Polyethylene Oxide Based Polymer Electrolyte Research Articles

Influence of Carbon Black on Conductivity and Structure of Polyethylene Oxide Based Polymer Electrolyte Film

AbstractThe potential applications of carbon black are expected to grow as science and technology improve offering up new possibilities for innovation throughout disciplines included in the field of energy storage. The present work shows the influence of carbon black to improve the ionic conductivity of the polymer electrolyte. The synthesis of polyethylene oxide: ammonium iodide based polymer electrolyte incorporated with carbon black varying from 0.01 to 0.06 wt% with respect to PEO: NH4I system by solution casting method. Different characterizations like polarized optical microscopy (POM), impedance spectroscopy, and ionic transference number (tion) are studied in detail. The maximum ionic conductivity is achieved at 0.05 wt% carbon black shows 1.20 × 10−5 S cm−1 at ambient temperature. In accordance with POM data, the amorphous region has increased whereas the crystalline region has shrunk which further indicated the increase in ionic conductivity. The value of (tion) is calculated to be 0.97 which shows the system is ionic in nature. PEO based polymer electrolyte doped carbon black can be used for the fabrication of energy storage devices.

Ion Transport and Dielectric Studies on [PEO:TiO2]:NH4SCN Nanocomposite Polymer Electrolytes

AbstractAn improvement in ion transport behavior and dielectric properties of polyethylene oxide based polymer electrolytes have been investigated upon the dispersal of TiO2 nanoparticles. TiO2 nanoparticle is synthesized with the help of well‐known sol–gel technique. The different compositions of polymer electrolyte systems are prepared by the solution cast technique. Nanocomposite polymer electrolytes (NCPEs) films are synthesized by loading of nanoTiO2 particle in a pristine polymer electrolyte matrix. The structural and morphological behaviors of nanocomposite polymer electrolytes (NCPEs) have been subsequently characterized by XRD and SEM studies. The ionic behavior of synthesized NCPEs is ascertained by Wagner's polarization technique. AC and DC conductivity of polymer electrolyte films have been carried out using impedance spectroscopic techniques. Dielectric relaxation studies of polymer electrolytes are examined using impedance spectroscopic data. The conductivity relaxation mechanism of NCPEs has been concluded with the help of modulus formalism. DC conductivity of best ion‐conducting NCPEs at room temperature has been found to σ = 2.5 × 10−5 S cm−1. The electrode polarization effect has completely vanished in the dielectric and modulus formalism and the conductivity scaling data show a single master curve observed in ion dynamics. The change in ionic conductivity with frequency and temperature is studied by impedance spectroscopic investigations. The effect of salt on dielectric parameters of NCPEs is also extracted from impedance spectroscopic data to explore underlying ion dynamics.

In-situ modification of ultrathin and uniform layer on LiCoO2 particles for 4.2 V poly(ethylene oxide) based solid-state lithium batteries with excellent cycle performance

Poly(ethylene oxide) based polymer electrolytes(PEO-SPEs) suffer from a narrow electrochemical window and deliver poor electrochemical performance when coupling with 4.2 V cathode. This severely limits the scope of its application. Here, a combination of physical stirring and electrochemistry is used to form an ultrathin and uniform cladding layer on the LiCoO2 particles. The results show that in addition to the decomposition of LiPO2F2 during the charge/discharge cycling, decomposition reactions occur during the stirring and drying process by X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM). This novel method effectively improves the electrochemical performance of 4.2 V PEO based solid-state lithium batteries. In particular, the cell shows excellent and stable electrochemical performance, exhibiting a discharge capacity of 112.0 mAh g−1 after 200 cycles, a capacity retention rate of 79.4% and a capacity decay rate of approximately 0.1% per cycle when the surface of LiCoO2 is coated with 2 wt% LiPO2F2. In comparison, the discharge capacity of the unmodified LiCoO2 cathode is found to be only 75.6 mAh g−1 after 100 cycles, with a poor capacity retention rate of 56.8%. Based on the basis of the above research, a new process was explored and also shows excellent interfacial stability by dispersing LiPO2F2 directly inside the binder which with a discharge capacity of 109.2 mAh g−1 and a capacity retention rate of 84.5% after 145 cycles. This novel approach opens up a new pathway for solving the problem of interfacial stability between PEO based polymer electrolytes and high-voltage cathode.

Fast Li-ion transport and uniform Li-ion flux enabled by a double–layered polymer electrolyte for high performance Li metal battery

Polymer–based lithium metal batteries are considered to be one of the most promising Li–based energy storage systems for portable devices and flexible technologies. However, low ionic conductivity of polymer electrolytes and poor compatibility in electrode–electrolyte interfaces restrict the wide applications of polymer–based lithium metal batteries. Here we report a novel polycarbonate–polyethylene oxide based polymer electrolyte with a double layered structure to achieve fast Li–ion conduction and uniform Li-ion flux. Comprehensive experiments and simulations show the ion-dipolar pair of [C=O...Li+] is the main reason for Li+ conduction, and the balances of coupling/decoupling in Li+…TFSI– and Li+…PAN/PVEC synergistically facilitate a fast Li+ transport on the cathode side, which results in high Li+ transference number (0.602) and high ionic conductivity (1.56 × 10–4 S cm–1, 20 °C) of DLPE. Besides, uniform Li+ flux in PEGDMA-SiO2-Pyr14TSFI achieves stable Li/electrolyte interface rich in LiF and Li3N on the anode side. Benefit from this design, the DLPE–based LiFePO4 and LiNi0.8Co0.1Mn0.1O2 battery deliver high safety and high stable performances under various extreme conditions.

Enhancing Li+ transport kinetics of PEO-based polymer electrolyte with mesoporous silica-derived fillers for lithium-ion batteries

Solid state batteries show great improvement of safety compared to batteries with liquid electrolytes. Polyethylene oxide (PEO) has been the most classic solid polymer electrolyte matrix. However, PEO based polymer electrolyte with lithium salt suffers from high crystallinity, poor Li+ transport kinetics and low ionic conductivity, especially at room temperature, which hindered its further application. Herein, a mesoporous silica derived active filler has been prepared with Li+ contained ionic liquid physically immobilized in the nanopore structure. PEO based solid polymer electrolyte with the active filler shows low crystallinity of 30% and a remarkable high ionic conductivity of 4.3 × 10−4 S cm−1 at 60 °C, at the same time maintaining a good mechanical strength of 1.28 MPa. The assembled lithium symmetric battery shows stable and long cycle performance. And the Li/LiFePO4 also shows stable cycling performance, maintaining 88.4% initial capacity after 80 cycles at 0.1C at 60 °C.

Effect of bismuth sulfide on the electrical properties of polyethylene oxide based polymer electrolyte

Effect of bismuth sulfide on the electrical properties of polyethylene oxide based polymer electrolyte

Dielectric Studies of [PEO: CH3COOLi]: Graphite System Synthesized by Hot Press and Solution Cast Technique

Present paper deals with the study of dielectric properties in polyethylene oxide (PEO)—based polymer electrolytes subsequent to dispersal of graphite filler particles synthesized by hot press and solution cast technique. The formation of nanocomposites and changes in the structural and microstructural properties of the materials were investigated by X-ray diffraction, Infrared measurements and optical microscopy. A decrease in crystanillity or increase in amorphousity was found to be more for solution cast film in comparison to hot press film. Electrical and thermal properties of PEO based polymer electrolyte film are found to be enhanced with the addition of graphite powder not only by solution cast method but also by hot press method. The conductivity for film prepared by solution cast method was found be in the range of 10−2 S/cm whereas for film prepared by hot press method the conductivity was found to be in the range of 10−4 S/cm at increasing temperature. The dielectric behavior is analyzed using the dielectric permittivity (e’ and e’’) and tangent loss (tan δ). It is found that the dielectric permittivity (e’ and e’’) rises sharply towards low frequencies and maxima of tangent loss shifts towards higher frequencies for both the films.

Effect of Zirconia Nano Filler for Enhancing Energy Capacity in Polyethylene Oxide Based Polymer Electrolyte

Lithium ion batteries have become a popular power source for portable electronic equipments. It is found to be superior in gravimetric energy density as it provides about 1.5 times more energy compared to nickel hydride battery. In this study, Polyethylene Oxide based polymer electrolytes were used for investigation. PEO based solid polymer electrolyte films were prepared by solution casting technique with different concentration of salt and different %wt of zirconia nanofiller. The X-ray diffraction analysis was carried out for the identification of compounds available in the sample and to determine the relative concentrations by the intensities of pattern lines. Also the superposition of absorption bands of specific functional groups was confirmed with the infra-red spectrum of FTIR. The Complex Impedance Spectroscopy technique was further used to measure the cell admittance / impedance in a wide range of frequencies and analyzed in the complex admittance/ impedance plane. From the impedance test results it is observed that the conductivity of polymer electrolyte was improved from 7.39×10−4 Scm−1 to 5.24×10−3 Scm−1 after adding 3%wt of ZrO2 nanofiller with pure polymer. Set up of nano Lab is rare, new and uncommon. It is also an emerging technology. Fabrication of powder needs extra machines which are not popular among common people. It will become popular in the coming future. When particle size is reduced, the quantity of powder is reduced, quality is increased.

Optimization of iodide ion conductivity and nano filler effect for efficiency enhancement in polyethylene oxide (PEO) based dye sensitized solar cells

Efficiency enhancement is achieved in dye sensitized solar cells (DSSCs) fabricated with polyethylene oxide (PEO) based gel electrolyte by optimizing the iodide ion conductivity using a binary iodide salt and TiO2 nanofiller. The binary iodide salt system consists of K+ as the small cation and Pr4N+ as the large cation. The correlation between the efficiency variation and the short circuit current density variation with salt composition suggests that the improved iodide ion conductivity of the electrolyte plays a dominant role in enhancing the solar cell performance. The highest DSSC efficiency of 4.12% is obtained for the electrolyte with salt composition 25 wt% Pr4N+I−: 75wt.% KI. The incorporation of 2.5 wt% TiO2 nano fillers into the polymer electrolyte further enhances the solar cell efficiency to 5.31%, very likely due to the increased ionic mobility caused by the increased amorphous phase content of the PEO based polymer electrolyte.

Lithium ion transport and ion–polymer interaction in PEO based polymer electrolyte plasticized with ionic liquid

The polyethylene oxide (PEO) based lithium ion conducting polymer electrolytes complexed with lithium trifluoromethanesulfonate (LiCF 3SO 3 or LiTf) plasticized with an ionic liquid 1-ethyl 3-methyl imidazolium trifluoromethanesulfonate (EMITf) have been reported. Morphological, spectroscopic, thermal and electrochemical investigations demonstrate promising characteristics of the polymer films, suitable as electrolyte in various energy storage/conversion devices. Significant structural changes have been observed in the polymer electrolyte due to the ionic liquid addition, investigated by X-ray diffraction (XRD) and optical microscopy. The ion-polymer interaction, particularly the interaction of imidazolium cation with PEO chains, has been evidenced by IR and Raman spectroscopic studies. The optimized composition of the polymer electrolyte i.e. PEO 25.LiTf + 40 wt.% EMITf offer room temperature ionic conductivity of ~ 3 × 10 − 4 S cm − 1 with wide electrochemical stability window and excellent thermal stability. The ‘σ versus 1/T’ curves show apparent Arrhenius behavior below and above melting temperature. The ionic conductivity has been observed due to Li + ions, as confirmed from 7Li-NMR studies, though the component ions of ionic liquid and anions also contribute significantly to the overall conductivity.

Electrical conductivity of solvent free PEO based polymer electrolytes

Films of polyethylene oxide (PEO) based polymer electrolyte were prepared by the technique of solution casting. Propylene carbonate (PC) was employed as the plasticiser and lithium trifluoromethanesulfonate (LiCF3SO3) was used as the doping salt. The highest room temperature conductivity achieved in PC plasticised system is 8·12 × 10–6 S cm–1. The effects of PC on the frequency dependent dielectric properties of PEO based electrolytes were also investigated by impedance spectroscopy, in the temperature range from 300 to 343 K. The relaxation time for the ionic charge carriers τ was obtained from the variation of loss tangent (tanδ) as a function of frequency at various temperatures for sample with highest conductivity value. The linear behaviour of temperature dependence of τ with regression value 0·91 could be described by Arrhenius law. The results of ac conductivity were discussed with existing theoretical models to elucidate the mechanism of conductance in the prepared electrolyte system.

Enhancement of Ionic Conductivity of PEO Based Polymer Electrolyte by the Addition of Nanosize Ceramic Powders

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.

Lithium-Polymer Electrolytes Based on Polyurethane Acrylate Prepared by a Solvent-Free Method

A solvent-free, cross-linked polymer electrolyte based on polyurethane acrylate (PUA) containing LiTFSI has been prepared and tested in an all-solid-state lithium-polymer battery It was found that the new polymer electrolyte could be directly membranous in the absence of any solvent and could be coated directly on a lithium foil or a composite cathode to form an ultrathin membrane of 10-50 μm. The PUA electrolyte membrane was thermally stable to 220°C at the system and had a higher ionic conductivity than a polyethylene oxide based polymer electrolyte below 60°C. The cell exhibited a high initial capacity (190 mAh/g), a charge-discharge efficiency of above 99%, and could be operated at 40°C. © 2004 The Electrochemical Society. All rights reserved.

Photoelectrochemical solar cells with polyacrylonitrile-based and polyethylene oxide-based polymer electrolytes

Two types of photolectrochemical (PEC) solar cells, FTO/TiO2/dye/PAN, EC, PC, Pr4N + I � ,I 2/Pt/FTO, and FTO/TiO2/dye/PEO, EC, PC, KI/I2/Pt/FTO have been fabricated using a PAN-based gel polymer electrolyte and a PEO-based plasticised polymer electrolyte. The PAN-based gel electrolyte, made of polyacrylonitrile (PAN), ethylene carbonate (EC), propylene carbonate (PC) and tetrapropylammoniumiodide (Pr4N + I � ) as the complexing salt exhibited a room temperature conductivity of 2.9 � 10 � 1 Sm � 1 for the composition, PAN (13%):EC (31%):PC (45%):Pr4N + I � (7%):I2 (4%) by weight ratio. The PEO-based polymer electrolyte had a conductivity of 2.2 � 10 � 3 Sc m � 1 for the composition PEO (37.5%):EC (37.5%):PC (20.7%):KI (3.9%):I2 (0.4%). These solar cells have been characterised using current–voltage characteristics and action spectra. The PAN-based solar cells had an overall quantum efficiency of 2.3%. However, the PEO-based solar cells had an overall quantum efficiency of only 0.6%. r 2004 Elsevier B.V. All rights reserved.

Lithium-ion-conductive polyethylene oxide based polymer electrolytes containing tris(pentafluorophyenyl)borane

For enhancement of lithium-ion transference number, lithium-ion-conductive polymer electrolytes have been prepared from polyethylene oxide (PEO), lithium salt of LiCF 3SO 3 or LiF, plasticizer of polyethylene glycol dimethylether (PEGDME), and anion receptor of tris(pentafluorophenyl)borane (TPFB). Transport properties of the resultant polymer electrolytes have been studied by AC impedance spectroscopy. As a result, lithium-ion transference number increased with increasing TPFB due to the restriction of anion conduction by the interaction between anion and anion receptor. Effects of anion receptor on transport properties are discussed.

Influence of water absorption on poly–ethylene oxide-based polymer electrolytes complexed with ammonium, sodium and magnesium perchlorates

The influence of water absorption on polyethylene oxide and its complexes with NH4ClO4, NaClO4 and Mg(ClO4)2 (for O/M=10 and 3) has been studied. A quantitative estimation of water absorption kinetics has been carried out. The changes in microstructure and thermal behaviour due to water absorption have been studied using X-ray diffraction and thermogravimetric/differential thermal analyses. The electrical conductivity of different films has been measured as a function of relative humidity and explained in terms of the generation of free mobile ions due to water absorption. © 1998 Chapman & Hall