P(VAc-MMA) possess excellent thermal stability, fine mechanical performance and high ionic conductivity. The maximum ionic conductivity value was found to reach 1.27 × 10-3S·cm-1 at 25℃. The temperature dependence of the polymer electrolyte complexes appeared to obey Arrhenius equation.

  18. Novel composite polymer electrolyte for lithium air batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Deng; Li, Ruoshi; Huang, Tao; Yu, Aishui [Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Institute of New Energy, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2010-02-15

    Hydrophobic ionic liquid-silica-PVdF-HFP polymer composite electrolyte is synthesized and employed in lithium air batteries for the first time. Discharge performance of lithium air battery using this composite electrolyte membrane in ambient atmosphere shows a higher capacity of 2800 mAh g{sup -1} of carbon in the absence of O{sub 2} catalyst, whereas, the cell with pure ionic liquid as electrolyte delivers much lower discharge capacity of 1500 mAh g{sup -1}. When catalyzed by {alpha}-MnO{sub 2}, the initial discharge capacity of the cell with composite electrolyte can be extended to 4080 mAh g{sup -1} of carbon, which can be calculated as 2040 mAh g{sup -1} associated with the total mass of the cathode. The flat discharge plateau and large discharge capacity indicate that the hydrophobic ionic liquid-silica-PVdF-HFP polymer composite electrolyte membrane can effectively protect lithium from moisture invasion. (author)

  19. New polymer lithium secondary batteries based on ORMOCER (R) electrolytes-inorganic-organic polymers

    DEFF Research Database (Denmark)

    Popall, M.; Buestrich, R.; Semrau, G.

    2001-01-01

    Based on new plasticized inorganic-organic polymer electrolytes CM. Popall, M. Andrei, J. Kappel, J. Kron, K. Olma, B. Olsowski,'ORMOCERs as Inorganic-organic Electrolytes for New Solid State Lithium Batteries and Supercapacitors', Electrochim. Acta 43 (1998) 1155] new flexible foil-batteries in ......Based on new plasticized inorganic-organic polymer electrolytes CM. Popall, M. Andrei, J. Kappel, J. Kron, K. Olma, B. Olsowski,'ORMOCERs as Inorganic-organic Electrolytes for New Solid State Lithium Batteries and Supercapacitors', Electrochim. Acta 43 (1998) 1155] new flexible foil......-batteries in 'coffee bag arrangement' were assembled and tested. The electrolyte works as separator and binder for the cathodes. Self-diffusion NMR studies on the system (EC/PC/Li+N(SO2CF3)(2)(-)/ORMOCER(R)) resulted in cationic transport numbers t(+)) of 0.42 for the EC/PC/salt system and 0.35 for the ternary...

  20. Electrospun PVdF-PVC nanofibrous polymer electrolytes for polymer lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zhong Zheng [Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, College of Chemistry, Xiangtan University, Xiangtan 411105 (China); Cao Qi, E-mail: wjcaoqi@163.com [Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, College of Chemistry, Xiangtan University, Xiangtan 411105 (China); Jing Bo; Wang Xianyou; Li Xiaoyun; Deng Huayang [Key Laboratory of Environmentally Friendly Chemistry and Applications of Minister of Education, College of Chemistry, Xiangtan University, Xiangtan 411105 (China)

    2012-01-25

    Highlights: Black-Right-Pointing-Pointer The nanofibrous polymer electrolytes based on PVdF-PVC (8:2, w/w) prepared by electrospinning have an ionic conductivity of 2.25 Multiplication-Sign 10{sup -3} S cm{sup -1} at 25 Degree-Sign C. Black-Right-Pointing-Pointer The nanofibrous polymer electrolytes presented a good electrochemical stability up to 5.1 V (vs. Li/Li{sup +}). Black-Right-Pointing-Pointer The nanofibrous polymer electrolytes showed a very good charge/discharge and cycling performance. - Abstract: Nanofibrous membranes based on Poly (vinyl difluoride) (PVdF)-Poly (vinyl chloride) (PVC) (8:2, w/w) were prepared by electrospinning and then they were soaked in a liquid electrolyte to form polymer electrolytes (PEs). The morphology, thermal stability, function groups and crystallinity of the electrospun membranes were characterized by scanning electron microscope (SEM), thermal analysis (TG), Fourier transform infrared spectra (FT-IR) and differential scanning calorimetry (DSC), respectively. It was found that both electrolyte uptake and ionic conductivity of the composite PEs increased with the addition of PVC. The composite PVdF-PVC PEs had a high ionic conductivity up to 2.25 Multiplication-Sign 10{sup -3} S cm{sup -1} at 25 Degree-Sign C. These results showed that nanofibrous PEs based on PVdF-PVC were of great potential application in polymer lithium-ion batteries.

  1. Ion-Chain Dynamics in Polymer Electrolytes

    CERN Document Server

    Carlos, L D

    1996-01-01

    Representing polyether-salt systems by chains of interacting coordination shells, defined by the cation and by its nearest ligands, we derive the interaction potential between closest shells -- the inter-shells potential -- in terms of two-electron polarization effects. Values are presented for monovalent-based crystalline poly(ethylene oxide), PEO, electrolytes. For the eutectic composition $\\text{PEO}_{12} \\text{EuBr}_3$, the inter-shells energy is evaluated also by relating the empirical value of the nearest-ligands local-field potential with the variation of the $\\text{Eu}^{3+}$ concentration. Both methods give the same results.

  2. New Insights Into Dye-sensitized Solar Cells With Polymer Electrolytes

    OpenAIRE

    Nei De Freitas J.; Nogueira A.F.; De Paoli M.-A.

    2009-01-01

    Polymer electrolytes or gel polymer electrolytes are interesting alternatives to substitute liquid electrolytes in dye-sensitized solar cells (DSSC). The interest in this research field is growing continuously, reflected in the increase in the number of papers published each year concerning these materials. This feature article presents a brief review of the history and development of polymer electrolytes aiming at applications in DSSC. Recent improvements achieved by modifications of the com...

  3. All-solid-state proton battery using gel polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Kuldeep, E-mail: mishkuldeep@gmail.com [Department of Applied Science and Humanities, ABES Engineering College, Ghaziabad-201009, India and Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida-201307 (India); Pundir, S. S.; Rai, D. K. [Department of Physics and Materials Science and Engineering, Jaypee Institute of Information Technology, Noida-201307 (India)

    2014-04-24

    A proton conducting gel polymer electrolyte system; PMMA+NH{sub 4}SCN+EC/PC, has been prepared. The highest ionic conductivity obtained from the system is 2.5 × 10−4 S cm{sup −1}. The optimized composition of the gel electrolyte has been used to fabricate a proton battery with Zn/ZnSO{sub 4}⋅7H{sub 2}O anode and MnO{sub 2} cathode. The open circuit voltage of the battery is 1.4 V and the highest energy density is 5.7 W h kg−1 for low current drain.

  4. Characterization of Novel Castor Oil-Based Polyurethane Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Salmiah Ibrahim

    2015-04-01

    Full Text Available Castor oil-based polyurethane as a renewable resource polymer has been synthesized for application as a host in polymer electrolyte for electrochemical devices. The polyurethane was added with LiI and NaI in different wt% to form a film of polymer electrolytes. The films were characterized by using attenuated total reflectance-Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, linear sweep voltammetry and transference number measurement. The highest conductivity of 1.42 × 10−6 S cm−1 was achieved with the addition of 30 wt% LiI and 4.28 × 10−7 S·cm−1 upon addition of 30 wt% NaI at room temperature. The temperature dependence conductivity plot indicated that both systems obeyed Arrhenius law. The activation energy for the PU-LiI and PU-NaI systems were 0.13 and 0.22 eV. Glass transition temperature of the synthesized polyurethane decreased from −15.8 °C to ~ −26 to −28 °C upon salts addition. These characterizations exhibited the castor oil-based polyurethane polymer electrolytes have potential to be used as alternative membrane for electrochemical devices.

  5. Molecular Dynamics Simulation of Miscibility in Several Polymer Blends

    CERN Document Server

    Ahmadi, Amirhossein

    2009-01-01

    The miscibility in several polymer blend mixtures (polymethylmethacrylate/polystyrene, (1,4-cis) polyisoprene/polystyrene, and polymethylmethacrylate/polyoxyethylene) has been investigated using Molecular Dynamics simulations for atomistic representations of the polymer chains. The trajectories obtained from simulation boxes representing the mixtures have been analyzed in terms of the collective scattering structure function. The Flory-Huggins parameter is determined from fits of the simulation results for this function to the random phase approximation expression. The numerical values of this parameter and its variation with temperature obtained with this procedure show a general qualitative and quantitative agreement with existing experimental data for the different systems. These results together with those previously obtained for the polyvylmethylether/polystyrene blends with the same method are compared with data yielded by other computational simpler approaches.

  6. Phase diagrams of binary crystalline-crystalline polymer blends.

    Science.gov (United States)

    Matkar, Rushikesh A; Kyu, Thein

    2006-08-17

    A thermodynamically self-consistent theory has been developed to establish binary phase diagrams for two-crystalline polymer blends by taking into consideration all interactions including amorphous-amorphous, crystal-amorphous, amorphous-crystal, and crystal-crystal interactions. The present theory basically involves combination of the Flory-Huggins free energy for amorphous-amorphous isotropic mixing and the Landau free energy of polymer solidification (e.g., crystallization) of the crystalline constituents. The self-consistent solution via minimization of the free energy of the mixture affords determination of eutectic, peritectic, and azeotrope phase diagrams involving various coexistence regions such as liquid-liquid, liquid-solid, and solid-solid coexistence regions bound by liquidus and solidus lines. To validate the present theory, the predicted eutectic phase diagrams have been compared with the reported experimental binary phase diagrams of blends such as polyethylene fractions as well as polycaprolactone/trioxane mixtures.

  7. The production of stable bitumen-polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Jovanovic, J.; Sokic, M. (Faculty of Technology and Metallurgy, Univ. Belgrade (Yugoslavia)); Smiljanic, M.; Pab, I. (Highway Inst., Belgrade (Yugoslavia)); Neumann, H.J.; Rahimian, I. (German Inst. for Petroleum Research, Clausthal-Zellerfeld (Germany))

    1993-01-01

    If either blown bitumen or bitumens of inadequate origin and type are used for the production of bitumen-polymer blends containing SBS- and/or SBR-elastomers, it is often not possible to obtain stable homogeneous bitumen-polymer blends. In that case pretreatment of the elastomer component is necessary. The production of stable bitumen-polymer blends from SBS- and SBR-elastomers and blown bitumens from Yugoslav refineries in Novi Sad and Pancevo were studied in this paper. Pretreatment of the elastomer components was performed with a residue of the distillation of fatty acids and/or with pyrolysis oil from a naphtha steam pyrolysis unit. Infrared spectroscopy was used to determine the kinetics of the dissolution of the elastomers in the bitumen. The rate of dissolution of SBR-elastomer was practically independent of the bitumen type. In the case of SBS-elastomer, however, the kinetics of the dissolving process was strongly influenced by the bitumen type. The origin of bitumen influenced the dissolution kinetics too. (orig.).

  8. Polymer electrolyte membrane assembly for fuel cells

    Science.gov (United States)

    Yen, Shiao-Ping S. (Inventor); Kindler, Andrew (Inventor); Yavrouian, Andre (Inventor); Halpert, Gerald (Inventor)

    2002-01-01

    An electrolyte membrane for use in a fuel cell can contain sulfonated polyphenylether sulfones. The membrane can contain a first sulfonated polyphenylether sulfone and a second sulfonated polyphenylether sulfone, wherein the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone have equivalent weights greater than about 560, and the first sulfonated polyphenylether and the second sulfonated polyphenylether sulfone also have different equivalent weights. Also, a membrane for use in a fuel cell can contain a sulfonated polyphenylether sulfone and an unsulfonated polyphenylether sulfone. Methods for manufacturing a membrane electrode assemblies for use in fuel cells can include roughening a membrane surface. Electrodes and methods for fabricating such electrodes for use in a chemical fuel cell can include sintering an electrode. Such membranes and electrodes can be assembled into chemical fuel cells.

  9. Thermally responsive polymer electrolytes for inherently safe electrochemical energy storage

    Science.gov (United States)

    Kelly, Jesse C.

    Electrochemical double layer capacitors (EDLCs), supercapacitors and Li-ion batteries have emerged as premier candidates to meet the rising demands in energy storage; however, such systems are limited by thermal hazards, thermal runaway, fires and explosions, all of which become increasingly more dangerous in large-format devices. To prevent such scenarios, thermally-responsive polymer electrolytes (RPEs) that alter properties in electrochemical energy storage devices were designed and tested. These RPEs will be used to limit or halt device operation when temperatures increase beyond a predetermined threshold, therefore limiting further heating. The development of these responsive systems will offer an inherent safety mechanism in electrochemical energy storage devices, while preserving the performance, lifetimes, and versatility that large-format systems require. Initial work focused on the development of a model system that demonstrated the concept of RPEs in an electrochemical device. Aqueous electrolyte solutions of polymers exhibiting properties that change in response to temperature were developed for applications in EDLCs and supercapacitors. These "smart materials" provide a means to control electrochemical systems where polymer phase separation at high temperatures affects electrolyte properties and inhibits device performance. Aqueous RPEs were synthesized using N-isopropylacrylamide, which governs the thermal properties, and fractions of acrylic acid or vinyl sulfonic acids, which provide ions to the solution. The molecular properties of these aqueous RPEs, specifically the ionic composition, were shown to influence the temperature-dependent electrolyte properties and the extent to which these electrolytes control the energy storage characteristics of a supercapacitor device. Materials with high ionic content provided the highest room temperature conductivity and electrochemical activity; however, RPEs with low ionic content provided the highest "on

  10. Super Soft All-Ethylene Oxide Polymer Electrolyte for Safe All-Solid Lithium Batteries

    OpenAIRE

    Luca Porcarelli; Claudio Gerbaldi; Federico Bella; Jijeesh Ravi Nair

    2016-01-01

    Here we demonstrate that by regulating the mobility of classic −EO− based backbones, an innovative polymer electrolyte system can be architectured. This polymer electrolyte allows the construction of all solid lithium-based polymer cells having outstanding cycling behaviour in terms of rate capability and stability over a wide range of operating temperatures. Polymer electrolytes are obtained by UV-induced (co)polymerization, which promotes an effective interlinking between the polyethylene o...

  11. Hybrid proton-conducting membranes for polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Romero, Pedro [Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra (Barcelona) (Spain)]. E-mail: pedro.gomez@icmab.es; Asensio, Juan Antonio [Institut de Ciencia de Materials de Barcelona (CSIC), Campus UAB, E-08193 Bellaterra (Barcelona) (Spain); Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, E-08017 Barcelona (Spain); Borros, Salvador [Institut Quimic de Sarria, Universitat Ramon Llull, Via Augusta 390, E-08017 Barcelona (Spain)

    2005-08-30

    The synthesis and characterization of a novel hybrid organic-inorganic material formed by phosphomolybdic acid H{sub 3}PMo{sub 12}O{sub 40} (PMo{sub 12}) and poly(2,5-benzimidazole) (ABPBI) is reported. This material, composed of two proton-conducting components, can be cast in the form of membranes from methanesulfonic acid (MSA) solutions. Upon impregnation with phosphoric acid, the hybrid membranes present higher conductivity than the best ABPBI polymer membranes impregnated in the same conditions. These electrolyte membranes are stable up to 200 deg. C, and have a proton conductivity of 3 x 10{sup -2} S cm{sup -1} at 185 deg. C without humidification. These properties make them very good candidates as membranes for polymer electrolyte membrane fuel cells (PEMFC) at temperatures of 100-200 deg. C.

  12. Understanding ternary poly(potassium benzimidazolide)-based polymer electrolytes

    DEFF Research Database (Denmark)

    Aili, David; Jankova Atanasova, Katja; Han, Junyoung;

    2016-01-01

    swelling, high electrolyte uptake, dramatic plasticization and increase of the ion conductivity for the formed poly(potassium benzimidazolide)-based structure. Further increasing the concentration of the bulk solution to 50 wt.% resulted in dehydration and extensive crystallization of the polymer matrix......Poly(2,20-(m-phenylene)-5,50-bisbenzimidazole) (m-PBI) can dissolve large amounts of aqueous electrolytes to give materials with extraordinary high ion conductivity and the practical applicability has been demonstrated repeatedly in fuel cells, water electrolysers and as anion conducting component...... in fuel cell catalyst layers. This work focuses on the chemistry of m-PBI in aqueous potassium hydroxide. Equilibration in aqueous KOH with concentrations of 15e20 wt.% was found to result in ionization of the polymer, causing released intermolecular hydrogen bonding. This allowed for extensive volume...

  13. Hydrocarbon-Based Polymer Electrolyte Membranes: Importance of Morphology on Ion Transport and Membrane Stability.

    Science.gov (United States)

    Shin, Dong Won; Guiver, Michael D; Lee, Young Moo

    2017-03-03

    A fundamental understanding of polymer microstructure is important in order to design novel polymer electrolyte membranes (PEMs) with excellent electrochemical performance and stabilities. Hydrocarbon-based polymers have distinct microstructure according to their chemical structure. The ionic clusters and/or channels play a critical role in PEMs, affecting ion conductivity and water transport, especially at medium temperature and low relative humidity (RH). In addition, physical properties such as water uptake and dimensional swelling behavior depend strongly on polymer morphology. Over the past few decades, much research has focused on the synthetic development and microstructural characterization of hydrocarbon-based PEM materials. Furthermore, blends, composites, pressing, shear field, electrical field, surface modification, and cross-linking have also been shown to be effective approaches to obtain/maintain well-defined PEM microstructure. This review summarizes recent work on developments in advanced PEMs with various chemical structures and architecture and the resulting polymer microstructures and morphologies that arise for potential application in fuel cell, lithium ion battery, redox flow battery, actuators, and electrodialysis.

  14. The Properties of Concentrations in a Polymer Blend

    Institute of Scientific and Technical Information of China (English)

    YunHUANG; DeluZHAO

    1997-01-01

    For the flexible polymer molecule the concepts of two concentrations,namely,segmental and molecular concentrations have been proposed in this paper.The former is equivalent to the volume fraction.The latter can be defined as the number of the gravity centers of macromolecules,or as the number of the chainheads per unit volume.The two concentrations should be correlated each other by the conformational function of the polymer chain and could be used in different thermodynamic equations.on the bases of these concepts it has been proved that the Flory-Huggins mixing entropy should be the result of the mixing “ideal chainhead gases”.The general correlation between the mixing free energy and the scattering function(Structureal factor)of polymer blends has been studied based on the general thermodynamic fluctuation theory.When the Flory-Huggins mixing free energy was adopted.de Gennes scattering function of polymer blend can be derivated.

  15. Improved power conversion efficiency of dye-sensitized solar cells using side chain liquid crystal polymer embedded in polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Woosum [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of); Lee, Jae Wook, E-mail: jlee@donga.ac.kr [Department of Chemistry, Dong-A University, Busan 604-714 (Korea, Republic of); Gal, Yeong-Soon [Polymer Chemistry Lab, College of General Education, Kyungil University, Hayang 712-701 (Korea, Republic of); Kim, Mi-Ra, E-mail: mrkim2@pusan.ac.kr [Department of Polymer Science and Engineering, Pusan National University, Busan 609-735 (Korea, Republic of); Jin, Sung Ho, E-mail: shjin@pusan.ac.kr [Department of Chemistry Education, and Department of Frontier Materials Chemistry, and Institute for Plastic Information and Energy Materials, Pusan National University, Busan 609-735 (Korea, Republic of)

    2014-02-14

    Side chain liquid crystal polymer (SCLCP) embedded in poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-co-HFP)-based polymer electrolytes (PVdF-co-HFP:side chain liquid crystal polymer (SCLCP)) was prepared for dye-sensitized solar cell (DSSC) application. The polymer electrolytes contained tetrabutylammonium iodide (TBAI), iodine (I{sub 2}), and 8 wt% PVdF-co-HFP in acetonitrile. DSSCs comprised of PVdF-co-HFP:SCLCP-based polymer electrolytes displayed enhanced redox couple reduction and reduced charge recombination in comparison to those of the conventional PVdF-co-HFP-based polymer electrolyte. The significantly increased short-circuit current density (J{sub sc}, 10.75 mA cm{sup −2}) of the DSSCs with PVdF-co-HFP:SCLCP-based polymer electrolytes afforded a high power conversion efficiency (PCE) of 5.32% and a fill factor (FF) of 0.64 under standard light intensity of 100 mW cm{sup −2} irradiation of AM 1.5 sunlight. - Highlights: • We developed the liquid crystal polymer embedded on polymer electrolyte for DSSCs. • We fabricated the highly efficient DSSCs using polymer electrolyte. • The best PCE achieved for P1 is 5.32% using polymer electrolyte.

  16. Synthesis and characterization of aminated perfluoro polymer electrolytes

    Science.gov (United States)

    Page-Belknap, Zachary Stephan Glenn

    Polymer electrolytes have been developed for use in anion exchange membrane fuel cells for years. However, due to the highly corrosive environment within these fuel cells, poor chemical stability of the polymers and low ion conductivity have led to high development costs and thus prevention from widespread commercialization. The work in this study aims to provide a solution to these problems through the synthesis and characterization of a novel polymer electrolyte. The 800 EW 3M PFSA sulfonyl fluoride precursor was aminated with 3-(dimethylamino)-1-propylamine to yield a functional polymer electrolyte following quaternization, referred to in this work as PFSa-PTMa. 1 M solutions of LiPF6, HCL, KOH, NaOH, CsOH, NaHCO3 and Na2CO3 were used to exchange the polymer to alternate counterion forms. Chemical structure analysis was performed using both FT and ATR infrared spectroscopy to confirm sulfonyl fluoride replacement and the absence of sulfonic acid sites. Mechanical testing of the polymer, following counterion exchange with KOH, at saturated conditions and 60 ºC exhibited a tensile strength of 13 +/- 2.0 MPa, a Young's modulus of 87 +/- 16 MPa and a degree of elongation reaching 75% +/- 9.1%, which indicated no mechanical degradation following exposure to a highly basic environment. Conductivities of the polymer in the Cl- and OH- counterion forms at saturated conditions and 90 ºC were observed at 26 +/- 8.0 mS cm-1 and 1.1 +/- 0.1 mS cm-1, respectively. OH- conductivities were slightly above those observed for CO32- and HCO 3- counterions at the same conditions, 0.63 +/- 0.18 and 0.66 +/- 0.21 mS cm-1 respectively. The ion exchange capacity (IEC) of the polymer in the Cl- counterion form was measured via titration at 0.57 meq g-1 which correlated to 11.2 +/- 0.10 water molecules per ion site when at 60ºC and 95% relative humidity. The IEC of the polymer in the OH- counterion form following titration expressed nearly negligible charge density, less than 0.01 meq

  17. Polymer chain organization in tensile-stretched poly(ethylene oxide)-based polymer electrolytes

    Science.gov (United States)

    Burba, Christopher M.; Woods, Lauren; Millar, Sarah Y.; Pallie, Jonathan

    2011-01-01

    Polymer chain orientation in tensile-stretched poly(ethylene oxide)-lithium trifluoromethanesulfonate polymer electrolytes are investigated with polarized infrared spectroscopy as a function of the degree of strain and salt composition (ether oxygen atom to lithium ion ratios of 20:1, 15:1, and 10:1). The 1359 and 1352 cm-1 bands are used to probe the crystalline PEO and P(EO)3LiCF3SO3 domains, respectively, allowing a direct comparison of chain orientation for the two phases. Two-dimensional correlation FT-IR spectroscopy indicates that the two crystalline domains align at the same rate as the polymer electrolytes are stretched. Quantitative measurements of polymer chain orientation obtained through dichroic infrared spectroscopy show that chain orientation predominantly occurs between strain values of 150% and 250%, regardless of salt composition investigated. There are few changes in chain orientation for either phase when the films are further elongated to a strain of 300%; however, the PEO domains are slightly more oriented at the high strain values. The spectroscopic data are consistent with stretching-induced melt-recrystallization of the unoriented crystalline domains in the solution-cast polymer films. Stretching the films pulls polymer chains from the crystalline domains, which subsequently recrystallize with the polymer helices parallel to the stretch direction. If lithium ion conduction in crystalline polymer electrolytes is viewed as consisting of two major components (facile intra-chain lithium ion conduction and slow helix-to-helix inter-grain hopping), then alignment of the polymer helices will affect the ion conduction pathways for these materials by reducing the number of inter-grain hops required to migrate through the polymer electrolyte. PMID:22184475

  18. Polymer chain organization in tensile-stretched poly(ethylene oxide)-based polymer electrolytes.

    Science.gov (United States)

    Burba, Christopher M; Woods, Lauren; Millar, Sarah Y; Pallie, Jonathan

    2011-12-15

    Polymer chain orientation in tensile-stretched poly(ethylene oxide)-lithium trifluoromethanesulfonate polymer electrolytes are investigated with polarized infrared spectroscopy as a function of the degree of strain and salt composition (ether oxygen atom to lithium ion ratios of 20:1, 15:1, and 10:1). The 1359 and 1352 cm(-1) bands are used to probe the crystalline PEO and P(EO)(3)LiCF(3)SO(3) domains, respectively, allowing a direct comparison of chain orientation for the two phases. Two-dimensional correlation FT-IR spectroscopy indicates that the two crystalline domains align at the same rate as the polymer electrolytes are stretched. Quantitative measurements of polymer chain orientation obtained through dichroic infrared spectroscopy show that chain orientation predominantly occurs between strain values of 150% and 250%, regardless of salt composition investigated. There are few changes in chain orientation for either phase when the films are further elongated to a strain of 300%; however, the PEO domains are slightly more oriented at the high strain values. The spectroscopic data are consistent with stretching-induced melt-recrystallization of the unoriented crystalline domains in the solution-cast polymer films. Stretching the films pulls polymer chains from the crystalline domains, which subsequently recrystallize with the polymer helices parallel to the stretch direction. If lithium ion conduction in crystalline polymer electrolytes is viewed as consisting of two major components (facile intra-chain lithium ion conduction and slow helix-to-helix inter-grain hopping), then alignment of the polymer helices will affect the ion conduction pathways for these materials by reducing the number of inter-grain hops required to migrate through the polymer electrolyte.

  19. Novel polymer blends with thermoplastic starch

    Science.gov (United States)

    Taghizadeh, Ata

    A new class of polymers known as "bioplastics" has emerged and is expanding rapidly. This class consists of polymers that are either bio-based or biodegradable, or both. Among these, polysaccharides, namely starch, are of great interest for several reasons. By gelatinizing starch via plasticizers, it can be processed in the same way as thermoplastic polymers with conventional processing equipment. Hence, these bio-based and biodegradable plastics, with their low source and refinery costs, as well as relatively easy processability, have made them ideal candidates for incorporation into various current plastic products. Four different plasticizers have been chosen here for gelatinization of thermoplastic starch (TPS): glycerol, sorbitol, diglycerol and polyglycerol, with the latter two being used for the first time in such a process. Two methodological categories are used. The first involves a calorimetric method (Differential Scanning Calorimetry) as well as optical microscopy; these are "static" methods where no shear is applied A wide range of starch/water/plasticizer compositions were prepared to explore the gelatinization regime for each plasticizer. The onset and conclusion gelatinization temperatures for sorbitol and glycerol were found to be in the same vicinity, while diglycerol and polyglycerol showed significantly higher transition temperatures. The higher molecular weight and viscosity of polyglycerol allow this transition to occur at an even higher temperature than with diglycerol. This is due to the increase in molecular weight and viscosity of the two new plasticizers, as well as their significant decrease in water solubility. It is demonstrated that the water/plasticizer ratio has a pronounced effect on gelatinization temperatures. When plasticizer content was held constant and water content was increased, it was found that the gelatinization temperature decreased for all the plasticizers. Meanwhile, when the water content was held constant and the

  20. Photocured PEO-based solid polymer electrolyte and its application to lithium-polymer batteries

    Science.gov (United States)

    Kang, Yongku; Kim, Hee Jung; Kim, Eunkyoung; Oh, Bookeun; Cho, Jae Hyun

    A solid polymer electrolyte (SPE) based on polyethylene oxide (PEO) is prepared by photocuring of polyethylene glycol acrylates. The conductivity is greatly enhanced by adding low molecular weight poly(ethylene glycol) dimethylether (PEGDME). The maximum conducticity is 5.1×10 -4 S cm -1 at 30°C. These electrolytes display oxidation stability up to 4.5 V against a lithium reference electrode. Reversible electrochemical plating/stripping of lithium is observed on a stainless steel electrode. Li/SPE/LiMn 2O 4 as well as C(Li)/SPE/LiCoO 2 cells have been fabricated and tested to demonstrate the applicability of the resulting polymer electrolytes in lithium-polymer batteries.

  1. Novel Molecular Architectures Developed for Improved Solid Polymer Electrolytes for Lithium Polymer Batteries

    Science.gov (United States)

    Meador, Mary Ann B.; Kinder, James D.; Bennett, William R.

    2002-01-01

    Lithium-based polymer batteries for aerospace applications need the ability to operate in temperatures ranging from -70 to 70 C. Current state-of-the-art solid polymer electrolytes (based on amorphous polyethylene oxide, PEO) have acceptable ionic conductivities (10-4 to 10-3 S/cm) only above 60 C. Higher conductivity can be achieved in the current systems by adding solvent or plasticizers to the solid polymer to improve ion transport. However, this can compromise the dimensional and thermal stability of the electrolyte, as well as compatibility with electrode materials. One of NASA Glenn Research Center's objectives in the PERS program is to develop new electrolytes having unique molecular architectures and/or novel ion transport mechanisms, leading to good ionic conductivity at room temperature and below without solvents or plasticizers.

  2. X-ray photoelectron spectroscopic investigation of conducting polymer blends.

    Science.gov (United States)

    Süzer, S; Toppare, L; Hallam, K R; Allen, G C

    1996-06-01

    Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.

  3. Tetrazole substituted polymers for high temperature polymer electrolyte fuel cells

    DEFF Research Database (Denmark)

    Henkensmeier, Dirk; My Hanh Duong, Ngoc; Brela, Mateusz

    2015-01-01

    interesting for use in a high temperature fuel cell (HT PEMFC). Based on these findings, two polymers incorporating the proposed TZ groups were synthesised, formed into membranes, doped with PA and tested for fuel cell relevant properties. At room temperature, TZ-PEEN and commercial meta-PBI showed...

  4. The Role of Polymer Electrolytes in Drug Delivery

    Science.gov (United States)

    Latham, R. J.; Linford, R. G.; Schlindwein, W. S.

    2002-12-01

    30 years ago Michel Armand, who was working on intercalation cathode materials in high energy power sources, identified the need to develop flexible, ionically conducting, electronically insulating electrolyte materials to accommodate the gross dimensional changes that occur on charge and discharge. In 1973, Peter Wright produced the first such materials designed for this purpose. His "polymer electrolytes" consisted of thin films of sodium or potassium salts dissolved in poly (ethylene oxide) PEO. Many polymer electrolytes had been developed in the ensuing years. Those for power source use have focussed on Lithium as the conducting species whereas complementary materials have been utilised for sensor and other applications. It is well known that the flexible matrix, a heteropolymer usually modified by additives such as plasticisers and/or inert fillers, provides a facile conducting pathway for ions. It is a significant disadvantage of many early polymer electrolytes that both the electrochemically active cations and the charge-compensating anions were mobile. Classic methods of drug delivery have embraced a number of routes into the site of pharmacological action, including ingestion into the lung, the digestive tract or the colon; injection into muscle tissue; and intravenous delivery through a catheter (a "drip"). Modern preference, wherever possible, is for a non-invasive route to minimise the chance of cross infection, especially of the AIDS virus. The skin, which is the largest organ in the human body, is a particularly appealing route as, in the absence of wounds and blemishes, it offers a natural, high-integrity, barrier to the outside world. Skin patches containing active drug that is allowed to diffuse across the external skin barrier into the bloodstream now enjoy wide application but a problem is that the rate of egress is often slow. Transport can be enhanced by artificially dilating the skin pores and/or by opening up additional pores by the

  5. Preparation and characterization of a mixing soft-segment waterborne polyurethane polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    Feng Wu; Yue JiaoLi; Ren Jie Chen; Shi Chen

    2009-01-01

    The mixing soft-segment WPU (waterborne polyurethane) polymer electrolytes were synthesized by using PEO (poly(ethylene oxide)) and PDMS (polydimethylsiloxane) as the soft segments. These polymer electrolytes exhibit good thermal and electro-chemical stability. The conductivity of the gel polymer electrolyte is 2.52×10-3 S/cm at 25 ℃ with the LiTFSI/(DMC + EC) content of 130%.

  6. Preliminary study of application of Moringa oleifera resin as polymer electrolyte in DSSC solar cells

    Science.gov (United States)

    Saehana, Sahrul; Darsikin, Muslimin

    2016-04-01

    This study reports the preliminary study of application of Moringa oleifera resin as polymer electrolyte in dye-sensitized solar cell (DSSC). We found that polymer electrolyte membrane was formed by using solution casting methods. It is observed that polymer electrolyte was in elastic form and it is very potential to application as DSSC component. Performance of DSSC which employing Moringa oleifera resin was also observed and photovoltaic effect was found.

  7. Oxygen reduction on carbon supported platinum catalysts in high temperature polymer electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Hjuler, Hans Aage; Bjerrum, Niels

    2000-01-01

    improve the oxygen reduction kinetics due to increased oxygen solubility and suppressed adsorption of phosphoric acid anions. Further enhancement of the catalytic activity can be obtained by operating the polymer electrolytes at higher temperatures. Efforts have been made to develop a polymer electrolyte......Oxygen reduction on carbon supported platinum catalysts has been investigated in H3PO4, H3PO4-doped Nafion and polybenzimidazole (PBI) polymer electrolytes in a temperature range up to 190 degrees C. Compared with pure H3PO4, the combination of H3PO4 and polymer electrolytes can significantly...

  8. Methods of enhancing conductivity of a polymer-ceramic composite electrolyte

    Science.gov (United States)

    Kumar, Binod (Inventor)

    2003-01-01

    Methods for enhancing conductivity of polymer-ceramic composite electrolytes are provided which include forming a polymer-ceramic composite electrolyte film by a melt casting technique and uniaxially stretching the film from about 5 to 15% in length. The polymer-ceramic composite electrolyte is also preferably annealed after stretching such that it has a room temperature conductivity of from 10.sup.-4 S cm.sup.-1 to 10.sup.-3 S cm.sup.-1. The polymer-ceramic composite electrolyte formed by the methods of the present invention may be used in lithium rechargeable batteries.

  9. Polymer electrolytes based on aromatic lithium sulfonyl-imide compounds; Electrolytes polymeres a base de sulfonylimidures de lithium aromatiques

    Energy Technology Data Exchange (ETDEWEB)

    Reibel, L.; Bayoudh, S. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Institut Charles Sadron; Baudry, P. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches; Majastre, H. [Bollore Technologies, 29 - Quimper (France); Herlem, G. [UFR de Sciences et Techniques, L.E.S., 25 - Besancon (France)

    1996-12-31

    This paper presents ionic conductivity results obtained with polymer electrolytes and also with propylene carbonate solutions. The domain of electrochemical activity of this salt has been determined using cycle volt-amperometry in propylene carbonate. Preliminary experiments on the stability of the polymer electrolyte with respect to the lithium electrode have been carried out for a possible subsequent use in lithium batteries. (J.S.) 4 refs.

  10. Composite polymer electrolyte membranes supported by non-woven fabrics for lithium-ion polymer batteries

    Institute of Scientific and Technical Information of China (English)

    TANG Dingguo; LIU Jianhong; QI Lu; CHEN Hui; CI Yunxiang

    2005-01-01

    Poly(vinylidene fluoride-co-hexafluoropropyle- ne) (PVDF-HFP) is one of the most popular polymers for polymer electrolyte membranes because of its excellent operating characteristics and superior electrochemical properties. The electrochemical performances of polymer electrolyte membrane can be enhanced by evenly dispersing nano-meter SiO2 particles in the polymer. In this paper, non-woven fabrics were immersed in the mixed solution of PVDF-HFP/ SiO2/butanone/butanol/plasticizer, and then dried in a vacuum oven to remove the solvents and the plasticizer and to make porous composite polymer electrolyte membranes. The prepared composite membranes supported by non-woven fabrics boast good mechanical strength and excellent electrochemical properties: the electrochemical stability window is 4.8 V vs. Li+/Li, and the ionic conductivity is 3.35×10-4 S/cm (around 60% of that of a common PE membrane) at room temperature. The lithium-ion polymer battery assembled by the composite membrane exhibits high rate capability and excellent cycling performance.

  11. Lithium Polymer Electrolytes Based On PMMA / PEG And Penetrant Diffusion In Kraton Penta-Block Ionomer

    Science.gov (United States)

    Meng, Yan

    The study of diffusion in polymeric material is critical to many research fields and applications, such as polymer morphology, protective coatings (paints and varnishes), separation membranes, transport phenomena, polymer electrolytes, polymer melt, and controlled release of drugs from polymer carriers [1-9]. However, it is still a challenge to understand, predict and control the diffusion of molecules and ions of different sizes in polymers [2]. This work studied the medium to long range diffusion of species (i.e., ions and molecules) in solid polymer electrolytes based on poly(ethylene glycol)/poly(methyl methacrylate) (PEG/PMMA) for Li-based batteries, and polymeric permselective membranes via pulsed-field gradient NMR and a.c. impedance. Over the past decades polymer electrolytes have attracted much attention because of their promising technological application as an ion-conducting medium in solid-state batteries, fuel cells, electrochromic displays, and chemical sensors [10, 11]. However, despite numerous studies related to ionic transport in these electrolytes the understanding of the migration mechanism is still far from being complete, and progress in the field remains largely empirical [10, 12-15]. Among various candidates for solid polymer electrolyte (SPE) material, the miscible polymer pair, poly(ethylene oxide)/poly(methyl methacrylate) (PEO/PMMA), is an attractive one, because there is a huge difference in mobility between PEO and PMMA in their blends, and PEO chains remain exceptionally mobile in the blend even at temperature below the glass transition temperature of the blend [ 16]. Thus the mechanical strength and dimensional stability is maintained by PMMA component, while the chain motions or rearrangements of the PEO component virtually contribute to the ion transport [17]. The current work prepared two types of SPE based on poly(ethylene glycol) (PEG) /PMMA (40/60 by weight) for Li-based batteries: lithium bis(trifluoromethylsulfonylimide) (Li

  12. Research Progress in Hyperbranched/Star Polymer Electrolyte%超支化/星形聚合物电解质的研究进展

    Institute of Scientific and Technical Information of China (English)

    任士通; 贺丽娟; 常贺飞; 党小飞; 张辽云; 李化毅

    2012-01-01

    Compared with liquid electrolyte, polymer electrolyte has widely attracted researchers' attention, and has the potential to replace organic liquid electrolyte because of the advantages such as easy processing, flexible design, light weight, safety and non-toxicity. Hyperbranched/star polymer with amorphousness, low glass transition temperature and unique topology has been studied as solid polymer electrolyte. In this review, research progress in hyperbranched/star polymer electrolyte is presented. Special interests are focused on the hyperbranched/star polymer-based electrolytes, hyperbranched/star polymer blend-based electrolyte. Besides, the application of hyperbranched/star polymer based single ion electrolyte for lithium ion battery is also prospected.%与液体电解质相比较,聚合物电解质以其易加工、设计灵活、质量轻、安全无毒的特点而受到人们的广泛关注,具有取代液态电解质的潜在应用价值,而超支化/星形聚合物以其无定形、低玻璃化转变温度、支化结构等特点可被用于固态电解质。本文综述了超支化/星形聚合物电解质材料的研究进展,重点介绍了超支化/星形聚合物基电解质和超支化/星形聚合物共混基电解质,并对超支化/星形聚合物单一离子导体在锂离子电池方面的应用前景作了概述。

  13. LIQUID-LIQUID PHASE EQUILIBRIUM OF POLYMER SOLUTIONS AND POLYMER BLENDS UNDER POSITIVE AND NEGATIVE PRESSURE

    Institute of Scientific and Technical Information of China (English)

    Attila R.Imre

    2003-01-01

    In this paper we would like to give a brief review about the extensibility of the liquid-liquid locus into the negative pressure region. Negative pressure states are hardly explored; most researchers believe that the pressure scale ends at p = 0.We would like to show that this is not true, thep = 0 point is not a special point for liquids, it can be "easily" crossed. We are going to give a few example, where the extension of liquid-liquid locus for polymer blends and solutions below p = 0 gives us some interesting results, like the merging of UCST and LCST branches in weakly interacting polymer solutions or the reason why most UCST blends exhibit pressure induced immiscibility. Also, we will see what happens with the immiscibility island of aqueous polymer solutions when - reaching the critical molar mass - it "disappears".

  14. PE-g-MMA polymer electrolyte membrane for lithium polymer battery

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Kun; Hu, Xinguo; Yi, Tingfeng; Dai, Changsong [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2006-10-25

    PE-g-MMA membranes with different degrees of grafting (DG) were prepared by electron beam radiation-induced graft copolymerization of methylmethacrylate (MMA) monomer onto polyethylene (PE) separator. The grafted membranes (GMs) were characterized using SEM, FTIR. The new polymer electrolytes based on GMs were prepared through immersion in a solution of LiPF{sub 6}-EC/DMC (1:1 by volume). It was found that the GMs with different DG exhibited the different uptake and retention ability of liquid electrolyte. Moreover, the ion conductivities of activated polymer electrolytes (APEs) were also found to vary with the different DG and reached a magnitude of 10{sup -3}Scm{sup -1} at the DG of 42%. Compared with those containing PE separators, the LiCoO{sub 2}-MCMB coin cells containing GMs demonstrated better cycle life and excellent rate performance. (author)

  15. PE-g-MMA polymer electrolyte membrane for lithium polymer battery

    Energy Technology Data Exchange (ETDEWEB)

    Gao Kun [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)]. E-mail: gaokun@hit.edu.cn; Hu Xinguo [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Yi Tingfeng [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Dai Changsong [Departments of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China)

    2006-10-25

    PE-g-MMA membranes with different degrees of grafting (DG) were prepared by electron beam radiation-induced graft copolymerization of methylmethacrylate (MMA) monomer onto polyethylene (PE) separator. The grafted membranes (GMs) were characterized using SEM, FTIR. The new polymer electrolytes based on GMs were prepared through immersion in a solution of LiPF{sub 6}-EC/DMC (1:1 by volume). It was found that the GMs with different DG exhibited the different uptake and retention ability of liquid electrolyte. Moreover, the ion conductivities of activated polymer electrolytes (APEs) were also found to vary with the different DG and reached a magnitude of 10{sup -3} S cm{sup -1} at the DG of 42%. Compared with those containing PE separators, the LiCoO{sub 2}-MCMB coin cells containing GMs demonstrated better cycle life and excellent rate performance.

  16. Compatibility Studies on Elastomers and Polymers with Ethanol Blended Gasoline

    Directory of Open Access Journals (Sweden)

    J. S. Dhaliwal

    2014-01-01

    Full Text Available This paper reports the compatibility studies of 10% ethanol blended gasoline (E10 with four types of elastomer materials, namely, Neoprene rubber, Nitrile rubber, hydrogenated Nitrile butadiene rubber (HNBR, and Polyvinyl chloride/Nitrile butadiene rubber blend (PVC/NBR, and two types of plastic materials, namely, Nylon-66 and Polyoxymethylene (Delrin. These materials have applications in automotives as engine seals, gaskets, fuel system seals and hoses, and so forth. Two types of the ethanol blended gasoline mixtures were used: (a gasoline containing 5% ethanol (E5, which is commercial form of gasoline available in India, and (b gasoline containing 10% ethanol (E10. The above materials were immersed in E5 and E10 for 500 hrs at 55°C. A set of eight different properties in E5 and E10 (visual inspection, weight change, volume change, tensile strength, percent elongation, flexural strength, impact strength, and hardness were measured after completion of 500 hrs and compared with reference specimens (specimens at 55°C without fuel and specimens at ambient conditions. Variation observed in different materials with respect to the above eight properties has been used to draw inference about the compatibility of these elastomeric/polymer materials with E10 fuel vis-à-vis E5 fuels. The data presented in this study is comparative in nature between the results of E10 and E5.

  17. Gelation Behavior of Poly (Vinylidene Fluoride )-based Gel Polymer Electrolyte

    Institute of Scientific and Technical Information of China (English)

    WANG Biao-bing; GU Li-xia

    2006-01-01

    Poly ( vinylidene fluoride ) ( PVdF )-based gel polymer electrolytes with various compositions were prepared by solution casting technique. The kinetics of gelation was analyzed via the correlation between the apparent gelation rate and concentration of PVdF at a given temperature.Combination the results of the kinetics of gelation and the DSC study, it revealed that the phase separation was the major behavior and the fibrils were the major junction joints of the three-dimensional network even in the ease the concentration of PVdF was higher than 25 wt%. The porous surface observed by ESEM also reflected that the phase separation took place during the gelation.

  18. Conductivity Studies of the Plasticized-Poly(methylmethacrylate) Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    A.Ahmad; Z.Osman

    2007-01-01

    1 Results In this work,five systems of polymethylmethacrylate (PMMA)-based polymer electrolytes films have been prepared by the solution casting technique.The five systems are the (PMMA-EC) system,the (PMMA + PC) system,the (PMMA+LiCF3SO3) system,the ([PMMA+EC]+LiCF3SO3) system and the ([PMMA+PC]+LiCF3SO3) system.The conductivity for each system is characterized using impedance spectroscopy.The conductivity of the pure PMMA,the (PMMA+EC) system and the (PMMA+PC) system at room temperature is 2.37×10-9,3...

  19. Polymer electrolyte fuel cells: flow field for efficient air operation

    Energy Technology Data Exchange (ETDEWEB)

    Buechi, F.N.; Tsukada, A.; Haas, O.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    A new flow field was designed for a polymer electrolyte fuel cell stack with an active area of 200 cm{sup 2} for operation at low air stoichiometry and low air over pressure. Optimum of gas flow and channel dimensions were calculated based on the required pressure drop in the fluid. Single cells and a bi-cell stack with the new flow field show an improved current/voltage characteristic when operated at low air stoichiometries as compared to that of the previous non optimized design. (author) 4 figs., 3 refs.

  20. Polymer electrolyte fuel cells physical principles of materials and operation

    CERN Document Server

    Eikerling, Michael

    2014-01-01

    The book provides a systematic and profound account of scientific challenges in fuel cell research. The introductory chapters bring readers up to date on the urgency and implications of the global energy challenge, the prospects of electrochemical energy conversion technologies, and the thermodynamic and electrochemical principles underlying the operation of polymer electrolyte fuel cells. The book then presents the scientific challenges in fuel cell research as a systematic account of distinct components, length scales, physicochemical processes, and scientific disciplines. The main part of t

  1. Cold-start characteristics of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Mishler, Jeff [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Wang, Yun [UNIV. CAL. RIVERSIDE; Mishler, Jeff [UNIV. CAL. RIVERSIDE; Mukherjee, Partha P [ORNL

    2010-01-01

    In this paper, we investigate the electrochemical reaction kinetics, species transport, and solid water dynamics in a polymer electrolyte fuel cell (PEFC) during cold start. A simplitied analysis is developed to enable the evaluation of the impact of ice volume fraction on cell performance during coldstart. Supporting neutron imaging data are also provided to reveal the real-time water evolution. Temperature-dependent voltage changes due to the reaction kinetics and ohmic loss are also analyzed based on the ionic conductivity of the membrane at subfreezing temperature. The analysis is valuable for the fundamental study of PEFC cold-start.

  2. Structure of phase-separated ferroelectric/ semiconducting polymer blends for organic non-volatile memories

    NARCIS (Netherlands)

    Mcneill, C.R.; Asadi, K.; Watts, B.; Blom, P.W.M.; Leeuw, D.M. de

    2010-01-01

    The phase-separated structure of blends of the ferroelectric polymer P(VDF-TrFE) and the semiconducting polymer P3HT used in organic non-volatile memories is revealed with soft X-ray spectromicroscopy. These thin-film blends show a columnar morphology, with P3HT-rich columns enclosed in a continuous

  3. Characterization of Polymer Blends: Optical Microscopy (*Polarized, Interference and Phase Contrast Microscopy*) and Confocal Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ramanathan, Nathan Muruganathan [ORNL; Darling, Seth B. [Argonne National Laboratory (ANL)

    2015-01-01

    Chapter 15 surveys the characterization of macro, micro and meso morphologies of polymer blends by optical microscopy. Confocal Microscopy offers the ability to view the three dimensional morphology of polymer blends, popular in characterization of biological systems. Confocal microscopy uses point illumination and a spatial pinhole to eliminate out-of focus light in samples that are thicker than the focal plane.

  4. Study on ion conductivity and crystallinity of composite polymer electrolytes based on poly(ethylene oxide)/poly(acrylonitrile) containing nano-sized Al2O3 fillers.

    Science.gov (United States)

    Kim, Mingyeong; Lee, Lyungyu; Jung, Yongju; Kim, Seok

    2013-12-01

    In this paper, composite polymer electrolytes were prepared by a blend of poly(ethylene oxide) (PEO) and poly(acrylonitrile) (PAN) as a polymer matrix, ethylene carbonate as a plasticizer, LiClO4 as a salt, and by containing a different content of nano-sized Al2O3. The composite films were prepared by using the solution casting method. The crystallinity and ionic conductivity of the polymer electrolytes was investigated using X-ray diffraction (XRD) and AC impedance method, respectively. The morphology of composite polymer electrolyte film was analyzed by SEM method. From the experimental results, by increasing the Al2O3 content, the crystallinity of PEO was reduced, and the ionic conductivity was increased. In particular, by a doping of 15 wt.% Al2O3 in PEO/PAN polymer blend, the CPEs showed the superior ionic conductivity. However, when Al2O3 content exceeds 15 wt.%, the ionic conductivity was decreased. From the surface morphology, it was concluded that the ionic conductivity was decreased because the CPEs showed a heterogenous morphology due to immiscibility or aggregation of the ceramic filler within the polymer matrix.

  5. Luminescent polymer electrolytes based on chitosan and containing europium triflate

    Institute of Scientific and Technical Information of China (English)

    R Alves; ASS de Camargo; A Pawlicka; MM Silva

    2016-01-01

    Solid polymer electrolytes based on chitosan and europium triflate were prepared by solvent casting and characterized by X-ray diffraction, scanning electron microscopy (SEM), atomic force microscopy (AFM), and photoluminescence spectroscopy. The X-ray diffraction exhibited that the samples were essentially amorphous with organized regions over the whole range of the salt content studied. The AFM analysis demonstrated that the smoother sample had roughness of 4.39 nm. Surface visualization through SEM revealed good homogeneity without any phase separation for more conductive samples and the less conductive showed some im-perfections on the surface. The emission and excitation spectra displayed the characteristic bands of Eu(CF3SO3)3 in addition to broad bands corresponding to the polymer host. The excited state5D0 lifetime values ranged from 0.29–0.37 ms for the studied samples.

  6. The influence of the amorphous polymer on conductivity, morphologies and thermal properties of polyether-based blends with addition of inorganic salt

    Science.gov (United States)

    Chan, C. H.; Sim, L. H.; Kammer, H. W.; Tan, W.

    2012-06-01

    Thermodynamic control of the dispersion of lithium (Li) salt in different phases of semicrystalline/amorphous polymer blends is elucidated in this study. Solid polymer electrolytes of poly(ethylene oxide) (PEO), epoxidized natural rubber (ENR), random copolymer of poly(acrylate) (PAc) and as well as polymer blends of PEO with ENR and PAc doped with various concentrations of Li salt were studied. The salt concentrations (CLi) of solid polymer electrolytes vary between CLi = 0.02 and 0.15. The influence of the ENR or PAc on the properties of PEO after addition of Li salt is discussed. Blends of PEO/ENR and PEO/PAc are immiscible by elucidation of the glass transition temperature (Tg) as well as the morphological analyses. PEO, ENR and PAc possess oxygen in their respective chemical structures, which may be able to coordinate with the Li salt added. Non uniformity of Li salt concentration in different phases of the blends is highlighted for both systems. The conductivity of PEO/ENR and PEO/PAc blends doped with Li salt is primarily governed by PEO. The results for Tg suggest that higher solubility of Li salt in PEO as compared to ENR in the former case and restricted ion transport in the glassy PAc (with Tg≈30°C after addition of Li salt in the latter system. These may be the attributing factors for the enhancement of conductivity of the doped-PEO/ENR blends as compared to that of the doped-PEO/PAc blends. This suggests that PEO exhibits greater extent of complexation with LiClO4 as compared to that of the ENR and PAc as supported by Fourier-transform infra-red (FTIR) studies.

  7. Investigation of polymer electrolyte based on agar and ionic liquids

    Directory of Open Access Journals (Sweden)

    M. M. Silva

    2012-12-01

    Full Text Available The possibility to use natural polymer as ionic conducting matrix was investigated in this study. Samples of agarbased electrolytes with different ionic liquids were prepared and characterized by physical and chemical analyses. The ionic liquids used in this work were 1-ethyl-3-methylimidazolium ethylsulfate, [C2mim][C2SO4], 1-ethyl-3-methylimidazolium acetate, [C2mim][OAc] and trimethyl-ethanolammonium acetate, [Ch][OAc]. Samples of solvent-free electrolytes were prepared and characterized by ionic conductivity measurements, thermal analysis, electrochemical stability, X-ray diffraction, scanning electron microscopy and Fourier Transform infrared spectroscopy. Electrolyte samples are thermally stable up to approximately 190°C. All the materials synthesized are semicrystalline. The electrochemical stability domain of all samples is about 2.0 V versus Li/Li+. The preliminary studies carried out with electrochromic devices (ECDs incorporating optimized compositions have confirmed that these materials may perform as satisfactory multifunctional component layers in the field of ‘smart windows’, as well as ECD-based devices.

  8. Chitosan-gold-Lithium nanocomposites as solid polymer electrolyte.

    Science.gov (United States)

    Begum, S N Suraiya; Pandian, Ramanathaswamy; Aswal, Vinod K; Ramasamy, Radha Perumal

    2014-08-01

    Lithium micro batteries are emerging field of research. For environmental safety biodegradable films are preferred. Recently biodegradable polymers have gained wide application in the field of solid polymer electrolytes. To make biodegradable polymers films plasticizers are usually used. However, use of plasticizers has disadvantages such as inhomogenities in phases and mechanical instability that will affect the performance of Lithium micro batteries. We have in this research used gold nanoparticles that are environmentally friendly, instead of plasticizers. Gold nanoparticles were directly template upon chitosan membranes by reduction process so as to enhance the interactions of Lithium with the polymer. In this article, for the first time the characteristics of Chitosan-gold-Lithium nanocomposite films are investigated. The films were prepared using simple solution casting technique. We have used various characterization tools such as Small Angle Neutron Scattering (SANS), XRD, FTIR, Raman, FESEM, and AFM, Light scattering, Dielectric and electrical conductivity measurements. Our investigations show that incorporation of gold results in enhancement of conductivity in Lithium containing Chitosan films. Also it affects the dielectric characteristics of the films. We conclude through various characterization tools that the enhancement in the conductivity was due to the retardation of crystal growth of lithium salt in the presence of gold nanoparticles. A model is proposed regarding the formation of the new nanocomposite. The conductivity of these biodegradable films is comparable to those of the current inorganic Lithium micro batteries. This new chitosan-Au-Li nanocomposite has potential applications in the field of Lithium micro batteries.

  9. Polybenzimidazoles based on high temperature polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Linares Leon, Jose Joaquin; Camargo, Ana Paula M.; Ashino, Natalia M.; Morgado, Daniella L.; Frollini, Elisabeth; Paganin, Valdecir A.; Gonzalez, Ernesto Rafael [Universidade de Sao Paulo (IQSC/USP), Sao Carlos, SP (Brazil); Bajo, Justo Lobato [University of Castilla-La Mancha, Ciudad Real (Spain). Dept. of Chemical Engineering

    2010-07-01

    This work presents an interesting approach in order to enhance the performance of Polymer Electrolyte Membrane Fuel Cells (PEMFC) by means of an increase in the operational temperature. For this, two polymeric materials, Poly(2,5-bibenzimidazole) (ABPBI) and Poly[2,2'-(m-phenyl en)-5,5' bib enzimidazol] (PBI), impregnated with phosphoric acid have been utilized. These have shown excellent properties, such as thermal stability above 500 deg C, reasonably high conductivity when impregnated with H{sub 3}PO{sub 4} and a low permeability to alcohols compared to Nafion. Preliminary fuel cells measurements on hydrogen based Polymer Electrolyte Membrane Fuel Cell (PEMFC) displayed an interestingly reasonable good fuel cell performance, a quite reduced loss when the hydrogen stream was polluted with carbon monoxide, and finally, when the system was tested with an ethanol/water (E/W) fuel, it displayed quite promising results that allows placing this system as an attractive option in order to increase the cell performance and deal with the typical limitations of low temperature Nafion-based PEMFC. (author)

  10. Solid polymer electrolyte composite membrane comprising a porous support and a solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide

    Science.gov (United States)

    Liu, Han; Mittelsteadt, Cortney K; Norman, Timothy J; Griffith, Arthur E; LaConti, Anthony B

    2015-02-24

    A solid polymer electrolyte composite membrane and method of manufacturing the same. According to one embodiment, the composite membrane comprises a thin, rigid, dimensionally-stable, non-electrically-conducting support, the support having a plurality of cylindrical, straight-through pores extending perpendicularly between opposing top and bottom surfaces of the support. The pores are unevenly distributed, with some or no pores located along the periphery and more pores located centrally. The pores are completely filled with a solid polymer electrolyte, the solid polymer electrolyte including a dispersed reduced noble metal or noble metal oxide. The solid polymer electrolyte may also be deposited over the top and/or bottom surfaces of the support.

  11. Thermal and transport properties of the polymer electrolyte based on poly(vinyl alcohol)-KOH-H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, I. [Universidad del Valle, Cali (Colombia). Departamento de Mat. y Fisica; Castillo, R.; Vargas, R.A. [Universidad Tec. del Choco, Quibdo (Colombia). Departamento de Fisica

    2003-06-30

    In this work we report the preparation of a series of alkaline solid electrolyte membranes, based on poly(vinyl alcohol) (PVOH), potassium hydroxide (KOH) and water (PVOH-KOH-H{sub 2}O). They were characterized by electrical conductivity measurements using impedance spectroscopy (EIS), by thermal measurements, using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The most conducting membranes were composed of 45% PVOH, 15% of KOH and 40% wt. of water whose conductivity reaches the value of 2.3x10{sup -3} S cm{sup -1} at room temperature. Temperature dependence of conductivity was found to follow an Arrhenius type behavior rather than the free volume type behavior associated with ion transport mechanism on polymer motion. The conducting phases are established between the observed glass transition of the blends at about 190 K up to where the water content in the sample is completely dehydrated, that is to say, 450 K. The effect of the humidity on the electrolytic characteristics of a cell M / Polymer / M (where M is stainless steel, silver) is quite remarkable. Changes in the conductivity of the polymer at room temperature between 1x10{sup -5} and 2.3x10{sup -3} S cm{sup -1} when the relative humidity changes between the 25 and 85%, respectively, have been observed. The results are explained in terms of the plastification effects of water on the polymer and the presence of a (KOH/H{sub 2}O) separated phase in the polymer. This new alkaline solid electrolyte is interesting from the point of view of its potential application as humidity sensor or electrolytic separator in alkaline batteries. (author)

  12. Poly(vinylidene fluoride)-based, co-polymer separator electrolyte membranes for lithium-ion battery systems

    Science.gov (United States)

    Costa, C. M.; Gomez Ribelles, J. L.; Lanceros-Méndez, S.; Appetecchi, G. B.; Scrosati, B.

    2014-01-01

    In the present paper we report and discuss the physicochemical properties of novel electrolyte membranes, based on poly(vinylidenefluoride-co-trifluoroethylene), PVdF-TrFE, and poly(vinylidenefluoride-co-hexafluoropropylene), PVdF-HFP, co-polymer hosts and the PVdF-TrFE/poly(ethylene oxide (PEO) blend as separators for lithium battery systems. The results have shown that the examined separator membranes, particularly those based on the PVdF co-polymers, are able to uptake large liquid amounts leading to high ionic conductivity values. Tests performed on Li/LiFePO4 and Li/Sn-C cells have revealed very good cycling performance even at high current rates and 100% of DOD, approaching the results achieved in liquid electrolytes. A capacity fading lower than 0.002% per cycle was observed. Particularly, the Li/LiFePO4 cathode cells have exhibited excellent rate capability, being still able to deliver at 2C above 89% of the capacity discharged at 0.1C. These results, in conjunction with the about 100% coulombic efficiency, suggest very good electrolyte/electrode compatibility, which results from the high purity and stability of the electrolyte and electrode materials and the cell manufacturing.

  13. Imprintable, bendable, and shape-conformable polymer electrolytes for versatile-shaped lithium-ion batteries.

    Science.gov (United States)

    Kil, Eun-Hye; Choi, Keun-Ho; Ha, Hyo-Jeong; Xu, Sheng; Rogers, John A; Kim, Mi Ri; Lee, Young-Gi; Kim, Kwang Man; Cho, Kuk Young; Lee, Sang-Young

    2013-03-13

    A class of imprintable, bendable, and shape-conformable polymer electrolyte with excellent electrochemical performance in a lithium battery system is reported. The material consists of a UV-cured polymer matrix, high-boiling point liquid electrolyte, and Al2 O3 nanoparticles, formulated for use in lithium-ion batteries with 3D-structured electrodes or flexible characteristics. The unique structural design and well-tuned rheological characteristics of the UV-curable electrolyte mixture, in combination with direct UV-assisted nanoimprint lithography, allow the successful fabrication of polymer electrolytes in geometries not accessible with conventional materials.

  14. Oxygen reduction on carbon supported platinum catalysts in high temperature polymer electrolytes

    DEFF Research Database (Denmark)

    Qingfeng, Li; Bergqvist, R. S.; Hjuler, H. A.

    1999-01-01

    Oxygen reduction on carbon supported platinum catalysts has been investigated in H3PO4, H3PO4-doped Nafion and PBI polymer electrolytes in a temperature range from 80 to 190°C. Compared with pure H3PO4, using the H3PO4 doped Nafion and PBI polymer electrolytes can significantly improve the oxygen...

  15. Examination of the fundamental relation between ionic transport and segmental relaxation in polymer electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yangyang [ORNL; Fan, Fei [ORNL; Agapov, Alexander L [ORNL; Saito, Tomonori [ORNL; Yang, Jun [ORNL; Yu, Xiang [ORNL; Hong, Kunlun [ORNL; Mays, Jimmy [University of Tennessee, Knoxville (UTK); Sokolov, Alexei P [ORNL

    2014-01-01

    Replacing traditional liquid electrolytes by polymers will significantly improve electrical energy storage technologies. Despite significant advantages for applications in electrochemical devices, the use of solid polymer electrolytes is strongly limited by their poor ionic conductivity. The classical theory predicts that the ionic transport is dictated by the segmental motion of the polymer matrix. As a result, the low mobility of polymer segments is often regarded as the limiting factor for development of polymers with sufficiently high ionic conductivity. Here, we show that the ionic conductivity in many polymers can be strongly decoupled from their segmental dynamics, in terms of both temperature dependence and relative transport rate. Based on this principle, we developed several polymers with superionic conductivity. The observed fast ion transport suggests a fundamental difference between the ionic transport mechanisms in polymers and small molecules and provides a new paradigm for design of highly conductive polymer electrolytes.

  16. A general approach toward enhancement of pseudocapacitive performance of conducting polymers by redox-active electrolytes

    KAUST Repository

    Chen, Wei

    2014-12-01

    A general approach is demonstrated where the pseudocapacitive performance of different conducting polymers is enhanced in redox-active electrolytes. The concept is demonstrated using several electroactive conducting polymers, including polyaniline, polypyrrole, and poly(3,4-ethylenedioxythiophene). As compared to conventional electrolytes, the redox-active electrolytes, prepared by simply adding a redox mediator to the conventional electrolyte, can significantly improve the energy storage capacity of pseudocapacitors with different conducting polymers. The results show that the specific capacitance of conducting polymer based pseudocapacitors can be increased by a factor of two by utilization of the redox-active electrolytes. In fact, this approach gives some of the highest reported specific capacitance values for electroactive conducting polymers. Moreover, our findings present a general and effective approach for the enhancement of energy storage performance of pseudocapacitors using a variety of polymeric electrode materials. © 2014 Elsevier B.V. All rights reserved.

  17. Polaron pair mediated triplet generation in polymer/fullerene blends

    KAUST Repository

    Dimitrov, Stoichko D.

    2015-03-04

    Electron spin is a key consideration for the function of organic semiconductors in light-emitting diodes and solar cells, as well as spintronic applications relying on organic magnetoresistance. A mechanism for triplet excited state generation in such systems is by recombination of electron-hole pairs. However, the exact charge recombination mechanism, whether geminate or nongeminate and whether it involves spin-state mixing is not well understood. In this work, the dynamics of free charge separation competing with recombination to polymer triplet states is studied in two closely related polymer-fullerene blends with differing polymer fluorination and photovoltaic performance. Using time-resolved laser spectroscopic techniques and quantum chemical calculations, we show that lower charge separation in the fluorinated system is associated with the formation of bound electron-hole pairs, which undergo spin-state mixing on the nanosecond timescale and subsequent geminate recombination to triplet excitons. We find that these bound electron-hole pairs can be dissociated by electric fields.

  18. Study on properties of gel polymer electrolytes of PVDF-HFP%凝胶聚合物PVDF-HFP电解质膜的性能研究

    Institute of Scientific and Technical Information of China (English)

    芮含笑; 乔庆东; 李琪

    2012-01-01

    The lithium ion batteries are commercialized due to their shape versatility, flexibility, and lightness and can meet the demands of microelectronic industries. Poly (vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) is one of the most popular polymers for gel polymer electrolytes (GPE) because of its high ionic conductivity, good mechanical, thermal, interfacial, and electrochemical stabilities. In this paper, the progress and the composition of solid polymer electrolyte based on PVDF-HFP was reviewed briefly and the preparation technology of the polymer electrolyte was introduced. The influences on the properties of the polymer electrolyte were analyzed. The progress of modified the polymer electrolyte were discussed, including the modification of filler, plasticizer, polymer, . Copolymerization and blending technologies. The development of polymer electrolyte in the future was also suggested.%锂离子电池由于形状多样化、灵活性及轻便等优点而用于商业化生产,满足微型电子工业的需要,而偏氟乙烯和六氟丙烯的共聚物PVDF-HFP由于较高的电导率,较好的机械强度和热稳定性,优良的界面特性和电化学性能而被认为是最受欢迎的一种聚合物电解质.主要综述了PVDF-HFP固体电解质的组成、制备方法和进展,讨论了PVDF-HFP电解质的改性措施:填料改性、增塑剂改性、共聚共混改性及聚合物改性.对今后的发展方向作了简单展望.

  19. Virus-Assembled Flexible Electrode-Electrolyte Interfaces for Enhanced Polymer-Based Battery Applications

    OpenAIRE

    Ayan Ghosh; Juchen Guo; Brown, Adam D.; Elizabeth Royston; Chunsheng Wang; Peter Kofinas; James N. Culver

    2012-01-01

    High-aspect-ratio cobalt-oxide-coated Tobacco mosaic virus (TMV-) assembled polytetrafluoroethylene (PTFE) nonstick surfaces were integrated with a solvent-free polymer electrolyte to create an anode-electrolyte interface for use in lithium-ion batteries. The virus-assembled PTFE surfaces consisted primarily of cobalt oxide and were readily intercalated with a low-molecular-weight poly (ethylene oxide) (PEO) based diblock copolymer electrolyte to produce a solid anode-electrolyte system. The ...

  20. Performance improvement of gel- and solid-state dye-sensitized solar cells by utilization the blending effect of poly (vinylidene fluoride-co-hexafluropropylene) and poly (acrylonitrile-co-vinyl acetate) co-polymers

    Science.gov (United States)

    Venkatesan, Shanmugam; Obadja, Nesia; Chang, Ting-Wei; Chen, Li-Tung; Lee, Yuh-Lang

    2014-12-01

    Poly (vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP) and poly (acrylonitrile-co-vinyl acetate) (PAN-VA) are used as gelator to prepare gel- and solid-state polymer electrolytes for dye sensitized solar cells (DSSCs) applications. The electrolytes prepared using PVDF-HFP have higher conductivities than those prepared using PAN-VA. In blended polymers, the conductivities of the electrolytes increase with increasing composition of PVDF-HFP; at 75% PVDF-HFP, conductivity of the blended polymer surpassed that of pure polymers. It is also found that the viscosity of the electrolyte prepared by PAN-VA (1.2 kPaS) is much lower than that by PVDF-HFP (11 kPaS). Therefore, increasing PAN-VA composition can decrease the viscosity of the electrolyte, improving the penetration of electrolytes in the TiO2 matrix. By controlling the ratio of PVDF-HFP/PAN-VA, the conductivity and viscosity of the electrolyte can be regulated and an optimal ratio based on the conversion efficiency of the gel- and solid state DSSCs is obtained at the ratio of 3/1. The highest efficiency achieved by the gel- and solid-state cells using the blending polymers are 6.3% and 4.88%, respectively, which are higher than those prepared using pure polymers (5.53% and 4.56%, respectively). The introduction of TiO2 fillers to the solid electrolyte can further increase the cell efficiency to 5.34%.

  1. Electrical Properties of Polymer/Carbon Nanotube Blends

    Science.gov (United States)

    Salgado-Delgado, R.; Olarte-Paredes, A.; Vargas-Galarza, Z.; García-Hernández, E.; Salgado-Delgado, A. M.; Rubio-Rosas, E.; Campos-Álvarez, J.; Castaño, V. M.

    2016-10-01

    Electrical and morphological properties of a novel composite, consisting of polypyrrole (PPy)/carbon black (CB)/carbon nanotubes (CNT), within a polyethylene (PE) matrix, are reported. The electrical properties were studied according to the type of filler (i.e. PPy, CB or CNT). The resistivity, analyzed by the Van der Pauw method, shows values in the range of (1E+15 for PE to 1.07E-01 for M15) Ω cm. The filler is distributed as one phase within the blended matrix and/or at the interface between the polymers, thus producing a highly homogeneous material. The morphology and degree of dispersion of the PPy/CB/CNTs in the PE matrix at different concentrations were investigated by scanning electron microscopy.

  2. Optical characterization of phase transitions in pure polymers and blends

    Energy Technology Data Exchange (ETDEWEB)

    Mannella, Gianluca A.; Brucato, Valerio; La Carrubba, Vincenzo, E-mail: vincenzo.lacarrubba@unipa.it [Department of Civil, Environmental, Aerospace and Materials Engineering (DICAM), University of Palermo, Viale delle Scienze, Ed. 8, 90128 Palermo (Italy)

    2015-12-17

    To study the optical properties of polymeric samples, an experimental apparatus was designed on purpose and set up. The sample is a thin film enclosed between two glass slides and a PTFE frame, with a very thin thermocouple placed on sample for direct temperature measurement. This sample holder was placed between two aluminum slabs, equipped with a narrow slit for optical measurements and with electrical resistances for temperature control. Sample was enlightened by a laser diode, whereas transmitted light was detected with a photodiode. Measurements were carried out on polyethylene-terephtalate (PET) and two different polyamides, tested as pure polymers and blends. The thermal history imposed to the sample consisted in a rapid heating from ambient temperature to a certain temperature below the melting point, a stabilization period, and then a heating at constant rate. After a second stabilization period, the sample was cooled. The data obtained were compared with DSC measurements performed with the same thermal history. In correspondence with transitions detected via DSC (e.g. melting, crystallization and cold crystallization), the optical signal showed a steep variation. In particular, crystallization resulted in a rapid decrease of transmitted light, whereas melting gave up an increase of light transmitted by the sample. Further variations in transmitted light were recorded for blends, after melting: those results may be related to other phase transitions, e.g. liquid-liquid phase separation. All things considered, the apparatus can be used to get reliable data on phase transitions in polymeric systems.

  3. New high-throughput methods of investigating polymer electrolytes

    Science.gov (United States)

    Alcock, Hannah J.; White, Oliver C.; Jegelevicius, Grazvydas; Roberts, Matthew R.; Owen, John R.

    2011-03-01

    Polymer electrolyte films have been prepared by solution casting techniques from precursor solutions of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP), lithium-bis(trifluoromethane) sulfonimide (LiTFSI), and propylene carbonate (PC). Arrays of graded composition were characterised by electrochemical impedance spectroscopy (EIS), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) using high throughput techniques. Impedance analysis showed the resistance of the films as a function of LiTFSI, PC and polymer content. The ternary plot of conductivity shows an area that combines a solid-like mechanical stability with high conductivity, 1 × 10-5 S cm-1 at the composition 0.55/0.15/0.30 wt% PVdF-HFP/LiTFSI/PC, increasing with PC content. In regions with less than a 50 wt% fraction of PVdF-HFP the films were too soft to give meaningful results by this method. The DSC measurements on solvent free, salt-doped polymers show a reduced crystallinity, and high throughput XRD patterns show that non-polar crystalline phases are suppressed by the presence of LiTFSI and PC.

  4. Electrocatalysis in Water Electrolysis with Solid Polymer Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Rasten, Egil

    2001-10-01

    Development and optimization of the electrodes in a water electrolysis system using a polymer membrane as electrolyte have been carried out in this work. A cell voltage of 1.59 V (energy consumption of about 3.8 kWh/Nm{sub 3} H{sub 2}) has been obtained at practical operation conditions of the electrolysis cell (10 kA . m2, 90{sup o}C) using a total noble metal loading of less than 2.4 mg.cm{sub 2} and a Nafion -115 membrane. It is further shown that a cell voltage of less than 1.5 V is possible at the same conditions by combination of the best electrodes obtained in this work. The most important limitation of the electrolysis system using polymer membrane as electrolyte has proven to be the electrical conductivity of the catalysts due to the porous backing/current collector system, which increases the length of the current path and decreases the cross section compared to the apparent one. A careful compromise must therefore be obtained between electrical conductivity and active surface area, which can be tailored by preparation and annealing conditions of the metal oxide catalysts. Anode catalysts of different properties have been developed. The mixed oxide of Ir-Ta (85 mole% Ir) was found to exhibit highest voltage efficiency at a current density of 10 kA.m{sub 2} or below, whereas the mixed oxide of Ir and Ru (60-80 mole% Ir) was found to give the highest voltage efficiency for current densities of above 10 kA.m{sub 2}. Pt on carbon particles, was found to be less suitable as cathode catalyst in water electrolysis. The large carbon particles introduced an unnecessary porosity into the catalytic layer, which resulted in a high ohmic drop. Much better voltage efficiency was obtained by using Pt-black as cathode catalyst, which showed a far better electrical conductivity. Ru-oxide as cathode catalyst in water electrolysis systems using a polymer electrolyte was not found to be of particular interest due to insufficient electrochemical activity and too low

  5. Composite gel polymer electrolyte for lithium ion batteries

    Science.gov (United States)

    Naderi, Roya

    Composite gel polymer electrolyte (CGPE) films, consisting of poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) as the membrane, DMF and PC as solvent and plasticizing agent, mixture of charge modified TiO2 and SiO 2 nano particles as ionic conductors, and LiClO4+LiPF 6 as lithium salts were fabricated. Following the work done by Li et al., CGPE was coated on an O2-plasma treated trilayer polypropylene-polyethylene-polypropylene membrane separator using solution casting technique in order to improve the adhesive properties of gel polymer electrolyte to the separator membrane and its respective ionic conductivity due to decreasing the bulk resistance. In acidic CGPE with, the mixture of acid treated TiO2 and neutral SiO2 nano particles played the role of the charge modified nano fillers with enhanced hydroxyl groups. Likely, the mixture of neutral TiO 2 nano particles with basic SiO2 prepared through the hydrolization of tetraethyl orthosilicate (TEOS) provided a more basic environment due to the residues of NH4OH (Ammonium hydroxide) catalyst. The O2 plasma treated separator was coated with the solution of PVDF-HFP: modified nano fillers: Organic solvents with the mixture ratio of 0.1:0.01:1. After the evaporation of the organic solvents, the dried coated separator was soaked in PC-LiClO4+LiPF6 in EC: DMC:DEC (4:2:4 in volume) solution (300% wt. of PVDF-HFP) to form the final CGPE. Lim et al. has reported the enhanced ionic conductivity of 9.78*10-5 Scm-1 in an acidic composite polystyrene-Al2O3 solid electrolyte system with compared to that of basic and neutral in which the ionic conductivity undergoes an ion hopping process in solid interface rather than a segmental movement of ions through the plasticized polymer chain . Half-cells with graphite anode and Li metal as reference electrode were then assembled and the electrochemical measurements and morphology examinations were successfully carried out. Half cells demonstrated a considerable change in their

  6. Effect of Poly(Ether Urethane)Introduction on the Performance of Polymer Electrolyte for All-Solid-State Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yan-Fang; XIANG Wan-Chun; FANG Shi-Bi; CHEN Shen; ZHOU Xiao-Wen; ZHANG Jing-Bo; LIN Yuan

    2009-01-01

    The introduction of poly(ether urethane)(PEUR)into polymer electrolyte based on poly(ethylene oxide),LiI and I_2,has significantly increased the ionic conductivity by nearly two orders of magnitudes.An increment of I_3~- diffusion coefficient is also observed.All-solid-state dye-sensitized solar cells are constructed using the polymer electrolytes.It was found that PEUR incorporation has a beneficial effect on the enhancement of open circuit voltage V_(OC) by shifting the band edge of TiO_2 to a negative value.Scanning electron microscope images indicate the perfect interfacial contact between the TiO_2 electrode and the blend electrolyte.

  7. Solid Polymer Electrolytes Based on Cross-linkable Oligo (oxyethylene)-Branched Oligo (organophosphazenes)

    Institute of Scientific and Technical Information of China (English)

    Shuhua Zhou; Shibi Fang

    2005-01-01

    @@ 1Introduction Solid polymer electrolytes have attracted considerable interest because of their potential application in secondary high energy density lithium batteries. The poly(ethylene oxide)(PEO) has been widely studied as the classical polymer matrix for solid polymer electrolytes. However, the poor room temperature conductivity due to its crystalline is the principal problem to be overcomed. This has prompted many researchers to attempt to modify the properties of PEO.

  8. Surface Characterization of Polymer Blends by XPS and ToF-SIMS

    Directory of Open Access Journals (Sweden)

    Chi Ming Chan

    2016-08-01

    Full Text Available The surface properties of polymer blends are important for many industrial applications. The physical and chemical properties at the surface of polymer blends can be drastically different from those in the bulk due to the surface segregation of the low surface energy component. X-ray photoelectron spectroscopy (XPS and time-of-flight secondary mass spectrometry (ToF-SIMS have been widely used to characterize surface and bulk properties. This review provides a brief introduction to the principles of XPS and ToF-SIMS and their application to the study of the surface physical and chemical properties of polymer blends.

  9. The model of stress distribution in polymer electrolyte membrane

    CERN Document Server

    Atrazhev, Vadim V; Dmitriev, Dmitry V; Erikhman, Nikolay S; Sultanov, Vadim I; Patterson, Timothy; Burlatsky, Sergei F

    2014-01-01

    An analytical model of mechanical stress in a polymer electrolyte membrane (PEM) of a hydrogen/air fuel cell with porous Water Transfer Plates (WTP) is developed in this work. The model considers a mechanical stress in the membrane is a result of the cell load cycling under constant oxygen utilization. The load cycling causes the cycling of the inlet gas flow rate, which results in the membrane hydration/dehydration close to the gas inlet. Hydration/dehydration of the membrane leads to membrane swelling/shrinking, which causes mechanical stress in the constrained membrane. Mechanical stress results in through-plane crack formation. Thereby, the mechanical stress in the membrane causes mechanical failure of the membrane, limiting fuel cell lifetime. The model predicts the stress in the membrane as a function of the cell geometry, membrane material properties and operation conditions. The model was applied for stress calculation in GORE-SELECT.

  10. Segmented polymer electrolyte membrane fuel cells - A review

    Energy Technology Data Exchange (ETDEWEB)

    Perez, Luis C.; Brandao, Lucia; Mendes, Adelio [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Roberto Frias, 4200-465 Porto (Portugal); Sousa, Jose M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Roberto Frias, 4200-465 Porto (Portugal); Chemistry Department, University of Tras-os-Montes e Alto Douro, Apartado 202, 5001-911 Vila-Real Codex (Portugal)

    2011-01-15

    A complex interaction of many design, assembling and operating parameters as well as the properties of the materials used in the construction of polymer electrolyte membrane fuel cells (PEMFC) result in an uneven electrochemical performance over the MEA active area. For more than one decade, segmented PEMFC (SFC) have been used to study the factors responsible for that uneven performance. This paper reviews relevant literature related to SFC published since 1998 focusing on the three most important SFC design techniques: (1) printed circuit board, (2) resistors network and (3) Hall effect sensors. First, the three techniques are described and fundamental considerations for its design, construction and electrochemical characterization are provided. After that, the effect of most important parameters on the current density distribution is highlighted. Finally, representative results combining current density distribution measurements with other analytical techniques for distributed analysis are presented. (author)

  11. Polymer electrolyte fuel cell mini power unit for portable application

    Energy Technology Data Exchange (ETDEWEB)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E. [CNR-ITAE, via Salita S. Lucia sopra Contesse n. 5, 98126 S. Lucia, Messina (Italy); Zerbinati, O. [Universita del Piemonte Orientale, Dip. di Scienze dell' Ambiente e della Vita, via Bellini 25/g, 15100 Alessandria (Italy)

    2007-06-20

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H{sub 2} supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm{sup 2} and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance. (author)

  12. Polymer electrolyte fuel cell mini power unit for portable application

    Science.gov (United States)

    Urbani, F.; Squadrito, G.; Barbera, O.; Giacoppo, G.; Passalacqua, E.; Zerbinati, O.

    This paper describes the design, realisation and test of a power unit based on a polymer electrolyte fuel cell, operating at room temperature, for portable application. The device is composed of an home made air breathing fuel cell stack, a metal hydride tank for H 2 supply, a dc-dc converter for power output control and a fan for stack cooling. The stack is composed by 10 cells with an active surface of 25 cm 2 and produces a rated power of 15 W at 6 V and 2 A. The stack successfully runs with end-off fed hydrogen without appreciable performance degradation during the time. The final assembled system is able to generate 12 W at 9.5 V, and power a portable DVD player for 3 h in continuous. The power unit has collected about 100 h of operation without maintenance.

  13. Advances in Ceramic Supports for Polymer Electrolyte Fuel Cells

    Directory of Open Access Journals (Sweden)

    Oran Lori

    2015-08-01

    Full Text Available Durability of catalyst supports is a technical barrier for both stationary and transportation applications of polymer-electrolyte-membrane fuel cells. New classes of non-carbon-based materials were developed in order to overcome the current limitations of the state-of-the-art carbon supports. Some of these materials are designed and tested to exceed the US DOE lifetime goals of 5000 or 40,000 hrs for transportation and stationary applications, respectively. In addition to their increased durability, the interactions between some new support materials and metal catalysts such as Pt result in increased catalyst activity. In this review, we will cover the latest studies conducted with ceramic supports based on carbides, oxides, nitrides, borides, and some composite materials.

  14. Resistive switching memory based on bioinspired natural solid polymer electrolytes.

    Science.gov (United States)

    Raeis Hosseini, Niloufar; Lee, Jang-Sik

    2015-01-27

    A solution-processed, chitosan-based resistive-switching memory device is demonstrated with Pt/Ag-doped chitosan/Ag structure. The memory device shows reproducible and reliable bipolar resistive switching characteristics. A memory device based on natural organic material is a promising device toward the next generation of nonvolatile nanoelectronics. The memory device based on chitosan as a natural solid polymer electrolyte can be switched reproducibly between high and low resistance states. In addition, the data retention measurement confirmed the reliability of the chitosan-based nonvolatile memory device. The transparent Ag-embedded chitosan film showed an acceptable and comparable resistive switching behavior on the flexible plastic substrate as well. A cost-effective, environmentally benign memory device using chitosan satisfies the functional requirements of nonvolatile memory operations.

  15. On a Pioneering Polymer Electrolyte Fuel Cell Model

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Adam Z.; Meyers, Jeremy P.

    2010-07-07

    "Polymer Electrolyte Fuel Cell Model" is a seminal work that continues to form the basis for modern modeling efforts, especially models concerning the membrane and its behavior at the continuum level. The paper is complete with experimental data, modeling equations, model validation, and optimization scenarios. While the treatment of the underlying phenomena is limited to isothermal, single-phase conditions, and one-dimensional flow, it represents the key interactions within the membrane at the center of the PEFC. It focuses on analyzing the water balance within the cell and clearly demonstrates the complex interactions of water diffusion and electro-osmotic flux. Cell-level and system-level water balance are key to the development of efficient PEFCs going forward, particularly as researchers address the need to simplify humidification and recycle configurations while increasing the operating temperature of the stack to minimize radiator requirements.

  16. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells.

    Science.gov (United States)

    Johánek, Viktor; Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis) mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side) downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc.) on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein) polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed) subjected to a wide range of conditions.

  17. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Science.gov (United States)

    Ostroverkh, Anna; Fiala, Roman; Rednyk, Andrii; Matolín, Vladimír

    2016-01-01

    The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis) mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side) downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc.) on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein) polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed) subjected to a wide range of conditions. PMID:28042492

  18. Mass Spectrometry of Polymer Electrolyte Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Viktor Johánek

    2016-01-01

    Full Text Available The chemical analysis of processes inside fuel cells under operating conditions in either direct or inverted (electrolysis mode and their correlation with potentiostatic measurements is a crucial part of understanding fuel cell electrochemistry. We present a relatively simple yet powerful experimental setup for online monitoring of the fuel cell exhaust (of either cathode or anode side downstream by mass spectrometry. The influence of a variety of parameters (composition of the catalyst, fuel type or its concentration, cell temperature, level of humidification, mass flow rate, power load, cell potential, etc. on the fuel cell operation can be easily investigated separately or in a combined fashion. We demonstrate the application of this technique on a few examples of low-temperature (70°C herein polymer electrolyte membrane fuel cells (both alcohol- and hydrogen-fed subjected to a wide range of conditions.

  19. PREPARATION AND CHARACTERIZATION OF AMIDATED PECTIN BASED POLYMER ELECTROLYTE MEMBRANES

    Institute of Scientific and Technical Information of China (English)

    R.K.Mishra; A.Anis; S.Mondal; M.Dutt; A.K.Banthia

    2009-01-01

    The work presents the synthesis and characterization of ami dated pectin(AP)based polymer electrolyte membranes(PEM)crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA)and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(YM and YN)are calculated based on the results of organic elemental analysis.FTIR spectroscopy indicated the presence of primary and secondary amide absorption bands.XRD pattern of membranes clearly indicates that there is a considerable increase in crystallinity as compared to parent pectin.TGA studies indicate that AP is less thermally stable than reference pectin.A maximum room temperature conductivity of 1.098×10-3 Scm-1 is obtained in the membrane,which is designated as AP-3.These properties make them good candidates for low cost biopolymer electrolyte membranes for fuel cell applications.

  20. Ionic Liquid based polymer electrolytes for electrochemical sensors

    Directory of Open Access Journals (Sweden)

    Jakub Altšmíd

    2015-09-01

    Full Text Available Amperometric NO2 printed sensor with a new type of solid polymer electrolyte and a carbon working electrode has been developed. The electrolytes based on 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonylimide [EMIM][N(Tf2], 1-butyl-3-methylimidazolium trifluoromethanesulfonate [BMIM][CF3SO3] and 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF4] ionic liquids were immobilized in poly(vinylidene fluoride matrix [PVDF]. The analyte, gaseous nitrogen dioxide, was detected by reduction at -500 mV vs. platinum pseudoreference electrode. The sensors showed a linear behavior in the whole tested range, i.e., 0 - 5 ppm and their sensitivities were in order of 0.3 x∙10-6 A/ppm. The sensor sensitivity was influenced by the electric conductivity of printing formulation; the higher the conductivity, the higher the sensor sensitivity. The rise/recovery times were in order of tens of seconds. The use of  screen printing technology and platinum pseudoreference electrode simplify the sensor fabrication and it does not have any negative effect on the sensor stability.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7371

  1. Polymer Electrolyte Membrane (PEM) Fuel Cells Modeling and Optimization

    Science.gov (United States)

    Zhang, Zhuqian; Wang, Xia; Shi, Zhongying; Zhang, Xinxin; Yu, Fan

    2006-11-01

    Performance of polymer electrolyte membrane (PEM) fuel cells is dependent on operating parameters and designing parameters. Operating parameters mainly include temperature, pressure, humidity and the flow rate of the inlet reactants. Designing parameters include reactants distributor patterns and dimensions, electrodes dimensions, and electrodes properties such as porosity, permeability and so on. This work aims to investigate the effects of various designing parameters on the performance of PEM fuel cells, and the optimum values will be determined under a given operating condition.A three-dimensional steady-state electrochemical mathematical model was established where the mass, fluid and thermal transport processes are considered as well as the electrochemical reaction. A Powell multivariable optimization algorithm will be applied to investigate the optimum values of designing parameters. The objective function is defined as the maximum potential of the electrolyte fluid phase at the membrane/cathode interface at a typical value of the cell voltage. The robustness of the optimum design of the fuel cell under different cell potentials will be investigated using a statistical sensitivity analysis. By comparing with the reference case, the results obtained here provide useful tools for a better design of fuel cells.

  2. Characterizations of Chitosan-Based Polymer Electrolyte Photovoltaic Cells

    Directory of Open Access Journals (Sweden)

    M. H. Buraidah

    2010-01-01

    Full Text Available The membranes 55 wt.% chitosan-45 wt.% NH4I, 33 wt.% chitosan-27 wt.% NH4I-40 wt.% EC, and 27.5 wt.% chitosan-22.5 wt.% NH4I-50 wt.% buthyl-methyl-imidazolium-iodide (BMII exhibit conductivity of 3.73×10−7, 7.34×10−6, and 3.43×10−5 S cm−1, respectively, at room temperature. These membranes have been used in the fabrication of solid-state solar cells with configuration ITO/TiO2/polymer electrolyte membrane/ITO. It is observed that the short-circuit current density increases with conductivity of the electrolyte. The use of anthocyanin pigment obtained by solvent extraction from black rice and betalain from the callus of Celosia plumosa also helps to increase the short-circuit current.

  3. Polymer Brush Grafted Nanoparticles and Their Impact on the Morphology Evolution of Polymer Blend Films

    Science.gov (United States)

    Chung, Hyun-Joong; Ohno, Kohji; Composto, Russell

    2013-03-01

    We present an novel pathway to control the location of nanoparticles (NPs) in phase-separating polymer blend films containing poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN). Because hydrophobic polymer phases have a small interfacial energy, ~1 mJ/m2, subtle changes in the NP surface functionality can be used to guide NPs to either the interface between immiscible polymers or into one of the phases. Based on this idea, we designed a class of NPs grafted with PMMA brushes. These PMMA brushes were grown from the NP surface by atom transfer radical polymerization (ATRP), which results in chains terminated with chlorine atoms. The chain end can be substituted with protons (H) by dehalogenation. As a result, the NPs are strongly segregated at the interface when grafted PMMA chains are short (Mn =1.8K) and the end group is Cl, whereas NPs partition into PMMA-rich phase when chains are long (Mn =160K) and/or when chains are terminated with hydrogen. The Cl end groups and shorter chain length cause an increase in surface energy for the NPs. The increase in surface energy of short-chained NPs can be attributed to (i) an extended brush conformation (entropic) and/or (ii) a high density of ``unfavorable'' end groups (enthalpic). Finally, the impact of NPs on the morphological evolution of the polymer blend films will be discussed. Ref: H.-J.Chung et al., ACS Macro Lett. 1(1), 252-256 (2012).

  4. Polylactic Acid-Based Polymer Blends for Durable Applications

    Science.gov (United States)

    Finniss, Adam

    There has been considerable scientific interest in both research and commercial communities as of late in the area of biologically based or sourced plastics. As the consumption of petroleum rises and concerns about climate change increase, this field is likely to grow even larger. One bioplastic that has received a great deal of attention is polylactic acid (PLA). In the past, this material was used mainly in medical or specialty applications, but advancements in manufacturing have led to a desire to use PLA more widely, especially in durable applications. Unfortunately, PLA has several drawbacks that hinder more widespread usage of the material as a durable item: it has low ductility and impact strength in bulk applications, along with poor stability in the face of heat, humidity or liquid media. To combat these deficiencies, a number of techniques were investigated. Samples were annealed to create crystalline domains that would improve mechanical properties and reduce diffusion, blended with graphene to create barriers to diffusion throughout the material, or compounded with a polycarbonate (PC) polymer phase to protect the PLA phase and to enhance the mechanical properties of the blend. If a material containing biologically sourced components with good mechanical properties can be created, it would be desirable for durable uses such as electronics components or as an automotive grade resin. Crystallization experiments were carried out in a differential scanning calorimeter to determine the effects of heat treatment and additives on the rather slow crystallization kinetics of PLA polymer. It was determined that the blending in of the PC phase did not significantly alter the kinetics or mechanism of crystal growth. The addition of graphene to any PC/PLA formulation served as a nucleating agent which speeded up the crystallization kinetics markedly, in some cases by several orders of magnitude. Results obtained from these experiments were internally consistent

  5. High elastic modulus polymer electrolytes suitable for preventing thermal runaway in lithium batteries

    Science.gov (United States)

    Mullin, Scott; Panday, Ashoutosh; Balsara, Nitash Pervez; Singh, Mohit; Eitouni, Hany Basam; Gomez, Enrique Daniel

    2014-04-22

    A polymer that combines high ionic conductivity with the structural properties required for Li electrode stability is useful as a solid phase electrolyte for high energy density, high cycle life batteries that do not suffer from failures due to side reactions and dendrite growth on the Li electrodes, and other potential applications. The polymer electrolyte includes a linear block copolymer having a conductive linear polymer block with a molecular weight of at least 5000 Daltons, a structural linear polymer block with an elastic modulus in excess of 1.times.10.sup.7 Pa and an ionic conductivity of at least 1.times.10.sup.-5 Scm.sup.-1. The electrolyte is made under dry conditions to achieve the noted characteristics. In another aspect, the electrolyte exhibits a conductivity drop when the temperature of electrolyte increases over a threshold temperature, thereby providing a shutoff mechanism for preventing thermal runaway in lithium battery cells.

  6. Mechanical Properties and Adhesion of a Micro Structured Polymer Blend

    Directory of Open Access Journals (Sweden)

    Brunero Cappella

    2011-07-01

    Full Text Available A 50:50 blend of polystyrene (PS and poly(n-butyl methacrylate (PnBMA has been characterized with an Atomic Force Microscope (AFM in Tapping Mode and with force-distance curves. The polymer solution has been spin-coated on a glass slide. PnBMA builds a uniform film on the glass substrate with a thickness of @200 nm. On top of it, the PS builds an approximately 100 nm thick film. The PS-film undergoes dewetting, leading to the formation of holes surrounded by about 2 µm large rims. In those regions of the sample, where the distance between the holes is larger than about 4 µm, light depressions in the PS film can be observed. Topography, dissipated energy, adhesion, stiffness and elastic modulus have been measured on these three regions (PnBMA, PS in the rims and PS in the depressions. The two polymers can be distinguished in all images, since PnBMA has a higher adhesion and a smaller stiffness than PS, and hence a higher dissipated energy. Moreover, the polystyrene in the depressions shows a very high adhesion (approximately as high as PnBMA and its stiffness is intermediate between that of PnBMA and that of PS in the rims. This is attributed to higher mobility of the PS chains in the depressions, which are precursors of new holes.

  7. Performance of solid state supercapacitors based on polymer electrolytes containing different ionic liquids

    Science.gov (United States)

    Tiruye, Girum Ayalneh; Muñoz-Torrero, David; Palma, Jesus; Anderson, Marc; Marcilla, Rebeca

    2016-09-01

    Four Ionic Liquid based Polymer Electrolytes (IL-b-PE) were prepared by blending a Polymeric Ionic Liquid, Poly(diallyldimethylammonium) bis(trifluoromethanesulfonyl)imide (PILTFSI), with four different ionic liquids: 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI) (IL-b-PE1), 1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (PYR14FSI) (IL-b-PE2), 1-(2-hydroxy ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (HEMimTFSI) (IL-b-PE3), and 1-Butyl-1-methylpyrrolidinium dicyanamide, (PYR14DCA) (IL-b-PE4). Physicochemical properties of IL-b-PE such as ionic conductivity, thermal and electrochemical stability were found to be dependent on the IL properties. For instance, ionic conductivity was significantly higher for IL-b-PE2 and IL-b-PE4 containing IL with small size anions (FSI and DCA) than IL-b-PE1 and IL-b-PE3 bearing IL with bigger anion (TFSI). On the other hand, wider electrochemical stability window (ESW) was found for IL-b-PE1 and IL-b-PE2 having ILs with electrochemically stable pyrrolidinium cation and FSI and TFSI anions. Solid state Supercapacitors (SCs) were assembled with activated carbon electrodes and their electrochemical performance was correlated with the polymer electrolyte properties. Best performance was obtained with SC having IL-b-PE2 that exhibited a good compromise between ionic conductivity and electrochemical window. Specific capacitance (Cam), real energy (Ereal) & real power densities (Preal) as high as 150 F g-1, 36 Wh kg-1 & 1170 W kg-1 were found at operating voltage of 3.5 V.

  8. Dye-sensitized solar cell using 4-chloro-7-nitrobenzofurazan incorporated polyvinyl alcohol polymer electrolyte

    Science.gov (United States)

    Senthil, R. A.; Theerthagiri, J.; Madhavan, J.; Arof, A. K.

    2016-11-01

    The influence of 4-chloro-7-nitrobenzofurazan (CNBF) on ionic conductivity of polyvinyl alcohol/KI/I2 (PVA/KI/I2) electrolytes was investigated in the present study. The pure and CNBF incorporated PVA/KI/I2 electrolyte films were prepared by solution casting method using dimethyl sulfoxide as a solvent. These polymer electrolyte films were characterized using Fourier transform infrared spectroscopy, X-ray diffractometer, UV-Vis spectrophotometer and impedance analysis. The ionic conductivities of polymer electrolyte films were calculated from impedance analysis. The pure PVA/KI/I2 electrolyte exhibited the ionic conductivity of 1.649 × 10-5 S cm-1 at room temperature and this value was significantly increased to 1.490 × 10-4 S cm-1 when CNBF was incorporated into the PVA/KI/I2 electrolyte. This might be due to the decrease in the crystallinity of the polymer and increase in the ionic mobility of charge carriers. The performance of the DSSCs using both pure and CNBF incorporated PVA/KI/I2 electrolytes were compared. A DSSC fabricated with CNBF incorporated PVA/KI/I2 electrolyte showed an improved power conversion efficiency of 3.89 % than that of the pure PVA/KI/I electrolyte (1.51 %). These results suggest that CNBF incorporated PVA/KI/I2 electrolyte could be used as a potential electrolyte for DSSC.

  9. High Ionic Conductivity of Composite Solid Polymer Electrolyte via In Situ Synthesis of Monodispersed SiO2 Nanospheres in Poly(ethylene oxide).

    Science.gov (United States)

    Lin, Dingchang; Liu, Wei; Liu, Yayuan; Lee, Hye Ryoung; Hsu, Po-Chun; Liu, Kai; Cui, Yi

    2016-01-13

    High ionic conductivity solid polymer electrolyte (SPE) has long been desired for the next generation high energy and safe rechargeable lithium batteries. Among all of the SPEs, composite polymer electrolyte (CPE) with ceramic fillers has garnered great interest due to the enhancement of ionic conductivity. However, the high degree of polymer crystallinity, agglomeration of ceramic fillers, and weak polymer-ceramic interaction limit the further improvement of ionic conductivity. Different from the existing methods of blending preformed ceramic particles with polymers, here we introduce an in situ synthesis of ceramic filler particles in polymer electrolyte. Much stronger chemical/mechanical interactions between monodispersed 12 nm diameter SiO2 nanospheres and poly(ethylene oxide) (PEO) chains were produced by in situ hydrolysis, which significantly suppresses the crystallization of PEO and thus facilitates polymer segmental motion for ionic conduction. In addition, an improved degree of LiClO4 dissociation can also be achieved. All of these lead to good ionic conductivity (1.2 × 10(-3) S cm(-1) at 60 °C, 4.4 × 10(-5) S cm(-1) at 30 °C). At the same time, largely extended electrochemical stability window up to 5.5 V can be observed. We further demonstrated all-solid-state lithium batteries showing excellent rate capability as well as good cycling performance.

  10. Enhancement of ionic conductivity of PEO based polymer electrolyte by the addition of nanosize ceramic powders.

    Science.gov (United States)

    Wang, G X; Yang, L; Wang, J Z; Liu, H K; Dou, S X

    2005-07-01

    The ionic conductivity of polyethylene oxide (PEO) based solid polymer electrolytes (SPEs) has been improved by the addition of nanosize ceramic powders (TiO2 and AL2O3). The PEO based solid polymer electrolytes were prepared by the solution-casting method. Electrochemical measurement shows that the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte has the best ionic conductivity (about 10(-4) S cm(-1) at 40-60 degrees C). The lithium transference number of the 10 wt% TiO2 PEO-LiClO4 polymer electrolyte was measured to be 0.47, which is much higher than that of bare PEO polymer electrolyte. Ac impedance testing shows that the interface resistance of ceramic-added PEO polymer electrolyte is stable. Linear sweep voltammetry measurement shows that the PEO polymer electrolytes are electrochemically stable in the voltage range of 2.0-5.0 V versus a Li/Li+ reference electrode.

  11. Characterization of gamma irradiated plasticized carboxymethyl cellulose (CMC)/gum arabic (GA) polymer blends as absorbents for dyestuffs

    Indian Academy of Sciences (India)

    Sayeda M Ibrahim; Issa M Mousaa; Mervat S Ibrahim

    2014-05-01

    Polymer blends based on carboxymethylcellulose (CMC) and gum arabic (GA) were prepared by solution casting method. Glycerol was added to the polymer blend solution as a plasticizer with different ratios (2.5, 5, 10 and 20%). Then, the plasticized blends were exposed to gamma irradiation at different doses (5, 10 and 20 kGy). The physical properties of the plasticized polymer blends were investigated in terms of gel fraction (%) and swelling percent (%). Thermal properties were investigated by TGA. Also, the structure of the plasticized polymer blends was characterized by Fourier transform infrared spectroscopy. Scanning electron microscope was investigated in order to examine the compatibility between two polymers in the blend and also between polymer blend and plasticizer. The prepared plasticized polymer blends were used as an adsorbent for different dyestuffs. The sorption of dyestuffs by the plasticized polymer blend was determined by a method based on spectroscopic analysis. The results showed that the plasticized polymer blend has a high affinity for basic, acid, reactive and direct dyes. The obtained results showed that using glycerol as plasticizer improved the swellability of polymer blend and also the dye uptake (%).

  12. Composite Electrolytes for Lithium Batteries: Ionic Liquids in APTES Crosslinked Polymers

    Science.gov (United States)

    Tigelaar, Dean M.; Meador, Mary Ann B.; Bennett, William R.

    2007-01-01

    Solvent free polymer electrolytes were made consisting of Li(+) and pyrrolidinium salts of trifluoromethanesulfonimide added to a series of hyperbranched poly(ethylene oxide)s (PEO). The polymers were connected by triazine linkages and crosslinked by a sol-gel process to provide mechanical strength. The connecting PEO groups were varied to help understand the effects of polymer structure on electrolyte conductivity in the presence of ionic liquids. Polymers were also made that contain poly(dimethylsiloxane) groups, which provide increased flexibility without interacting with lithium ions. When large amounts of ionic liquid are added, there is little dependence of conductivity on the polymer structure. However, when smaller amounts of ionic liquid are added, the inherent conductivity of the polymer becomes a factor. These electrolytes are more conductive than those made with high molecular weight PEO imbibed with ionic liquids at ambient temperatures, due to the amorphous nature of the polymer.

  13. Novel Stable Gel Polymer Electrolyte: Toward a High Safety and Long Life Li-Air Battery.

    Science.gov (United States)

    Yi, Jin; Liu, Xizheng; Guo, Shaohua; Zhu, Kai; Xue, Hailong; Zhou, Haoshen

    2015-10-28

    Nonaqueous Li-air battery, as a promising electrochemical energy storage device, has attracted substantial interest, while the safety issues derived from the intrinsic instability of organic liquid electrolytes may become a possible bottleneck for the future application of Li-air battery. Herein, through elaborate design, a novel stable composite gel polymer electrolyte is first proposed and explored for Li-air battery. By use of the composite gel polymer electrolyte, the Li-air polymer batteries composed of a lithium foil anode and Super P cathode are assembled and operated in ambient air and their cycling performance is evaluated. The batteries exhibit enhanced cycling stability and safety, where 100 cycles are achieved in ambient air at room temperature. The feasibility study demonstrates that the gel polymer electrolyte-based polymer Li-air battery is highly advantageous and could be used as a useful alternative strategy for the development of Li-air battery upon further application.

  14. Modification of PE/PP Polymer Blend Nanocomposites with EPR and EVA Copolymers

    Directory of Open Access Journals (Sweden)

    Jelenčić, J.

    2010-04-01

    Full Text Available During the last decade, the use of polyolephinic polymers has been growing in a wide range of fields of applicability and the most widely used polymers are polyethylene and polypropylene. They can be processed separately to produce items with certain properties as well as in the form of blends, where special combinations of properties and price are intended. As it is known, polyethylene (PE and polypropylene (PP are incompatible and the weak interfacial bond strength between the phases directly linked to the blend morphology and results in poor mechanical properties. The properties of many polymer blends arise from the fine-scale structural arrangements or blend morphologies obtained during processing in addition to the proportion of each polymer type present. Compounding PE/PP blends with a single compatibilizer or their combination or some other additives as nanofiller, results in multi-component composites of great interest to research as they enable simultaneous improvement in the final properties of the blend. In addition, it is well known that the extrusion process has a significant effect on the dispersion of the filler in the blends. In this work, the mutual effect of the nanofiller silicium-dioxide (SiO2 and the compatibilizers ethylene-propylene copolymer (EPR and ethylene-vinyl acetate copolymer (EVA on the properties of blends based on polyethylene and polypropylene were studied. The morphology of the samples prepared with nanofiller and compatibilizers is much finer in comparison to the virgin blend. Better dispersion of nanofiller will result in better stability of the polymer blend and decrease in polymer flammability. The addition of the nanofiller and compatibilizers produced an increase in the elasticity especially for the samples prepared in the two-stage extrusion process where the nanofiller was first extruded with PE matrix and then with other polymers of the blends. SEM micrographs confirm finer morphology of samples

  15. The use of Functionalized Nanoparticles as Non-specific Compatibilizers for Polymer Blends

    Energy Technology Data Exchange (ETDEWEB)

    W Zhang; M Lin; A Winesett; O Dhez; L Kilcoyne; H Ade; M rubinstein; K Shafi; A Ulman; et al.

    2011-12-31

    The ability to form blends of polymers offers the opportunity of creating a new class of materials with enhanced properties. In addition to the polymer components, recent advances in nanoengineering have resulted in the development of nanosized inorganic particles that can be used to improve the properties of the blend, such as the flammability and the mechanical properties. While traditional methods using copolymer compatibilizers have been used to strengthen polymer blends, here, we show that the inorganic nanosized filler additive can also serve as a compatibilizer as it can localize to the interface between the polymers. We use experimental and theoretical studies to show the fundamental mechanisms by which inorganic fillers with large aspect ratio and at least one-dimension in the nanometer range, can act as non-specific compatibilizers for polymer blends. We examine a series of nanosized fillers, ranging from nanotubes to nanoclays (with varying aspect ratios) in a model polystyrene (PS)/poly(methylmethacyralate) (PMMA) blend. Using a number of experimental techniques such as transmission electron microscopy (TEM), scanning tunneling X-ray microscopy (STXM), and atomic force microscopy (AFM) we postulate that the mechanism of compatibilization occurs as a result of the fillers forming in situ grafts with the immiscible polymers. We also use theoretical studies to show that the aspect ratio and the bending energy of the fillers play a key role in the compatibilization process. Our results indicate that the compatibilization is a general phenomenon, which should occur with all large aspect ratio nanofiller additives to polymer blends.

  16. Dynamics, Miscibility, and Morphology in Polymer-Molecule Blends: The Impact of Chemical Functionality

    KAUST Repository

    Do, Khanh

    2015-10-22

    In the quest to improve the performance of organic bulk-heterojunction solar cells, many recent efforts have focused on developing molecular and polymer alternatives to commonly used fullerene acceptors. Here, molecular dynamics simulations are used to investigate polymer-molecule blends comprised of the polymer donor poly(3-hexylthiophene) (P3HT) with a series of acceptors based on trialkylsilylethynyl-substituted pentacene. A matrix of nine pentacene derivatives, consisting of systematic chemical variation both in the nature of the alkyl groups and electron-withdrawing moieties appended to the acene, is used to draw connections between the chemical structure of the acene acceptor and the nanoscale properties of the polymer-molecule blend. These connections include polymer and molecular diffusivity, donor-acceptor packing and interfacial (contact) area, and miscibility. The results point to the very significant role that seemingly modest changes in chemical structure play during the formation of polymer-molecule blend morphologies.

  17. Optical study of pi-conjugated polymers and pi-conjugated polymers/fullerene blends

    Science.gov (United States)

    Drori, Tomer

    In this research, we studied the optical properties of a variety of pi-conjugated polymers and pi-conjugated polymers/fullerene blends, using various continuous wave optical spectroscopies. We found an illumination-induced metastable polaron-supporting phase in films of a soluble derivative of poly-p-phenylene vinylene (MEH-PPV). Pristine, MEH-PPV polymer films in the dark do not show long-lived photogenerated polarons. Prolonged UV illumination, however, is found to induce a reversible, metastable phase characterized by its ability to support abundant long-lived photogenerated polarons. We also discovered a photobleaching band in our photomodulation measurement around 0.9eV that scales with and thus is related to the observed polaron band. In the dark, the illumination-induced metastable phase reverts back to the phase of the original MEH-PPV within about 30 min at room temperature. We also applied our experimental techniques in polymer/fullerene blends for studying the photophysics of bulk heterostructures with below-gap excitation. In contrast to the traditional view, we found that below-gap excitation, which is incapable of generating intrachain excitons, nevertheless efficiently generates polarons on the polymer chains and fullerene molecules. Using frequency dependence photomodulation, we distinguished between the two mechanisms of photoinduced charge transfer using above-gap and below-gap excitations, and found a distinguishable long polaron lifetime when photogenerated with below-gap excitation. The polaron action spectrum extends deep inside the gap as a result of a charge-transfer complex state formed between the polymer chain and fullerene molecule. Using the electroabsorption technique, we were able to detect the optical transition of the charge transfer complex state that lies below the gap of the polymer and the fullerene. With appropriate design engineering the long-lived polarons might be harvested in solar cell devices. Another system studied was

  18. Simulation of nanostructured electrodes for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Rao, Sanjeev M.; Xing, Yangchuan

    Aligned carbon nanotubes (CNTs) with Pt uniformly deposited on them are being considered in fabricating the catalyst layer of polymer electrolyte membrane (PEM) fuel cell electrodes. When coated with a proton conducting polymer (e.g., Nafion) on the Pt/CNTs, each Pt/CNT acts as a nanoelectrode and a collection of such nanoelectrodes constitutes the proposed nanostructured electrodes. Computer modeling was performed for the cathode side, in which both multicomponent and Knudsen diffusion were taken into account. The effect of the nanoelectrode lengths was also studied with catalyst layer thicknesses of 2, 4, 6, and 10 μm. It was observed that shorter lengths produce better electrode performance due to lower diffusion barriers and better catalyst utilization. The effect of spacing between the nanoelectrodes was studied. Simulation results showed the need to have sufficiently large gas pores, i.e., large spacing, for good oxygen transport. However, this is at the cost of obtaining large electrode currents due to reduction of the number of nanoelectrodes per unit geometrical area of the nanostructured electrode. An optimization of the nanostructured electrodes was obtained when the spacing was at about 400 nm that produced the best limiting current density.

  19. Characterization of plasticized PMMA–LiBF4 based solid polymer electrolytes

    Indian Academy of Sciences (India)

    S Rajendran; T Uma

    2000-02-01

    Polymer electrolyte films prepared from poly(methyl methacrylate) and LiBF4 with different concentrations of plasticizer (DBP) are described. The formation of polymer–salt complex has been confirmed by FTIR spectral studies. The temperature dependence of conductivity of polymer films seems to obey the VTF relation. Values of conductivities of the polymer complexes are presented and discussed.

  20. Zirconium dioxide nanofilled poly(vinylidene fluoride-hexafluoropropylene) complexed with lithium trifluoromethanesulfonate as composite polymer electrolyte for electrochromic devices

    Energy Technology Data Exchange (ETDEWEB)

    Puguan, John Marc C.; Chinnappan, Amutha [Department of Energy and Biotechnology, Energy and Environment Fusion Technology Center, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of); Kostjuk, Sergei V. [Research Institute for Physical Chemical Problems, Belarusian State University, Minsk 220030 (Belarus); Kim, Hern, E-mail: hernkim@mju.ac.kr [Department of Energy and Biotechnology, Energy and Environment Fusion Technology Center, Myongji University, Yongin, Gyeonggi-do 449-728 (Korea, Republic of)

    2015-09-15

    Highlights: • Successful synthesis of electrolyte by blending PVdF-HFP, ZrO{sub 2} and LiCF{sub 3}SO{sub 3}. • ZrO{sub 2} increased electrolyte conductivity by two orders of magnitude. • ZrO{sub 2} doubled bulk mechanical strength of electrolyte in terms of Young’s modulus. • Electrolytes gave a optimum optical transmittance of 52.6%. - Abstract: Poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) polymer electrolyte containing zirconium dioxide nanocrystals (ZrO{sub 2}-NC) and lithium trifluoromethanesulfonate (LiCF{sub 3}SO{sub 3}) has been synthesized using the conventional solution casting method. The addition of ZrO2-NC into the polymeric substrate gave remarkable properties in terms of the electrolyte’s ionic conductivity as well as its bulk mechanical strength. The enhanced amorphicity of the polymeric substrate due to ZrO{sub 2} and the nanofiller’s high dielectric constant make an excellent combination to increase the ionic conductivity (above 10{sup −4} S cm{sup −1}). Increasing the nanofiller content raises the ionic conductivity of the electrolyte by two orders of magnitude of which the optimum is 2.65 × 10{sup −4} S cm{sup −1} at 13.04 wt% ZrO{sub 2}-NC loading. Also, the Young’s modulus, an indicator of electrolyte’s mechanical stability, dramatically increased to 207 MPa upon loading 13.04 wt% ZrO{sub 2}-NC. Using UV–vis spectroscopy, the electrolytes with 13.04% ZrO{sub 2}-NC scanned from 200–800 nm wavelengths exhibited a maximum optical transmittance of 52.6% at 10 μm film thickness. The enhanced conductivity, high mechanical strength and reasonable optical transmittance shown by our composite polymer electrolyte make an excellent electrolyte for future energy saving smart windows such as electrochromic devices.

  1. The electrolyte challenge for a direct methanol-air polymer electrolyte fuel cell operating at temperatures up to 200 C

    Science.gov (United States)

    Savinell, Robert; Yeager, Ernest; Tryk, Donald; Landau, Uziel; Wainright, Jesse; Gervasio, Dominic; Cahan, Boris; Litt, Morton; Rogers, Charles; Scherson, Daniel

    1993-01-01

    Novel polymer electrolytes are being evaluated for use in a direct methanol-air fuel cell operating at temperatures in excess of 100 C. The evaluation includes tests of thermal stability, ionic conductivity, and vapor transport characteristics. The preliminary results obtained to date indicate that a high temperature polymer electrolyte fuel cell is feasible. For example, Nafion 117 when equilibrated with phosphoric acid has a conductivity of at least 0.4 Omega(exp -1)cm(exp -1) at temperatures up to 200 C in the presence of 400 torr of water vapor and methanol vapor cross over equivalent to 1 mA/cm(exp 2) under a one atmosphere methanol pressure differential at 135 C. Novel polymers are also showing similar encouraging results. The flexibility to modify and optimize the properties by custom synthesis of these novel polymers presents an exciting opportunity to develop an efficient and compact methanol fuel cell.

  2. Substructure formation during pattern transposition from substrate into polymer blend film

    NARCIS (Netherlands)

    Cyganik, P; Budkowski, A; Steiner, U; Rysz, J; Bernasik, A; Walheim, S; Postawa, Z; Raczkowska, J

    2003-01-01

    A chemical pattern on a substrate is transposed into thin films of a ternary polymer blend during spin-casting from a common solvent. One of the blend components intercalates at interfaces between the other two phases to reduce their interfacial energy. As a result, an extensive substructure is form

  3. 3D-morphology reconstruction of nanoscale phase-separation in polymer memory blends

    NARCIS (Netherlands)

    Khikhlovskyi, V.; Breemen, A.J.J.M. van; Michels, J.J.; Janssen, R.A.J.; Gelinck, G.H.; Kemerink, M.

    2015-01-01

    In many organic electronic devices functionality is achieved by blending two or more materials, typically polymers or molecules, with distinctly different optical or electrical properties in a single film. The local scale morphology of such blends is vital for the device performance. Here, a simple

  4. Phase behavior of confined polymer blends and nanoparticle composites

    Science.gov (United States)

    Chung, Hyun-Joong

    We have investigated phase behavior in polymer blend films of poly(methyl methacrylate) (PMMA) and poly(styrene-ran-acrylonitrile) (SAN) with 33wt% AN content and their nanoparticle (NP) composites by using the combination of imaging techniques, including atomic force microscopy (AFM), focused-ion beam (FIB), transmission and scanning electron microscopy (TEM and SEM), as well as depth profiling techniques of Rutherford backscattering spectrometry (RBS) and elastic recoil detection (ERD). For neat PMMA:SAN films, we present a novel morphology map based on pattern development mechanisms. Six distinct mechanisms are found for thickness values (d) and bulk compositions between 50-1000 nm and φPMMA = 0.3 to 0.8, respectively. When PMMA is depleted from the mid-layer by preferential wetting at φ PMMA = 0.3 (A), stable PMMA/SAN/PMMA trilayer structure is obtained. With increasing φPMMA (0.4 to 0.7), pattern development is driven by phase separation in the mid-layer, which produces circular domains (B), irregular domains (C), and bicontinuous patterns (D). Here, the growth of circular domains can be explained by the coalescence mechanism, which predicts ξ˜(sigma/eta) 1/3d2/3t1/3 , where ξ, sigma, and eta are correlation length between domains, interfacial tension between phases, and viscosity, respectively. In bicontinuous patterns, hydrodynamic pumping mechanism is suppressed with thickness confinement. When SAN composition is lean, φPMMA = 0.8 (E), the SAN phase is minority component in the mid-layer and breaks up into droplets in smooth PMMA film. When film thickness is less than 80 nm at φPMMA = 0.4 or 0.5 (F), films initially display trilayer structure, which then ruptures upon dewetting of the SAN mid-layer. Building upon the understanding of the neat PMMA:SAN blend films, we have performed the first systematic on the effect of NPs in morphology evolution and stability of polymer blend films. Whereas the location of NP impacts morphology evolution, silica

  5. EFFECTIVENESS OF ANNEALING TREATMENT AND POLYMER BLENDS ON I-V CHARACTERISTSICS OF POLYMER SOLAR CELL

    Directory of Open Access Journals (Sweden)

    Erlyta Septa Rosa

    2014-12-01

    Full Text Available This research reports on a fabrication of polymer solar cells based on blends of two widely used polymeric semiconductors i.e. poly(2-methoxy-5-(3,7-dimethyloctyloxy-para phenylene vinylene (MDMO-PPV and the soluble fullerene C60 derivative [6,6 phenyl C61-butyric acid methyl ester] (PCBM. The devices were fabricated on an indium tin oxide (ITO coated glass substrate. After cleaned and dried, a poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate (PEDOT:PSS in H2O was spin coated onto the freshly prepared substrate and then dried in a vacuum oven at 120°C for 60 minutes. A blend of MDMO-PPV and PCBM in chlorobenzene was spin coated on the top and dried in a nitrogen ambient at room temperature for 24 hours. The devices were transferred to a sputtering system where an aluminum was coated. Some of the devices then were annealed in a vacuum oven at 60°C for 60 minutes. Finally, the devices were encapsulated by placing a sealant between the back of the devices and glass slides and then cured in a vacuum oven at temperature 100°C for 10 minutes. For characterization, the devices were illuminated with a xenon lamp at the intensity of 27 mW/cm2 and the temperature at approximately 25°C. The influence of the annealing treatment and polymer blends on the photovoltaic performance of the devices was also discussed here. The best performance was obtained from the device with a blend ratio of 1:1 MDMO-PPV/PCBM without annealing treatment. The typical power efficiency was 0.01% with open circuit voltage of 0.347 V, short circuit current of 0.064 mA, and maximum power of 0.006 mW.

  6. A General Formula for Ion Concentration-Dependent Electrical Conductivities in Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Mahardika P. Aji

    2012-01-01

    Full Text Available Problem statement: The aim of this study is to develop a model for describing the effect of ion concentration on the electrical conductivity of polymer electrolytes by considering two mechanisms simultaneously: Enhancements of ion concentration and amorphous phase. Approach: The problems based on new observations in polymer electrolyte when ion concentration in the polymer electrolytes was increased, both the fraction of amorphous phase and the charge carriers increase simultaneously. The model was based on the assumption when ions were inserted into the polymer host, there was an optimum distance between ions at which the ions move easily throughout the polymer. The average distance between ions in the polymer depends on the ion concentration. And we also considered the effect of ion concentration on the amorphous phase in the polymer. Results: We inspected the validity of the model by comparing the model predictions with various experimental data. The new analytical expressions for the electrical conductivity dependent of ion concentration was developed by considering two mechanisms simultaneously in polymer electrolytes, i.e., enhancement of the carries concentration and amorphous phase fraction. Interestingly, most of fitting parameters were not arbitrarily selected, but were derived from the appropriate experimental data. Conclusion: The model can be used to explain the conductivity behavior of other polymer electrolyte systems by selecting appropriately less number of parameters. This model result is fully supported by available experimental data.

  7. SIFAT POLIMER DAN KEMAMPUAN TERBIODEGRADASI BLEND BIODEGRADABLE POLYMER POLI (L-ASAM LAKTAT (PLLA

    Directory of Open Access Journals (Sweden)

    Johnner P Sitompul

    2014-12-01

    Full Text Available  Poly(D,L-lactic acid (PDLLA and poly(ethylene glycol (PEG was used to modify mechanical and biodegradability properties of poly(L-lactic acid (PLLA through solution blending method using solvent mixture of dichloromethane-ethanol. Polymer samples were then characterized using FTIR, DSC, UTM, and enzymatic degradation test. FTIR spectrum of pure PLLA showed specific IR absorption peaks at wavenumber of 3504 cm-1 (-OH, 1757 cm-1 (-C=O, and 1381 cm-1 (-CH3 symmetric. Further, polymer blend samples showed absorption peak shifts at 1755 cm-1 and 1382 cm-1 for PLLA/PDLLA due to stereocomplex interaction and at 3429 cm-1 due to hydrogen bond interaction. DSC results showed that there was melting temperature depression for all polymer blend samples compared to pure PLLA with increasing of either PDLLA or PEG composition. In PLLA/PDLLA, two melting points were discovered because of homocrystallite and stereocomplex phase formation. While PLLA/PEG samples showed increasing crystallinity to 69% at 20%-wt PEG composition. Mechanical analysis showed that 10%-wt of PDLLA addition in PLLA produced better mechanical performance than pure PLLA while 20%-wt of PEG addition showed highest elongation at break with the value of 89%. Polymer blend samples were degradable during enzymatic degradation test represented by percent weight loss with maximum value of 21% for PLLA/PEG sample. Keywords: polymer properties, solution-blending, Poly(lactic acid, polymer blend, enzymatic degradation

  8. Performance of ferrite fillers on electrical behavior of polymer nanocomposite electrolyte

    Science.gov (United States)

    Pandey, Kamlesh; Mauli Dwivedi, Mrigank; Singh, Markandey; Agrawal, S. L.

    2011-04-01

    Dispersal of nanofillers in polymer electrolytes have shown to improve the ionic properties of Polyethylene oxide (PEO)-based polymer electrolytes in recent times. The effects of different nanoferrite fillers (i.e., Al-Zn ferrite, Mg-Zn ferrite, and Zn ferrite) on the electrical transport properties have been studied here on the composite polymer electrolyte system. The interaction of salt/filler with electrolyte has been investigated by XRD studies. SEM image and infrared spectral studies give an indication of nanocomposite formation. In conductivity studies, all electrolyte systems are seen to follow universal power law. Composition dependence (with ferrite filler) gives the maximum conductivity in [93PEO-7NH4SCN]: X ferrite (where X = 2% in Al-Zn ferrite, 1% Mg-Zn ferrite, and 1% Zn ferrite) system.

  9. Gel-based composite polymer electrolytes with novel hierarchical mesoporous silica network for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang Xiaoliang; Cai Qiang [Department of Materials Science and Engineering, and State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Fan Lizhen [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Hua Tao; Lin Yuanhua [Department of Materials Science and Engineering, and State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Nan Cewen [Department of Materials Science and Engineering, and State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China)], E-mail: cwnan@tsinghua.edu.cn

    2008-11-15

    In the present work, novel gel-based composite polymer electrolytes for lithium batteries were prepared by introducing a hierarchical mesoporous silica network to the poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)-based gel electrolytes. As compared with the PVDF-HFP-based gel electrolytes with/without conventional nano-sized silica fillers, the novel electrolytes have shown more homogeneous microstructure, higher ionic conductivity and better mechanical stability, which could be caused by the strong silica network and the effective interactions among the polymer, the liquid electrolytes and the silica. Moreover, the cell with this kind of electrolytes could achieve a discharge capacity as much as 150 mAh g{sup -1} at room temperature (LiCoO{sub 2} as the cathode active material), with high Coulomb efficiency.

  10. Gel-based composite polymer electrolytes with novel hierarchical mesoporous silica network for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiao-Liang; Cai, Qiang; Hua, Tao; Lin, Yuan-Hua; Nan, Ce-Wen [Department of Materials Science and Engineering, and State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China); Fan, Li-Zhen [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2008-11-15

    In the present work, novel gel-based composite polymer electrolytes for lithium batteries were prepared by introducing a hierarchical mesoporous silica network to the poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP)-based gel electrolytes. As compared with the PVDF-HFP-based gel electrolytes with/without conventional nano-sized silica fillers, the novel electrolytes have shown more homogeneous microstructure, higher ionic conductivity and better mechanical stability, which could be caused by the strong silica network and the effective interactions among the polymer, the liquid electrolytes and the silica. Moreover, the cell with this kind of electrolytes could achieve a discharge capacity as much as 150 mAh g{sup -1} at room temperature (LiCoO{sub 2} as the cathode active material), with high Coulomb efficiency. (author)

  11. PVDF-HFP-based porous polymer electrolyte membranes for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Ruiying; Liu, Bowen; Zhu, Zhongzheng; Liu, Yun; Li, Jianling; Wang, Xindong [Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083 (China); Li, Qingfeng [Department of Chemistry, Technology University of Denmark, DK-2800 Lyngby (Denmark)

    2008-10-01

    As a potential electrolyte for lithium-ion batteries, a porous polymer electrolyte membrane based on poly(vinylidenefluoride-hexafluoropropylene) (PVDF-HFP) was prepared by a phase inversion method. The casting solution, effects of the solvent and non-solvent and addition of micron scale TiO{sub 2} particles were investigated. The membranes were characterized by SEM, XRD, AC impedance, and charge/discharge tests. By using acetone as the solvent and water as the non-solvent, the prepared membranes showed good ability to absorb and retain the lithium ion containing electrolyte. Addition of micron TiO{sub 2} particles to the polymer electrolyte was found to enhance the tensile strength, electrolyte uptake, ion conductivity and the electrolyte/electrode interfacial stability of the membrane. (author)

  12. EFFECTIVENESS OF ANNEALING TREATMENT AND POLYMER BLENDS ON I-V CHARACTERISTSICS OF POLYMER SOLAR CELL

    OpenAIRE

    Erlyta Septa Rosa; Shobih Shobih

    2014-01-01

    This research reports on a fabrication of polymer solar cells based on blends of two widely used polymeric semiconductors i.e. poly(2-methoxy-5-(3,7-dimethyloctyloxy)-para phenylene vinylene) (MDMO-PPV) and the soluble fullerene C60 derivative [6,6 phenyl C61-butyric acid methyl ester] (PCBM). The devices were fabricated on an indium tin oxide (ITO) coated glass substrate. After cleaned and dried, a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) in H2O was spin coated ont...

  13. Reversible control of electrochemical properties using thermally-responsive polymer electrolytes.

    Science.gov (United States)

    Kelly, Jesse C; Pepin, Mark; Huber, Dale L; Bunker, Bruce C; Roberts, Mark E

    2012-02-14

    A thermally responsive copolymer is designed to modulate the properties of an electrolyte solution. The copolymer is prepared using pNIPAM, which governs the thermal properties, and acrylic acid, which provides the electrolyte ions. As the polymer undergoes a thermally activated phase transition, the local environment around the acid groups is reversibly switched, decreasing ion concentration and conductivity. The responsive electrolyte is used to control the activity of redox electrodes with temperature.

  14. Polymer electrolytes composed of lithium tetrakis(pentafluorobenzenethiolato) borate and poly(fluoroalkylcarbon)s

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Konno, Akinori; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2005-08-26

    Lithium ion conducting polymer electrolytes were prepared by mixing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB) with poly(vinylidene fluoride) (PVDF) or poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). Their films were prepared by hot pressing and are investigated for ionic conductivity and thermal properties. LiTPSB is insoluble in PVDF. Ionic conductivity was largely dependent on the salt content for LiTPSB-PVDF composite polymer electrolytes, and exhibited higher ionic conductivity than homogeneous LiTFSI-PVDF based polymer electrolytes. Melting point and crystallinity of PVDF were independent on LiTPSB content, resulting in no difference for melting point and crystallinity between pure PVDF and LiTPSB-PVDF. Ionic conductivity was effectively improved by incorporation of 18-crown-6 or kryptofix222 for LiTPSB-PVDF based polymer electrolytes. (author)

  15. Optimization of polymer electrolytes for quasi-solid-state dye-sensitized solar cells

    Institute of Scientific and Technical Information of China (English)

    ZHANG Changneng; WANG Miao; ZHOU Xiaowen; LIN Yuan; FANG Shibi; LI Xueping; XIAO Xuri; CEN Kuang

    2004-01-01

    The photoelectrochemical properties of the quasi-solid-state dye-sensitized solar cells based on polymer electrolytes consisting of polyethylene oxide (PEO) with the additions of nano-TiO2 and ionic liquid of MPII (1-methyl-3-propylimidazolium iodide) were studied. By using a composite polymer electrolyte of PEO:LiI:TiO2:MPII:I2 = 3:3:3:7:1 (in mol ratio), the solar energy conversion efficiency of 3.2% under 100 Mw·cm-2 was obtained, which was 8 times higher than that of the cell using polymer electrolyte without any additives. The effect of the additives was attributed to the increase of ionic conductivity of the polymer electrolytes.

  16. Synthesis and Ionic Conductivity of Network Polymer Electrolytes with Internal Plasticizers

    Institute of Scientific and Technical Information of China (English)

    Jun Jie KANG; Shi Bi FANG

    2004-01-01

    Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.

  17. Crosslinked polymer gel electrolytes based on polyethylene glycol methacrylate and ionic liquid for lithium battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Chen [ORNL; Sun, Xiao-Guang [ORNL; Dai, Sheng [ORNL

    2013-01-01

    Gel polymer electrolytes were synthesized by copolymerization polyethylene glycol methyl ether methacrylate with polyethylene glycol dimethacrylate in the presence of a room temperature ionic liquid, methylpropylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MPPY TFSI). The physical properties of gel polymer electrolytes were characterized by thermal analysis, impedance spectroscopy, and electrochemical tests. The ionic conductivities of the gel polymer electrolytes increased linearly with the amount of MPPY TFSI and were mainly attributed to the increased ion mobility as evidenced by the decreased glass transition temperatures. Li||LiFePO4 cells were assembled using the gel polymer electrolytes containing 80 wt% MPPY TFSI via an in situ polymerization method. A reversible cell capacity of 90 mAh g 1 was maintained under the current density of C/10 at room temperature, which was increased to 130 mAh g 1 by using a thinner membrane and cycling at 50 C.

  18. New Microporous Polymer Electrolyte Based on Polysiloxane Grafted with Imidazolium Iodide Moieties for DSSC

    Directory of Open Access Journals (Sweden)

    Yan Yang

    2011-01-01

    Full Text Available Two types of polysiloxane grafted with different ratio of imidazolium iodide moieties (IL-SiO2 have been synthesized to develop a micro-porous polymer electrolyte for quasi-solid-state dye-sensitized solar cells. The samples were characterized by 1HNMR, FT-IR spectrum, XRD, TEM and SEM, respectively. Moreover, the ionic conductivity of the electrolytes was measured by electrochemical workstation. Nanostructured polysiloxane containing imidazolium iodide showed excellent compatibility with organic solvent and polymer matrix for its ionic liquid characteristics. Increasing the proportion of imidazolium iodide moieties in polysiloxane improved the electrochemical behavior of the gel polymer electrolyte. A dye-sensitized solar cell with gel polymer electrolyte yielded an open-circuit voltage of 0.70 V, short-circuit current of 11.19 mA cm−2, and the conversion efficiency of 3.61% at 1 sun illumination.

  19. Characterization and optimization of polymer electrolyte fuel cell electrodes

    Science.gov (United States)

    Boyer, Christopher Carter

    Experimental characterization and modeling were combined to find a procedure for optimizing the design of polymer electrolyte membrane fuel cell (PEMFC) electrodes. The mass transfer and kinetic properties of the active layer used in electrodes fabricated at the Center for Electrochemical Systems and Hydrogen Research (CESHR) were characterized as a function of electrolyte polymer content NafionRTM, DuPont, Fayetteville, NC) and catalyst loading for different types of platinum catalysts (E-Tek, Natick, MA). Expressions from limiting cases of the fuel cell model showed the combination of electrode materials for maximum current density at maximum catalyst utilization. Models describing the fuel cell behavior were selected and used to explain how different operating pressures affect the system power density and efficiency. An "inert layer" method was developed to determine the effective proton conductivity of the active layer. A "buffer layer" method was developed to determine the oxygen diffusivity in the gas pores. A review of the literature and experiments at CESHR was used to determine the oxygen reduction activity of the active layer. Finally, a fitting method was developed to measure the agglomerate diffusivity from cell tests. A PEMFC model demonstrated that operating the fuel cell pressurized can improve the power density at high currents because of oxygen mass transport. limitations in the substrate. However. as better electrode designs improve oxygen mass transfer, pressurized operation will lose this advantage. In addition, the model confirmed that oxygen enrichment systems require too much energy to separate oxygen from air to improve the net performance of a fuel cell. From limiting approximations of the solutions of the differential material balances in the fuel cell model, a simple set of analytical expressions were derived that predict the optimum active layer thickness and maximum current density based on the materials of construction and operating

  20. Electrochemical characterization of an ambient temperature rechargeable Li battery based on low molecular weight polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Bonino, F.; Croce, F.; Panero, S. (Dept. of Chemistry, Univ. of Rome ' La Sapienza' , Rome (Italy))

    1994-06-01

    Preliminary applications of low molecular weight polymer electrolyte (PEG) and lithium salt in lithium rechargeable batteries have been reported. The electrochemical characteristics of these electrolytes have been tested by cyclic voltammetry, charge-discharge cycles and ac impedance methods. Surface layers appear to be present on both electrodes, but they develop upon time with different extension

  1. Investigation of solid polymer electrolyte gas sensor with different electrochemical techniques

    Science.gov (United States)

    Strzelczyk, A.; Jasinski, G.; Chachulski, B.

    2016-01-01

    In this work solid polymer electrolyte (SPE) amperometric sulphur dioxide sensor is investigated. Nafion was used as a membrane electrode and 1M sulphuric acid as an internal electrolyte. Sensor response to sulphur dioxide was measured. Besides traditional constant voltage amperometry also different electrochemical techniques were used. Results obtained by these methods are compared.

  2. A novel composite microporous polymer electrolyte prepared with molecule sieves for Li-ion batteries

    Science.gov (United States)

    Jiang, Yan-Xia; Chen, Zuo-Feng; Zhuang, Quan-Chao; Xu, Jin-Mei; Dong, Quan-Feng; Huang, Ling; Sun, Shi-Gang

    Molecular sieves of NaY, MCM-41, and SBA-15 were used as fillers in a poly(vinylidene fluoride- co-hexafluoropropylene) (PVdF-HFP) copolymer matrix to prepare microporous composite polymer electrolyte. The SBA-15-based composite polymer film was found to show rich pores that account for an ionic conductivity of 0.50 mS cm -1. However, the MCM-41 and NaY composite polymer films exhibited compact structure without any pores, and the addition of MCM-41 even resulted in aggregation of fillers in the polymer matrix. These differences were investigated and interpreted by their different compatibility with DMF solvent and PVdF-HFP matrix. Results of linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) have revealed that the addition of SBA-15 has extended the electrochemical stability window of polymer electrolyte, enhanced the interfacial stability of polymer electrolyte with lithium electrode, and inhibited also the crystallization of PVdF-HFP matrix. Half-cell of Li/SBA-15-based polymer electrolyte/MCF was assembled and tested. The results have demonstrated that the coulombic efficiency of the first cycle was around 87.0% and the cell remains 94.0% of the initial capacity after 20 cycles, which showed the potential application of the composite polymer electrolyte in lithium ion batteries.

  3. A novel composite microporous polymer electrolyte prepared with molecule sieves for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Yan-Xia; Chen, Zuo-Feng; Zhuang, Quan-Chao; Xu, Jin-Mei; Dong, Quan-Feng; Huang, Ling; Sun, Shi-Gang [State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 422, South Road of Siming, Xiamen 361005 (China)

    2006-10-06

    Molecular sieves of NaY, MCM-41, and SBA-15 were used as fillers in a poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) copolymer matrix to prepare microporous composite polymer electrolyte. The SBA-15-based composite polymer film was found to show rich pores that account for an ionic conductivity of 0.50mScm{sup -1}. However, the MCM-41 and NaY composite polymer films exhibited compact structure without any pores, and the addition of MCM-41 even resulted in aggregation of fillers in the polymer matrix. These differences were investigated and interpreted by their different compatibility with DMF solvent and PVdF-HFP matrix. Results of linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) have revealed that the addition of SBA-15 has extended the electrochemical stability window of polymer electrolyte, enhanced the interfacial stability of polymer electrolyte with lithium electrode, and inhibited also the crystallization of PVdF-HFP matrix. Half-cell of Li/SBA-15-based polymer electrolyte/MCF was assembled and tested. The results have demonstrated that the coulombic efficiency of the first cycle was around 87.0% and the cell remains 94.0% of the initial capacity after 20 cycles, which showed the potential application of the composite polymer electrolyte in lithium ion batteries. (author)

  4. Photoeletricity Capability of Imager Detector with Coated Blends of Polymer and Perylene or Coronene

    Institute of Scientific and Technical Information of China (English)

    YANG Bing; LI Ying; XIE Ming-Gui

    2003-01-01

    Perylene and coronene have been synthesized with good yield via the Dields-Alder reaction. They have good photoluminescence properties and could transfer ultraviolet light to visible-light. To find an easy way of making a better ultraviolet charge coupled device, we blended perylene or coronene with polymers. Then, these blends were analysed by the photoluminescence spectrum. The results indicate that the blends have larger fluorescence intensity than pure perylene or coronene. Through spreading these blends on image detectors, organic image detectors with good ultraviolet photoelectricity capability were prepared.

  5. Water Transport Analysis in Polymer Electrolyte Membrane Fuel Cells by Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    S.Tsushima; S.Hirai

    2007-01-01

    1 Results Polymer electrolyte fuel cells (PEFCs) have beenintensively developedfor future vehicle applications andon-site power generation owing to its high energy efficiency and high power density.In PEFCs ,appropriatewater management to maintain polymer electrolyte membrane (PEM) hydratedis of great i mportance ,becausethe ion conductivity of membraneislower at lower water content .Consequently,it is of great interest to watercontent and water transport process in PEMs during fuel cell operation.

  6. Design, Synthesis, and Characterization of High Performance Polymer Electrolytes for Printed Electronics and Energy Storage

    Science.gov (United States)

    2016-03-31

    AFRL-AFOSR-VA-TR-2016-0168 Design, Synthesis, and Characterization of High Performance Polymer Electrolytes for Printed Electronics and Energy ...Sep 2015 4. TITLE AND SUBTITLE Design, Synthesis, and Characterization of High Performance Polymer Electrolytes for Printed Electronics and Energy ... energy storage. This project produced 11 peer reviewed papers and results in the training of 3 graduate students and two postdoctoral fellows. The

  7. Flexible High-Energy Polymer-Electrolyte-Based Rechargeable Zinc-Air Batteries.

    Science.gov (United States)

    Fu, Jing; Lee, Dong Un; Hassan, Fathy Mohamed; Yang, Lin; Bai, Zhengyu; Park, Moon Gyu; Chen, Zhongwei

    2015-10-07

    A thin-film, flexible, and rechargeable zinc-air battery having high energy density is reported particularly for emerging portable and wearable electronic applications. This freeform battery design is the first demonstrated by sandwiching a porous-gelled polymer electrolyte with a freestanding zinc film and a bifunctional catalytic electrode film. The flexibility of both the electrode films and polymer electrolyte membrane gives great freedom in tailoring the battery geometry and performance.

  8. Fabrication of Pt deposited on carbon nanotubes and performance of its polymer electrolyte membrane fuel cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A new method of depositing nano-sized Pt particles on the surface of the carbon nano-tubes was introduced, and the performance of Pt/carbon nanotube compound on polymer electrolyte membrane fuel cells was measured. The experimental results show that the fine platinum particles (about 3 nm) were well dispersed on carbon nanotubes, which demonstrates the excellent catalytic properties of the Pt/CNTs compound in polymer electrolyte membrane fuel cells.

  9. Electrode structures of polymer-electrolyte fuel cells (PEFC). An electron microscopy approach to the characterization of the electrode structure of polymer electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Scheiba, Frieder

    2009-01-28

    Polymer electrolyte fuel cells (PEFC) have a complex electrode structure, which usually consists of a catalyst, a catalyst support, a polymer electrolyte and pores. The materials used are largely amorphous, have a strong defective structure or have particle diameter of only a few nanometers. In the electrode the materials form highly disordered aggregated structures. Both aspects complicate a systematic structural analysis significantly. However, thorough knowledge of the electrode structure, is needed for systematic advancement of fuel cell technology and to obtain a better understanding of mass and charge carrier transport processes in the electrode. Because of the complex structure of the electrode, an approach based on the examination of electrode thin-sections by electron microscopy was chosen in this work to depicting the electrode structure experimentally. The present work presents these studies of the electrode structure. Some fundamental issues as the influence of the polymer electrolyte concentration and the polarity of the solvent used in the electrode manufacturing process were addressed. During the analysis particular attention was payed to the distribution and structure of the polymer electrolyte. A major problem to the investigations, were the low contrast between the polymer electrolyte, the catalyst support material and the embedding resin. Therefore, dilerent techniques were investigated in terms of their ability to improve the contrast. In this context, a computer-assisted acquisition procedure for energy filtered transmission electron microscopy (EF-TEM) was developed. The acquisition procedure permits a significant extension of the imageable sample. At the same time, it was possible to substantially reduce beam damage of the specimen and to minimize drift of the sample considerably. This allowed unambiguous identification of the polymer electrolyte in the electrode. It could further be shown, that the polymer electrolyte not only coats the

  10. Polymer electrolyte fuel cell stack research and development

    Energy Technology Data Exchange (ETDEWEB)

    Squadrito, G.; Barbera, O.; Giacoppo, G.; Urbani, F.; Passalacqua, E. [Istituto di Tecnologie Avanzate per l' Energia ' ' Nicola Giordano' ' del CNR (CNR, ITAE), via Salita per, Santa Lucia sopra Contesse 5, Messina (Italy)

    2008-04-15

    The research activity in polymer electrolyte fuel cell (PEFC) is oriented to the evolution of components and devices for the temperature range from 20 to 130{sup o}C, and covers all the aspects of this matter: membranes and electrodes, fuel cell stack engineering (design and manufacturing) and characterization, computational modelling and small demonstration systems prototyping. Particular attention is devoted to portable and automotive application. Membranes research is focused on thermostable polymers (polyetheretherketone, polysulphone, etc.) and composite membranes able to operate at higher temperature (>100{sup o}C) and lower humidification than the commercial Nafion {sup registered}, while Pt load reduction and gas diffusion layer improvement are the main goals for the electrode development. PEFC stack engineering and characterization activity involve different aspects such as the investigation of new materials for stack components, fuel cell modelling and performance optimization by computational techniques, single cell and stack electrochemical characterization, development of investigation tools for stack monitoring and data acquisition. A lot of work has been focused to the fuel cell stack architecture, assembling, gas leakage and cross-over reduction (gasketing), flow field and manifold design. Computational fluid dynamics studies have been performed to investigate and improve reactants distribution inside the cell. A flow field design methodology, developed in this framework and related to serpentine like flow field, is actually under investigation. All of these aspects of PEFC stack research are realized in the framework of National and European research projects, or in collaboration with industries and other research centres. In the present work our stack research activity is reported and the most important results are also considered. (author)

  11. Hydrogen-fueled polymer electrolyte fuel cell systems for transportation.

    Energy Technology Data Exchange (ETDEWEB)

    Ahluwalia, R.; Doss, E.D.; Kumar, R.

    1998-10-19

    The performance of a polymer electrolyte fuel cell (PEFC) system that is fueled directly by hydrogen has been evaluated for transportation vehicles. The performance was simulated using a systems analysis code and a vehicle analysis code. The results indicate that, at the design point for a 50-kW PEFC system, the system efficiency is above 50%. The efficiency improves at partial load and approaches 60% at 40% load, as the fuel cell operating point moves to lower current densities on the voltage-current characteristic curve. At much lower loads, the system efficiency drops because of the deterioration in the performance of the compressor, expander, and, eventually, the fuel cell. The results also indicate that the PEFC system can start rapidly from ambient temperatures. Depending on the specific weight of the fuel cell (1.6 kg/kW in this case), the system takes up to 180s to reach its design operating conditions. The PEFC system has been evaluated for three mid-size vehicles: the 1995 Chrysler Sedan, the near-term Ford AIV (Aluminum Intensive Vehicle) Sable, and the future P2000 vehicle. The results show that the PEFC system can meet the demands of the Federal Urban Driving Schedule and the Highway driving cycles, for both warm and cold start-up conditions. The results also indicate that the P2000 vehicle can meet the fuel economy goal of 80 miles per gallon of gasoline (equivalent).

  12. Electrostatics of polymer translocation events in electrolyte solutions.

    Science.gov (United States)

    Buyukdagli, Sahin; Ala-Nissila, T

    2016-07-07

    We develop an analytical theory that accounts for the image and surface charge interactions between a charged dielectric membrane and a DNA molecule translocating through the membrane. Translocation events through neutral carbon-based membranes are driven by a competition between the repulsive DNA-image-charge interactions and the attractive coupling between the DNA segments on the trans and the cis sides of the membrane. The latter effect is induced by the reduction of the coupling by the dielectric membrane. In strong salt solutions where the repulsive image-charge effects dominate the attractive trans-cis coupling, the DNA molecule encounters a translocation barrier of ≈10 kBT. In dilute electrolytes, the trans-cis coupling takes over image-charge forces and the membrane becomes a metastable attraction point that can trap translocating polymers over long time intervals. This mechanism can be used in translocation experiments in order to control DNA motion by tuning the salt concentration of the solution.

  13. Polymer-polymer miscibility in PEO/cationic starch and PEO/hydrophobic starch blends

    Directory of Open Access Journals (Sweden)

    2010-08-01

    Full Text Available The main purposes were evaluating the influence of different starches on the miscibility with Poly(ethylene oxide (PEO and their effects on the spherulite growth rate. Polymer-polymer miscibility in PEO/cationic starch and PEO/hydrophobic starch blends consisting of different w/w ratios (100/0, 95/05, 90/10, 80/20, 70/30, 65/35 and 60/40 was investigated. This analysis was based on the depression in the equilibrium melting temperature (Tm0. By treating the data of thermal analysis (Differential Scanning Calorimetry – DSC with Nishi-Wang equation, a positive value (0.68 was found for the interaction parameter of PEO/cationic starch. For PEO/hydrophobic starch blends, a negative value (–0.63 was obtained for the interaction parameter. The results suggested that PEO/cationic starch system should be immiscible. However, the system PEO/hydrophobic starch was considered to be miscible in the whole range of studied compositions. Through optical microscopy analysis, it was concluded that the spherulite growth rate is significantly affected by changing the amount and the type of starch as well.

  14. Phase diagrams and kinetics of solid-liquid phase transitions in crystalline polymer blends

    Science.gov (United States)

    Matkar, Rushikesh A.

    A free energy functional has been formulated based on an order parameter approach to describe the competition between liquid-liquid phase separation and solid-liquid phase separation. In the free energy description, the assumption of complete solvent rejection from the crystalline phase that is inherent in the Flory diluent theory was removed as solvent has been found to reside in the crystalline phase in the form of intercalates. Using this approach, we have calculated various phase diagrams in binary blends of crystalline and amorphous polymers that show upper or lower critical solution temperature. Also, the discrepancy in the chi values obtained from different experimental methods reported in the literature for the polymer blend of poly(vinylidenefluoride) and poly(methylmethacrylate) has been discussed in the context of the present model. Experimental phase diagram for the polymer blend of poly(caprolactone) and polystyrene has also been calculated. Of particular importance is that the crystalline phase concentration as a function of temperature has been calculated using free energy minimization methods instead of assuming it to be pure. In the limit of complete immiscibility of the solvent in the crystalline phase, the Flory diluent theory is recovered. The model is extended to binary crystalline blends and the formation of eutectic, peritectic and azeotrope phase diagrams has been explained on the basis of departure from ideal solid solution behavior. Experimental eutectic phase diagram from literature of a binary blend of crystalline polymer poly(caprolactone) and trioxane were recalculated using the aforementioned approach. Furthermore, simulations on the spatio temporal dynamics of crystallization in blends of crystalline and amorphous polymers were carried out using the Ginzburg-Landau approach. These simulations have provided insight into the distribution of the amorphous polymer in the blends during the crystallization process. The simulated results

  15. Thermally stable hyperbranched polyether-based polymer electrolyte for lithium-ion batteries

    Science.gov (United States)

    Wu, Feng; Feng, Ting; Wu, Chuan; Bai, Ying; Ye, Lin; Chen, Junzheng

    2010-01-01

    A thermally stable polymer matrix, comprising hyperbranched polyether PHEMO (poly(3-{2-[2-(2-hydroxyethoxy) ethoxy] ethoxy}methyl-3'-methyloxetane)) and PVDF-HFP (poly(vinylidene fluoride-hexafluoropropylene)), has been successfully prepared for applications in lithium-ion batteries. This type of polymer electrolyte has been made by adding different amounts of lithium bis(oxalate)borate (LiBOB) to the polymer matrix. Its thermal and structural properties were measured using differential scanning calorimetry and x-ray diffraction. Experimental results show that the polymer electrolyte system possesses good thermal stability, with a decomposition temperature above 420 °C. The ionic conductivity of the polymer electrolyte system is dependent on the lithium salt content, reaching a maximum of 1.1 × 10-5 S cm-1 at 30 °C and 2.3 × 10-4 S cm-1 at 80 °C when doped with 10 wt% LiBOB.

  16. Laser Raman and ac impedance spectroscopic studies of PVA: NH4NO3 polymer electrolyte.

    Science.gov (United States)

    Hema, M; Selvasekarapandian, S; Hirankumar, G; Sakunthala, A; Arunkumar, D; Nithya, H

    2010-01-01

    Ion conducting polymer electrolyte PVA:NH(4)NO(3) has been prepared by solution casting technique and characterized using XRD, Raman and ac impedance spectroscopic analyses. The amorphous nature of the polymer films has been confirmed by XRD and Raman spectroscopy. An insight into the deconvoluted Raman peaks of upsilon(1) vibration of NO(3)(-) anion for the polymer electrolyte reveals the dominancy of ion aggregates at higher NH(4)NO(3) concentration. From the ac impedance studies, the highest ion conductivity at 303 K has been found to be 7.5x10(-3)Scm(-1) for 80PVA:20NH(4)NO(3). The conductivity of the polymer electrolytes has been found to depend on the degree of dissociation of the salt in the host polymer matrix. The combination of the above-mentioned analyses has proven worth while and in fact necessary in order to achieve better understanding of these complex systems.

  17. An investigation of PVdF/PVC-based blend electrolytes with EC/PC as plasticizers in lithium battery applications

    Science.gov (United States)

    Rajendran, S.; Sivakumar, P.

    2008-03-01

    Solid polymer electrolytes (SPEs) composed of poly(vinylidene fluoride) (PVdF)-poly(vinyl chloride) (PVC) complexed with lithium perchlorate (LiClO 4) as salt and ethylene carbonate (EC)/propylene carbonate (PC) as plasticizers were prepared using solvent-casting technique, with different weight ratios of EC and PC. The amorphicity and complexation behavior of the polymer electrolytes were confirmed using X-ray diffraction (XRD) and FTIR studies. TG/DTA and scanning electron microscope (SEM) studies explained the thermal stability and surface morphology of electrolytes, respectively. The prepared thin films were subjected to AC impedance measurements as a function of temperature ranging from 302 to 373 K. The temperature-dependence conductivity of polymer films seems to obey VTF relation.

  18. A novel approach to the analysis of distributed shear banding in polymer blends

    NARCIS (Netherlands)

    Pijnenburg, KGW; Van der Giessen, E

    2003-01-01

    The toughness of glassy polymers can be enhanced by blending with rubber particles. The consensus is that this toughening is due to massive plastic deformation of the matrix that takes place once the particles have cavitated. Micromechanical studies of regular stackings of particles in a polymer mat

  19. Biodegradable-Polymer-Blend-Based Surgical Sealant with Body-Temperature-Mediated Adhesion.

    Science.gov (United States)

    Behrens, Adam M; Lee, Nora G; Casey, Brendan J; Srinivasan, Priya; Sikorski, Michael J; Daristotle, John L; Sandler, Anthony D; Kofinas, Peter

    2015-12-22

    The development of practical and efficient surgical sealants has the propensity to improve operational outcomes. A biodegradable polymer blend is fabricated as a nonwoven fiber mat in situ. After direct deposition onto the tissue of interest, the material transitions from a fiber mat to a film. This transition promotes polymer-substrate interfacial interactions leading to improved adhesion and surgical sealant performance.

  20. Porous polymer electrolytes with high ionic conductivity and good mechanical property for rechargeable batteries

    Science.gov (United States)

    Liang, Bo; Jiang, Qingbai; Tang, Siqi; Li, Shengliang; Chen, Xu

    2016-03-01

    Porous polymer electrolytes (PPEs) are attractive for developing lithium-ion batteries because of the combined advantages of liquid and solid polymer electrolytes. In the present study, a new porous polymer membrane doped with phytic acid (PA) is prepared, which is used as a crosslinker in polymer electrolyte matrix and can also plasticize porous polymer electrolyte membranes, changing them into soft tough flexible materials. A PEO-PMMA-LiClO4-x wt.% PA (x = weight of PA/weight of polymer, PEO: poly(ethylene oxide); PMMA: poly(methyl methacrylate)) polymer membrane is prepared by a simple evaporation method. The effects of the ratio of PA to PEO-PMMA on the properties of the porous membrane, including morphology, porous structure, and mechanical property, are systematically studied. PA improves the porous structure and mechanical properties of polymer membrane. The maximum tensile strength and elongation of the porous polymer membranes are 20.71 MPa and 45.7% at 15 wt.% PA, respectively. Moreover, the PPEs with 15 wt.% PA has a conductivity of 1.59 × 10-5 S/cm at 20 °C, a good electrochemical window (>5 V), and a low interfacial resistance. The results demonstrate the compatibility of the mechanical properties and conductivity of the PPEs, indicating that PPEs have good application prospects for lithium-ion batteries.

  1. Honeycomb-like porous gel polymer electrolyte membrane for lithium ion batteries with enhanced safety

    Science.gov (United States)

    Zhang, Jinqiang; Sun, Bing; Huang, Xiaodan; Chen, Shuangqiang; Wang, Guoxiu

    2014-08-01

    Lithium ion batteries have shown great potential in applications as power sources for electric vehicles and large-scale energy storage. However, the direct uses of flammable organic liquid electrolyte with commercial separator induce serious safety problems including the risk of fire and explosion. Herein, we report the development of poly(vinylidene difluoride-co-hexafluoropropylene) polymer membranes with multi-sized honeycomb-like porous architectures. The as-prepared polymer electrolyte membranes contain porosity as high as 78%, which leads to the high electrolyte uptake of 86.2 wt%. The PVDF-HFP gel polymer electrolyte membranes exhibited a high ionic conductivity of 1.03 mS cm-1 at room temperature, which is much higher than that of commercial polymer membranes. Moreover, the as-obtained gel polymer membranes are also thermally stable up to 350°C and non-combustible in fire (fire-proof). When applied in lithium ion batteries with LiFePO4 as cathode materials, the gel polymer electrolyte demonstrated excellent electrochemical performances. This investigation indicates that PVDF-HFP gel polymer membranes could be potentially applicable for high power lithium ion batteries with the features of high safety, low cost and good performance.

  2. Phase Separation of Silicon-Containing Polymer/Polystyrene Blends in Spin-Coated Films.

    Science.gov (United States)

    Li, Yang; Hu, Kai; Han, Xiao; Yang, Qinyu; Xiong, Yifeng; Bai, Yuhang; Guo, Xu; Cui, Yushuang; Yuan, Changsheng; Ge, Haixiong; Chen, Yanfeng

    2016-04-19

    In this Article, two readily available polymers that contain silicon and have different surface tensions, polydimethylsiloxane (PDMS) and polyphenylsilsequioxane (PPSQ), were used to produce polymer blends with polystyrene (PS). Spin-coated thin films of the polymer blends were treated by O2 reactive-ion etching (RIE). The PS constituent was selectively removed by O2 RIE, whereas the silicon-containing phase remained because of the high etching resistance of silicon. This selective removal of PS substantially enhanced the contrast of the phase separation morphologies for better scanning electron microscope (SEM) and atomic force microscope (AFM) measurements. We investigated the effects of the silicon-containing constituents, polymer blend composition, concentration of the polymer blend solution, surface tension of the substrate, and the spin-coating speed on the ultimate morphologies of phase separation. The average domain size, ranging from 100 nm to 10 μm, was tuned through an interplay of these factors. In addition, the polymer blend film was formed on a pure organic layer, through which the aspect ratio of the phase separation morphologies was further amplified by a selective etching process. The formed nanostructures are compatible with existing nanofabrication techniques for pattern transfer onto substrates.

  3. Hydrophilic-hydrophobic polymer blend for modulation of crystalline changes and molecular interactions in solid dispersion.

    Science.gov (United States)

    Van Ngo, Hai; Nguyen, Phuc Kien; Van Vo, Toi; Duan, Wei; Tran, Van-Thanh; Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh

    2016-11-20

    This research study aimed to develop a new strategy for using a polymer blend in solid dispersion (SD) for dissolution enhancement of poorly water-soluble drugs. SDs with different blends of hydrophilic-hydrophobic polymers (zein/hydroxypropyl methylcellulose - zein/HPMC) were prepared using spray drying to modulate the drug crystal and polymer-drug interactions in SDs. Physicochemical characterizations, including power X-ray diffraction and Fourier transform infrared spectroscopy, were performed to elucidate the roles of the blends in SDs. Although hydrophobic polymers played a key role in changing the model drug from a crystal to an amorphous state, the dissolution rate was limited due to the wetting property. Fortunately, the hydrophilic-hydrophobic blend not only reduced the drug crystallinity but also resulted in a hydrogen bonding interaction between the drugs and the polymer for a dissolution rate improvement. This work may contribute to a new generation of solid dispersion using a blend of hydrophilic-hydrophobic polymers for an effective dissolution enhancement of poorly water-soluble drugs.

  4. Distinct difference in ionic transport behavior in polymer electrolytes depending on the matrix polymers and incorporated salts.

    Science.gov (United States)

    Seki, Shiro; Susan, Md Abu Bin Hasan; Kaneko, Taketo; Tokuda, Hiroyuki; Noda, Akihiro; Watanabe, Masayoshi

    2005-03-10

    Two different electrolyte salts, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and a room temperature ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI), were incorporated into network polymers to obtain ion-conductive polymer electrolytes. Network polymers of poly(ethylene oxide-co-propylene oxide) (P(EO/PO)) and poly(methyl methacrylate) (PMMA) were chosen as matrixes for LiTFSI and EMITFSI, respectively. Both of the polymer electrolytes were single-phase materials and were completely amorphous. Ionic conductivity of the polymer electrolytes was measured over a wide temperature range, with the lowest temperatures close to or below the glass transition temperatures (Tg). The Arrhenius plots of the conductivity for both of the systems exhibited positively curved profiles and could be well fit to the Vogel-Tamman-Fulcher (VTF) equation. The conductivity of the PMMA/EMITFSI electrolytes was higher at most by 3 orders of magnitude than that of the LiTFSI/P(EO/ PO) electrolytes at ambient temperature. When the ideal glass transition temperature, T0 (one of the VTF fitting parameters), was compared with the Tg, a difference in the ionic conduction was apparent in these systems. In the P(EO/PO)/LiTFSI electrolytes, the T0 and Tg increased in parallel with salt concentration and the T0 was lower than the Tg by ca. 50 degrees C. On the contrary, the difference between the T0 and the Tg increased with increasing content of PMMA in the PMMA/EMITFSI electrolytes, with the observed difference in the concentration range studied reaching up to ca. 100 degrees C. The conductivity at the Tg, sigma(Tg), for the LiTFSI/P(EO/PO) electrolytes was on the order of 10(-14-)10(-13) S cm(-1) and increased with increasing salt concentration, whereas that for the PMMA/EMITFSI polymer electrolytes reached 10(-7) S cm(-1) when the concentration of PMMA was high. The ion transport mechanism was discussed in terms of the concepts of coupling

  5. Preparation and characterization of chitosan - polystyrene polymer blends

    Science.gov (United States)

    Mascarenhas, N. P.; Gonsalves, R. A.; Goveas, J. J.; Shetty, T. C. S.; Crasta, V.

    2016-05-01

    To enhance the physical and mechanical properties of Chitosan (CS) and to improve the functionality of CS towards some specific applications, we have blended CS with polystyrene (PS) to form blended films. The Fourier Transform Infrared Spectroscopy (FT-IR) has been performed on the prepared films to confirm functional groups and formation of the blends. Thermal analysis (TGA and DSC) is carried out to study thermal stability of the blended films. From X-ray diffraction (XRD) studies, the material reveals amorphous nature and hence it may be used for adsorption process. The versatility of the blends, such as film-forming ability, hydrophilicity, biodegradability and biocompatibility are comparable with the existing blends.

  6. Synthesis and Characterization of a Novel Polymer Electrolyte for Lithium-ion Battery

    Institute of Scientific and Technical Information of China (English)

    Yan Ping Liang; Hong Zhu MA; Bo WANG

    2004-01-01

    A novel polymer electrolyte with the formula of Li2B4O7-PVA for lithium-ion battery was synthesized and its ion conductivity and mechanical properties were also tested. It is found that the conductivity of the prepared polymer electrolytes is higher than that of LiClO4/PEO or LiClO4/EC-DMC by two or three orders in magnitude and a large delocalized bond formed in Li2B4O7-PVA lead to transportation of Li ion easier, this electrolyte possesses high thermo-stability and can be used under 200°C.

  7. Dielectric behavior of different nanofillers incorporated in PVC-PMMA based polymer electrolyte membranes

    Science.gov (United States)

    Sowmya, G.; Pradeepa, P.; Kalaiselvimary, J.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-01

    The Poly (methyl methacrylate) (PMMA)-Poly (vinyl chloride) (PVC) based polymer electrolytes were prepared by solvent casting technique. The prepared polymer electrolytes were subjected to conductivity studies by using electrochemical impedance spectroscopy and the maximum ionic conductivity value was found to be 0.8011 × 10-3 Scm-1 at 303K for PVC (17.5wt%) - PMMA (7.5wt %) - LiClO4 (8wt %) - PC (67wt %) - BaTiO3 (8wt%) electrolyte system. The dielectric behavior of the samples also studied.

  8. Alkaline solid polymer electrolytes and their application to rechargeable batteries; Electrolytes solides polymeres alcalins application aux generateurs electrochimiques rechargeables

    Energy Technology Data Exchange (ETDEWEB)

    Guinot, S.

    1996-03-15

    A new family of solid polymer electrolytes (SPE) based on polyoxyethylene (POE), KOH and water is investigated in view of its use in rechargeable batteries. After a short review on rechargeable batteries, the preparation of various electrolyte compositions is described. Their characterization by differential scanning calorimetry (DSC), thermogravimetric analysis, X-ray diffraction and microscopy confirm a multi-phasic structure. Conductivity measurements give values up to 10 sup -3 S cm sup -1 at room temperature. Their use in cells with nickel as negative electrode and cadmium or zinc as positive electrode has been tested; cycling possibility has been shown to be satisfactory. (C.B.) 113 refs.

  9. Electrochemical performance of poly(vinyl alcohol)-based solid polymer electrolyte for lithium polymer batteries.

    Science.gov (United States)

    Kim, Young-Deok; Jo, Yun-Kyung; Jo, Nam-Ju

    2012-04-01

    Solid polymer electrolytes (SPEs) are an excellent alternative to liquid electrolytes due to their non-volatility, low toxicity, and high energy density. In this study, a SPE having the ion transport mechanism decoupled from segmental motion of a polymer based on poly(vinyl alcohol) (PVA) containing the salt lithium trifluoromethane sulfonate (LiCF3SO3, LiTf) has been prepared to overcome the low ionic conductivity of traditional SPEs at room temperature. PVA has a high glass transition temperature (358 K) and good mechanical properties, and despite being atactic, it can crystallize, especially if highly hydrolyzed. From an ac impedance analysis, it was found that the ionic conductivity of the PVA-based SPE increased with increasing salt concentration. In particular, a dramatic increase was observed between 40 and 50 wt% of salt. The ionic conduction mechanism of the PVA-based SPE is proposed based on intensive study using FT-IR spectroscopic measurements, XRD and AFM. Through measurements of linear sweep voltammetry (LSV) and cyclic voltammetry (CV), it is also found that the SPE with PVA and LiCF3SO3 has good electrochemical stability.

  10. Virus-Assembled Flexible Electrode-Electrolyte Interfaces for Enhanced Polymer-Based Battery Applications

    Directory of Open Access Journals (Sweden)

    Ayan Ghosh

    2012-01-01

    Full Text Available High-aspect-ratio cobalt-oxide-coated Tobacco mosaic virus (TMV- assembled polytetrafluoroethylene (PTFE nonstick surfaces were integrated with a solvent-free polymer electrolyte to create an anode-electrolyte interface for use in lithium-ion batteries. The virus-assembled PTFE surfaces consisted primarily of cobalt oxide and were readily intercalated with a low-molecular-weight poly (ethylene oxide (PEO based diblock copolymer electrolyte to produce a solid anode-electrolyte system. The resulting polymer-coated virus-based system was then peeled from the PTFE backing to produce a flexible electrode-electrolyte component. Electrochemical studies indicated the virus-structured metal-oxide PEO-based interface was stable and displayed robust charge transfer kinetics. Combined, these studies demonstrate the development of a novel solid-state electrode architecture with a unique peelable and flexible processing attribute.

  11. Preparation and characterization on nano-hybrid composite solid polymer electrolyte of PVdF-HFP /MG49-ZrO2 for battery application

    Science.gov (United States)

    Lee T., K.; Ahmad, A.; Hasyareeda, N.

    2014-09-01

    Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO2 has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure.

  12. Preparation and characterization on nano-hybrid composite solid polymer electrolyte of PVdF-HFP /MG49-ZrO{sub 2} for battery application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, T. K.; Ahmad, A. [Polymer Research Center, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor D. E. Malaysia and School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia); Hasyareeda, N. [School of Chemical Sciences and Food Technology, Faculty of Science and Technology (Malaysia)

    2014-09-03

    Initial study on nano composite polymer electrolyte of PVdF-HFP/MG49-ZrO{sub 2} has been done. The zirconium was synthesis via in-situ sol-gel method in a dissolved polymer blends. The effects of different concentrations of zirconium and pH values have been investigated on nano composite polymer (NCP). Analysis impedance show that only at 6 wt. % of zirconium for all pH values show a semi-circle arc which have lowest value of bulk resistance. No ionic conductivity value is obtain due to the absent of ion charge carriers. Analysis of XRD revealed that crystallinity phase of the nano composite polymer was affect by different pH values. However, no significant changes have been observed in IR bands. This could well indicate that different pH medium did not affect the chemical bonding in the structure.

  13. Membranes of polyindene sulfonated and PVA for use as polymer electrolyte; Membranas mistas de poli(indeno) sulfonado e PVA para uso como eletrolito polimerico

    Energy Technology Data Exchange (ETDEWEB)

    Loser, N.; Silva, B.B.R. da; Brum, F.J.B.; Forte, M.M.C. [Universidade Federal do Rio Grande do Sul - Escola de Engenharia, Porto Alegre, RS (Brazil)

    2010-07-01

    This study is focused on developing polymer poly electrolytes for fuel cell PEM and aims to evaluate the efficiency of sulfonated polyindene as A polymer electrolyte in blends with poly (vinyl alcohol) (PVA). For this, polyindene synthesized in the lab was functionalized with sulfonic groups (-SO{sub 3}H), using as sulfonation agent acetyl sulfate in 1,2-dichloroethane. The membranes of sulfonated polyindene (SPInd) and PVA were prepared in aqueous medium, using glutaraldehyde as a PVA cross linker. The membranes SPInd/PVA were evaluated on the content of sulfonic groups, ion exchange capacity (IEC), degree of swelling in water and thermal stability (TGA). Electrochemical impedance analysis was used for ionic conductivity evaluation and DMA for the mechanical strength of the membranes. Preliminary results show that the membranes showed ion exchange capacity about 3.2 m equiv/g and degree of swelling in water of 550%. (author)

  14. A flexible Li polymer primary cell with a novel gel electrolyte based on poly(acrylonitrile)

    Science.gov (United States)

    Akashi, Hiroyuki; Tanaka, Ko-ichi; Sekai, Koji

    The performance of a Li polymer primary cell with fire-retardant poly(acrylonitrile) (PAN)-based gel electrolytes is reported. By optimizing electrodes, electrolytes, the packaging material, and the structural design of the polymer cell, we succeeded in developing a "film-like" Li polymer primary cell with sufficient performance for practical use. The cell is flexible and less than 0.5 mm thick, which makes it suitable for a power source for some smart devices, such as an IC card. Fast cation conduction in the gel electrolyte minimizes the drop of the discharge capacity even at -20 °C. The high chemical stability of the gel electrolytes and the new packaging material allow the self-discharge rate to be limited to under 4.3%, which is equivalent to that of conventional coin-shaped or cylindrical Li-MnO 2 cells.

  15. White Polymer Light-Emitting Diodes Based on Exciplex Electroluminescence from Polymer Blends and a Single Polymer.

    Science.gov (United States)

    Liang, Junfei; Zhao, Sen; Jiang, Xiao-Fang; Guo, Ting; Yip, Hin-Lap; Ying, Lei; Huang, Fei; Yang, Wei; Cao, Yong

    2016-03-01

    In this Article, we designed and synthesized a series of polyfluorene derivatives, which consist of the electron-rich 4,4'-(9-alkyl-carbazole-3,6-diyl)bis(N,N-diphenylaniline) (TPA-Cz) in the side chain and the electron-deficient dibenzothiophene-5,5-dioxide (SO) unit in the main chain. The resulting copolymer PF-T25 that did not comprise the SO unit exhibited blue light-emission with the Commission Internationale de L'Eclairage coordinates of (0.16, 0.10). However, by physically blending PF-T25 with a blue light-emitting SO-based oligomer, a novel low-energy emission correlated to exciplex emerged due to the appropriate energy level alignment of TPA-Cz and the SO-based oligomers, which showed extended exciton lifetime as confirmed by time-resolved photoluminescent spectroscopy. The low-energy emission was also identified in copolymers consisting of SO unit in the main chain, which can effectively compensate for the high-energy emission to produce binary white light-emission. Polymer light-emitting diodes based on the exciplex-type single greenish-white polymer exhibit the peak luminous efficiency of 2.34 cd A(-1) and the maximum brightness of 12 410 cd m(-2), with Commission Internationale de L'Eclairage color coordinates (0.27, 0.39). The device based on such polymer showed much better electroluminescent stability than those based on blending films. These observations indicated that developing a single polymer with the generated exciplex emission can be a novel and effective molecular design strategy toward highly stable and efficient white polymer light-emitting diodes.

  16. Impact of Nanoparticles on the Microstructure and Properties of Immiscible Polymer Blends: Preliminary Investigations

    Science.gov (United States)

    Filippone, G.; Acierno, D.

    2010-06-01

    The control of the morphology represents one of the most important aspects in designing polymer blends. A particular arrangement of the phases known as co-continuity can be promoted within a narrow range of compositions and using appropriate expedients during the mixing process. The distinguishing feature of co-continuous morphologies is the mutual interpenetration of the phases, which is often desirable as it may result in a remarkable combination of functional and structural properties of the blend constituents. Besides acting on the composition and processing conditions, adding nanoparticles in polymer systems with an existing phase-separated morphology such as polymer blends represents an innovative way to promote co-continuity in blends with low amounts of either phase. In the present work we focus on this topic, investigating the ability of nanoparticles to affect the morphology and properties of different kinds of immiscible polymer blends. In addition, the implications of the microstructural changes promoted by the filler on the high-temperature mechanical behavior of the blends are discussed.

  17. NEW POLYMER ELECTROLYTE MEMBRANES FOR FUEL CELLS OPERATING ABOVE 100°C

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf; He, Ronghuan

    2003-01-01

    The state-of-the-art of PEMFC technology is based on perfluorosulfonic acid (PFSA) polymer membranes operating at a typical temperature of 80°C. The newest development in the field is alternative polymer electrolytes for operation above 100°C. This paper is devoted to a review on the development...

  18. Effects of Intercalation on the Hole Mobility of Amorphous Semiconducting Polymer Blends

    KAUST Repository

    Cates, Nichole C.

    2010-06-08

    Fullerenes have been shown to intercalate between the side chains of many crystalline and semicrystalline polymers and to affect the properties of polymer:fullerene bulk heterojunction solar cells. Here we present the first in-depth study of intercalation in an amorphous polymer. We study blends of the widely studied amorphous polymer poly(2-methoxy-5-(3studied amorphous polymer poly(,7·studied amorphous polymer poly(-dimethyloctyloxy)-p-phenylene vinylene) (MDMO-PPV) with a variety of molecules using photoluminescence measurements, scanning electron microscopy, and space-charge limited current mobility measurements. The blends with elevated hole mobilities exhibit complete photoluminescence quenching and show no phase separation in a scanning electron microscope. We conclude that intercalation occurs in MDMO-PPV:fullerene blends and is responsible for the increase in the MDMO-PPV hole mobility by several orders of magnitude when it is blended with fullerenes, despite the dilution of the hole-conducting polymer with an electron acceptor. © 2010 American Chemical Society.

  19. Polymer blend membranes for CO2 separation from natural gas

    Science.gov (United States)

    Mukhtar, H.; Mannan, H. A.; Minh, D.; Nasir, R.; Moshshim, D. F.; Murugesan, T.

    2016-06-01

    Polymeric membranes are dominantly used in industrial gas separation membrane processes. Enhancement in membranes permeability and/or selectivity is a key challenge faced by membrane researchers. The current work represents the effect of poyetherimide blending on separation performance of polysulfone membranes. Polysulfone/poyetherimide (PSF/PEI) blend flat sheet dense membranes were synthesized and tested for permeation analysis of CO2 and CH4 gases at 6, 8 and 10 bar pressure and 25oC temperature. Morphology and thermal properties of membranes were characterized by field emission scanning electron microscope (FESEM) and thermo gravimetric analysis (TGA) respectively. Blend membranes were dense and homogeneous as deduced from FESEM analysis. Thermal stability of synthesized blend membranes was maintained by blending with PEI as characterized by TGA results. Decrease in permeability of both gases was observed by the addition of PEI due to rigidity of PEI chains. Additionally, selectivity of synthesized blend membranes was enhanced by blending PEI and blend membranes show improved selectivity over pure PSF membrane. This new material has the capability to be used as gas separation membrane material.

  20. Organic dopant added polyvinylidene fluoride based solid polymer electrolytes for dye-sensitized solar cells

    Science.gov (United States)

    Senthil, R. A.; Theerthagiri, J.; Madhavan, J.

    2016-02-01

    The effect of phenothiazine (PTZ) as dopant on PVDF/KI/I2 electrolyte was studied for the fabrication of efficient dye-sensitized solar cell (DSSC). The different weight percentage (wt%) ratios (0, 20, 30, 40 and 50%) of PTZ doped PVDF/KI/I2 electrolyte films were prepared by solution casting method using DMF as a solvent. The following techniques such as Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), X-ray diffractometer (XRD) and AC-impedance analysis have been employed to characterize the prepared polymer electrolyte films. The FT-IR studies revealed the complex formation between PVDF/KI/I2 and PTZ. The crystalline and amorphous nature of polymer electrolytes were confirmed by DSC and XRD analysis respectively. The ionic conductivities of polymer electrolyte films were calculated from the AC-impedance analysis. The undoped PVDF/KI/I2 electrolyte exhibited the ionic conductivity of 4.68×10-6 S cm-1 and this value was increased to 7.43×10-5 S cm-1 when PTZ was added to PVDF/KI/I2 electrolyte. On comparison with different wt% ratios, the maximum ionic conductivity was observed for 20% PTZ-PVDF/KI/I2 electrolyte. A DSSC assembled with the optimized wt % of PTZ doped PVDF/KI/I2 electrolyte exhibited a power conversion efficiency of 2.92%, than the undoped PVDF/KI/I2 electrolyte (1.41%) at similar conditions. Hence, the 20% PTZ-PVDF/KI/I2 electrolyte was found to be optimal for DSSC applications.

  1. Solvent activities of the fluorinated solid polymer electrolyte/water system in fuel cells

    Science.gov (United States)

    Kim, Tae Hwan; Bae, Young Chan

    We modified the lattice fluid equation-of-state by the introducing Debye-Hückel equation. A thermodynamic model taking into account the specific interaction and ionic strength between the polymer and the solvent is proposed. The proposed model successfully predicts the vapor/liquid equilibria (VLE) of solvents and the solid polymer electrolyte (SPE). A generalized lattice fluid model is modified to describe the change of water activity in solid polymer electrolyte (SPE)/water systems. The calculated activity curves using the proposed model agree remarkably well with the experimental data.

  2. A new composite polymer electrolyte based on poly(ethyleneoxide)/polysiloxane/BMImTFSI/organomontmorillonite

    Institute of Scientific and Technical Information of China (English)

    Yue-Jiao Li; Feng Wu; Hu-Ren Chao; Shi Chen

    2013-01-01

    Composite polymer electrolytes based on poly(ethylene oxide)-polysiloxane/1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide/organomontmorillonite (PEO-PDMS/IL/OMMT) were prepared and characterized.Addition of both an ionic liquid and OMMT to the polymer base of PEO-PDMS resulted in an increase in ionic conductivity.At room temperature,the ionic conductivity of sample PPB1OO-OMMT4 was 2.19 × 10-3 S/cm.The composite polymer electrolyte also exhibited high thermal and electrochemical stability and may potentially be applied in lithium batteries.

  3. Two-dimensional simulation of polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Hum, B.; Li, X. [Waterloo Univ., ON (Canada). Dept. of Mechanical Engineering

    2002-07-01

    Polymer electrolyte membrane (PEM) fuel cells have fast startup, are highly energy efficient and have high power density, rendering them very suitable for use in zero-emission vehicles and on-site power cogeneration. Before the PEM fuel cell can reach widespread commercial use, the performance has to be improved regarding the minimization of all transport resistances. This can be done by considering the electrochemical reactions in the catalyst layers along with the physical transport of reactant gas flows, product and process water, heat and the charged particles in the individual cells and stacks. This paper presents the results of a two-dimensional numerical simulation of a steady, isothermal, fully humidified PEM fuel cell which was conducted to examine what happens in the catalyst layers. The finite volume method was used together with the alternating direction implicit algorithm. It was determined that the cathode catalyst layer has more pronounced changes in potential, reaction rate and current density generation compared to the anode catalyst layer. This is because of the large cathode activation overpotential and the low diffusion coefficient of oxygen. It was demonstrated that catalyst layers, by nature, are 2 dimensional, particularly in areas of low reactant concentrations. Maximum power density is limited by the depletion of one of the reactants in the catalyst layer. Both the fuel and oxidant supply must be managed simultaneously for optimal cell performance. It was concluded that cell performance is not greatly affected by flow direction. It was noted that this analysis can also be used for more complex cell design, such as cross flow between reactant streams and practical serpentine flow channel design. 11 refs., 2 tabs., 10 figs.

  4. Influence of nanoparticle-ion and nanoparticle-polymer interactions on ion transport and viscoelastic properties of polymer electrolytes.

    Science.gov (United States)

    Mogurampelly, Santosh; Sethuraman, Vaidyanathan; Pryamitsyn, Victor; Ganesan, Venkat

    2016-04-21

    We use atomistic simulations to probe the ion conductivities and mechanical properties of polyethylene oxide electrolytes containing Al2O3nanoparticles. We specifically study the influence of repulsive polymer-nanoparticle and ion-nanoparticle interactions and compare the results with those reported for electrolytes containing the polymorph β-Al2O3nanoparticles. We observe that incorporating repulsive nanoparticle interactions generally results in increased ionic mobilities and decreased elastic moduli for the electrolyte. Our results indicate that both ion transport and mechanical properties are influenced by the polymer segmental dynamics in the interfacial zones of the nanoparticle in the ion-doped systems. Such effects were seen to be determined by an interplay between the nanoparticle-polymer,nanoparticle-ion, and ion-polymer interactions. In addition, such interactions were also observed to influence the number of dissociated ions and the resulting conductivities. Within the perspective of the influence of nanoparticles on the polymer relaxation times in ion-doped systems, our results in the context of viscoelastic properties were consistent with the ionic mobilities. Overall, our results serve to highlight some issues that confront the efforts to use nanoparticle dispersions to simultaneously enhance the conductivity and the mechanical strength of polymer electrolyte.

  5. Polymer electrolytes based on room temperature ionic liquid: 2,3-dimethyl-1-octylimidazolium triflate.

    Science.gov (United States)

    Singh, Boor; Sekhon, S S

    2005-09-01

    Room temperature ionic liquid (DMOImTf) based upon 2,3-dimethyl-1-octylimidazolium cation and trifluoromethanesulfonate or triflate (CF(3)SO(3))(-) anion has been synthesized and shows conductivity of 5.68 mS/cm and viscosity of 26.4 cP at 25 degrees C. Ion conducting polymer electrolytes based on polymers (poly(ethylene oxide) (PEO) and polyvinylidenefluoride-co-hexafluoropropylene (PVdF-HFP)) and ionic liquid (DMOImTf) were prepared in film form by the casting technique. The conductivity of polymer electrolytes containing 0.5 M LiCF(3)SO(3) in PEO:DMOImTf taken in equal weight ratio increases with the addition of propylene carbonate (PC) while its mechanical stability improved by dispersing nanosize fumed silica. However, polymer electrolytes containing PVdF-HFP and ionic liquid show a high value of conductivity (10(-4)-10(-3) S/cm) alongwith better mechanical stability.

  6. Ambient Temperature Hybrid Polymer Electrolyte Based on Pvk + Pvdf-Hfp for Lithium Batteries

    Science.gov (United States)

    Michael, M. S.; Prabaharan, S. R. S.

    2002-12-01

    Proposed herein is a new ambient temperature Li+ conducting PVDF-HFP-co-polymer based hybrid polymer electrolyte with polyvinyl carbozole (PVK) as additive. The addition of the latter provides high ambient temperature electrolytic conductivity (σi) 0.7 × 10-3S/cm with an ionic transference number of 0.6, besides providing the thermoplastic flexibility to the whole matrix. The membrane is found to exhibit a wide electrochemical potential window, >4.5V against Li/Li+. When prepared properly, the membrane is dry and free standing, yet totally suitable for lithium polymer rechargeable batteries. This paper presents the preparation, microstructure and electrochemical characteristics of this new hybrid polymeric membrane. Finally, the dry polymeric electrolyte membrane has been employed in a lithium polymer cell against LT-LiCo0.8Ni0.2O2 as positive electrode and its interfacial behavior and electrochemical cycling results are presented.

  7. Nanopore gating with an anchored polymer in a switching electrolyte bias

    Science.gov (United States)

    Wells, Craig C.; Jou, Ining A.; Melnikov, Dmitriy V.; Gracheva, Maria E.

    2016-03-01

    In this work, we theoretically study the interaction between a solid state membrane equipped with a nanopore and a tethered, negatively charged polymer chain subjected to a time-dependent applied electrolyte bias. In order to describe the movement of the chain in the biomolecule-membrane system immersed in an electrolyte solution, Brownian dynamics is used. We show that we can control the polymer's equilibrium position with various applied electrolyte biases: for a sufficiently positive bias, the chain extends inside the pore, and the removal of the bias causes the polymer to leave the pore. Corresponding to a driven process, we find that the time it takes for a biomolecular chain to enter and extend into a nanopore in a positive bias almost increases linearly with chain length while the amount of time it takes for a polymer chain to escape the nanopore is mainly governed by diffusion.

  8. Development and characterization of poly(1-vinylpyrrolidone-co-vinyl acetate) copolymer based polymer electrolytes.

    Science.gov (United States)

    Sa'adun, Nurul Nadiah; Subramaniam, Ramesh; Kasi, Ramesh

    2014-01-01

    Gel polymer electrolytes (GPEs) are developed using poly(1-vinylpyrrolidone-co-vinyl acetate) [P(VP-co-VAc)] as the host polymer, lithium bis(trifluoromethane) sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14 × 10(-6) S cm(-1) for sample containing 25 wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303 K to 353 K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA) while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction analysis (XRD), respectively.

  9. Enhanced nanoscale imaging of polymer blends by temperature-controlled selective dissolution.

    Science.gov (United States)

    Friedel, Bettina; Ehrler, Bruno; Hüttner, Sven; Greenham, Neil C

    2012-01-23

    Nanoscale imaging on polymer blends is vital, especially in organic electronics. By using temperature-controlled selective dissolution, the 3D structure of a thin film becomes accessible without the expensive search for adequate orthogonal solvents. The method, which takes advantage of the temperature dependence of the solubility, is demonstrated to image P3HT:PCBM and P3HT:F8TBT photovoltaic blend films using atomic force and scanning electron microscopy.

  10. Shape-memory behavior of cross-linked semi-crystalline polymers and their blends

    Directory of Open Access Journals (Sweden)

    I. Kolesov

    2015-03-01

    Full Text Available The present study deals with thermally induced one-way and invertible two-way shape-memory effect (SME in covalent networks on the basis of crystallizable (copolymers and their blends and is an attempt to generalize the results of own investigation received by the authors in the last ten years. The main focus of work clearly lies on research of covalently crosslinked binary and ternary blends having two and three crystalline phases with different thermal stability, respectively. The existence of two or three crystalline phases possessing different melting and crystallization temperatures in heterogeneous polymer networks can lead to triple-shape or even quadruple-shape behavior of such networks. However, the performed investigations point to crucial effect of phase morphology of crosslinked polymer blends on multiplicity of their shapememory behavior beside the influence of blend content, crystallinity and cross-link density of blend phases as well as of processing conditions. For instance, triple-shape memory behavior in binary blends can be realized only if the continuous phase has a lower melting temperature than the dispersed phase. Cross-linked polymer blends are a facile alternative to expensive and complex synthesis of interpenetrating or block-copolymer networks used for shape memory polymers. In addition to findings of experimental investigation of SME in crystallizable covalent polymer networks, the results of modeling their shape-memory behavior on the basis of self-developed physically reasonable model have been briefly described and discussed. Thereby, good accordance between results of theory and experiment was achieved with physically justified fitting parameters.

  11. Poly(vinylidene fluoride-hexafluoropropylene) polymer electrolyte for paper-based and flexible battery applications

    Science.gov (United States)

    Aliahmad, Nojan; Shrestha, Sudhir; Varahramyan, Kody; Agarwal, Mangilal

    2016-06-01

    Paper-based batteries represent a new frontier in battery technology. However, low-flexibility and poor ionic conductivity of solid electrolytes have been major impediments in achieving practical mechanically flexible batteries. This work discuss new highly ionic conductive polymer gel electrolytes for paper-based battery applications. In this paper, we present a poly(vinylidene fluoride-hexafluoropropylene) (PVDH-HFP) porous membrane electrolyte enhanced with lithium bis(trifluoromethane sulphone)imide (LiTFSI) and lithium aluminum titanium phosphate (LATP), with an ionic conductivity of 2.1 × 10-3 S cm-1. Combining ceramic (LATP) with the gel structure of PVDF-HFP and LiTFSI ionic liquid harnesses benefits of ceramic and gel electrolytes in providing flexible electrolytes with a high ionic conductivity. In a flexibility test experiment, bending the polymer electrolyte at 90° for 20 times resulted in 14% decrease in ionic conductivity. Efforts to further improving the flexibility of the presented electrolyte are ongoing. Using this electrolyte, full-cell batteries with lithium titanium oxide (LTO) and lithium cobalt oxide (LCO) electrodes and (i) standard metallic current collectors and (ii) paper-based current collectors were fabricated and tested. The achieved specific capacities were (i) 123 mAh g-1 for standard metallic current collectors and (ii) 99.5 mAh g-1 for paper-based current collectors. Thus, the presented electrolyte has potential to become a viable candidate in paper-based and flexible battery applications. Fabrication methods, experimental procedures, and test results for the polymer gel electrolyte and batteries are presented and discussed.

  12. Poly(vinylidene fluoride-hexafluoropropylene polymer electrolyte for paper-based and flexible battery applications

    Directory of Open Access Journals (Sweden)

    Nojan Aliahmad

    2016-06-01

    Full Text Available Paper-based batteries represent a new frontier in battery technology. However, low-flexibility and poor ionic conductivity of solid electrolytes have been major impediments in achieving practical mechanically flexible batteries. This work discuss new highly ionic conductive polymer gel electrolytes for paper-based battery applications. In this paper, we present a poly(vinylidene fluoride-hexafluoropropylene (PVDH-HFP porous membrane electrolyte enhanced with lithium bis(trifluoromethane sulphoneimide (LiTFSI and lithium aluminum titanium phosphate (LATP, with an ionic conductivity of 2.1 × 10−3 S cm−1. Combining ceramic (LATP with the gel structure of PVDF-HFP and LiTFSI ionic liquid harnesses benefits of ceramic and gel electrolytes in providing flexible electrolytes with a high ionic conductivity. In a flexibility test experiment, bending the polymer electrolyte at 90° for 20 times resulted in 14% decrease in ionic conductivity. Efforts to further improving the flexibility of the presented electrolyte are ongoing. Using this electrolyte, full-cell batteries with lithium titanium oxide (LTO and lithium cobalt oxide (LCO electrodes and (i standard metallic current collectors and (ii paper-based current collectors were fabricated and tested. The achieved specific capacities were (i 123 mAh g−1 for standard metallic current collectors and (ii 99.5 mAh g−1 for paper-based current collectors. Thus, the presented electrolyte has potential to become a viable candidate in paper-based and flexible battery applications. Fabrication methods, experimental procedures, and test results for the polymer gel electrolyte and batteries are presented and discussed.

  13. Development and characterization of biodegradable polymer blends - PHBV/PCL irradiated with gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Rosario, F. [Faculdade de Tecnologia da Zona Leste (FATEC-ZL), Sao Paulo, SP (Brazil). Centro Paulo Souza; Casarin, S.A.; Agnelli, J.A.M. [Universidade Federal de Sao Carlos (DEMa/UFSCar), SP (Brazil). Dept. de Engenharia de Materiais; Souza Junior, O.F. de [Universidade de Sao Paulo (IFSC/USP), Sao Carlos, SP (Brazil). Inst. de Fisica

    2010-07-01

    This paper presents the results of a study that aimed to develop PHBV biodegradable polymer blends, in a major concentration with PCL, irradiate the pure polymers and blends in two doses of gamma radiation and to analyze the changes in chemical and mechanical properties. The blends used in this study were from natural biodegradable copolymer poly (hydroxybutyrate-valerate) (PHBV) and synthetic biodegradable polymer poly (caprolactone) (PCL 2201) with low molar mass (2,000 g/mol). Several samples were prepared in a co-rotating twin-screw extruder and afterwards, the tensile specimens were injected for the irradiation treatment with 50 kGy to 100 kGy doses and for the mechanical tests. The characterization of the samples before and after the irradiation treatments was performed through scanning electron microscopy (SEM), dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC) and mechanical tensile tests. (author)

  14. Stable Lithium Deposition Generated from Ceramic-Cross-Linked Gel Polymer Electrolytes for Lithium Anode.

    Science.gov (United States)

    Tsao, Chih-Hao; Hsiao, Yang-Hung; Hsu, Chun-Han; Kuo, Ping-Lin

    2016-06-22

    In this work, a composite gel electrolyte comprising ceramic cross-linker and poly(ethylene oxide) (PEO) matrix is shown to have superior resistance to lithium dendrite growth and be applicable to gel polymer lithium batteries. In contrast to pristine gel electrolyte, these nanocomposite gel electrolytes show good compatibility with liquid electrolytes, wider electrochemical window, and a superior rate and cycling performance. These silica cross-linkers allow the PEO to form the lithium ion pathway and reduce anion mobility. Therefore, the gel not only features lower polarization and interfacial resistance, but also suppresses electrolyte decomposition and lithium corrosion. Further, these nanocomposite gel electrolytes increase the lithium transference number to 0.5, and exhibit superior electrochemical stability up to 5.0 V. Moreover, the lithium cells feature long-term stability and a Coulombic efficiency that can reach 97% after 100 cycles. The SEM image of the lithium metal surface after the cycling test shows that the composite gel electrolyte with 20% silica cross-linker forms a uniform passivation layer on the lithium surface. Accordingly, these features allow this gel polymer electrolyte with ceramic cross-linker to function as a high-performance lithium-ionic conductor and reliable separator for lithium metal batteries.

  15. Study Tensile Strength and Wear Rate for Unsaturated Polyester Resin and Nitrile butadiene Rubber Polymer Blend

    Directory of Open Access Journals (Sweden)

    Entihaa G. Daway

    2015-06-01

    Full Text Available Binary polymer blend was prepared by mechanical mixing method of unsaturated polyester resin with Nitrile Butadiene Rubber (NBR with different weight ratios (0, 5, 10 and 15 % of (NBR. Tensile characteristics and wear rates of these blends were studied for all mixing ratios. The microstructure of fracture surfaces of the prepared samples were investigated by optical microscope. The results were showed that strain rates of the resin material increase after blending it with rubber while the ultimate tensile strength and Young’s modulus values of it will decrease. It is also noticed that the wear rate of resin decreases with increasing of (NBR content.

  16. Hot Hole Transfer Increasing Polaron Yields in Hybrid Conjugated Polymer/PbS Blends.

    Science.gov (United States)

    Strein, Elisabeth; deQuilettes, Dane W; Hsieh, Stephen T; Colbert, Adam E; Ginger, David S

    2014-01-01

    We use quasi-steady-state photoinduced absorption (PIA) to study charge generation in blends of poly(3-hexylthiophene-2,5-diyl) (P3HT) with PbS nanocrystal quantum dots as a function of excitation energy. We find that, per photon absorbed, the yield of photogenerated holes present on the conjugated polymer increases with pump energy, even at wavelengths where only the quantum dots absorb. We interpret this result as direct evidence for transfer of hot holes in these conjugated polymer/quantum dot blends. These results help understand the operation of hybrid organic/inorganic photovoltaics.

  17. Preparation and characterization of plasticized high molecular weight PVC-based polymer electrolytes

    Indian Academy of Sciences (India)

    S Ramesh; Geok Bee Teh; Rong-Fuh Louh; Yong Kong Hou; Pung Yen Sin; Lim Jing Yi

    2010-02-01

    Poly(vinyl chloride) (PVC)-based polymer electrolytes films consisting of lithium trifluromethanesulfonate (LiCF3SO3)-ethylene carbonate (EC) were prepared by the solution-casting method. Ionic conductivities of the electrolytes have been determined by an impedance studies in the temperature range of 298–373 K. Complexation of the prepared electrolytes is studied by X-ray diffraction (XRD) analysis. Thermogravimetric analysis (TGA) was used to confirm the thermal stability of the polymer electrolytes. The conductivity–temperature plots were found to follow an Arrhenius nature. All these films are found to be thermally stable until 132–167°C.

  18. Multiphase transport in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Gauthier, Eric D.

    Polymer electrolyte membrane fuel cells (PEMFCs) enable efficient conversion of fuels to electricity. They have enormous potential due to the high energy density of the fuels they utilize (hydrogen or alcohols). Power density is a major limitation to wide-scale introduction of PEMFCs. Power density in hydrogen fuel cells is limited by accumulation of water in what is termed fuel cell `flooding.' Flooding may occur in either the gas diffusion layer (GDL) or within the flow channels of the bipolar plate. These components comprise the electrodes of the fuel cell and balance transport of reactants/products with electrical conductivity. This thesis explores the role of electrode materials in the fuel cell and examines the fundamental connection between material properties and multiphase transport processes. Water is generated at the cathode catalyst layer. As liquid water accumulates it will utilize the largest pores in the GDL to go from the catalyst layer to the flow channels. Water collects to large pores via lateral transport at the interface between the GDL and catalyst layer. We have shown that water may be collected in these large pores from several centimeters away, suggesting that we could engineer the GDL to control flooding with careful placement and distribution of large flow-directing pores. Once liquid water is in the flow channels it forms slugs that block gas flow. The slugs are pushed along the channel by a pressure gradient that is dependent on the material wettability. The permeable nature of the GDL also plays a major role in slug growth and allowing bypass of gas between adjacent channels. Direct methanol fuel cells (DMFCs) have analogous multiphase flow issues where carbon dioxide bubbles accumulate, `blinding' regions of the fuel cell. This problem is fundamentally similar to water management in hydrogen fuel cells but with a gas/liquid phase inversion. Gas bubbles move laterally through the porous GDL and emerge to form large bubbles within the

  19. Understanding the transport processes in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Cheah, May Jean

    Polymer electrolyte membrane (PEM) fuel cells are energy conversion devices suitable for automotive, stationary and portable applications. An engineering challenge that is hindering the widespread use of PEM fuel cells is the water management issue, where either a lack of water (resulting in membrane dehydration) or an excess accumulation of liquid water (resulting in fuel cell flooding) critically reduces the PEM fuel cell performance. The water management issue is addressed by this dissertation through the study of three transport processes occurring in PEM fuel cells. Water transport within the membrane is a combination of water diffusion down the water activity gradient and the dragging of water molecules by protons when there is a proton current, in a phenomenon termed electro-osmotic drag, EOD. The impact of water diffusion and EOD on the water flux across the membrane is reduced due to water transport resistance at the vapor/membrane interface. The redistribution of water inside the membrane by EOD causes an overall increase in the membrane resistance that regulates the current and thus EOD, thereby preventing membrane dehydration. Liquid water transport in the PEM fuel cell flow channel was examined at different gas flow regimes. At low gas Reynolds numbers, drops transitioned into slugs that are subsequently pushed out of the flow channel by the gas flow. The slug volume is dependent on the geometric shape, the surface wettability and the orientation (with respect to gravity) of the flow channel. The differential pressure required for slug motion primarily depends on the interfacial forces acting along the contact lines at the front and the back of the slug. At high gas Reynolds number, water is removed as a film or as drops depending on the flow channel surface wettability. The shape of growing drops at low and high Reynolds number can be described by a simple interfacial energy minimization model. Under flooding conditions, the fuel cell local current

  20. Super Soft All-Ethylene Oxide Polymer Electrolyte for Safe All-Solid Lithium Batteries

    Science.gov (United States)

    Porcarelli, Luca; Gerbaldi, Claudio; Bella, Federico; Nair, Jijeesh Ravi

    2016-01-01

    Here we demonstrate that by regulating the mobility of classic -EO- based backbones, an innovative polymer electrolyte system can be architectured. This polymer electrolyte allows the construction of all solid lithium-based polymer cells having outstanding cycling behaviour in terms of rate capability and stability over a wide range of operating temperatures. Polymer electrolytes are obtained by UV-induced (co)polymerization, which promotes an effective interlinking between the polyethylene oxide (PEO) chains plasticized by tetraglyme at various lithium salt concentrations. The polymer networks exhibit sterling mechanical robustness, high flexibility, homogeneous and highly amorphous characteristics. Ambient temperature ionic conductivity values exceeding 0.1 mS cm-1 are obtained, along with a wide electrochemical stability window (>5 V vs. Li/Li+), excellent lithium ion transference number (>0.6) as well as interfacial stability. Moreover, the efficacious resistance to lithium dendrite nucleation and growth postulates the implementation of these polymer electrolytes in next generation of all-solid Li-metal batteries working at ambient conditions.

  1. STRUCTURAL, THERMAL AND CONDUCTIVITY STUDIES OF PAN-LIBF4 POLYMER ELECTROLYTES

    Directory of Open Access Journals (Sweden)

    S. K. NIPPANI

    2016-11-01

    Full Text Available The polymer electrolytes with various compositions of Polyacrylonitrile/N-N Dimethylformamide (DMF/Lithiumtetrafluoroborate (LiBF4 are synthesized by solution casting technique. The free standing, clear and transparent 60-80 micron thick films are formed. The promising structural and complexation changes in polymer electrolytes have been explored by X-ray diffraction (XRD and Fourier transform infra-red (FTIR techniques. The thermal properties of all solid polymer electrolytes (SPE were studied by Thermo gravimetric Analyzer (TGA and Differential Thermal Analyzer (DTA. The electrical properties, i.e., ionic conductivity of solid polymer electrolytes has been measured as a function of temperature and composition. A Polymer membrane for 3 wt. % of salt has a conductivity of 3.06x10-4 mScm-1 at room temperature and 1.53x10-3 mScm-1 at 358K. The conductivity values increased with increase in temperature and offered an ionic conductivity of the order of 10-3 mScm-1 at temperatures 358K. Activation energy, enthalpy and entropy values are determined for all polymer complexes.

  2. 聚合物复合电解质的界面结构与控制%Interface Structure and Control of Composite Polymer Electrolytes

    Institute of Scientific and Technical Information of China (English)

    张亚峰; 龚克成

    2001-01-01

    The effects of interface structures on the ion conductivity and mechanical property in multiphase systems forming by blending solid polymer electrolytes with polymer,plasticizer or inorganic powder is mainly discussed in this paper. It is indicated that choosing proper modifier and blending ways to control the interface structure and form highly conductive interface to the most is an effective way to gain solid polymer electrolytes with high conductivity and excellent mechanical property.%本文主要讨论了聚合物固体电解质与聚合物、增塑剂和无机物等复合形成的多相聚合物复合电解质中,界面结构对离子电导率和机械性能的影响。指出选择适当的改性剂及复合方法,控制界面的结构和形态,形成尽可能多的高导电的界面,是获得电导率高和机械性能良好的聚合物固体电解质的有效途径。

  3. Nafion and modified-Nafion membranes for polymer electrolyte fuel cells: An overview

    Indian Academy of Sciences (India)

    A K Sahu; S Pitchumani; P Sridhar; A K Shukla

    2009-06-01

    Polymer electrolyte fuel cells (PEFCs) employ membrane electrolytes for proton transport during the cell reaction. The membrane forms a key component of the PEFC and its performance is controlled by several physical parameters, viz. water up-take, ion-exchange capacity, proton conductivity and humidity. The article presents an overview on Nafion membranes highlighting their merits and demerits with efforts on modified-Nafion membranes.

  4. Novel Amphiphilic Polymer Gel Electrolytes Based on PEG-b-GMA-co-MMA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Gel polymer electrolytes for lithium battery have been widely investigated recently because of their high ion conductivity at room temperature. We synthesized and characterized novel gel electrolytes based on amphiphilic copolymethacrylates containing different lengths of ethylene oxide (EO) chain as ionophilic units and methyl methacrylate (MMA) chain as ionophobic units[1]. Their electrochemical properties were also measured.1H NMR and FTIR analysis results elucidated that PEG-b-glycidyl met...

  5. [Some aspects of water electrolysis with the use of a solid polymer electrolyte].

    Science.gov (United States)

    Zorina, N G

    2006-01-01

    Electrochemical process in cells with a solid polymer electrolyte is dependent on catalyst durability in harsh environments and catalyst sputtering technology to ensure efficient power consumption. Active polymer electrolytes will permit to reduce substantially non-productive layouts and design a cost-effective, compact and safe system generator of high-purity oxygen and hydrogen. The existing designs of combined oxide systems integrating rear-earth and earth metals with a structure of Ln3+x Me2+1-x CoO3 containing perofskites were shown to be active catalysts in cells with a solid polymer electrolyte, and the sputtering technology was proven to reduce non-productive layouts in 2 or 2.5 times.

  6. Recent advances in solid polymer electrolyte fuel cell technology with low platinum loading electrodes

    Science.gov (United States)

    Srinivasan, Supramaniam; Manko, David J.; Koch, Hermann; Enayetullah, Mohammad A.; Appleby, A. John

    1989-01-01

    Of all the fuel cell systems only alkaline and solid polymer electrolyte fuel cells are capable of achieving high power densities (greater than 1 W/sq cm) required for terrestrial and extraterrestrial applications. Electrode kinetic criteria for attaining such high power densities are discussed. Attainment of high power densities in solid polymer electrolyte fuel cells has been demonstrated earlier by different groups using high platinum loading electrodes (4 mg/sq cm). Recent works at Los Alamos National Laboratory and at Texas A and M University (TAMU) demonstrated similar performance for solid polymer electrolyte fuel cells with ten times lower platinum loading (0.45 mg/sq cm) in the electrodes. Some of the results obtained are discussed in terms of the effects of type and thickness of membrane and of the methods platinum localization in the electrodes on the performance of a single cell.

  7. Advances in the high performance polymer electrolyte membranes for fuel cells.

    Science.gov (United States)

    Zhang, Hongwei; Shen, Pei Kang

    2012-03-21

    This critical review tersely and concisely reviews the recent development of the polymer electrolyte membranes and the relationship between their properties and affecting factors like operation temperature. In the first section, the advantages and shortcomings of the corresponding polymer electrolyte membrane fuel cells are analyzed. Then, the limitations of Nafion membranes and their alternatives to large-scale commercial applications are discussed. Secondly, the concepts and approaches of the alternative proton exchange membranes for low temperature and high temperature fuel cells are described. The highlights of the current scientific achievements are given for various aspects of approaches. Thirdly, the progress of anion exchange membranes is presented. Finally, the perspectives of future trends on polymer electrolyte membranes for different applications are commented on (400 references).

  8. Solid State Polymer Electrolytes for Dye-sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Introduction Over the past decade,Dye-sensitized solar cells (DSSCs) have been intensively investigated as potential alternatives to conventional inorganic photovoltaic devices due to their low production cost and high energy conversion[1-4]. This type of solar cell has achieved an impressive energy conversion efficiency of over 10%,whose electrolyte is a voltaic organic liquid solvent containing iodide/triiodide as redox couple.However,the use of a liquid electrolyte brings difficulties in the practi...

  9. In situ ceramic fillers of electrospun thermoplastic polyurethane/poly(vinylidene fluoride) based gel polymer electrolytes for Li-ion batteries

    Science.gov (United States)

    Wu, Na; Cao, Qi; Wang, Xianyou; Li, Sheng; Li, Xiaoyun; Deng, Huayang

    Gel polymer electrolyte films based on thermoplastic polyurethane (TPU)/poly(vinylidene fluoride) (PVdF) with and without in situ ceramic fillers (SiO 2 and TiO 2) are prepared by electrospinning 9 wt% polymer solution at room temperature. The electrospun TPU-PVdF blending membrane with 3% in situ TiO 2 shows a highest ionic conductivity of 4.8 × 10 -3 S cm -1 with electrochemical stability up to 5.4 V versus Li +/Li at room temperature and has a high tensile strength (8.7 ± 0.3 MPa) and % elongation at break (110.3 ± 0.2). With the superior electrochemical and mechanical performance, it is very suitable for application in polymer lithium ion batteries.

  10. Compliant glass-polymer hybrid single ion-conducting electrolytes for lithium batteries.

    Science.gov (United States)

    Villaluenga, Irune; Wujcik, Kevin H; Tong, Wei; Devaux, Didier; Wong, Dominica H C; DeSimone, Joseph M; Balsara, Nitash P

    2016-01-05

    Despite high ionic conductivities, current inorganic solid electrolytes cannot be used in lithium batteries because of a lack of compliance and adhesion to active particles in battery electrodes as they are discharged and charged. We have successfully developed a compliant, nonflammable, hybrid single ion-conducting electrolyte comprising inorganic sulfide glass particles covalently bonded to a perfluoropolyether polymer. The hybrid with 23 wt% perfluoropolyether exhibits low shear modulus relative to neat glass electrolytes, ionic conductivity of 10(-4) S/cm at room temperature, a cation transference number close to unity, and an electrochemical stability window up to 5 V relative to Li(+)/Li. X-ray absorption spectroscopy indicates that the hybrid electrolyte limits lithium polysulfide dissolution and is, thus, ideally suited for Li-S cells. Our work opens a previously unidentified route for developing compliant solid electrolytes that will address the challenges of lithium batteries.

  11. A Synopsis of Interfacial Phenomena in Lithium-Based Polymer Electrolyte Electrochemical Cells

    Science.gov (United States)

    Baldwin, Richard S.; Bennett, William R.

    2007-01-01

    The interfacial regions between electrode materials, electrolytes and other cell components play key roles in the overall performance of lithium-based batteries. For cell chemistries employing lithium metal, lithium alloy or carbonaceous materials (i.e., lithium-ion cells) as anode materials, a "solid electrolyte interphase" (SEI) layer forms at the anode/electrolyte interface, and the properties of this "passivating" layer significantly affect the practical cell/battery quality and performance. A thin, ionically-conducting SEI on the electrode surface can beneficially reduce or eliminate undesirable side reactions between the electrode and the electrolyte, which can result in a degradation in cell performance. The properties and phenomena attributable to the interfacial regions existing at both anode and cathode surfaces can be characterized to a large extent by electrochemical impedance spectroscopy (EIS) and related techniques. The intention of the review herewith is to support the future development of lithium-based polymer electrolytes by providing a synopsis of interfacial phenomena that is associated with cell chemistries employing either lithium metal or carbonaceous "composite" electrode structures which are interfaced with polymer electrolytes (i.e., "solvent-free" as well as "plasticized" polymer-binary salt complexes and single ion-conducting polyelectrolytes). Potential approaches to overcoming poor cell performance attributable to interfacial effects are discussed.

  12. Fabrication of stable photovoltachromic cells using a solvent-free hybrid polymer electrolyte.

    Science.gov (United States)

    Yang, Ming-Che; Cho, Hsun-Wei; Wu, Jih-Jen

    2014-08-21

    In this work, photovoltachromic cells (PVCCs) are fabricated using a solvent-free polyethylene glycol (PEG)-titanium hybrid polymer electrolyte. With appropriate addition of 1,2-dimethyl-3-propylimidazolium iodide in the electrolyte, the range of tunable colored-state transmittance of the PVCC is enlarged due to an improved fill factor. A transmittance modulation larger than 40% can be maintained for at least 3 months, demonstrating the good long-term stability of PVCCs fabricated using the solvent-free PEG-Ti hybrid electrolyte.

  13. Study on the Ion Association in PVdF-based Gel Polymer Electrolyte

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Gel polymer electrolytes based on the poly (vinylidene fluoride) (PVdF) and the electrolyte of LiClO4 in propylene carbonate (PC) were prepared by the solution casting technique. The ionic conductivity of the gel electrolytes was concentration of lithium salt. Because of the strong coulombiq attractions, the dissolved salt ions might aggregate into ion pairs and multiple ion aggregates. The analysis of DSC and X-ray diffraction revealed that the ions association occurred at higher concentration of lithium salt.

  14. Polymer electrolytes for rechargeable lithium batteries. Final report; Polymere Elektrolyte fuer wiederaufladbare Lithium-Batterien. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Sandner, B. [Halle-Wittenberg Univ., Merseburg (Germany). Inst. fuer Technische und Makromolekulare Chemie; Wegner, G.; Meyer, W. [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Bronstert, B.; Moehwald, H.; Hennig, I. [BASF AG, Ludwigshafen am Rhein (Germany). Kunststofflaboratorium

    1999-07-01

    Rechargeable lithium batteries with water-free organic electrolytes have the highest energy density of all battery systems. Some of their weak points, e.g. concerning safety, cell production, cost etc. could be overcome by replacing the liquid low-molecular electrolytes with polymer electrolytes. The investigation focused on acrylically unsaturated oligomers/prepolymers. [German] Wiederaufladbare Lithiumbatterien mit wasserfreien organischen Elektrolyten sind die Akkumulatoren mit der hoechsten Energiedichte. Durch Ersatz der fluessigen niedermolekularen Elektrolyte durch Polymerfestelektrolyte koennen manche Schwachpunkte dieser Batterien, vor allem bezueglich Sicherheit, Zellfertigung, Kosten, etc., ausgeraeumt werden. Ausgangspunkt der Arbeiten waren acrylisch ungesaettigte Oligomere/Praepolymere. (orig.)

  15. Morphological analysis of Polyethersulfone/polyvinyl Acetate blend membrane synthesized at various polymer concentrations

    Science.gov (United States)

    Hadi, S. H. A. A.; Mannan, H. A.; Mukhtar, H.; Shaharun, M. S.; Murugesan, T.

    2016-06-01

    This paper reports the effect of varying polymer concentration i.e. solvent/polymer ratio on the morphology and gas transport behaviour of polyethersulfone/polyvinyl acetate blend membrane. The solvent used was dimethylformamide, while the manipulated variable was polymer concentration. The concentrations were varied from 75-90 weight % solvent. A homogeneous surface with dense cross-section structure membranes were successfully developed as deduced from FESEM images. The permeability of CO2 and CH4 gases increased with increasing polymer concentration and an improved CO2/CH4 selectivity was observed. These observation made from the characterization justified the applicability of the blend to be synthesized as membrane for gas separation.

  16. Towards a stable ion-solvating polymer electrolyte for advanced alkaline water electrolysis

    DEFF Research Database (Denmark)

    Aili, David; Wright, Andrew G.; Kraglund, Mikkel Rykær

    2017-01-01

    Advanced alkaline water electrolysis using ion-solvating polymer membranes as electrolytes represents a new direction in the field of electrochemical hydrogen production. Polybenzimidazole membranes equilibrated in aqueous KOH combine the mechanical robustness and gas-tightness of a polymer...... stability in alkaline environments. The novel electrolytes are extensively characterized with respect to physicochemical and electrochemical properties and the chemical stability is assessed in 0-50 wt% aqueous KOH for more than 6 months at 88 degrees C. In water electrolysis tests using porous 3...

  17. Computational modeling study on polymer electrolyte membranes for fuel cell applications

    Science.gov (United States)

    Choe, Yoong-Kee; Tsuchida, Eiji

    2016-12-01

    Properties of polymer electrolyte membranes (PEMs) for use in polymer electrolyte membrane fuel cells (PEFCs) were investigated using the first-principles molecular dynamics simulations. One important issue in PEMs is how to improve the proton conductivity of PEMs under low hydration conditions. Results of the simulation show that perfluorinated type membranes such as Nafion exhibit excellent hydrophilic/hydrophobic phase separation while a hydrocarbon membrane has a relatively poor phase separation property. We found that such a poor phase separation behavior of a hydrocarbon membrane arise from hydrophilic functional groups attached to the PEMs.

  18. Layer Formation and Annihilation in an Immiscible Polymer Blend under Electric and Shear Flow Fields

    OpenAIRE

    Na, Yang-Ho; Yoshino, Ayaka; Tominaga, Shinsuke; Orihara, Hiroshi; Ujie, Seiji; Nagaya, Tomoyuki

    2006-01-01

    Simultaneous observation of morphological change and measurement of shear stress in an immiscible polymer blend of a liquid crystalline polymer (LCP) and a methyl phenyl silicone oil (MPS) were carried out in electric and shear flow fields by using a system combining a rheometer and a confocal scanning laser microscope (CSLM). Under shear flow and no electric field a thin MPS layer with low viscosity was formed between two parallel plates of the rheometer, which reduced the app...

  19. Nanocrystalline porous TiO2 electrode with ionic liquid impregnated solid polymer electrolyte for dye sensitized solar cells.

    Science.gov (United States)

    Singh, Pramod K; Kim, Kang-Wook; Kim, Ki-Il; Park, Nam-Gyu; Rhee, Hee-Woo

    2008-10-01

    This communication reports the detailed fabrication of electrodes and solid polymer electrolyte with ionic liquid (IL) as an electrolyte for dye sensitized solar cell (DSSC). Thick porous TiO2 film has been obtained by spreading and sintering TiO2 colloidal paste using "doctor blade" and characterized by SEM, TEM and XRD. The polymer electrolyte was PEO:KI/I2 incorporated with 1-ethyl 3-methylimidazolium thiocyanate (EMImSCN) as IL. Dispersal of IL in the polymer electrolyte improved the ionic conductivity and cell efficiency.

  20. Synthesis and characterization of an electrolyte system based on a biodegradable polymer

    Directory of Open Access Journals (Sweden)

    K. Sownthari

    2013-06-01

    Full Text Available A polymer electrolyte system has been developed using a biodegradable polymer namely poly-ε-caprolactone (PCL in combination with zinc triflate [Zn(CF3SO32] in different weight percentages and characterized during this investigation. Free-standing thin films of varying compositions were prepared by solution casting technique. The successful doping of the polymer has been confirmed by means of Fourier transform infrared spectroscopy (FTIR by analyzing the carbonyl (C=O stretching region of the polymer. The maximum ionic conductivity obtained at room temperature (25°C was found to be 8.8x10–6 S/cm in the case of PCL complexed with 25 wt% Zn(CF3SO32 which is five orders of magnitude higher than that of the pure polymer host material. The increase in amorphous phase with an increase in salt concentration of the prepared polymer electrolyte has also been confirmed from the concordant results obtained from X-ray diffraction (XRD, differential scanning calorimetry (DSC and scanning electron microscopic (SEM analyses. Furthermore, the electrochemical stability window of the prepared polymer electrolyte was found to be 3.7 V. An electrochemical cell has been fabricated based on Zn/MnO2 electrode couple as an application area and its discharge characteristics were evaluated.

  1. Fabrication and characterization of polymer blends and composites derived from biopolymers

    Science.gov (United States)

    Sharma, Suraj

    This research focuses on fabricating blends and composites from natural polymers especially from proteins and natural epoxy, and describing the properties of plastics made from them. Specifically, plastic samples from partially denatured feathermeal and bloodmeal proteins, derived from the animal co-products (rendering) industry, were successfully produced through a compression molding process. The modulus (stiffness) of the material obtained was found to be comparable with that of commercial synthetic materials, such as polystyrene, but was found to have lower toughness characteristics, which is a common phenomenon among plastics produced from animal and plant proteins. Therefore, this study explored blending methods for improving the toughness. Plastic forming conditions for undenatured animal proteins such as chicken egg whites albumin and whey, used as a model, were established to prepare plastics from their blends with animal co-product proteins. The resultant plastic samples from these biomacromolecular blends demonstrated improved mechanical properties that were also compared with the established theoretical models known for polymer blends and composites. Moreover, plastics from albumin of chicken egg whites and human serum have demonstrated their potential in medical applications that require antibacterial properties. Another natural polymer vegetable oil-based epoxy, especially epoxidized linseed oil, showed significant potential to replace petroleum-derived resins for use as a matrix for composites in structural applications. Moreover, the research showed the benefits of ultrasonic curing, which can help in preparing the out-of-autoclave composites.

  2. Structural, Thermal, and Electrical Properties of PVA-Sodium Salicylate Solid Composite Polymer Electrolyte

    Directory of Open Access Journals (Sweden)

    Noorhanim Ahad

    2012-01-01

    Full Text Available Structural, thermal, and electrical properties of solid composite polymer electrolytes based on poly (vinyl alcohol complexed with sodium salicylate were studied. The polymer electrolytes at different weight percent ratios were prepared by solution casting technique. The changes in the structures of the electrolytes were characterized by XRD, which revealed the amorphous domains of the polymer which increased with increase of sodium salicylate concentration. The complexion of the polymer electrolytes were confirmed by FTIR studies. Thermal gravimetric analysis (TGA was used to study the thermal stability of the polymer below 523 K. The decomposition decreases with increasing sodium salicylate concentration. The conductivity and dielectric properties were measured using an impedance analyzer in frequency range of 20 Hz to 1 MHz and narrow temperature range of 303 to 343 K. The conductivity increased with increase of sodium salicylate concentration and temperature. The dielectric constant and dielectric loss increased with the increase in temperature and decreased with the increase in sodium salicylate concentration.

  3. Preparation and Characterization of a Hybrid Solid Polymer Electrolyte Consisting of Poly(Ethyleneoxide) and Poly(Acrylonitrile) for Polymer-Battery Application

    OpenAIRE

    Nookala, Munichandraiah; Scanlon, Lawrence G; Marsh, Richard A

    1997-01-01

    For application in an ambient temperature solid state lithium battery a highly dimensionally-stable polymer electrolyte based on polyethyleneoxide (PEO) suffers from low ionic conductivity, whereas a highly conducting gel electrolyte based on polyacrylonitrile (PAN) suffers from low dimensional stability. In order to overcome these problems, a hybrid solid polymer electrolyte (HSPE) was prepared using PEO, PAN, propylene carbonate (PC), ethylene carbonate (EC) and lithium perchlorate. The HSP...

  4. Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency

    Science.gov (United States)

    2010-06-01

    Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency by Douglas M. Kroll B.S...Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase

  5. Morphology and conductivity of in-situ PEO-LiClO4-TiO2 composite polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    PAN Chun-yue; FENG Qing; WANG Li-jun; ZHANG Qian; CHAO Meng

    2007-01-01

    PEO-LiClO4-TiO2 composite polymer electrolyte films were prepared. TiO2 was formed directly in matrix by hydrolysis and condensation reaction of tetrabutyl titanate. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. The glass transition temperature and the crystallinity of composite polymer electrolytes are decreased compared with those of PEO-LiClO4 polymer electrolyte film. The results show that TiO2 particles are uniformly dispersed in PEO-LiClO4-5%TiO2 composite polymer electrolyte film. The maximal conductivity of 5.5×10-5 S/cm at 20 ℃ of PEO-LiClO4-TiO2 film is obtained at 5% mass fraction of TiO2.

  6. Effect of organic-inorganic hybrid P123-em-SBA15 on lithium transport properties of composite polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    XI Jingyu; HUANG Xiaobin; TANG Xiaozhen

    2004-01-01

    A novel PEO-based composite polymer electrolyte by using organic-inorganic hybrid EO20PO70EO20-em- mesoporous silica (P123-em-SBA15) as the filler has been developed. The experiment results show that P123-em- SBA15 can enhance the lithium-ion transference number of the composite polymer electrolyte, which is induced by the special topology structure of P123 in P123-em-SBA15 hybrid. In addition, room temperature ionic conductivity of the composite polymer electrolyte can also be increased by about two orders of magnitude. The excellent lithium transport properties suggest that PEO-LiClO4-P123-em-SBA15 composite polymer electrolyte can be used as electrolyte materials for all solid-state rechargeable lithium polymer batteries.

  7. Liquid phase demixing in ferroelectric/semiconducting polymer blends: an experimental and theoretical study

    NARCIS (Netherlands)

    Michels, J.J.; Breemen, A.J.J.M. van; Usman, K.; Gelinck, G.H.

    2011-01-01

    This article describes a combined experimental and theoretical study on nanophase structure development as a result of liquid phase demixing in solution-cast blends of the organic semiconductor poly(9,9'-dioctyl fluorene) (PFO) and the ferroelectric polymer poly(vinylidene fluoride-co-trifluoroethyl

  8. Ab initio study of energy-level alignments in polymer-dye blends

    NARCIS (Netherlands)

    Pasveer, W.F.; Bobbert, P.A.; Michels, M.A.J.; Langeveld-Voss, B.M.W.; Schoo, H.F.M.; Bastiaansen, J.J.A.M.

    2003-01-01

    Polymers with a small amount of dye blended in offer an attractive possibility to change the color of the emitted light by changing the dye. We present ab initio calculations within density-functional theory of the HOMO/ LUMO energies for dipyrrolomethane dyes, polyphenylenevinylene and polyfluorene

  9. Investigation of the pressure dependence of the Gibbs potential for polymer blends by means of SANS

    DEFF Research Database (Denmark)

    Janssen, S.; Schwahn, D.; Springer, T.;

    1995-01-01

    The temperature and pressure dependence of the Flory-Huggins parameter was determined for several polymer blends from the SANS structure factor S(Q --> 0) for pressures less than or equal to 1.2 kbar. It can be split into an enthalpic and an entropic part. Furthermore, the radius of gyration...

  10. Correlating structure with fluorescence emission in phase-separated conjugated-polymer blends.

    Science.gov (United States)

    Chappell, John; Lidzey, David G; Jukes, Paul C; Higgins, Anthony M; Thompson, Richard L; O'Connor, Stephen; Grizzi, Ilaria; Fletcher, Robert; O'Brien, Jim; Geoghegan, Mark; Jones, Richard A L

    2003-09-01

    Blends of conjugated polymers are frequently used as the active semiconducting layer in light-emitting diodes and photovoltaic devices. Here we report the use of scanning near-field optical microscopy, scanning force microscopy and nuclear-reaction analysis to study the structure of a thin film of a phase-separated blend of two conjugated polymers prepared by spin-casting. We show that in addition to the well-known micrometre-scale phase-separated morphology of the blend, one of the polymers preferentially wets the surface and forms a 10-nm-thick, partially crystallized wetting layer. Using near-field microscopy we identify unexpected changes in the fluorescence emission from the blend that occurs in a 300-nm-wide band located at the interface between the different phase-separated domains. Our measurements provide an insight into the complex structure of phase-separated conjugated-polymer thin films. Characterizing and controlling the properties of the interfaces in such films will be critical in the further development of efficient optoelectronic devices.

  11. Spatial degradation mapping and componentwise degradation tracking in polymer-fullerene blends

    DEFF Research Database (Denmark)

    Pedersen, Emil Bøje Lind; Tromholt, Thomas; Madsen, Morten Vesterager;

    2014-01-01

    Using X-ray absorption the effects of photodegradation in active layer materials for polymer solar cells are investigated. Through the observation of changes in the X-ray absorption energy spectra the degradation of the individual components is tracked in blends of poly-3-hexyl-thiophene (P3HT...

  12. Flow induced formation of dual-phase continuity in polymer blends and alloys

    DEFF Research Database (Denmark)

    Lyngaae-Jørgensen, Jørgen; Chtcherbakova, E.A.; Utracki, L.A.

    1997-01-01

    showed that an addition of block copolymer may narrow the volume fraction range where bi-continuous phase structures are formed. Both annealing in the molten stale and shearing history influence the measured phi(cr) for formation of bi-continuous phase structure in amorphous immiscible polymer blends....

  13. Hot pressed K+ ion conducting solid polymer electrolytes: synthesis, ion conduction and polymeric battery fabrication

    Science.gov (United States)

    Chandra, Angesh

    2016-07-01

    Synthesis and ion transport studies of hot pressed K+ ion conducting solid polymer electrolytes (SPEs): (1 - x) PEO: x KBr, where 0 polymer-salt complexation in SPE composition: (70:30) with conductivity ( σ) 5.01 × 10-7 S cm-1 from the room temperature conductivity measurements. Materials characterization and polymer-salt complexations of present SPEs have been explained with the help of various techniques viz. X-ray diffraction, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy technique. To explain the ion conduction in the present SPEs, temperature dependent ionic conductivity ( σ), ionic mobility ( μ), mobile ion concentration ( n), ionic transference number ( t ion ) and ionic drift velocity ( v d ) have been calculated with the help of various experimental techniques. A solid state polymer battery is also fabricated by using the present SPE as an electrolyte and have been calculated their important cell parameters at room temperature.

  14. Property modification of Nafion via polymer blending with ethylene vinyl alcohol "polyimide" (Conference Presentation)

    Science.gov (United States)

    Hwang, Taeseon; Nam, Jungsoo; Shen, Qi; Trabia, Sarah; Suhr, Jonghwan; Lee, Dong-Chan; Kim, Kwang Jin

    2016-04-01

    The blended ion exchange membrane between Nafion and ethylene vinyl alcohol (EVOH) was used for fabrication of the ionic polymer-metal composite (IPMC) to redeem inherent drawbacks of Nafion such as high cost or environment-unfriendliness. EVOH solution was blended in Nafion solution by a volume ratio of 15 and 30 % membranes were prepared through solution casting method. The prepared blended Nafion membranes can be fabricated IPMCs with deposition of platinum electrode onto its surface without crack or delamination. The surface resistance of all prepared IPMCs is measured through 2 point probe. This study investigated the chemical structure and thermal properties of prepared membranes. Moreover, we characterized the cross-section morphology and studied the electromechanical performances (displacement and blocking force) of prepared IPMC actuators. The IPMC actuators with proposed blended Nafion membranes were demonstrated comparable electromechanical performance by significantly reducing the content of Nafion.

  15. High-performance ferroelectric memory based on phase-separated films of polymer blends

    KAUST Repository

    Khan, Mohammad A.

    2013-10-29

    High-performance polymer memory is fabricated using blends of ferroelectric poly(vinylidene-fluoride-trifluoroethylene) (P(VDF-TrFE)) and highly insulating poly(p-phenylene oxide) (PPO). The blend films spontaneously phase separate into amorphous PPO nanospheres embedded in a semicrystalline P(VDF-TrFE) matrix. Using low molecular weight PPO with high miscibility in a common solvent, i.e., methyl ethyl ketone, blend films are spin cast with extremely low roughness (Rrms ≈ 4.92 nm) and achieve nanoscale phase seperation (PPO domain size < 200 nm). These blend devices display highly improved ferroelectric and dielectric performance with low dielectric losses (<0.2 up to 1 MHz), enhanced thermal stability (up to ≈353 K), excellent fatigue endurance (80% retention after 106 cycles at 1 KHz) and high dielectric breakdown fields (≈360 MV/m). © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. The Effects of Branching and Deuterium Labeling on Polymer Blend Miscibility

    Science.gov (United States)

    Defelice, Jeffrey; Higgins, Julia; Lipson, Jane

    Local structural or chemical changes made to one component of a polymer blend can have a significant impact on miscibility. In this talk we will focus on several blends involving linear and 4-arm star polystyrene (PS), both hydrogenous and deuterated, and poly(vinylmethylether) (PVME). We consider the effect of the structural change on the miscibility of PS/PVME, then turn to the added effect of deuterium labeling, both on this blend and for isotopic PS mixtures. Using our Locally Correlated Lattice (LCL) model we are able to identify trends in the physical properties of pure components, such as: free volume, thermal expansion coefficient, and cohesive energy density. We find that branching and labeling, both independently and cumulatively, affect pure component properties. Our ability to correlate structural and chemical changes with trends in physical properties leads to predictions about the compatibility of pure components, and thus their blend miscibility. The authors gratefully acknowledge support from NSF DMR-1403757 and GAANN.

  17. Development of Polymer Electrolyte Membranes for High Temperature PEFCs

    Institute of Scientific and Technical Information of China (English)

    A.Carbone; R.Pedicini; A.Saccà; I.Gatto; E.Passalacqua

    2007-01-01

    1 Introduction During the last decades the research has been devoted to the development of non-perfluorinated polymers[1,2], as an alternative to commercial perfluorosulphonic membranes. There are several non-perfluorinated materials suitable for these systems that should have as a fundamental requirement a good thermal stability of the original polymer. The studied polymers consist of polyaromatic or polyetherocyclic repeat units like polyetheretherketone (PEEK). Many papers have been published about t...

  18. Durability aspects of polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Sethuraman, Vijay Anand

    activity. The H2O 2 selectivity in ORR was independent of oxygen concentration but increased with decrease in water activity (i.e., decreased humidity). Presences of trace impurities (such as CO, H2S, NH3, etc.) in the fuel also affect PEMFC durability. Among these impurities, H 2S causes significantly higher performance loss and irreversible catalytic poisoning. A concise mechanism for the poisoning kinetics of H2S on composite solid polymer electrolyte Pt (SPE-Pt) electrode was validated experimentally by charge balances and theoretically by a model, which predicted the oxidation current as a function of the applied potential. H2S dissociatively adsorbed onto SPE-Pt electrode as linear and bridge bonded sulfur (S) species and, under favorable potentials, underwent electro-oxidation to sulfur and then to sulfur dioxide (SO2). Fraction of the adsorbed S species remained as 'hard-to-oxidize' adsorbents and caused irreversible loss of catalytic activity. Deactivation of bridge sites occurred first followed by the loss of linear sites. A method to estimate the catalytic sites irreversibly lost due to sulfur poisoning was developed.

  19. Novelionic Polymer Electrolytes for Dye Sensitized Solar Cell

    Institute of Scientific and Technical Information of China (English)

    Li Wang; Shibi Fang; Yuan Lin

    2005-01-01

    @@ 1Introduction In recent years, dye-sensitized solar cells(DSC) based on nanocrystalline porous TiO2 films have attracted much attention because of their relatively higher efficiency and low cost compared with conventional inorganic photovoltaic devices[1]. This type of solar cell has achieved an impressive photo-to-energy conversion efficiency of over 10% where the electrolyte is volatile organic liquid solvents containing I-/I-3- as redox couple. Because of high volatilities, solvent losses occur during long-term operations, resulting in lowered DSC performances.And leakage of liquid electrolyte also limits the durability of DSC.

  20. Performance of dielectric nanocomposites: matrix-free, hairy nanoparticle assemblies and amorphous polymer-nanoparticle blends.

    Science.gov (United States)

    Grabowski, Christopher A; Koerner, Hilmar; Meth, Jeffrey S; Dang, Alei; Hui, Chin Ming; Matyjaszewski, Krzysztof; Bockstaller, Michael R; Durstock, Michael F; Vaia, Richard A

    2014-12-10

    Demands to increase the stored energy density of electrostatic capacitors have spurred the development of materials with enhanced dielectric breakdown, improved permittivity, and reduced dielectric loss. Polymer nanocomposites (PNCs), consisting of a blend of amorphous polymer and dielectric nanofillers, have been studied intensely to satisfy these goals; however, nanoparticle aggregates, field localization due to dielectric mismatch between particle and matrix, and the poorly understood role of interface compatibilization have challenged progress. To expand the understanding of the inter-relation between these factors and, thus, enable rational optimization of low and high contrast PNC dielectrics, we compare the dielectric performance of matrix-free hairy nanoparticle assemblies (aHNPs) to blended PNCs in the regime of low dielectric contrast to establish how morphology and interface impact energy storage and breakdown across different polymer matrices (polystyrene, PS, and poly(methyl methacrylate), PMMA) and nanoparticle loadings (0-50% (v/v) silica). The findings indicate that the route (aHNP versus blending) to well-dispersed morphology has, at most, a minor impact on breakdown strength trends with nanoparticle volume fraction; the only exception being at intermediate loadings of silica in PMMA (15% (v/v)). Conversely, aHNPs show substantial improvements in reducing dielectric loss and maintaining charge/discharge efficiency. For example, low-frequency dielectric loss (1 Hz-1 kHz) of PS and PMMA aHNP films was essentially unchanged up to a silica content of 50% (v/v), whereas traditional blends showed a monotonically increasing loss with silica loading. Similar benefits are seen via high-field polarization loop measurements where energy storage for ∼15% (v/v) silica loaded PMMA and PS aHNPs were 50% and 200% greater than respective comparable PNC blends. Overall, these findings on low dielectric contrast PNCs clearly point to the performance benefits of

  1. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed...

  2. New polymer electrolytes for low temperature fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sundholm, F.; Elomaa, M.; Ennari, J.; Hietala, S.; Paronen, M. [Univ. of Helsinki (Finland). Lab. of Polymer Chemistry

    1998-12-31

    Proton conducting polymer membranes for demanding applications, such as low temperature fuel cells, have been synthesised and characterised. Pre-irradiation methods are used to introduce sulfonic acid groups, directly or using polystyrene grafting, in stable, preformed polymer films. The membranes produced in this work show promise for the development of cost-effective, highly conducting membranes. (orig.)

  3. The Effect of Lithium Iodide to the Properties of Carboxymethyl κ-Carrageenan/Carboxymethyl Cellulose Polymer Electrolyte and Dye-Sensitized Solar Cell Performance

    Directory of Open Access Journals (Sweden)

    Siti Rudhziah Che Balian

    2016-05-01

    Full Text Available This study was undertaken to investigate the solid biopolymer electrolytes based on a carboxymethyl κ-carrageenan/carboxymethyl cellulose blend complexed with lithium iodide of various weight ratios. The complexation of the doping salt with the polymer blend was confirmed by Fourier transform infrared spectroscopy. Ionic conductivity of the film was determined by impedance spectroscopy in the frequency range of 10 Hz to 4 MHz and in the temperature range of 303–338 K. The ionic conductivity increased with the increase in lithium iodide concentration as well as temperature. The membrane comprising 30 wt % of lithium iodide was found to give the highest conductivity of 3.89 × 10−3 S·cm−1 at room temperature. The increase in conductivity was associated with the increase in the number as well as the mobility of the charge carries. The conductivity increase with temperature followed the Vogel–Tamman–Fulcher model. The fabricated dye-sensitive solar cell, FTO/TiO2-dye/CMKC/CMCE-LiI (30 wt % +I2/Pt exhibited the highest conversion efficiency of 0.11% at a light intensity of 100 mW·cm−2. This indicated that the biopolymer blend electrolyte system has potential for use in dye-sensitized solar cells.

  4. Bismaleimide/Preceramic Polymer Blends for Hybrid Material Transition Regions. Part 1. Processing and Characterization (Postprint)

    Science.gov (United States)

    2014-01-01

    polymer matrix composite to a ceramic matrix composite. Thermal and elemental analysis, and morphology characterization of RD-730 preceramic polymer blends, which convert to silicon carbide upon pyrolysis, and Matrimid A/B polymer (a bismaleimide), were carried out as a function of cure cycle. Cure cycles were chosen to vary the resin viscosity during processing in order to affect the amount of phase separation observed. The results were then used to associate processing parameters with the miscibility of the two resins and the likelihood of producing a hybrid

  5. Preparation of a Star Network PEG-based Gel Polymer Electrolyte and Its Application to Electrochromic Devices

    Institute of Scientific and Technical Information of China (English)

    GONG Yong-Feng; FU Xiang-Kai; ZHANG Shu-Peng; JIANG Qing-Long

    2007-01-01

    A star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized,and its corresponding gel polymer electrolyte based on lithium perchlorate and plasticizers EC/PC with the character being colorless and highly transparent has been also prepared. The polymer host was characterized and confirmed to be of a star network and an amorphous structure by FTIR, 1H NMR and XRD studies. The polymer host hold good mechanical properties for pentaerythritol cross-linking. Maximum ionic conductivity of the prepared electrolyte showed that the thermal stability was up to at least 150 ℃. The gel polymer electrolyte was further evaluated in electrochromic devices fabricated by transparent PET-ITO and electrochromically active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolyte as ionic conductor material in electrochrornic devices.

  6. Linear correlation between rheological, mechanical and mucoadhesive properties of polycarbophil polymer blends for biomedical applications.

    Science.gov (United States)

    De Souza Ferreira, Sabrina Barbosa; Da Silva, Jéssica Bassi; Borghi-Pangoni, Fernanda Belincanta; Junqueira, Mariana Volpato; Bruschi, Marcos Luciano

    2017-02-14

    Polycarbophil is widely used in a variety of pharmaceutical formulations, mainly for their strong ability to adhere to the epithelial and mucous barriers (bio/mucoadhesion). On the other hand, its association with the thermoresponsive polymer (poloxamer 407) has been poorly explored. This work investigates the rheological, mechanical and mucoadhesive properties of polymer blends containing polycarbophil and poloxamer 407, in order to select the best formulations for biomedical and pharmaceutical applications. Mechanical (hardness, compressibility, adhesiveness, softness, and mucoadhesion) and rheological characteristics (consistency index, yield value and hysteresis area) showed that 20% (w/w) poloxamer 407- polymer blends exhibited higher values parameters. However, the rheological interaction parameter, which was more sensible than the mechanical interaction parameter, revealed higher synergism for systems comprising 15% (w/w) poloxamer 407, due to the system organization and polymers' properties. Furthermore, gelation temperatures were appropriated, suggesting that polymer blends can be used as biomedical materials, and displaying easy administration, enhanced retention and prolonged residence time at the site of application. Therefore, rheological, mechanical and mucoadhesive characterization provided a rational basis for selecting appropriated systems, useful for mucoadhesive drug delivery systems and biomedical applications.

  7. Effect of TiO{sub 2} Inclusion in the Poly(vinylidene fluoride-co-hexafluoropropylene)-Based Polymer Electrolyte of Dye-Sensitized Solar Cell

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kwang Man; Kang, Man Gu; Ryu, Kwang Sun; Chang, Soon Ho [Electronics and Telecommunications Research Institute, Daejeon (Korea, Republic of); Park, Nam Gyu [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2006-02-15

    The lack of long-term stability, however, could occur by the leakage or evaporation of liquid electrolyte components. Many efforts were paid to replace the liquid electrolyte by various types of quasi-solid-state polymer electrolyte. The approach of using polymer electrolytes has been attracted with high interest but usually resulted in lower conversion efficiency than conventional Graetzel cell with liquid electrolyte. Among many polymer electrolytes, the poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) as polymer matrix material in DSSC has been known to be quite useful because of its photoelectrochemical stability under potential application. The previous result of PVdF-HFP polymer electrolyte presented somewhat low conversion efficiency of about 2-3%. We have considered that the low efficiency might be due to the inhibition of ion migration by the viscosity originated from polymer chain obstacles. Thus, we tried to modify the PVdF-HFP polymer electrolyte system to improve ion migration.

  8. Microfibrillated cellulose as reinforcement for Li-ion battery polymer electrolytes with excellent mechanical stability

    Science.gov (United States)

    Chiappone, A.; Nair, Jijeesh R.; Gerbaldi, C.; Jabbour, L.; Bongiovanni, R.; Zeno, E.; Beneventi, D.; Penazzi, N.

    Methacrylic-based thermo-set gel-polymer electrolyte membranes obtained by a very easy, fast and reliable free radical photo-polymerisation process and reinforced with microfibrillated cellulose particles are here presented. The morphology of the composite electrolytes is investigated by scanning electron microscopy and their thermal behaviour (characteristic temperatures, degradation temperature) are investigated by thermo-gravimetric analysis and differential scanning calorimetry. The composite membranes prepared exhibit excellent mechanical properties, with a Young's modulus as high as about 80 MPa at ambient temperature. High ionic conductivity (approaching 10 -3 S cm -1 at 25 °C) and good overall electrochemical performances are maintained, enlightening that such specific approach would make these hybrid organic, cellulose-based composite polymer electrolyte systems a strong contender in the field of thin and flexible lithium based power sources.

  9. High efficiency dye-sensitized nanocrystalline solar cells based on ionic liquid polymer gel electrolyte.

    Science.gov (United States)

    Wang, Peng; Zakeeruddin, Shaik M; Exnar, Ivan; Grätzel, Michael

    2002-12-21

    An ionic liquid polymer gel containing 1-methyl-3-propylimidazolium iodide (MPII) and poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) has been employed as quasi-solid-state electrolyte in dye-sensitized nanocrystalline TiO2 solar cells with an overall conversion efficiency of 5.3% at AM 1.5 illumination.

  10. Solid Polymer Electrolyte (SPE) fuel cell technology, program review, phase 2

    Science.gov (United States)

    1976-01-01

    The purpose of the solid polymer electrolyte (SPE) fuel cell program is to advance the SPE fuel cell technology in four target areas. These areas are: (1) reduced fuel cell costs; (2) reduced fuel cell weight; (3) improved fuel cell efficiency; and (4) increased systems compatibility.

  11. Numerical investigations on two-phase flow in polymer electrolyte fuel cells

    NARCIS (Netherlands)

    Qin, C.Z.

    2012-01-01

    Numerical modeling plays an important role in understanding various transport processes in polymer electrolyte fuel cells (PEFCs). It can not only provide insights into the development of new PEFC architectures, but also optimize operating conditions for better cell performance. Water balance is cri

  12. The electrochemical redox processes in methacrylate-based polymer electrolytes II. - Study on microelectrodes

    Energy Technology Data Exchange (ETDEWEB)

    Nadherna, Martina [Institute of Inorganic Chemistry of the AS CR, v.v.i., 250 68 Husinec-Rez (Czech Republic)] [Department of Analytical Chemistry, Faculty of Science, Charles University in Prague, Albertov 2030, 128 40 Prague 2 (Czech Republic); Reiter, Jakub, E-mail: reiter@iic.cas.c [Institute of Inorganic Chemistry of the AS CR, v.v.i., 250 68 Husinec-Rez (Czech Republic)

    2010-08-01

    The electrochemical behaviour of ferrocene was studied in different gel polymer electrolytes based on methyl, ethyl and 2-ethoxyethyl methacrylate and compared to the liquid aprotic solution (propylene carbonate). Voltammetric and chronoamperometric measurements on microelectrodes were conducted in order to describe the qualitative as well as quantitative behaviour of ferrocene in different conditions. Heterogeneous electron-transfer rate constants and diffusion coefficients of ferrocene in polymer electrolytes were estimated to be 1.1-7.8 x 10{sup -3} cm s{sup -1} and 4-13 x 10{sup -8} cm{sup 2} s{sup -1} depending on the electrolyte composition. The influence of the polymer polarity, ferrocene concentration and level of polymer cross-linkage on the kinetics of ferrocene oxidation and its transport was discussed. The electrolytes with poly(2-ethoxyethyl methacrylate) exhibit the highest ionic conductivity (2-4 x 10{sup -4} S cm{sup -1}) as well as diffusion coefficient of ferrocene (1.3 x 10{sup -7} cm{sup 2} s{sup -1}) in their structure.

  13. Modelling multiphase flow inside the porous media of a polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Berning, Torsten; Kær, Søren Knudsen

    2011-01-01

    Transport processes inside polymer electrolyte membrane fuel cells (PEMFC’s) are highly complex and involve convective and diffusive multiphase, multispecies flow through porous media along with heat and mass transfer and electrochemical reactions in conjunction with water transport through an el...

  14. Two-phase flow modeling for the cathode side of a Polymer electrolyte fuel cell

    NARCIS (Netherlands)

    Qin, C.; Rensink, D.; Fell, S.; Hassanizadeh, S.M.

    2012-01-01

    Liquid water flooding in micro gas channels is an important issue in the water management of polymer electrolyte fuel cells (PEFCs). However, in most previous numerical studies liquid water transport in the gas channels (GC) has been simplified by the mist flow assumption. In this work, we present a

  15. Fabrication of tissue engineering scaffolds through solid-state foaming of immiscible polymer blends

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Changchun; Li Wei [Department of Mechanical Engineering, University of Texas, Austin, TX 78712 (United States); Ma Liang [Department of Mechanical Engineering, University of Washington, Seattle, WA 98195-2600 (United States); Yao Donggang, E-mail: weiwli@austin.utexas.edu [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2011-12-15

    In scaffold-based tissue engineering, the fabrication process is important for producing suitable microstructures for seeded cells to grow and reformulate. In this paper, we present a new approach to scaffold fabrication by combining the solid-state foaming and the immiscible polymer-blending method. The proposed approach has the advantage of being versatile and able to create a wide range of pore size and porosity. The proposed method is studied with polylactic acid (PLA) and polystyrene (PS) blends. The interconnected porous structure was created by first foaming the PLA/PS blend and then extracting the PS phase. The solid-state foaming experiments were conducted under various conditions to achieve the desired pore sizes. It is shown that the PS phase of the PLA/PS blend can be extracted much faster in the foamed samples and the pore size of the scaffolds can be easily controlled with proper gas foaming parameters. The average pore size achieved in the foaming process ranged from 20 to 70 {mu}m. After PS extraction, both pore size and porosity can be further improved. For example, the pore size and porosity increased from 48 {mu}m and 49% to 59 {mu}m and 67%, respectively, after the PS extraction process. The fabricated porous scaffolds were used to culture human osteoblast cells. Cells grew well and gradually formed a fibrous structure. The combined solid-state foaming and immiscible polymer blending method provides a new technique for fabricating tissue-engineering scaffolds.

  16. Morphology control in polymer blend fibers—a high throughput computing approach

    Science.gov (United States)

    Sesha Sarath Pokuri, Balaji; Ganapathysubramanian, Baskar

    2016-08-01

    Fibers made from polymer blends have conventionally enjoyed wide use, particularly in textiles. This wide applicability is primarily aided by the ease of manufacturing such fibers. More recently, the ability to tailor the internal morphology of polymer blend fibers by carefully designing processing conditions has enabled such fibers to be used in technologically relevant applications. Some examples include anisotropic insulating properties for heat and anisotropic wicking of moisture, coaxial morphologies for optical applications as well as fibers with high internal surface area for filtration and catalysis applications. However, identifying the appropriate processing conditions from the large space of possibilities using conventional trial-and-error approaches is a tedious and resource-intensive process. Here, we illustrate a high throughput computational approach to rapidly explore and characterize how processing conditions (specifically blend ratio and evaporation rates) affect the internal morphology of polymer blends during solvent based fabrication. We focus on a PS: PMMA system and identify two distinct classes of morphologies formed due to variations in the processing conditions. We subsequently map the processing conditions to the morphology class, thus constructing a ‘phase diagram’ that enables rapid identification of processing parameters for specific morphology class. We finally demonstrate the potential for time dependent processing conditions to get desired features of the morphology. This opens up the possibility of rational stage-wise design of processing pathways for tailored fiber morphology using high throughput computing.

  17. Significant Enhancement of Mechanical and Thermal Properties of Thermoplastic Polyester Elastomer by Polymer Blending and Nanoinclusion

    Directory of Open Access Journals (Sweden)

    Manwar Hussain

    2016-01-01

    Full Text Available Thermoplastic elastomer composites and nanocomposites were fabricated via melt processing technique by blending thermoplastic elastomer (TPEE with poly(butylene terephthalate (PBT thermoplastic and also by adding small amount of organo modified nanoclay and/or polytetrafluoroethylene (PTFE. We study the effect of polymer blending on the mechanical and thermal properties of TPEE blends with and without nanoparticle additions. Significant improvement was observed by blending only TPEE and virgin PBT polymers. With a small amount (0.5 wt.% of nanoclay or PTFE particles added to the TPEE composite, there was further improvement in both the mechanical and thermal properties. To study mechanical properties, flexural strength (FS, flexural modulus (FM, tensile strength (TS, and tensile elongation (TE were all investigated. Thermogravimetric analysis (TGA and differential scanning calorimetry (DSC were used to analyze the thermal properties, including the heat distortion temperature (HDT, of the composites. Scanning electron microscopy (SEM was used to observe the polymer fracture surface morphology. The dispersion of the clay and PTFE nanoparticles was confirmed by transmission electron microscopy (TEM analysis. This material is proposed for use as a baffle plate in the automotive industry, where both high HDT and high modulus are essential.

  18. Water-based thixotropic polymer gel electrolyte for dye-sensitized solar cells.

    Science.gov (United States)

    Park, Se Jeong; Yoo, Kichoen; Kim, Jae-Yup; Kim, Jin Young; Lee, Doh-Kwon; Kim, Bongsoo; Kim, Honggon; Kim, Jong Hak; Cho, Jinhan; Ko, Min Jae

    2013-05-28

    For the practical application of dye-sensitized solar cells (DSSCs), it is important to replace the conventional organic solvents based electrolyte with environmentally friendly and stable ones, due to the toxicity and leakage problems. Here we report a noble water-based thixotropic polymer gel electrolyte containing xanthan gum, which satisfies both the environmentally friendliness and stability against leakage and water intrusion. For application in DSSCs, it was possible to infiltrate the prepared electrolyte into the mesoporous TiO2 electrode at the fluidic state, resulting in sufficient penetration. As a result, this electrolyte exhibited similar conversion efficiency (4.78% at 100 mW cm(-2)) and an enhanced long-term stability compared to a water-based liquid electrolyte. The effects of water on the photovoltaic properties were examined elaborately from the cyclic voltammetry curves and impedance spectra. Despite the positive shift in the conduction band potential of the TiO2 electrode, the open-circuit voltage was enhanced by addition of water in the electrolyte due to the greater positive shift in the I(-)/I3(-) redox potential. However, due to the dye desorption and decreased diffusion coefficient caused by the water content, the short-circuit photocurrent density was reduced. These results will provide great insight into the development of efficient and stable water-based electrolytes.

  19. Composite materials for polymer electrolyte membrane microbial fuel cells.

    Science.gov (United States)

    Antolini, Ermete

    2015-07-15

    Recently, the feasibility of using composite metal-carbon, metal-polymer, polymer-carbon, polymer-polymer and carbon-carbon materials in microbial fuel cells (MFCs) has been investigated. These materials have been tested as MFC anode catalyst (microorganism) supports, cathode catalysts and membranes. These hybrid materials, possessing the properties of each component, or even with a synergistic effect, would present improved characteristics with respect to the bare components. In this paper we present an overview of the use of these composite materials in microbial fuel cells. The characteristics of the composite materials as well as their effect on MFC performance were compared with those of the individual component and/or the conventionally used materials.

  20. Nanoporous Polymer-Ceramic Composite Electrolytes for Lithium Metal Batteries

    KAUST Repository

    Tu, Zhengyuan

    2013-09-16

    A nanoporous composite material that offers the unique combination of high room-temperature ionic conductivity and high mechanical modulus is reported. When used as the separator/electrolyte in lithium batteries employing metallic lithium as anode, the material displays unprecedented cycling stability and excellent ability to prevent premature cell failure by dendrite-induced short circuits © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Film-thickness dependence of structure formation in ultra-thin polymer blend films

    CERN Document Server

    Gutmann, J S; Stamm, M

    2002-01-01

    We investigated the film-thickness dependence of structure formation in ultra-thin polymer blend films prepared from solution. As a model system we used binary blends of statistical poly(styrene-co-p-bromostyrene) copolymers of different degrees of bromination. Ultra-thin-film samples differing in miscibility and film thickness were prepared via spin coating of common toluene solutions onto silicon (100) substrates. The resulting morphologies were investigated with scanning force microscopy, reflectometry and grazing-incidence scattering techniques using both X-rays and neutrons in order to obtain a picture of the sample structure at and below the sample surface. (orig.)

  2. Tailoring the color of electrochromic polymer devices by stoichiometric control of blends and copolymers

    Science.gov (United States)

    Meeker, David Lloyd

    A systematic study of the color and optical properties of electrochromic devices using stoichiometric combinations of polymer blends and copolymers is presented. Monomers of N-phenyl-2-(5/sp /prime-vinyl-2/sp /prime- thienyl)-5-(2/prime'-thienyl)-pyrrole (SNPhS) and N-vinyl carbazole (NVC) are combined into two forms: homopolymer blends, and copolymers. The homopolymers poly N-phenyl-2-(5 /sp /prime-vinyl-2 /sp/prime-thienyl)- 5-(2 /prime'-thienyl)-pyrrole (PSNPhS) and poly (N-vinylcarbazole) (PVK) were blended together according to the stoichiometric mass ratios (1:4), (3:2) and (4:1) of (PSNPhS:PVK) respectively. Copolymers were prepared using feed stock ratios identical to the polymer blends, which produced the respective stoichiometric ratios (3:7), (3:2) and (7:3) of (PSNPhS:PVK). Photoluminescence (PL) and photoluminescence excitation spectroscopy (PLE) allowed the identification of excimer formation in dilute solutions of the blends and copolymers. Two excimer emission bands at 373 nm and 420 nm in were attributed to poly(N-vinyl carbazole), in the partial overlap and sandwich configuration. Analysis of the PL data indicated that the effects of these excimers on the color of the electrochromic devices was minimized by avoiding (1:1) stoichiometric combinations of PVK and PSNPhS. Films of the polymeric materials were characterized by optical absorption, and spectroelectrochemistry. Solid state devices were assembled and their spectrocolorimetery measurements correlated with the stoichiometric ratios of copolymers and polymer blends. Analysis using Commission International de l'Eclairage (CIE) L*a*b* color coordinates determined that stoichiometric adjustment of polymer blends and copolymers yields a strong correlation (R2 = 0.99) with the amount of SNPhS present in the device. It was found that blends access the widest range of color adjustments, while copolymers provide the most precise means of tailoring color over a narrow range.

  3. Thermally stable hyperbranched polyether-based polymer electrolyte for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu Feng; Feng Ting; Wu Chuan; Bai Ying; Chen Junzheng [School of Chemical Engineering and Environment, Beijing Institute of Technology, Beijing 10081 (China); Ye Lin, E-mail: chuanwu@bit.edu.c [School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 10081 (China)

    2010-01-27

    A thermally stable polymer matrix, comprising hyperbranched polyether PHEMO (poly(3-{l_brace}2-[2-(2-hydroxyethoxy) ethoxy] ethoxy{r_brace}methyl-3'-methyloxetane)) and PVDF-HFP (poly(vinylidene fluoride-hexafluoropropylene)), has been successfully prepared for applications in lithium-ion batteries. This type of polymer electrolyte has been made by adding different amounts of lithium bis(oxalate)borate (LiBOB) to the polymer matrix. Its thermal and structural properties were measured using differential scanning calorimetry and x-ray diffraction. Experimental results show that the polymer electrolyte system possesses good thermal stability, with a decomposition temperature above 420 {sup 0}C. The ionic conductivity of the polymer electrolyte system is dependent on the lithium salt content, reaching a maximum of 1.1 x 10{sup -5} S cm{sup -1} at 30 {sup 0}C and 2.3 x 10{sup -4} S cm{sup -1} at 80 {sup 0}C when doped with 10 wt% LiBOB.

  4. Nanomaterials for Polymer Electrolyte Membrane Fuel Cells; Materials Challenges Facing Electrical Energy Storate

    Energy Technology Data Exchange (ETDEWEB)

    Gopal Rao, MRS Web-Editor; Yury Gogotsi, Drexel University; Karen Swider-Lyons, Naval Research Laboratory

    2010-08-05

    Symposium T: Nanomaterials for Polymer Electrolyte Membrane Fuel Cells Polymer electrolyte membrane (PEM) fuel cells are under intense investigation worldwide for applications ranging from transportation to portable power. The purpose of this seminar is to focus on the nanomaterials and nanostructures inherent to polymer fuel cells. Symposium topics will range from high-activity cathode and anode catalysts, to theory and new analytical methods. Symposium U: Materials Challenges Facing Electrical Energy Storage Electricity, which can be generated in a variety of ways, offers a great potential for meeting future energy demands as a clean and efficient energy source. However, the use of electricity generated from renewable sources, such as wind or sunlight, requires efficient electrical energy storage. This symposium will cover the latest material developments for batteries, advanced capacitors, and related technologies, with a focus on new or emerging materials science challenges.

  5. Ionic Liquid-Based Polymer Electrolytes via Surfactant-Assisted Polymerization at the Plasma-Liquid Interface.

    Science.gov (United States)

    Tran, Quoc Chinh; Bui, Van-Tien; Dao, Van-Duong; Lee, Joong-Kee; Choi, Ho-Suk

    2016-06-29

    We first report an innovative method, which we refer to as interfacial liquid plasma polymerization, to chemically cross-link ionic liquids (ILs). By this method, a series of all-solid state, free-standing polymer electrolytes is successfully fabricated where ILs are used as building blocks and ethylene oxide-based surfactants are employed as an assisted-cross-linking agent. The thickness of the films is controlled by the plasma exposure time or the ratio of surfactant to ILs. The chemical structure and properties of the polymer electrolyte are characterized by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), differential scanning calorimetry (DSC), and electrochemical impedance spectroscopy (EIS). Importantly, the underlying polymerization mechanism of the cross-linked IL-based polymer electrolyte is studied to show that fluoroborate or halide anions of ILs together with the aid of a small amount of surfactants having ethylene oxide groups are necessary to form cross-linked network structures of the polymer electrolyte. The ionic conductivity of the obtained polymer electrolyte is 2.28 × 10(-3) S·cm(-1), which is a relatively high value for solid polymer electrolytes synthesized at room temperature. This study can serve as a cornerstone for developing all-solid state polymer electrolytes with promising properties for next-generation electrochemical devices.

  6. Charge Transfer Channels in Formation of Exciplex in Polymer Blends

    Institute of Scientific and Technical Information of China (English)

    DOU Fei; ZHANG Xin-Ping

    2011-01-01

    The strong dependence of photoluminescence of charge transfer excited states or exciplex in a blend film of poly(9,9'-dioctylBuorene-co-benzothiadiazole) (F8BT) and poly(9,9'-dioctyl6uorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-l,4- phenylenediamine) (PFB) on the excitation wavelengths and morphology is investigated. The experimental results reveal that electron transfer in the LUMOs from PFB to F8BT is more efficient than hole transfer in the HOMOs from PFB to F8BT for the formation of exciplex at the interfacial junctions between these two types of molecules in the blend Sim. Furthermore, energy transfer from the blue-emitting PFB to the green-emitting F8BT at the interfaces introduces an additional two-step channel and thus enhances the formation of an exciplex. This is important for understanding of charge generation and separation in organic bulk heterojunctions and for design of optoelectronic devices.%@@ The strong dependence of photoluminescence of charge transfer excited states or exciplex in a blend film of poly(9,9'-dioctylfluorene-co-benzothiadiazole)(F8BT)and poly(9,9'-dioctylfluorene-co-bis-N,N'-(4-butylphenyl)-bis-N,N'-phenyl-1,4-phenylenediamine)(PFB)on the excitation wavelengths and morphology is investigated.The experimental results reveal that electron transfer in the LUMOs from PFB to F8BT is more efficient than hole transfer in the HOMOs from PFB to F8BT for the formation of exciplex at the interfacial junctions between these two types of molecules in the blend film.Furthermore,energy transfer from the blue-emitting PFB to the green-emitting F8BT at the interfaces introduces an additional two-step channel and thus enhances the formation of an exciplex.This is important for understanding of charge generation and separation in organic bulk heterojunctions and for design of optoelectronic devices.

  7. Nano integrated lithium polymer electrolytes based on anodic aluminum oxide (AAO) templates

    Science.gov (United States)

    Bokalawela, Roshan S. P.

    Since their discovery in the 1970s, polymer electrolytes have been actively studied because they have properties important for many device applications. However, even after 40 years, the detailed mechanisms of conductivity in these electrolytes are still not completely understood. Moreover, the conductivity in polymer electrolytes is one of the limiting factors of these devices so that different methods to enhance conductivity are actively being explored. One proposed method of enhancing the conductivity is to confine the polymer electrolyte in the nanoscale, but the study of material properties at the nanoscale is challenging in this area. In this work, we confine poly(ethylene oxide) lithium triflate (PEO:LiTf)(X:1)X=10,30 polymer electrolytes in carefully fabricated nanometer-diameter anodized aluminum oxide (AAO) pore structures. We demonstrate two orders of magnitude higher conductivity in the confined structures versus that of bulk films. Using x-ray characterization we show that this increased conductivity is associated with ordered PEO polymer chains aligned in the template pore direction. The activation energy of the AAO-confined polymer electrolyte is found to be smaller than that of the unconfined melt and about half that of the unconfined solid. This result indicates that not only is the room-temperature confined polymer ordered, but that this order persists at temperatures where the nano-confined polymer electrolyte is expected to be a liquid. The geometric bulk resistances of the electrolytes were obtained by AC-impedance spectra, from which the ionic conductivities were calculated. The Arrhenius plots of temperature dependent ionic conductivities showed that the usual melting temperature of the PEO phase in confined PEO:LiTf(X:1) X=10,30 is suppressed and a single activation energy was evident throughout the temperature range 25--90 °C. Wide-angle x-ray scattering (WAXS) patterns show that the polymer chains in both the pure PEO and PEO:LiTf(10

  8. Synthesis and Characterization of a New Network Polymer Electrolyte Containing Polyether in the Main Chains and Side Chains

    Institute of Scientific and Technical Information of China (English)

    Wang; Cheng-chien; Chen; Chuh-yung

    2007-01-01

    1 Results A new network polymer electrolyte matrix with polyether in the side chains and main chains was synthesized by the azo-macroinitiator method and urethane reaction.The macroinitiator,polymer and network polymer were confirmed by Fourier-transform infrared (FT-IR) spectroscopy and 1H NMR.FT-IR was also used to study the environment of lithium ions doped in these network polymer electrolytes.Three important groups are considered: N-H,carbonyl,and ether groups.The thermal properties of the polymer ...

  9. Thermal Analysis, Mechanical and Rheological Behaviour of Melt Manufactured Polyethylene/Liquid Crystal Polymer Blends

    Directory of Open Access Journals (Sweden)

    Ilze ELKSNITE

    2011-07-01

    Full Text Available Modification of properties of conventional thermoplastics with thermotropic liquid crystal polymers, from one hand, allows decrease their viscosities, substantially facilitating processing conditions, and, from another hand, allows increase their exploitation properties. Orientation of the labile structure of liquid crystal polymer in extrusion or injection moulding causes specific reinforcement (so-called self-reinforcement to occur in the blends containing liquid crystal polymer. Up to now the effect of self-reinforcement is mostly investigated in the blends, containing considerable amount of liquid crystal polymer. In this research the effect of minor amounts of liquid crystalline co-polyester modifier on the properties of polyethylene is investigated. Various compositions of laboratory synthesized hydroxybenzoic acid /polyethylene terephtalate copolymer containing polyethylene composites have been manufactured by thermoplastic blending. It has been observed that 1 modulus of elasticity, yield strength and ultimate strength increase with raising the content of liquid crystalline modifier; 2 void content in the investigated polyethylene/liquid crystal copolymer composites is not greater that 1 %; 3 addition of liquid crystalline co-polyester modifier improves arrangement of PE crystalline phase.http://dx.doi.org/10.5755/j01.ms.17.2.483

  10. Radiation processing of indigenous natural polymers. Properties of radiation modified blends from sago-starch for biodegradable composite

    Energy Technology Data Exchange (ETDEWEB)

    Ghazali, Z.; Dahlan, K.Z. [Malaysian Institute for Nuclear and Technology Research (MINT), Bangi, Kajang (Malaysia); Wongsuban, B.; Idris, S.; Muhammad, K. [Universiti Putra Malaysia, Faculty of Food Science and Biotechnology, Department of Food Science, Serdang (Malaysia)

    2001-03-01

    Research and development on biodegradable polymer blends and composites have gained wider interest to offer alternative eco-friendly products. Natural polysaccharide such as sago-starch offers the most promising raw material for the production of biodegradable composites. The potential of sago, which is so abundant in Malaysia, to produce blends for subsequent applications in composite material, was evaluated and explored. Blends with various formulations of sago starch and polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) polymers were prepared and subjected to radiation modification using electron beam irradiation. The effect of irradiation on the sago and its blends was evaluated and their properties were characterized. The potential of producing composite from sago blends was explored. Foams from these blends were produced using microwave oven while films were produced through casting method. The properties such as mechanical, water absorption, expansion ratio, and biodegradability were characterized and reported in this paper. (author)

  11. Characterization by Confocal Laser Scanning Microscopy of the Phase Composition at Interfaces in Thick Films of Polymer Blends

    Directory of Open Access Journals (Sweden)

    Sandro Lattante

    2014-01-01

    Full Text Available Confocal Laser Scanning Microscopy (CLSM has been used as a fast, user-friendly, and noninvasive tool for characterizing the phase composition differences at the substrate and air interfaces in thick films of polymer blends. A clearly different phase composition at the blend/glass interface and at the blend/air interface has been detected. We show that PCBM preferentially accumulates at the glass/blend interface, while P3HT preferentially accumulates at the blend/air interface, by comparing the integrated signal intensity of the luminescence coming from both interfaces. Our results demonstrate that CLSM can be used conveniently for the fast identification of a preferential phase segregation at interfaces in polymer blends. This is useful in the research field on devices (like sensors or planar waveguides that are based on very thick layers (thickness higher than 1 μm.

  12. Correlation between ionic conductivity and fluidity of polymer gel electrolytes containing NH4CF3SO3

    Indian Academy of Sciences (India)

    Harinder Pal Singh; Rajiv Kumar; S S Sekhon

    2005-08-01

    Nonaqueous polymer gel electrolytes containing ammonium triflate (NH4CF3SO3) and dimethylacetamide (DMA) with polymethylmethacrylate (PMMA) as the gelling polymer have been synthesized which show high value of conductivity (∼ 10-2 S/cm) at 25°C. The conductivity of polymer gel electrolytes containing different concentrations of NH4CF3SO3 shows a small decrease with the addition of PMMA and this has been correlated with the variation of fluidity of these gel electrolytes. The small decrease in conductivity with PMMA addition shows that polymer plays the role of stiffener and this is supported by FTIR results which also indicates the absence of any active interaction between polymer and NH4CF3SO3 in these gel electrolytes.

  13. Polymer blend lithography: A versatile method to fabricate nanopatterned self-assembled monolayers

    Directory of Open Access Journals (Sweden)

    Cheng Huang

    2012-09-01

    Full Text Available A rapid and cost-effective lithographic method, polymer blend lithography (PBL, is reported to produce patterned self-assembled monolayers (SAM on solid substrates featuring two or three different chemical functionalities. For the pattern generation we use the phase separation of two immiscible polymers in a blend solution during a spin-coating process. By controlling the spin-coating parameters and conditions, including the ambient atmosphere (humidity, the molar mass of the polystyrene (PS and poly(methyl methacrylate (PMMA, and the mass ratio between the two polymers in the blend solution, the formation of a purely lateral morphology (PS islands standing on the substrate while isolated in the PMMA matrix can be reproducibly induced. Either of the formed phases (PS or PMMA can be selectively dissolved afterwards, and the remaining phase can be used as a lift-off mask for the formation of a nanopatterned functional silane monolayer. This “monolayer copy” of the polymer phase morphology has a topographic contrast of about 1.3 nm. A demonstration of tuning of the PS island diameter is given by changing the molar mass of PS. Moreover, polymer blend lithography can provide the possibility of fabricating a surface with three different chemical components: This is demonstrated by inducing breath figures (evaporated condensed entity at higher humidity during the spin-coating process. Here we demonstrate the formation of a lateral pattern consisting of regions covered with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS and (3-aminopropyltriethoxysilane (APTES, and at the same time featuring regions of bare SiOx. The patterning process could be applied even on meter-sized substrates with various functional SAM molecules, making this process suitable for the rapid preparation of quasi two-dimensional nanopatterned functional substrates, e.g., for the template-controlled growth of ZnO nanostructures.

  14. Understanding constraint release in star/linear polymer blends

    KAUST Repository

    Shivokhin, M. E.

    2014-04-08

    In this paper, we exploit the stochastic slip-spring model to quantitatively predict the stress relaxation dynamics of star/linear blends with well-separated longest relaxation times and we analyze the results to assess the validity limits of the two main models describing the corresponding relaxation mechanisms within the framework of the tube picture (Doi\\'s tube dilation and Viovy\\'s constraint release by Rouse motions of the tube). Our main objective is to understand and model the stress relaxation function of the star component in the blend. To this end, we divide its relaxation function into three zones, each of them corresponding to a different dominating relaxation mechanism. After the initial fast Rouse motions, relaxation of the star is dominated at intermediate times by the "skinny" tube (made by all topological constraints) followed by exploration of the "fat" tube (made by long-lived obstacles only). At longer times, the tube dilation picture provides the right shape for the relaxation of the stars. However, the effect of short linear chains results in time-shift factors that have never been described before. On the basis of the analysis of the different friction coefficients involved in the relaxation of the star chains, we propose an equation predicting these time-shift factors. This allows us to develop an analytical equation combining all relaxation zones, which is verified by comparison with simulation results. © 2014 American Chemical Society.

  15. PREPARATION AND CHARACTERIZATION OF PVA BASED SOLID POLYMER ELECTROLYTES FOR ELECTROCHEMICAL CELL APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    Anji Reddy Polu; Ranveer Kumar

    2013-01-01

    Solid polymer electrolyte films containing poly(vinyl alcohol) (PVA) and magnesium nitrate (Mg(NO3)2) were prepared by solution casting technique and characterized by using XRD,FT1R,DSC and AC impedance spectroscopic analysis.The amorphous nature of the polymer electrolyte films has been confirmed by XRD.The complex formation between PVA and Mg salt has been confirmed by FTIR.The glass transition temperature decreases with increasing the Mg salt concentration.The AC impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte films in the range of 303-383 K,and the temperature dependence seems to obey the Arrhenius behavior.Transport number measurements show that the charge transport is mainly due to ions.Electrochemical cell of configuration Mg/(PVA + Mg(NO3)2) (70:30)/(I2 + C + electrolyte) has been fabricated.The discharge characteristics of the cell were studied for a constant load of 100 kΩ.

  16. SAXS/DSC/WAXD study of temperature evolution in nanocomposite polymer electrolytes with different nanofillers.

    Science.gov (United States)

    Turković, A; Dubcek, P; Juraić, K; Bernstorff, S

    2012-11-01

    Polymer electrolytes are nanostructured materials which are very attractive components for batteries and opto-electronic devices. (PEO)8ZnCl2 polymer electrolytes were prepared from PEO and ZnCl2. The nanocomposites (PEO)8ZnCI2 themselves contained TiO2, Al2O3, MgO, ZnO and V2O5 nanograins. In this work, the influence of the Al2O3, MgO and V2O5 nanograins on the morphology and ionic conductivity of the nanocomposite was systematically studied by transmission small-angle X-ray scattering simultaneously recorded with wide-angle X-ray diffraction and differential scanning calorimetry at the synchrotron ELETTRA (Trieste, Italy). These three measurement methods yielded insight into the temperature-dependent changes of the grains of the electrolyte. The heating and cooling rate was 0.5 degrees C/min. Environment friendly galvanic cells as well as solar cells of the second generation are to be constructed with such nanocomposite polymer as electrolyte.

  17. Innovative polymer nanocomposite electrolytes: nanoscale manipulation of ion channels by functionalized graphenes.

    Science.gov (United States)

    Choi, Bong Gill; Hong, Jinkee; Park, Young Chul; Jung, Doo Hwan; Hong, Won Hi; Hammond, Paula T; Park, Hoseok

    2011-06-28

    The chemistry and structure of ion channels within the polymer electrolytes are of prime importance for studying the transport properties of electrolytes as well as for developing high-performance electrochemical devices. Despite intensive efforts on the synthesis of polymer electrolytes, few studies have demonstrated enhanced target ion conduction while suppressing unfavorable ion or mass transport because the undesirable transport occurs through an identical pathway. Herein, we report an innovative, chemical strategy for the synthesis of polymer electrolytes whose ion-conducting channels are physically and chemically modulated by the ionic (not electronic) conductive, functionalized graphenes and for a fundamental understanding of ion and mass transport occurring in nanoscale ionic clusters. The functionalized graphenes controlled the state of water by means of nanoscale manipulation of the physical geometry and chemical functionality of ionic channels. Furthermore, the confinement of bound water within the reorganized nanochannels of composite membranes was confirmed by the enhanced proton conductivity at high temperature and the low activation energy for ionic conduction through a Grotthus-type mechanism. The selectively facilitated transport behavior of composite membranes such as high proton conductivity and low methanol crossover was attributed to the confined bound water, resulting in high-performance fuel cells.

  18. Study on characteristics of PVDF/nano-clay composite polymer electrolyte using PVP as pore-forming agent

    Energy Technology Data Exchange (ETDEWEB)

    Dyartanti, Endah R., E-mail: heru.susanto@undip.ac.id, E-mail: endah-rd@uns.ac.id [Departement of Chemical Engineering, Sebelas Maret University, Surakarta (Indonesia); Department of Chemical Engineering, Diponegoro University, Semarang (Indonesia); Purwanto, Agus [Departement of Chemical Engineering, Sebelas Maret University, Surakarta (Indonesia); Widiasa, I. Nyoman; Susanto, Heru, E-mail: heru.susanto@undip.ac.id, E-mail: endah-rd@uns.ac.id [Department of Chemical Engineering, Diponegoro University, Semarang (Indonesia)

    2016-02-08

    Polyvinylidene fluoride (PVDF) based polymer electrolytes have a high dielectric constant, which can assist in greater ionization of lithium salts. The main advantages of PVDF are its durability in long battery operation and its ability to be a good ion conductor. However, the limitation of this polymer is its crystalline molecular structure. Dispersing nano-particles in the polymer matrix may improve the characteristics of the PVDF polymer. This paper aims to investigate the impact of nano-clay addition on the characteristics of PVDF polymer to be used as a polymer electrolyte membrane. In addition, the effect of poly(vinyl pyrrolidone) (PVP) is also investigated. The membrane was prepared by phase separation method whereas the polymer electrolyte membranes was prepared by immersing into 1 M lithium hexafluorophosphate (LiPF{sub 6}) in ethylene carbonate/dimethyl carbonate (EC/DMC) electrolytes for 1 h. The membranes were characterized by scanning electron microscope (SEM), porosity and electrolyte uptake and performance in battery cell. The results showed that both nano-clay and PVP have significant impacts on the improvement of PVDF membranes to be used as polymer electrolyte.

  19. Ionic conductivity and transport properties of poly(vinylidene fluoride-co-hexafluoropropylene)-based solid polymer electrolytes

    Science.gov (United States)

    Abreha, Merhawi; Subrahmanyam, A. R.; Siva Kumar, J.

    2016-08-01

    Polymer electrolytes containing poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and various concentrations of lithium triflate were prepared to determine the optimal polymer-salt composition for maximum ionic conductivity. Complex formation was ascertained from X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) studies. The conductivity measurements reveal that the ionic conductivity of the polymer electrolytes containing various salt concentrations increases with temperature and obeys the Arrhenius rule. It is found that the electrolyte containing 25 wt.% of lithium triflate exhibits the highest room temperature conductivity. Moreover, Ionic transference measurements show predominance of ionic motion.

  20. Blends of guayule natural rubber latex with commercial latex polymers

    Science.gov (United States)

    Guayule (Parthenium argentatum) is a woody desert shrub that produces natural rubber, cis-1,4 polyisoprene, by biosynthesis. It is currently cultivated in the southwestern United States as a source of latex and rubber for commercial development. Guayule latex is similar to Hevea latex in polymer mo...

  1. Advancing Polymer-Supported Ionogel Electrolytes Formed via Radical Polymerization

    Science.gov (United States)

    Visentin, Adam F.

    Applications ranging from consumer electronics to the electric grid have placed demands on current energy storage technologies. There is a drive for devices that store more energy for rapid consumption in the case of electric cars and the power grid, and safer, versatile design options for consumer electronics. Electrochemical double-layer capacitors (EDLCs) are an option that has garnered attention as a means to address these varied energy storage demands. EDLCs utilize charge separation in electrolytes to store energy. This energy storage mechanism allows for greater power density (W kg -1) than batteries and higher energy density (Wh kg-1) than conventional capacitors - along with a robust lifetime in the range of thousands to millions of charge-discharge cycles. Safety and working voltage windows of EDLCs currently on the market are limited by the organic solvents utilized in the electrolyte. A potential solution lies in the replacement of the organic solvents with ionic liquids, or room-temperature molten salts. Ionic liquids possess many superior properties in comparison to conventional solvents: wide electrochemical window, low volatility, nonflammability, and favorable ionic conductivity. It has been an endeavor of this work to exploit these advantages while altering the liquid form factor into a gel. An ionic liquid/solid support scaffold composite electrolyte, or ionogel, adds additional benefits: flexible device design, lower encapsulation weight, and elimination of electrolyte leakage. This work has focused on investigations of a UV-polymerizable monomer, poly(ethylene glycol) diacrylate, as a precursor for forming ionogels in situ. The trade-off between gaining mechanical stability at the cost of ionic conductivity has been investigated for numerous ionogel systems. While gaining a greater understanding of the interactions between the gel scaffold and ionic liquid, an ionogel with the highest known ionic conductivity to date (13.1 mS cm-1) was

  2. Static and dynamic filtrations of different clay, electrolytes, polymer systems; Filtrations statiques et dynamiques de differents systemes argile, electrolytes, polymere

    Energy Technology Data Exchange (ETDEWEB)

    Li, Y.

    1996-04-16

    Filtration properties of model drilling fluids composed of water, clays, electrolytes and water soluble polymers have been studied in static and dynamic conditions on paper filters and rock slices. Filtration experiments combined with cake observations by cryo-S.E.M. and T.E.M., show the influence of the size shape of clay particles as well as their associating mode in suspension, on the texture of the cake, its permeability, and relaxation properties. These parameters depend on the nature of the electrolyte. The polymer reduces the cake permeability by enhancing the dispersion of the clay within the suspension, but mainly by plugging the porous network due its auto aggregation properties. The cake construction in dynamic conditions, is related to the state of aggregation of the initial suspension, its poly-dispersity, its sensitivity to shear rates, and also, to the permeability of the cake built at the beginning of the filtration. In all cases, the rate of thickening of the cake is slower and larger filtrate volumes are obtained compared to the static conditions. Shear rate has two effects: first, to dissociate the weak aggregates in suspension, second, to impose a size selection of the particles in the case of a poly-dispersed suspension. At high shear rates, a cake of constant thin thickness is quickly obtained. The thickness of this limiting cake depends on the fraction of small particles present in suspension, or that can be formed by dissociation of weak aggregates under shear rate. The permeability of this limiting cake formed in dynamic conditions is, as in static conditions, controlled by the size and the shape of the particles that form the cake or by the presence of a build loss reducer water soluble polymer. Filtrations carried out on Fontainebleau sandstones allow to visualize the internal cake and to precise the risks of formation damage by the drilling fluid. (author) 127 refs.

  3. Small angle neutron scattering data of polymer electrolyte membranes partially swollen in water

    Directory of Open Access Journals (Sweden)

    Yue Zhao

    2016-06-01

    Full Text Available In this article, we show the small-angle neutron scattering (SANS data obtained from the polymer electrolyte membranes (PEMs equilibrated at a given relative humidity. We apply Hard-Sphere (HS structure model with Percus–Yervick interference interactions to analyze the dataset. The molecular structure of these PEMs and the morphologies of the fully water-swollen membranes have been elucidated by Zhao et al. “Elucidation of the morphology of the hydrocarbon multi-block copolymer electrolyte membranes for proton exchange fuel cells” [1].

  4. Polybenzimidazole and sulfonated polyhedral oligosilsesquioxane composite membranes for high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Aili, David; Allward, Todd; Alfaro, Silvia Martinez

    2014-01-01

    Composite membranes based on poly(2,2′(m-phenylene)-5,5́bibenzimidazole) (PBI) and sulfonated polyhedral oligosilsesquioxane (S-POSS) with S-POSS contents of 5 and 10wt.% were prepared by solution casting as base materials for high temperature polymer electrolyte membrane fuel cells. With membranes...... humidified conditions in the 120-180°C temperature range. The conductivity improvements were also confirmed by in situ fuel cell tests at 160°C and further supported by the electrochemical impedance spectroscopy data based on the operating membrane electrode assemblies, demonstrating the technical...... feasibility of the novel electrolyte materials....

  5. Effect of Methanol Crossover in a Liquid-FeedPolymer-Electrolyte Direct Methanol Fuel Cell

    OpenAIRE

    Ravikumar, MK; Shukla, AK

    1996-01-01

    The performance of a liquid-feed direct methanol fuel cell employing a proton-exchange membrane electrolyte with Pt-Ru/C as anode and Pt/C as cathode is reported. The fuel cell can deliver a power density of ca. 0.2 $W/cm^2$ at 95°C, sufficient to suggest that the stack construction is well worthwhile.Methanol crossover across the polymer electrolyte at concentrations beyond 2 M methanol affects the performance of the cell which appreciates with increasing operating temperature.

  6. [Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

    Science.gov (United States)

    1998-01-01

    The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

  7. Controlling of the surface energy of the gate dielectric in organic field-effect transistors by polymer blend

    NARCIS (Netherlands)

    Gao, Jia; Asadi, Kamal; Xu, Jian Bin; An, Jin

    2009-01-01

    In this letter, we demonstrate that by blending insulating polymers, one can fabricate an insulating layer with controllable surface energy for organic field-effect transistors. As a model system, we used copper phthalocyanine evaporated on layers of polymethyl metacrylate blended with polystyrene w

  8. The Characterization of Comblike Polymer Electrolyte by Means of NMR

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The comblike polymers based on poly (styrene-co-maleic anhydride) backbone with poly (ethylene glycol) methyl ether as side chains were synthesized and characterized by 1H NMR, with the result compared with that of IR.It is found that it is both feasible and simple to synthesize this kind of compounds with the help of 1H NMR.

  9. Preparation and characterization of nanocomposite polymer electrolytes poly(vinylidone fluoride)/nanoclay

    Energy Technology Data Exchange (ETDEWEB)

    Rahmawati, Suci A.; Sulistyaningsih,; Putro, Alviansyah Z. A.; Widyanto, Nugroho F.; Jumari, Arif; Purwanto, Agus; Dyartanti, Endah R., E-mail: endahrd@uns.ac.id [Research Group of Battery & Advanced Material, Department of Chemical Engineering, Sebelas Maret University, Jl. Ir. Sutami 36 A Kentingan, Surakarta Indonesia 57126 (Indonesia)

    2016-02-08

    Polymer electrolytes are defined as semi solid electrolytes used as separator in lithium ion battery. Separator used as medium for transfer ions and to prevent electrical short circuits in battery cells. To obtain the optimal battery performance, separator with high porosity and electrolyte uptake is required. This can reduce the resistance in the transfer of ions between cathode and anode. The main objective of this work is to investigate the impact of different solvent (Dimethyl acetamide (DMAc), N-methyl-2-pyrrolidone (NMP) and dimethyl formamide (DMF)), pore forming agent poly(vinylpyrolidone) (PVP) and nanoclay as filler in addition of membrane using phase inversion method on the morphology, porosity, electrolyte uptake and degree of crystallinity. The membrane was prepared by the phase inversion method by adding PVP and Nanoclay using different solvents. The phase inversion method was prepared by dissolving Nanoclay and PVP in solvent for 1-2 hours, and then add the PVDF with stirring for 4 hours at 60°C. The membranes were characterized by porosity test, electrolyte uptake test, scanning electron microscope (SEM), and X-ray diffraction (XRD). The results showed that DMAc as solvent gives the highest value of porosity and electrolyte uptake. The addition of nanoclay and PVP enlarge the size of the pores and reduce the degree of crystallinity. So, the usage of DMAc as solvent is better than NMP or DMF.

  10. Evaluation of interactive effects on the ionic conduction properties of polymer gel electrolytes.

    Science.gov (United States)

    Saito, Yuria; Okano, Miki; Kubota, Keigo; Sakai, Tetsuo; Fujioka, Junji; Kawakami, Tomohiro

    2012-08-23

    Ionic mobility of electrolyte materials is essentially determined by the nanoscale interactions, the ion-ion interactions and ion-solvent interactions. We quantitatively evaluated the interactive situation of the lithium polymer gel electrolytes through the measurements of ionic conductivity and diffusion coefficients of the mobile species of the lithium polymer electrolytes. The interactive force between the cation and anion in the gel depended on the mixing ratio of the binary solvent, ethylene carbonate plus dimethyl carbonate (EC/DMC). The gel with the solvent (3:7 EC:DMC) showed minimal cation-anion interaction, which is the cause of the highest ionic mobility compared with those of the other gels with different solvents. This suggests that the cation-anion interaction does not simply depend on the dielectric constant of the solvent but is associated with the solvation condition of the lithium. In the case of the gel with the 3:7 EC/DMC solvent, most of the EC species strongly coordinate to a lithium ion, forming the stable solvated lithium, Li(EC)(3)(+), and there are no residual EC species for exchange with them. As a result, the solvating EC species would be a barrier that restricts the anion attack to the lithium leading to the smallest cation-anion interaction. On the other hand, interaction between the cation and polar sites, hydroxyl and oxygen groups of ether of the polyvinyl butyral (PVB) and polyethylene oxide (PEO) polymer, respectively, in the gels was another dominant factor responsible for cation mobility. It increased with increasing polar site concentration per lithium. In case of the PVB gels, cation-anion interaction increased with an increasing polymer fraction of the gel contrary to the independent feature of PEO gels with the change of the polymer fraction. This indicates that the cation-anion interaction is associated with the polymer structure of the gel characterized by the kind and configuration of polar groups, molecular weight, and

  11. Experimental Study on the Molecular Dimension and Configuration of Polymer and Its Flow Characteristics from Electrolyte Effect

    Institute of Scientific and Technical Information of China (English)

    LU,Xiangguo; WANG,Xiaoyan; JIANG,Weidong

    2009-01-01

    Molecular clew dimension and configuration of polymer,and flow characteristics of polymer solution were studied from electrolyte effect,by making use of dynamic light scattering (DLS),scanning electron microscopy (SEM),apparent viscosity method and core flow experiment.It can be observed that with the electrolyte concentration increasing,there exists a variation trend of "decreasing,increasing and decreasing again" to the molecular clew dimension of the polymer.The compression action of Ca2+ or Mg2+ to the double electrode layer of polymer molecules is more powerful by comparison against Na+,which results in that Ca2+ and Mg2+ have a more extensive effect on the viscosity of polymer solution,and clew dimensions and their distribution.With the electrolyte concentration increasing,the polymer molecular configuration of multi-layer stereoscopic random reticulation transformed into a dendritic one.During the succeeding water flooding,the variation degree of injection pressure of core was mainly determined by the swelling extent of molecular clew of retained polymer and the produced amount of polymer.And the bigger the molecular weight of polymer is,the stronger the compression or swelling action of electrolyte to the molecule clews is,and the greater the increasing degree of injection pressure during succeeding water flooding is.The greater difference of electrolyte concentrations in used water between polymer flooding and succeeding water flooding can result in greater increasing degree of injection pressure during the succeeding water flooding.So,an advisable increasing in difference of electrolyte concentrations in used water between the polymer flooding and succeeding water flooding was proposed when designing the polymer flooding performance in oilfields,which has promising result for improving effect of polymer flooding.

  12. Polystyrene-Al2O3 composite solid polymer electrolyte for lithium secondary battery

    Science.gov (United States)

    Lim, Yu-Jeong; An, Yu-Ha; Jo, Nam-Ju

    2012-01-01

    In a common salt-in-polymer electrolyte, a polymer which has polar groups in the molecular chain is necessary because the polar groups dissolve lithium salt and coordinate cations. Based on the above point of view, polystyrene [PS] that has nonpolar groups is not suitable for the polymer matrix. However, in this PS-based composite polymer-in-salt system, the transport of cations is not by segmental motion but by ion-hopping through a lithium percolation path made of high content lithium salt. Moreover, Al2O3 can dissolve salt, instead of polar groups of polymer matrix, by the Lewis acid-base interactions between the surface group of Al2O3 and salt. Notably, the maximum enhancement of ionic conductivity is found in acidic Al2O3 compared with neutral and basic Al2O3 arising from the increase of free ion fraction by dissociation of salt. It was revealed that PS-Al2O3 composite solid polymer electrolyte containing 70 wt.% salt and 10 wt.% acidic Al2O3 showed the highest ionic conductivity of 9.78 × 10-5 Scm-1 at room temperature.

  13. Enhancement of Li+ ion conductivity in solid polymer electrolytes using surface tailored porous silica nanofillers

    Science.gov (United States)

    Mohanta, Jagdeep; Singh, Udai P.; Panda, Subhendu K.; Si, Satyabrata

    2016-09-01

    The current study represents the design and synthesis of polyethylene oxide (PEO)-based solid polymer electrolytes by solvent casting approach using surface tailored porous silica as nanofillers. The surface tailoring of porous silica nanostructure is achieved through silanization chemistry using 3-glycidyloxypropyl trimethoxysilane in which silane part get anchored to the silica surface whereas epoxy group get stellated from the silica surface. Surface tailoring of silica with epoxy group increases the room temperature electrochemical performances of the resulting polymer electrolytes. Ammonical hydrolysis of organosilicate precursor is used for both silica preparation and their surface tailoring. The composite solid polymer electrolyte films are prepared by solution mixing of PEO with lithium salt in presence of silica nanofillers and cast into film by solvent drying, which are then characterized by impedance measurement for conductivity study and wide angle x-ray diffraction for change in polymer crystallinity. Room temperature impedance measurement reveals Li+ ion conductivity in the order of 10-4 S cm-1, which is correlated to the decrease in PEO crystallinity. The enhancement of conductivity is further observed to be dependent on the amount of silica as well as on their surface characteristics.

  14. Structural and electrochemical properties of succinonitrile-based gel polymer electrolytes: role of ionic liquid addition.

    Science.gov (United States)

    Suleman, Mohd; Kumar, Yogesh; Hashmi, S A

    2013-06-20

    Experimental studies on the novel compositions of gel polymer electrolytes, comprised of plastic crystal succinonitrile (SN) dispersed with pyrrolidinium and imidazolium-based ionic liquids (ILs) entrapped in a host polymer poly(vinylidine fluoride-co-hexafluoropropylene) (PVdF-HFP), are reported. The gel electrolytes are in the form of free-standing films with excellent mechanical, thermal, and electrochemical stability. The introduction of even a small content (~1 wt %) of ionic liquid (1-butyl-1-methylpyrrolidinium bis(trifluoromethyl-sulfonyl)imide (BMPTFSI) or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf) in the PVdF-HFP/SN system (1:4 w/w) enhances the electrical conductivity by 4 orders of magnitude, that is, from ~10(-7) to ~10(-3) S cm(-1) at room temperature. The structural changes due to the entrapment of SN or SN/ILs mixtures and ion-SN-polymer interactions are examined by Fourier transform infrared (FTIR)/Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimmetry (DSC). Various physicochemical properties and fast ion conduction in the gel polymer membranes show their promising characteristics as electrolytes in different ionic devices including supercapacitors.

  15. 'All-solid-state' electrochemistry of a protein-confined polymer electrolyte film.

    Science.gov (United States)

    Parthasarathy, Meera; Pillai, Vijayamohanan K; Mulla, Imtiaz S; Shabab, Mohammed; Khan, M I

    2007-12-07

    Interfacial redox behavior of a heme protein (hemoglobin) confined in a solid polymer electrolyte membrane, Nafion (a perfluoro sulfonic acid ionomer) is investigated using a unique 'all-solid-state' electrochemical methodology. The supple phase-separated structure of the polymer electrolyte membrane, with hydrophilic pools containing solvated protons and water molecules, is found to preserve the incorporated protein in its active form even in the solid-state, using UV-visible, Fluorescence (of Tryptophan and Tyrosine residues) and DRIFT (diffuse reflectance infrared Fourier transform) spectroscopy. More specifically, solid-state cyclic voltammetry and electrochemical impedance of the protein-incorporated polymer films reveal that the Fe2+-form of the entrapped protein is found to bind molecular oxygen more strongly than the native protein. In the 'all-solid-state' methodology, as there is no need to dip the protein-modified electrode in a liquid electrolyte (like the conventional electrochemical methods), it offers an easier means to study a number of proteins in a variety of polymer matrices (even biomimetic assemblies). In addition, the results of the present investigation could find interesting application in a variety of research disciplines, in addition to its fundamental scientific interest, including protein biotechnology, pharmaceutical and biomimetic chemistry.

  16. Structural and optical characterization of PVA:KMnO4 based solid polymer electrolyte

    Science.gov (United States)

    Abdullah, Omed Gh.; Aziz, Shujahadeen B.; Rasheed, Mariwan A.

    Solid polymer electrolyte films of polyvinyl alcohol (PVA) doped with a different weight percent of potassium permanganate (KMnO4) were prepared by standard solution cast method. XRD and FTIR techniques were performed for structural study. Complex formation between the PVA polymer and KMnO4 salt was confirmed by Fourier transform infrared (FTIR) spectroscopy. The description of crystalline nature of the solid polymer electrolyte films has been confirmed by XRD analysis. The UV-Visible absorption spectra were analyzed in terms of absorption formula for non-crystalline materials. The fundamental optical parameters such as optical band gap energy, refractive index, optical conductivity, and dielectric constants have been investigated and showed a clear dependence on the KMnO4 concentration. The observed value of optical band gap energy for pure PVA is about 6.27 eV and decreases to a value 3.12 eV for the film sample formed with 4 wt% KMnO4 salt. The calculated values of refractive index and the dielectric constants of the polymer electrolyte films increase with increasing KMnO4 content.

  17. A Review on the Fabrication of Electrospun Polymer Electrolyte Membrane for Direct Methanol Fuel Cell

    Directory of Open Access Journals (Sweden)

    Hazlina Junoh

    2015-01-01

    Full Text Available Proton exchange membrane (PEM is an electrolyte which behaves as important indicator for fuel cell’s performance. Research and development (R&D on fabrication of desirable PEM have burgeoned year by year, especially for direct methanol fuel cell (DMFC. However, most of the R&Ds only focus on the parent polymer electrolyte rather than polymer inorganic composites. This might be due to the difficulties faced in producing good dispersion of inorganic filler within the polymer matrix, which would consequently reduce the DMFC’s performance. Electrospinning is a promising technique to cater for this arising problem owing to its more widespread dispersion of inorganic filler within the polymer matrix, which can reduce the size of the filler up to nanoscale. There has been a huge development on fabricating electrolyte nanocomposite membrane, regardless of the effect of electrospun nanocomposite membrane on the fuel cell’s performance. In this present paper, issues regarding the R&D on electrospun sulfonated poly (ether ether ketone (SPEEK/inorganic nanocomposite fiber are addressed.

  18. Polymer-ionic liquid nano-composites electrolytes: Electrical, thermal and morphological properties

    Energy Technology Data Exchange (ETDEWEB)

    Missan, Harinder Pal Singh, E-mail: harinder.missan@sta.uwi.edu [Fuel Cell Materials Research Lab, Department of Physics, University of West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago); Lalia, Boor Singh [Fuel Cell Materials Research Lab, Department of Physics, University of West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago); Karan, Kunal [Fuel Cell Research Center, Queens University, Kingston, Ontario, K7L 5L9 (Canada); Maxwell, Anderson [Department of Chemistry, University of West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago)

    2010-11-25

    Room temperature ionic liquid (IL): 1-methyl-3-hexylimidazolium imide (HxMImTFSI) has been synthesized showing a high conductivity value of 4.3 mS/cm at room temperature. Polymer electrolytes (PEs) have been developed by impregnating the RTIL in poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP) matrix with different binary compositions which have different molecular weights. PE's that are synthesized with the polymer having an average molecular weight of 400,000 shows highest room temperature conductivity of 4.86 x 10{sup -4} S/cm at room temperature for (3:7 weight ratio). The nano-composite polymer electrolytes (NCPEs) were prepared by dispersing nano-tubular titania in the PE. Thermal stability of the IL and NCPEs was investigated using TGA (Thermogravimetric Analysis) and DSC (Differential Scanning Calorimetric) studies showing the stability of these electrolytes in excess of 250 deg. C. High ionic conductivity has been observed of the order of 10{sup -4} S/cm at RT and 10{sup -3} S/cm at 120 deg. C for NCPE having composition 3:7 ratio of polymer and IL and containing 2 wt% nano-tubular titania. SEM studies show that there is an improvement in the morphology of the NCPEs with the addition of nano-tubular titania.

  19. Development and Characterization of Poly(1-vinylpyrrolidone-co-vinyl acetate Copolymer Based Polymer Electrolytes

    Directory of Open Access Journals (Sweden)

    Nurul Nadiah Sa’adun

    2014-01-01

    Full Text Available Gel polymer electrolytes (GPEs are developed using poly(1-vinylpyrrolidone-co-vinyl acetate [P(VP-co-VAc] as the host polymer, lithium bis(trifluoromethane sulfonimide [LiTFSI] as the lithium salt and ionic liquid, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl imide [EMImTFSI] by using solution casting technique. The effect of ionic liquid on ionic conductivity is studied and the optimum ionic conductivity at room temperature is found to be 2.14 × 10−6 S cm−1 for sample containing 25 wt% of EMImTFSI. The temperature dependence of ionic conductivity from 303 K to 353 K exhibits Arrhenius plot behaviour. The thermal stability of the polymer electrolyte system is studied by using thermogravimetric analysis (TGA while the structural and morphological properties of the polymer electrolyte is studied by using Fourier transform infrared (FTIR spectroscopy and X-ray diffraction analysis (XRD, respectively.

  20. A Solution-Doped Polymer Semiconductor:Insulator Blend for Thermoelectrics

    KAUST Repository

    Kiefer, David

    2016-09-01

    Poly(ethylene oxide) is demonstrated to be a suitable matrix polymer for the solution-doped conjugated polymer poly(3-hexylthiophene). The polarity of the insulator combined with carefully chosen processing conditions permits the fabrication of tens of micrometer-thick films that feature a fine distribution of the F4TCNQ dopant:semiconductor complex. Changes in electrical conductivity from 0.1 to 0.3 S cm−1 and Seebeck coefficient from 100 to 60 μV K−1 upon addition of the insulator correlate with an increase in doping efficiency from 20% to 40% for heavily doped ternary blends. An invariant bulk thermal conductivity of about 0.3 W m−1 K−1 gives rise to a thermoelectric Figure of merit ZT ∼ 10−4 that remains unaltered for an insulator content of more than 60 wt%. Free-standing, mechanically robust tapes illustrate the versatility of the developed dopant:semiconductor:insulator ternary blends.

  1. Polymer Blends Containing Liquid Crystalline Component Cholesteryl Palmitate-containing Blends%含液晶成分的掺杂共聚物和胆甾醇基棕榈酸盐(或酯)掺合物

    Institute of Scientific and Technical Information of China (English)

    Maria-Cristina; Popescu; Cornelia; Vasile; Daniela; Filip; Doina; Macocinschi; Gh.; Singurel

    2005-01-01

    @@ Physical blends containing macromolecular compounds and low molecular weight liquid crystals (LCs) have important applications. LCs are used as reinforcements for amorphous polymers or in display devices.

  2. Can superabsorbent polymers mitigate shrinkage in cementitious materials blended with supplementary cementitious materials?

    DEFF Research Database (Denmark)

    Snoeck, Didier; Jensen, Ole Mejlhede; De Belie, Nele

    2016-01-01

    A promising way to mitigate autogenous shrinkage in cementitious materials with a low water-to-binder ratio is internal curing by the use of superabsorbent polymers. Superabsorbent polymers are able to absorb multiple times their weight in water and can be applied as an internal water reservoir...... shrinkage in materials blended with fly ash or blast-furnace slag remain scarce, especially after one week of age. This paper focuses on the autogenous shrinkage by performing manual and automated shrinkage measurements up to one month of age. Without superabsorbent polymers, autogenous shrinkage...... was reduced in cement pastes with the supplementary cementitious materials versus Portland cement pastes. At later ages, the rate of autogenous shrinkage is higher due to the pozzolanic activity of the supplementary cementitious materials. Internal curing by means of superabsorbent polymers is successful...

  3. Blending of styrene-block-butadiene-block-styrene copolymer with sulfonated vinyl aromatic polymers

    OpenAIRE

    Ruggeri, Giacomo; Passaglia, Elisa; Giorgi, Ivan; Picchioni, Francesco; Aglietto, Mauro

    2001-01-01

    Different polymers containing sulfonic groups attached to the phenyl rings were prepared by sulfonation of polystyrene (PS) and styrene-block-(ethylene-co-1-butene)-block-styrene (SEBS). The sulfonation degree (SD) was varied between 1 and 20 mol% of the styrene units. Polyphase materials containing sulfonated units were prepared by blending styrene-block-butadiene-block-styrene (SBS), with both sulfonated PS and sulfonated SEBS in a Brabender mixer. Such a procedure was performed as an alter...

  4. Poly(cyclohexadiene)-Based Polymer Electrolyte Membranes for Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Mays, Jimmy W.

    2011-03-07

    The goal of this research project was to create and develop fuel cell membranes having high proton conductivity at high temperatures and high chemical and mechanical durability. Poly(1,3-cyclohexadiene) (PCHD) is of interest as an alternative polymer electrolyte membrane (PEM) material due to its ring-like structure which is expected to impart superior mechanical and thermal properties, and due to the fact that PCHD can readily be incorporated into a range of homopolymer and copolymer structures. PCHD can be aromatized, sulfonated, or fluorinated, allowing for tuning of key performance structure and properties. These factors include good proton transport, hydrophilicity, permeability (including fuel gas impermeability), good mechanical properties, morphology, thermal stability, crystallinity, and cost. The basic building block, 1,3-cyclohexadiene, is a hydrocarbon monomer that could be inexpensively produced on a commercial scale (pricing typical of other hydrocarbon monomers). Optimal material properties will result in novel low cost PEM membranes engineered for high conductivity at elevated temperatures and low relative humidities, as well as good performance and durability. The primary objectives of this project were: (1) To design, synthesize and characterize new non-Nafion PEM materials that conduct protons at low (25-50%) RH and at temperatures ranging from room temperature to 120 C; and (2) To achieve these objectives, a range of homopolymer and copolymer materials incorporating poly(cyclohexadiene) (PCHD) will be synthesized, derivatized, and characterized. These two objectives have been achieved. Sulfonated and crosslinked PCHD homopolymer membranes exhibit proton conductivities similar to Nafion in the mid-RH range, are superior to Nafion at higher RH, but are poorer than Nafion at RH < 50%. Thus to further improve proton conductivity, particularly at low RH, poly(ethylene glycol) (PEG) was incorporated into the membrane by blending and by

  5. Effects of Thermal Annealing Upon the Morphology of Polymer-Fullerene Blends

    KAUST Repository

    Verploegen, Eric

    2010-08-18

    Grazing incidence X-ray scattering (GIXS) is used to characterize the morphology of poly(3-hexylthiophene) (P3HT)-phenyl-C61-butyric acid methyl ester (PCBM) thin film bulk heterojunction (BHJ) blends as a function of thermal annealing temperature, from room temperature to 220 °C. A custom-built heating chamber for in situ GIXS studies allows for the morphological characterization of thin films at elevated temperatures. Films annealed with a thermal gradient allow for the rapid investigation of the morphology over a range of temperatures that corroborate the results of the in situ experiments. Using these techniques the following are observed: the melting points of each component; an increase in the P3HT coherence length with annealing below the P3HT melting temperature; the formation of well-oriented P3HT crystallites with the (100) plane parallel to the substrate, when cooled from the melt; and the cold crystallization of PCBM associated with the PCBM glass transition temperature. The incorporation of these materials into BHJ blends affects the nature of these transitions as a function of blend ratio. These results provide a deeper understanding of the physics of how thermal annealing affects the morphology of polymer-fullerene BHJ blends and provides tools to manipulate the blend morphology in order to develop high-performance organic solar cell devices. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. High-performance all-polymer solar cells via side-chain engineering of the polymer acceptor: the importance of the polymer packing structure and the nanoscale blend morphology.

    Science.gov (United States)

    Lee, Changyeon; Kang, Hyunbum; Lee, Wonho; Kim, Taesu; Kim, Ki-Hyun; Woo, Han Young; Wang, Cheng; Kim, Bumjoon J

    2015-04-17

    The effectiveness of side-chain engineering is demonstrated to produce highly efficient all-polymer solar cells (efficiency of 5.96%) using a series of naphthalene diimide-based polymer acceptors with controlled side chains. The dramatic changes in the polymer packing, blend morphology, and electron mobility of all-polymer solar cells elucidate clear trends in the photovoltaic performances.

  7. Influence of annealing and blending of photoactive polymers on their crystalline structure.

    Science.gov (United States)

    Ruderer, Matthias A; Prams, Stefan M; Rawolle, Monika; Zhong, Qi; Perlich, Jan; Roth, Stephan V; Müller-Buschbaum, Peter

    2010-12-02

    Thin photoactive polymer films of poly(3-octylthiophene-2,5-diyl) (P3OT) and poly(2,5-di(hexyloxy)cyanoterephthalylidene) (CN-PPV) are investigated. With X-ray reflectivity measurements, a linear concentration-thickness dependence is found for both polymers and the molecular weight of CN-PPV is determined from this concentration-thickness dependence. Based on the molecular weights, the critical blending ratio is determined. Grazing incidence wide-angle X-ray scattering (GIWAXS) is used to probe the crystallinity of thin films and to determine characteristic length scales of the crystalline structure. Moreover, the orientation of the crystalline parts regarding the substrate of both the homopolymer and the blended films is probed with GIWAXS. Temperature annealing is found to improve the crystallization for both homopolymers. In addition, reorientation of the predominant crystalline structures takes place. Blending both polymers reduces or even suppresses the crystallization during spin coating as well as temperature annealing. Absorption measurements complement the structural investigations.

  8. Electrochemical Performance of Solid Polymer Electrolyte PEO20-LiTf-Urea1.s

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ding; YAN Hui; ZHANG Huan; QI Lu

    2011-01-01

    A new solid polymer electrolyte PEO20-LiTf-Urea1.5 was prepared by solution casting technique. The energy of frontier orbitals for the components of the electrolyte was predicted by quantum chemistry calculations, and TG stability and electrochemical features were measured. Urea exhibited a lower HOMO energy than PEO, implying its enhanced stability against electrochemical oxidation. Experimentally addition of urea increases the ionic conductivity, which guarantees conductivity requirement for lithium ion batteries. It also results in significant improved electrochemical stability with good thermal stability. Favorable lithium stripping/plating performance is yielded, and it confirms the good stability of the solid electrolyte interphase for the PEO20-LiTf-Urea1.5 system.

  9. Electrochemistry study on PEO-LiClO4-ZSM5 composite polymer electrolyte

    Institute of Scientific and Technical Information of China (English)

    XI Jingyu; MA Xiaomei; CUI Mengzhong; HUANG Xiaobin; ZHENG Zhen; TANG Xiaozhen

    2004-01-01

    A novel all solid-state composite polymer electrolyte, PEO-LiClO4-LiZSM5, by using "shape-selective" molecular sieves ZSM-5 as filler was obtained by the solvent casting method. The experimental results showed that the addition of LiZSM5 could enhance the ionic conductivity of the pristine PEO-LiClO4 electrolyte, the ionic conductivity of PEO10-LiClO4-10%LiZSM5 achieved 1.4×10-5 S cm-1 at 25℃. Lithium ion transference number was tested by AC impedance combined with the steady-state current method, the results showed that LiZSM5 could improve the Li+ transference number of the CPE effectively. The broad electrochemical stability window ensured the use of PEO-Li- ClO4-LiZSM5 as electrolyte materials for all solid-state rechargeable lithium ion batteries.

  10. Electrochemical characterisation of an Os (II) conjugated polymer in aqueous electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    McCormac, Timothy [CREATE ' Centre for Research in Electroanalytical Technology' , Department of Applied Science, Institute of Technology Tallaght, Tallaght, Dublin 24 (Ireland)]. E-mail: tim.mccormac@it_tallaght.ie; Cassidy, John F. [School of Chemistry, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Crowley, Karl [School of Chemistry, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Trouillet, Lise [Laboratoire d' Electrochimie Moleculaire et Structures des Interfaces, UMR 5819 CEA-CNRS-University Grenoble 1, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France); Lafolet, Frederic [Laboratoire d' Electrochimie Moleculaire et Structures des Interfaces, UMR 5819 CEA-CNRS-University Grenoble 1, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France); Guillerez, Stephane [Laboratoire d' Electrochimie Moleculaire et Structures des Interfaces, UMR 5819 CEA-CNRS-University Grenoble 1, CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 09 (France)

    2006-04-25

    The electrochemical behaviour of an Os (II) complex of the structurally well-defined conjugated polymer alternating regioregularly alkylated thiophene and 2,2'-bipyridine units (P4Os) has been elucidated in aqueous solution. In typical aqueous electrolyte systems, the cyclic voltammogram of the resulting P4Os film exhibits a one-electron reversible process corresponding to the Os{sup 3+/2+} redox system. However, the observance of this reversible couple did depend upon the concentration of the supporting electrolyte. It was found that the Os{sup 3+} form did form ion-pairs with an anion from the electrolyte solution. Preliminary investigations into the homogeneous charge transport dynamics associated with this redox couple have been undertaken. The technique of cyclic voltammetry, and hence the Randles-Sevick expression, in conjunction with platinum microelectrodes have been employed to determine the D{sub CT}C value.

  11. Photochemical stability of conjugated polymers, electron acceptors and blends for polymer solar cells resolved in terms of film thickness and absorbance

    DEFF Research Database (Denmark)

    Tromholt, Thomas; Vesterager Madsen, Morten; Carlé, Jon Eggert

    2012-01-01

    Photochemical degradation at 1 sun under AM1.5G illumination was performed on six conjugated polymers and five different electron acceptors. Additionally, the respective polymer:PC60BM and P3HT:electron acceptor blends were studied, and all degradations were resolved in terms of film thickness...... and absorbance. A fully automated degradation setup allowed for inclusion of in excess of 1000 degradations in this study to enable a discussion of reliability of the technique. Degradation rates were found to increase exponentially with decreasing film absorbance for all materials. The relative stabilities...... within each material group were found to vary for both the pure polymers and the blends. The stability ranking between the materials of the pure polymers was found to be similar to the ranking for their respective blends, implying that the photochemical stability of a pure polymer is a good measure...

  12. Thin and flexible solid-state organic ionic plastic crystal-polymer nanofibre composite electrolytes for device applications.

    Science.gov (United States)

    Howlett, Patrick C; Ponzio, Florian; Fang, Jian; Lin, Tong; Jin, Liyu; Iranipour, Nahid; Efthimiadis, Jim

    2013-09-07

    All solid-state organic ionic plastic crystal-polymer nanofibre composite electrolytes are described for the first time. The new composite materials exhibit enhanced conductivity, excellent thermal, mechanical and electrochemical stability and allow the production of optically transparent, free-standing, flexible, thin film electrolytes (10's μms thick) for application in electrochemical devices. Stable cycling of a lithium cell incorporating the new composite electrolyte is demonstrated, including cycling at lower temperatures than previously possible with the pure material.

  13. Electrochemistry Study on PVC-LiClO4 Polymer Electrolyte Supported by Bengkulu Natural Bentonite for Lithium Battery

    Directory of Open Access Journals (Sweden)

    Ghufira

    2012-04-01

    Full Text Available In this research bentonite was used as filler to produce polymer electrolyte (PVCLiClO4. Some weight variation of bentonite have been made by addition, such as 0% wt/wt; 5% wt/wt ; 10% wt/wt ; 15% wt/wt ; 20% wt/wt ; and 25% wt/wt of bentonite to the mixture of 0,5 gramof PVC and 0,125 gram of LiClO4. Ionic conductivity of polymer electrolyte was tested using impedance spectroscopy. The result of the research was showed that a mixture of PVCBentonite(10% wt/wt-LiClO4 gives the highest ionic conductivity (4,86 x 10-3 S.Cm-1. This result indicated that the presence of natural bentonite can be used as a filler in the current composite polymer electrolyte and can increase the ionic conductivity of the polymer electrolyte.

  14. The NASA "PERS" Program: Solid Polymer Electrolyte Development for Advanced Lithium-Based Batteries

    Science.gov (United States)

    Baldwin, Richard S.; Bennett, William R.

    2007-01-01

    In fiscal year 2000, The National Aeronautics and Space Administration (NASA) and the Air Force Research Laboratory (AFRL) established a collaborative effort to support the development of polymer-based, lithium-based cell chemistries and battery technologies to address the next generation of aerospace applications and mission needs. The ultimate objective of this development program, which was referred to as the Polymer Energy Rechargeable System (PERS), was to establish a world-class technology capability and U.S. leadership in polymer-based battery technology for aerospace applications. Programmatically, the PERS initiative exploited both interagency collaborations to address common technology and engineering issues and the active participation of academia and private industry. The initial program phases focused on R&D activities to address the critical technical issues and challenges at the cell level. Out of a total of 38 proposals received in response to a NASA Research Announcement (NRA) solicitation, 18 proposals (13 contracts and 5 grants) were selected for initial award to address these technical challenges. Brief summaries of technical approaches, results and accomplishments of the PERS Program development efforts are presented. With Agency support provided through FY 2004, the PERS Program efforts were concluded in 2005, as internal reorganizations and funding cuts resulted in shifting programmatic priorities within NASA. Technically, the PERS Program participants explored, to various degrees over the lifetime of the formal program, a variety of conceptual approaches for developing and demonstrating performance of a viable advanced solid polymer electrolyte possessing the desired attributes, as well as several participants addressing all components of an integrated cell configuration. Programmatically, the NASA PERS Program was very successful, even though the very challenging technical goals for achieving a viable solid polymer electrolyte material or

  15. Solid-state sodium batteries using polymer electrolytes and sodium intercalation electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Y. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

    1996-08-01

    Solid-state sodium cells using polymer electrolytes (polyethylene oxide mixed with sodium trifluoromethanesulfonate: PEO{sub n}NaCF{sub 3}SO{sub 3}) and sodium cobalt oxide positive electrodes are characterized in terms of discharge and charge characteristics, rate capability, cycle life, and energy and power densities. The P2 phase Na{sub x}CoO{sub 2} can reversibly intercalate sodium in the range of x = 0.3 to 0.9, giving a theoretical specific energy of 440 Wh/kg and energy density of 1,600 Wh/l. Over one hundred cycles to 60% depth of discharge have been obtained at 0.5 mA/cm{sup 2}. Experiments show that the electrolyte/Na interface is stable and is not the limiting factor to cell cycle life. Na{sub 0.7}CoO{sub 2} composite electrodes containing various amounts of carbon black additive are investigated. The transport properties of polymer electrolytes are the critical factors for performance. These properties (the ionic conductivity, salt diffusion coefficient, and ion transference number) are measured for the PEO{sub n}NaCF{sub 3}SO{sub 3} system over a wide range of concentrations at 85 C. All the three transport properties are very salt-concentration dependent. The ionic conductivity exhibits a maximum at about n = 20. The transference number, diffusion coefficient, and thermodynamic factor all vary with salt concentration in a similar fashion, decreasing as the concentration increases, except for a local maximum. These results verify that polymer electrolytes cannot be treated as ideal solutions. The measured transport-property values are used to analyze and optimize the electrolytes by computer simulation and also cell testing. Salt precipitation is believed to be the rate limiting process for cells using highly concentrated solutions, as a result of lower values of these properties, while salt depletion is the limiting factor when a dilute solution is used.

  16. Amino-Functional Polybenzimidazole Blends with Enhanced Phosphoric Acid Mediated Proton Conductivity as Fuel Cell Electrolytes

    DEFF Research Database (Denmark)

    Aili, David; Javakhishvili, Irakli; Han, Junyoung;

    2016-01-01

    A new amino-functional polybenzimidazole copolymer is synthesized by homogeneous solution condensation polymerization from a novel monomer, N,N′-bis (2,4-diaminophenyl)-1,3-diaminopropane. The copolymer readily dissolves in organic solvents and shows good film forming characteristics. To balance...... the phosphoric acid uptake and to obtain mechanically robust membranes, the amino-functional polybenzimidazole derivative is blended with high molecular weight poly [2,2′-(m-phenylene)-5,5′-bisbenzimidazole] at different ratios. Due to the high acid uptake, the homogenous blend membranes show enhanced proton...

  17. Kinetic factors determining conducting filament formation in solid polymer electrolyte based planar devices.

    Science.gov (United States)

    Krishnan, Karthik; Aono, Masakazu; Tsuruoka, Tohru

    2016-08-01

    Resistive switching characteristics and conducting filament formation dynamics in solid polymer electrolyte (SPE) based planar-type atomic switches, with opposing active Ag and inert Pt electrodes, have been investigated by optimizing the device configuration and experimental parameters such as the gap distance between the electrodes, the salt inclusion in the polymer matrix, and the compliance current applied in current-voltage measurements. The high ionic conductivities of SPE enabled us to make scanning electron microscopy observations of the filament formation processes in the sub-micrometer to micrometer ranges. It was found that switching behaviour and filament growth morphology depend strongly on several kinetic factors, such as the redox reaction rate at the electrode-polymer interfaces, ion mobility in the polymer matrix, electric field strength, and the reduction sites for precipitation. Different filament formations, resulting from unidirectional and dendritic growth behaviours, can be controlled by tuning specified parameters, which in turn improves the stability and performance of SPE-based devices.

  18. Room temperature lithium metal batteries based on a new Gel Polymer Electrolyte membrane

    Science.gov (United States)

    Sannier, L.; Bouchet, R.; Grugeon, S.; Naudin, E.; Vidal, E.; Tarascon, J.-M.

    A new effective Gel Polymer Electrolyte membrane based on two polymers, the polyethylene oxide (PEO), a poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) copolymer and a plasticizer, the dibutylphtalate (DBP), was realized. This separator membrane was made by adjunction, through lamination, of an industrially made DBP/PVdF-HFP film and a homemade DBP/PEO thin film. Once the plasticizer was removed and the separator gelled by the electrolyte, the PEO enables the formation of a good interface with the lithium while the PVdF-HFP film brings the mechanical strength to the membrane. The electrochemical behavior of lithium batteries based on this bi-layer separator was investigated versus temperature, cycling potential and cycling rate. Owing to the promising results obtained with laboratory cells, a 1 Ah prototype was successfully assembled, and its cycling and rate performances were reported.

  19. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo [Department of Materials Science and Chemical Engineering, Faculty of Engineering, Shizuoka University, 3-5-1, Johoku, Hamamatsu 432-8561 (Japan)

    2006-06-01

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87wt.%)) exhibited ionic conductivity of 4x10{sup -4}Scm{sup -1} at 30{sup o}C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2V. (author)

  20. Lithium ion conductivity of gel polymer electrolytes containing insoluble lithium tetrakis(pentafluorobenzenethiolato) borate

    Science.gov (United States)

    Aoki, Takahiro; Ohta, Takayuki; Fujinami, Tatsuo

    Lithium ion conducting gel polymer electrolytes composed of insoluble lithium tetrakis(pentafluorobenzenethiolato) borate (LiTPSB), poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and ethylene carbonate-propylene carbonate mixed solvent (EC-PC) were prepared and their ionic conductivities and electrochemical stabilities were investigated. Ionic conductivity was largely dependent on the contents of EC-PC and LiTPSB. Gel polymer electrolyte containing optimized content of 50 (LiTPSB)-50 (PVDF-HFP/EC-PC (13:87 wt.%)) exhibited ionic conductivity of 4 × 10 -4 S cm -1 at 30 °C, lithium ion transference number of 0.33 and anodic oxidation potential of 4.2 V.