Poly Ethylene Oxide Polymer Electrolyte Research Articles

Review on Comparative Study of Solid Polymer Electrolyte Polyethylene Oxide (PEO) Doped with Ionic Liquid

AbstractFuture demands for energy shortages have prompted a lot of effort to be put into finding alternatives. The use of renewable energies as a revolutionary energy source has gained acceptance. Due to their high flexibility and the interaction between the electrode and the electrolyte, solid polymer electrolytes are employed as a favorable electrolyte for application of electrochemical devices to storage renewable energy. As these are easy in synthesis, have much lower mass density, shows high mechanical stability, also have low binding energy with salts, and high mobility of charge carriers, polyethylene Oxide (PEO) based electrolyte has attracted a lot of interest. Configuration rectification combining PEO with ionic liquids has been introduced to enhance the low ionic conductivity and poor thermodynamic stability of the PEO materials in high‐voltage devices at ambient temperature. This configuration modification can successfully validate the applications of PEO polymer electrolyte with large electro‐stable voltage ranges. Solution casting method has been used for the synthesis of polymer electrolyte. The essential physical characteristics of PEO in polymer matrices work as a polymer host in SPEs has been described in this review paper, along with several modifications to overcome these limitations. It has been seen that the addition of ionic liquid increases the all over conductivity of the solid polymer electrolyte in most cases also improves the electrical stability of the electrolyte.

Li1.3Al0.3Ti1.7(PO4)3 /PEO Polymer Double-Layer Electrolyte to Improve Electrochemical Properties of Li-CO2 Battery

Li−CO2 batteries are explored as promising power systems to alleviate environmental issues and to implement space applications. However, sluggish cathode kinetics of CO2 reduction/evolution result in low round-trip efficiency and poor cycling stability of the fabricated energy-storage devices.Herein, we design a double-layer solid electrolyte to decrease interfacial resistance. Li-CO2 battery with high stability and energy density was developed using Li1.3Al0.3Ti1.7(PO4)3 (LATP) as the solid-state electrolyte and a polyethylene oxide (PEO) polymer electrolyte film together. The oxide solid electrolyte LATP has temperature stability and physical solidity, but it has a metal substitution reaction with lithium metal and a low interfacial stability with the electrode. However, this drawback can be solved by using the polymer electrolyte PEO to avoid direct contact between the lithium metal electrode and LATP. The mechanism of the Li-CO2 battery, a carbon capture technology, is used, and the characteristics of the oxide solid electrolyte and polymer electrolyte are combined to suggest a new solution for improving the stability and performance of the battery.

A Hetero‐Layered, Mechanically Reinforced, Ultra‐Lightweight Composite Polymer Electrolyte for Wide‐Temperature‐Range, Solid‐State Sodium Batteries

AbstractThe practical use of polyethylene oxide polymer electrolyte in the solid‐state sodium metallic batteries (SSMBs) suffers from the retard Na+ diffusion at the room temperature, mechanical fragility as well as the oxidation tendency at high voltages. Herein, a hetero‐layered composite polymeric electrolyte (CPE) is proposed to enable the simultaneous interfacial stability with the high voltage cathodes (till 4.2 V) and Na metallic anode. Being incorporated within the polymer matrix, the sand‐milled Na3Zr2Si2PO12 nanofillers and nanocellulose scaffold collectively endow the thin‐layer (25 µm), ultralightweight (1.65 mg cm−2) CPE formation with an order of magnitude enhancement of the mechanical strength (13.84 MPa) and ionic conductivity (1.62 × 10−4 S cm−1) as compared to the pristine polymer electrolyte, more importantly, the improved dimension stability up to 180 °C. Upon the integration of the hetero‐layered CPE with the iron hexacyanoferrate FeHCF cathode (1 mAh cm−2) and the Na foil, the cell model can achieve the room‐temperature cycling stability (93.73% capacity retention for 200 cycles) as well as the high temperature tolerance till 80 °C, which inspires a quantum leap toward the surface‐wetting‐agent‐free, energy‐dense, wide‐temperature‐range SSMB prototyping.

Incorporating 2D γ-Al2O3 nanosheets into the flexible PEO-based solid electrolyte for lithium metal batteries

Solid polymer electrolytes using polyethylene oxide (PEO) are promising for boosting the safety of lithium metal batteries (LMBs), but suffer from low ionic conductivity due to high crystallinity and poor segment motion of PEO. Adding plasticizers like succinonitrile (SN) is one of the solutions to improve the ionic conductivity of PEO, but it sacrifices the cycle performances of LMBs. In addition, the ability to conduct lithium ions of PEO-SN matrixes is yet to be improved. Herein, two-dimensional γ-Al2O3 nanosheets are first introduced into the PEO-SN matrix to facilitate the long-range migration of lithium ions and improve the electrochemical properties of PEO-SN matrix, realizing the new design of traditional materials. The mechanism between γ-Al2O3 nanosheets and the polymer matrix is discussed. The addition of γ-Al2O3 nanosheets improves the ionic conductivities and cycle performances of PEO-LiTFSI-SN (PLS) electrolytes. In specific, the ionic conductivity at 25 °C of the PEO-LiTFSI-SN-Al2O3 nanosheet (PLS-A) electrolyte is up to 2.02 × 10−4 S cm−1. Meanwhile, the electrochemical properties of Li/PLS-A/LiFePO4 are tested, with a low overpotential change of 0.06 V, coulombic efficiency above 99.6%, and capacity retention of 95% at 0.5C and 60 °C after 50 cycles. The solid electrolyte system provides a feasible strategy for the application of 2D nanofillers in PEO polymer electrolytes.

Ultraviolet-cured polyethylene oxide-based composite electrolyte enabling stable cycling of lithium battery at low temperature

The room and low-temperature performances of solid-state lithium batteries are crucial to expand their practical application. Polyethylene oxide (PEO) has received great attention as the most representative polymer electrolyte matrix. However, most PEO-based solid-state batteries need to operate at high temperature due to low room temperature ionic conductivity. Improving the ionic conductivity by adding plasticizers or reducing the crystallinity of PEO often compromises its mechanical strength. Here, an amorphous PEO-based composite solid-state electrolyte is obtained by ultraviolet (UV) polymerizing PEO and methacryloyloxypropyltrimethoxy silane (KH570)-modified SiO2 which demonstrates both satisfactory mechanical performance and high ionic conductivity at room (3.37 × 10−4 S cm−1) and low temperatures (1.73 × 10−4 S cm−1 at 0 °C). In this electrolyte, the crystallinity of PEO is reduced through cross-linking, and therefore provides a fast Li+ ions transfer area. Moreover, the KH570-modified SiO2 inorganic particles promote the dissociation of lithium salts by Lewis acid centers to increase the ionic conductivity. Importantly, this kind of cross-linking networks endows the final electrolyte much higher mechanical strength than the pure PEO polymer electrolyte or PEO-inorganic filler blended systems. The solid-state LiFePO4/Li cell assembled with this electrolyte exhibits excellent cycling performance and high capacity at room and low temperatures.

Stabilizing Solid Electrolyte-Anode Interface in Li-Metal Batteries by Boron Nitride-Based Nanocomposite Coating

Summary Solid-state Li-metal batteries are promising to improve both safety and energy density compared to conventional Li-ion batteries. However, various high-performance and low-cost solid electrolytes are incompatible with Li, which is indispensable for enhancing energy density. Here, we utilize a chemically inert and mechanically robust boron nitride (BN) film as the interfacial protection to preclude the reduction of Li1.3Al0.3Ti1.7(PO4)3 (LATP) solid electrolyte by Li, which is validated by in situ transmission electron microscopy. When combined with ∼1–2 μm PEO polymer electrolyte at the Li/BN interface, Li/Li symmetric cells show a cycle life of over 500 h at 0.3 mA·cm−2. In contrast, the same configuration with bare LATP dies after 81 h. The LiFePO4/LATP/BN/PEO/Li solid-state batteries show high capacity retention of 96.6% after 500 cycles. This study offers a general strategy to protect solid electrolytes that are unstable against Li and opens possibilities for adopting them in solid-state Li-metal batteries.

Transport and Diffusion Properties in PEO-BaCl2 Polymer Electrolytes for Battery Applications

Barium chloride (BaCl2) doped polyethylene oxide (PEO) based solid polymer electrolyte (SPE) films are prepared using solution cast technique. Impedance analysis reveals that the ionic conductivity of pure PEO polymer enhances with frequency as well as BaCh concentrations, the maximum ac - ionic conductivity (1.09 × 10−4 Scm1) is observed at 10 wt% BaCl2 doped PEO polymer electrolyte films at high frequency. The temperature dependent conductivity studies were carried out for 10 wt% of BaCl2 concentration, here the maximum dc - ionic conductivity achieved is 1.44 × 10−2 Scm−1 at 333K temperature. From transport properties, it is observed that the transference number of ions in the polymer electrolyte system is 0.98 and electronic transference number are 0.019. Hence ions are the majority charge carriers than the electrons in BaCl2 doped PEO based solid polymer electrolytes. Diffusion coefficient study confirms the cations play a major role for the conduction mechanism with in the electrolyte system.

Influence of nanoparticle surface chemistry on ion transport in polymer nanocomposite electrolytes

Using atomistic molecular dynamics simulations, we study the ion diffusivities and conductivities of polyethylene oxide polymer electrolytes doped with LiBF4 salt and containing dispersed Al2O3 nanoparticles. We consider nanoparticles of two different surface chemistries: (a) containing acid rich surface sites (α‐Al2O3); (b) containing roughly equal acidic and basic surface sites (γ‐Al2O3). We compare the ionic diffusivities and conductivities of such systems with our earlier results [Mogurampelly et al. Macromolecules 2015, 48, 2773–2786] for systems containing basic surface sites on the nanoparticles (β‐Al2O3). In the presence of α‐Al2O3 and γ‐Al2O3 nanoparticles, we observe a monotonic decrease of ionic conductivities and mobilities with particle loading. These results are consistent with our earlier findings in the context of β‐Al2O3 nanoparticles. Our analysis identifies that the ionic mobilities and conductivities correlate with the combined effects of the changes in polymer segmental dynamics and the modifications in the local environment of ionic species arising from the introduction of nanoparticles.

Photovoltaic performance of curcumin as sensitizer in a solid-state solar cell

The sensitization of ZnO nanoparticles thin film with a natural substance curcumin and its use as photoanode in a solid-state dye-sensitized solar cell (SS-DSSC) employing TiO2 nanofiller modified polyethylene oxide (PEO) polymer electrolyte is reported. The diffuse reflectance spectrum (DRS) of the curcumin dye adsorbed ZnO thin film has exhibited a strong absorbance in the wavelength range of 380–520nm, indicating a good adsorption of curcumin dye molecules on the ZnO thin film surface. The photovoltaic performance of the SS-DSSC is evaluated under simulated solar light intensity of 600W/m2. The SS-DSSC with ZnO thin film electrode sensitized by curcumin has delivered a photocurrent density (Jsc) of 331×10−6Acm−2 and overall energy conversion efficiency (η) of 0.13%. The high charge transfer resistance exhibited by the solid-state PEO polymer electrolyte is responsible for the low Jscvalue of the cell. The stability of the SS-DSSC is proved through chronoamperometry study.

Effects of surfactant addition to polyethylene oxide polymer electrolytes in low and high concentrations

The effect of surfactant addition to polyethylene oxide (PEO) polymer electrolytes is studied. The initial goal of the research was to determine if a self-assembled monolayer (SAM) of surfactant molecules could be formed at the polymer interfaces through what we describe as the “blooming” method. In this method, the surfactant is added to the polymer solution before casting and the surfactant migrates to the surface, due to differences between bulk and surface free energies, during removal of the solvent as the film is formed. The surfactant used had the chemical formula of H–(–CH2–)32–(–CH2–CH2–O–)10–H where the hydrocarbon part of the molecule has the ability to self-assemble once they reach the surface of a PEO polymer electrolyte. These molecular surface layers stabilized the SEI layer formed between lithium metal and the polymer electrolyte. At a level of 8% by mass and above, there was significant interfacial stabilization. In addition to interface stabilization, it was found that the addition of the surfactant caused significant changes to the bulk of the polymer, yielding an order of magnitude higher conductivity in the bulk phase. The structure of the protective film at the surface was investigated by ATR-FTIR spectroscopy and AFM phase imaging.

Designing the 3D-microbattery geometry using the level-set method

Strategies for automatic design of power-optimized 3D-microbattery geometries are here investigated by utilization of the level-set method with structure topology optimization. The methodology is extended from solid mechanics to electrochemical systems, where battery operation is simulated using the Nernst–Planck equation. The calculations are carried out for the 3D-“trench” geometry with LiCoO2 and LiC6 as electrodes, separated with a LiPF6·PEO20 polyethylene oxide polymer electrolyte. With the goal to achieve a maximum uniform electrochemical activity over the electrode surface area, an optimized electrode design is produced by coating the current collectors non-uniformly with active material. This is shown to be an effect of the 3D design of the cell. Evaluation of the resulting optimized cell by simulations of the discharge process demonstrates uniform electrode material utilization and almost uniform current density distribution over the entire electrode–electrolyte interface. Comparisons between optimized and non-optimized geometries showed that the geometry optimization increased the cell performance up to 2.25 times. This effect is mainly achieved by minimizing the internal energy losses caused by non-uniformities in the ionic transport in the battery.

Study of nano-CdS prepared in methanolic solution and polymer electrolyte matrix

This present paper reports the study of cadmium sulphide (CdS) nanoparticles prepared under controlled condition in methanolic solution and also in polyethylene oxide polymer electrolyte matrix. The sulphurations of the cadmium salts were done in situ by a sodium sulphide solution. The concentration of the precursors has been controlled as detailed in the paper. All the preparation and characterization were carried out at room temperature. The nanoparticles were characterized by UV/Vis spectra in the range of 600 to 250 nm. The absence of bulk/micron size particles was noted in either of the system. The absorption edge near 510 nm indicates the presence of bulk CdS, whereas the presence of nanometer-sized particles is also reflected in low wavelength region. The sizes of the particles as well as particle distribution have been estimated using X-ray diffraction and scanning electron microscopy, respectively. A comparison in the spectra has been done for the sample prepared in either of the matrices. The particle size distribution in the polymeric matrix has been found to be more in comparison to that in the methanolic suspension. The polymer is reported to work as a binder, but not as a capping agent.

In situ production of CuS particles in polymer electrolyte matrix for mixed ion+electron conduction

Composites of polymer electrolyte polyethylene oxide (PEO) complexed with NH4ClO4, (PEO:NH4ClO4), having different weight ratios of dispersed semiconductor CuS (0–5 wt.%) have been prepared and characterized. The dispersal of CuS was achieved by its in situ formation in the viscous solution of polymer electrolyte (PEO:NH4ClO4) by sulfuration of CuSO4 using H2S. The band gap of CuS dispersed in the composites was found to be ~2.4 eV, which is higher than that of the bulk CuS for which it is 2.2 eV. Scanning electron microscopy studies show that the particle size varies from ~200 nm to several hundreds of nanometers. Polarization studies show that the semiconductor dispersed polymer composite so obtained has mixed ionic and electronic conduction. Detailed I–V studies show that the dispersoid is a p-type semiconductor.

Thermal and dielectric properties of PEO/EC/Pr4N+I− polymer electrolytes for possible applications in photo-electro chemical solar cells

The anion-conducting polymer electrolyte polyethylene oxide (PEO)/ethylene carbonate (EC)/Pr4N+I-/I-2 is a candidate material for fabricating photo-electrochemical (PEC) solar cells. Relatively high ionic conductivity values are obtained for the plasticized electrolytes; at room temperature, the conductivity increases from 7.6 x 10(-9) to 9.5 x 10(-5) S cm(-1) when the amount of EC plasticizer increases from 0% to 50% by weight. An abrupt conductivity enhancement occurs at the melting of the polymer; above the melting temperature, the conductivity can reach values of the order of 10(-3) S cm(-1). The melting temperature decreases from 66.1 to 45.1 A degrees C when the EC mass fraction is increased from 0% to 50%, and there is a corresponding reduction in the glass transition temperature from -57.6 to -70.9 A degrees C with the incorporation of the plasticizer. The static dielectric constant values, epsilon(s), increase with the mass fraction of plasticizer, from 3.3 for the unplasticized sample to 17.5 for the 50% EC sample. The dielectric results show only small traces of ion-pair relaxations, indicating that the amount of ion association is low. Thus, the iodide ion is well dissociated, and despite its large size and relatively low concentration in these samples, the iodide ion to ether oxygen ratio is 1:68, a relatively efficient charge carrier. A further enhancement of the ionic conductivity, especially at lower temperatures, is however desired for these applications.

Influence of silica aerogel on the properties of polyethylene oxide-based nanocomposite polymer electrolytes for lithium battery

In this study, a series of nanocomposite polymer electrolytes (NCPEs) with high conductivity and lithium ion transference number, PEO/LiClO 4/SAP, were prepared from high molecular weight polyethylene oxide (PEO), LiClO 4 and low content of homemade silica aerogel powder (SAP), which had higher surface area and pore volume than the conventional silica particle. From the SEM images it was found that the SAP nanoparticles were well dispersed in the PEO polymer electrolyte matrix. The characterization and interactions in the CPEs were studied by DSC, XRD, FT-IR and 7Li NMR analysis. The ac impedance results showed that the ionic conductivity of the CPE was significantly improved by the addition of the as-prepared SAP. The maximum ambient ionic conductivity obtained from the CPE with EO/Li = 6 and 2 wt.% of SAP (O6A2) was about threefold higher than that of the corresponding polymer electrolyte without SAP (O6). In addition, the lithium ion transference number ( t +) of O6A2 at 70 °C was as high as 0.67, which was also three times higher than that of O6 and has not been previously reported for the PEO–LiX-based polymer electrolytes.

Studies on semiconductor dispersed polymer electrolyte composite (PEO:NH4ClO4 + Bi2S3)

AbstractPolymer composites consisting of different amounts (0–10 wt%) of dispersed semiconducting Bi2S3 in the polymer electrolyte polyethylene oxide complexed with NH4ClO4 (PEO:NH4ClO4 + Bi2S3) have been prepared and characterized. The dispersal of Bi2S3 was achieved by its “in‐situ” formation in the polymeric solution by sulfuration of Bismuth nitrate by bubbling H2S. The dispersed Bi2S3 particles were found to be nano‐sized (∼20 nm) resulting in a higher band gap (∼1.8 eV) as compared to that of bulk Bi2S3 (∼1.4 eV). Detailed I –V and polarization studies show that the dispersed Bi2S3 is n‐type and a small (≤8%) electronic conductivity is introduced into the purely ionic (PEO:NH4ClO4) film making it a mixed ion + electron conducting polymer composite. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Optical and Electrical Properties of Pure and Doped PEO Polymer Electrolyte Films

A sodium ion conducting polymer electrolyte based on polyethylene oxide (PEO) complexed with NaFeF4 was prepared using solution cast technique. The complexation of the salt with PEO was confirmed by X‐ray diffraction (XRD) and infared spectroscopic (FTIR) studies. Optical absorption studies were made in the wavelength range 200–600 nm on pure and NaFeF4 doped PEO film. The absorption edge was observed at 4.62 eV for undoped PEO while it ranged from 3.86 to 3.61 eV for NaFeF4 doped films. The direct band gaps for undoped and NaLaF4 doped PEO films were found to be, respectively, 4.54 and 3.74, 3.63 and 3.54 eV while the indirect band gaps were 4.43 and 3.52, 3.38 and 3.26 eV, respectively. It was found that the energy gaps and band edge values shifted to lower energies on doping with NaFeF4 salt. Electrical measurements were made in the temperature range 300–370 K as a function of dopant concentration. The nature of charge transport in this system was determined using Wagner's polarization technique and was found to be predominantly due to ions.

Structural, electrical and optical properties of pure and NaLaF4 doped PEO polymer electrolyte films

A Sodium ion conducting polymer electrolyte based on Polyethylene oxide (PEO) complexed with Sodium lanthanum tetra fluoride (NaLaF4) was prepared using solution cast technique. The complexation of the salt with PEO was confirmed by X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopic (FTIR) studies. Differential Scanning Calorimetry (DSC) is carried out to determine the melting temperature of these electrolyte films. Electrical conductivity was measured in the temperature range 300–370 K as a function of dopant concentration as well as temperature. Optical absorption studies were made in the wavelength range 200–600 nm on pure and NaLaF4 doped PEO film. The absorption edge was observed at 4.62 eV for undoped PEO while it ranged from 3.16 to 3.5 eV for NaLaF4 doped films. The direct band gaps for undoped and NaLaF4 doped PEO films were found to be, respectively, 4.54 and 3.44, 3.24 and 3.12 eV while the indirect band gaps were 4.43 and 3.25, 3.05 and 2.9 eV, respectively. It was found that the energy gaps and band edge values shifted to lower energies on doping with NaLaF4 salt.

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.

Structural and transport characteristics of polyethylene oxide/phenolic resin blend solid polymer electrolytes

AbstractDetails on the structure and transport characteristics of the solid polymer electrolyte polyethylene oxide (PEO)/lithium salt (LiClO4) modified by novolac phenolic resin are presented here. From IR spectra it could be concluded that complex formation occurred through multiple interactions between the ether oxygen of PEO–lithium, phenolic lithium, and the phenolic ether oxygen of PEO. The free hydroxyl band in phenolic reflected that phenolic closely interacted with both the PEO polymer and ionic salt. With increasing salt content in PEO, the vibration band corresponding to the ClO anion (∼623 cm−1) displayed growth of a shoulder at ∼635 cm−1, suggesting the formation of Li+…ClO4− ion pairing. However, in the presence of phenolic, ion‐pairing formation was effectively suppressed, which suggested that the phenolic moiety facilitated a greater degree of LiClO4 salt dissociation. Activation energy analysis revealed two conducting pathways: one through the amorphous PEO and the other through the PEO/phenolic amorphous matrix. The high ion conductivity originated from effective salt dissociation and the establishment of a new conduction network formed by PEO and phenolic. Furthermore, the structural modification also extended the thermal stability and mechanical strength of the solid polymer electrolyte composite. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3866–3875, 2004