Solid polymer electrolyte based on waterborne polyurethane for all‐solid‐state lithium ion batteries

A series of solid polymer electrolytes (SPEs) based on comb‐like nonionic waterborne polyurethane (NWPU) and LiClO₄ are fabricated via a solvent free process. The NWPU‐based SPEs have sufficient mechanical strength which is beneficial to their dimensional stability. Differential scanning calorimetry analysis indicates that the phase separation occurs by the addition of the lithium salt. Scanning electron microscopy and X‐ray diffraction analyses illustrate the good compatibility between LiClO₄ and NWPU. Fourier transform infrared study reveals the complicated interactions among lithium ions with the amide, carbonyl and ether groups in such SPEs. AC impedance spectroscopy shows the conductivity of the SPEs exhibiting a linear Arrhenius relationship with temperature. The ionic conductivity of the SPE with the mass content of 15% LiClO₄ (SPE15) can reach 5.44 × 10^?6 S cm^?1 at 40 °C and 2.35 ×10^?3 S cm^?1 at 140 °C. The SPE15 possesses a wide electrochemical stability window of 0–5 V (vs. Li+/Li) and thermal stability at 140 °C. The excellent properties of this new NWPU‐based SPE are a promising solid electrolyte candidate for all‐solid‐state lithium ion batteries. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45554.     

High performance electrospun PVdF‐HFP/SiO2 nanocomposite membrane electrolyte for Li‐ion capacitors

Electrospun poly[(vinylidene fluoride)‐co ‐hexafluoropropylene]/silica (PVdF‐HFP/SiO₂) nanocomposite polymer membranes (esCPMs) were prepared by incorporating different weight percentages of SiO₂ nanoparticles onto electrospun PVdF‐HFP by electrospinning technique. The surface morphology of electrospun PVdF‐HFP nanocomposite membranes was characterized by scanning electron microscopy. The effect of SiO₂ nanoparticles incorporation onto electrospun PVdF‐HFP polymer membranes (esPMs) has been studied by XRD, DSC, TGA, and tensile analysis. The electrospun PVdF‐HFP/SiO₂ based nanocomposite membrane electrolytes (esCPMEs) were prepared by soaking the corresponding esCPMs into 1 M LiPF₆ in EC:DMC (1:1 vol/vol %). The ionic conductivity of the esCPMEs was studied by AC‐impedance studies and it was found that the incorporation of SiO₂ nanoparticles into PVdF‐HFP membrane has improved the ionic conductivity from 1.320 × 10^?3 S cm^?1 to 2.259 × 10^?3 S cm^?1. The electrochemical stability of the esCPME was studied by linear sweep voltammetry studies and it was found to be 2.87 V. Finally, a prototype LiCo_0.2Mn_1.8O₄//C Li‐ion capacitor (LIC) cell was fabricated with esCPME, which delivered a discharge capacitance of 128 F g^?1 at the current density of 1 A g^?1 and retained 86% of its discharge capacitance even after 10,000 cycles. These results demonstrated that the esCPMEs could be used as promising polymer membrane electrolyte for LICs. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45177.     

Quaternized polysulfone‐based nanocomposite membranes and improved properties by intercalated layered double hydroxide

Two anions (dodecylbenzenesulfonate anion and stearate anion) are employed to synthesize intercalated layered double hydroxides (LDH) by co‐precipitation method. Then the intercalated LDHs are incorporated in the casting solutions of chloromethylated polysulfone (CMPSF) for fabricating quaternized polysulfone/LDH nanocomposite membranes. Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, scanning electron microscopy, and mastersizer laser particle size analysis are used to characterize the structure and morphology of LDHs and membranes. The properties of the composite membranes including water uptake, mechanical property, thermal stability, and ionic conductivity are investigated. Compared with other anion exchange membranes, both nanocomposite membranes containing 5% LDH sheets displayed better balanced performance. They exhibit the ionic conductivity of 3.58 × 10^?2 S cm^?1 and 3.86 × 10^?2 S cm^?1 at 60°C, respectively. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

Preparation and performance analysis of barium titanate incorporated in corn starch‐based polymer electrolytes for electric double layer capacitor application

Polymer electrolyte membranes composing of corn starch as host polymer, lithium perchlorate (LiClO₄) as salt, and barium titanate (BaTiO₃) as composite filler are prepared using solution casting technique. Ionic conductivity is enhanced on addition of BaTiO₃ by reducing the crystallinity and increasing the amorphous phase content of the polymer electrolyte. The highest ionic conductivity of 1.28 × 10^?2 S cm^?1 is obtained for 10 wt % BaTiO₃ filler in corn starch‐LiClO₄ polymer electrolytes at 75°C. Glass transition temperature (T_g) of polymer electrolytes decreases as the amount of BaTiO₃ filler is increased, as observed in differential scanning calorimetry analysis. Scanning electron microscopy and thermogravimetric analysis are employed to characterize surface morphological and thermal properties of BaTiO₃‐based composite polymer electrolytes. The electrochemical properties of the electric double‐layer capacitor fabricating using the highest ionic conductivity polymer electrolytes is investigated using cyclic voltammetry and charge‐discharge analysis. The discharge capacitance obtained is 16.22 F g^?1. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43275.     

Comparative study of gamma and ion beam irradiation of polymeric nanocomposite on electrical conductivity

Poly(vinyl alcohol) (PVA) was used to prepare nanocomposites of multi‐wall carbon nanotubes (MWCNT) and functionalized carbon nanotubes (MWCNT‐NH₂) in existence of 2‐carboxyethyl acrylate oligomers (CEA). Radiation‐induced crosslinking of the prepared matrix was carried out via gamma and ion beam irradiation. A comparative study of gamma and ion beam irradiation effect on the electrical conductivity of nanocomposite was conducted. The gelation of the gamma irradiated matrix outperforms the ion beam irradiated matrix. The order of gelation is PVA > (PVA/CEA) > (PVA/CEA)‐MWCNT > (PVA/CEA)‐MWCNT‐NH₂. There is a significant reduction in the swelling of the nanocomposite. The formation of nanocomposites was confirmed by scanning electron microscopy, energy‐dispersive X‐ray (EDX) and FTIR examinations. The direct current electrical properties of PVA/nanocomposites are examined at room temperature by applying electric voltage from 1 to 20 V. The results revealed that the electrical conductivity is increased by adding the carbon nanotubes and irradiation by gamma and ion beam. At an applied electric voltage 20 V, in the electrical conductivity of the unirradiated PVA was from 9.20 × 10^?8 S cm^?1. After adding MWCNT an increase up to 4.70 × 10^?5 S cm^?1 was observed. While after ion beam irradiation, a further increase up to 9.30 × 10^?5 S cm^?1 was noticed. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46146.     

New all solid‐state polymer electrolyte based on epoxy resin and ionic liquid for high temperature applications

Flexible epoxy network loaded with high amount of ionic liquid (IL) 1‐decyl‐3‐methylimidazolium bromide ([DMIM]Br) has been reported by using a mixture of polyol amine as curing agent. The IL presents good electrochemical response even at 170 °C, as no evidence of redox reactions was observed. The incorporation of as high as 50 wt % of this IL within the epoxy matrix resulted in solid and flexible electrolyte with good thermal stability below 180 °C, as measured by thermogravimetric analysis and ionic conductivity of around 10^?6 S cm^?1 at room temperature and higher than 10^?3 S cm^?1 at high temperature. This electrolyte presented a prodigious potential for applications in electrochemical devices at high temperature like batteries and supercapacitors, and the flexibility of this solid electrolyte persist at low temperature because of its low glass transition temperature. Furthermore, leakage problems were not observed. Thereby, impedance spectroscopy and cyclic voltammetry were performed to characterize the electrochemical properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45838.     

Synthesis and characterization of proton conducting polymer electrolyte based on poly(N‐vinyl pyrrolidone)

This work aims at developing and characterizing a proton conducting polymer electrolyte based on Poly(N‐vinyl pyrrolidone) (PVP) doped with ammonium bromide (NH₄Br). Proton conducting polymer electrolytes based on PVP doped NH₄Br in different molar ratios have been prepared by solution casting technique using distilled water as solvent. The XRD pattern confirms the dissociation of salt. The FTIR analysis confirms the complex formation between the polymer and the salt. The conductivity analysis shows that the polymer electrolyte with 25 mol % NH₄Br has the highest conductivity equal to 1.06 × 10^?3 S cm^?1 at room temperature. Also it has been observed that the activation energy evaluated from the Arrhenius plot is low (0.50 eV) for 25 mol % NH₄Br doped polymer electrolyte. The influence of salt concentration on dc conductivity and activation energy of the polymer electrolyte has been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Improved performance of solid polymer electrolytes for structural batteries utilizing plasticizing co‐solvents

This study describes the formulation, curing, and characterization of solid polymer electrolytes (SPE) based on plasticized poly(ethylene glycol)‐methacrylate, intended for use in structural batteries that utilizes carbon fibers as electrodes. The effect of crosslink density, salt concentration, and amount of plasticizer has been investigated. Adding a plasticizing solvent increases the overall performance of the SPE. Increased ionic conductivity and mechanical performance can be attained compared to similar systems without plasticizer. At ambient temperature, ionic conductivity (σ) of 3.3 × 10^?5 S cm^?1, with a corresponding storage modulus (E ′) of 20 MPa are reached. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44917.     

Study of hyperbranched poly(glycidol) sulfate electrolyte

Hyperbranched poly(glycidol) alkali sulfate (SHPG‐M) was prepared based on hyperbranched poly(glycidol). Polyurethane–hyperbranched poly(glycidol) (PU–SHPG‐M) sulfate electrolyte is a kind of single ionic or cationic conducting polymer electrolyte. Such a single ionic polymer electrolyte can obviously reduce the polarization and has little decay of direct current (DC) conductivity. SHPG‐M was characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM) and impedance analysis. The optimum conductivity is ～3 × 10^?6 S·cm^?1, with 30–40% SHPG‐M in the polymer electrolyte at room temperature. The species of cation greatly effects the ionic conductivity of the polymer electrolyte; that is, σ_SHPG‐Li > σ_SHPG‐Na > σ_SHPG‐K, with same SHPG‐M content in the polymer electrolyte. The ionic conductivity increases with an increase of temperature, and the dependence of ionic conductivity on temperature fits the Arrhenius equation well. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1185–1190, 2003     

Fabrication and characterization of PEO/PPC polymer electrolyte for lithium‐ion battery

A new poly(propylene carbonate)/poly(ethylene oxide) (PEO/PPC) polymer electrolytes (PEs) have been developed by solution‐casting technique using biodegradable PPC and PEO. The morphology, structure, and thermal properties of the PEO/PPC polymer electrolytes were investigated by scanning electron microscopy, X‐ray diffraction, and differential scanning calorimetry methods. The ionic conductivity and the electrochemical stability window of the PEO/PPC polymer electrolytes were also measured. The results showed that the T_g and the crystallinity of PEO decrease, and consequently, the ionic conductivity increases because of the addition of amorphous PPC. The PEO/50%PPC/10%LiClO₄ polymer electrolyte possesses good properties such as 6.83 × 10^?5 S cm^?1 of ionic conductivity at room temperature and 4.5 V of the electrochemical stability window. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Amelioration of electrochemical and photovoltaic performances on P(VP‐co‐VAc) based gel polymer electrolyte by incorporating double salt for dye‐sensitized solar cells

Dye‐sensitized solar cell (DSSC) is an alternative photovoltaic application used to replace the liquid electrolyte dependent conventional photovoltaic cell. In this research, gel polymer electrolyte (GPE) was used to replace the unstable liquid electrolyte. This GPE consists of poly[1‐vinylpyrrolidone‐co‐vinyl acetate] (P[VP‐co‐VAc]), tetrabutylammonium iodide (TBAI), sodium iodide (NaI), iodine (I₂), ethylene carbonate (EC), and propylene carbonate (PC). The GPE was tested for its ionic conductivity and an optimum level was reached at sample with 30% TBAI and 6% NaI at 1.17 × 10^?3 S cm^?1. The DSSC was then fabricated with all GPEs and a photovoltaic performance study was conducted. As a result, the highest photovoltaic conversion efficiency (PCE), η for a single salt was 3.04% for 40% TBAI. When a second salt is added, the system showed improvement in efficiency, η to 4.54% with short circuit current density, J_sc of 11.02 mA cm^?2 and open circuit voltage, V_oc of 0.67 V and FF of 61%. The other changes after the addition of TBAI and NaI salts have been observed through X‐ray diffraction, Fourier transformation and thermal analysis studies. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43805.     

Preparation and characterization of a solid polymer electrolyte PEO‐ENR50 (80/20)‐LiCF3SO3

The preparation and characterization of a polymer electrolyte films containing 80 wt % of poly (ethylene oxide) (PEO) and 20 wt % epoxidized natural rubber (ENR50) complexed with LiCF₃SO₃ has been reported. The ac impedance data showed good conducting properties of the solid polymer electrolyte (SPE) films. The greatest room temperature ionic conductivity of 7.5 × 10^?5 S cm^?1 was obtained at 25 wt % of LiCF₃SO₃ salt. This result has been supported by differential scanning calorimeter and X‐ray diffraction analysis. Analysis differential scanning calorimetry showed the relative percentage of crystallinity and T_m of PEO decreased with the increasing wt % of LiCF₃SO₃. Analysis with X‐ray diffraction suggested that the semicrystalline nature of PEO turned to amorphous due to the presence of LiCF₃SO₃. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Gel Polymer Electrolyte with Anion‐Trapping Boron Moieties via One‐Step Synthesis for Symmetrical Supercapacitors

A novel gel polymer electrolyte (GPE) which is based on new synthesized boron‐containing monomer, benzyl methacrylate, 1 m LiClO₄/N,N‐dimethylformamidel liquid electrolyte solution is prepared through a one‐step synthesis method. The boron‐containing GPE (B‐GPE) not only displays excellent mechanical behavior, favorable thermal stability, but also exhibits an outstanding ionic conductivity of 2.33 mS cm^?1 at room temperature owing to the presence of anion‐trapping boron sites. The lithium ion transference in this gel polymer film at ambient temperature is 0.60. Furthermore, the symmetrical supercapacitor which is fabricated with B‐GPE as electrolyte and reduced graphene oxide as electrode demonstrates a broad potential window of 2.3 V. The specific capacitance of symmetrical B‐GPE supercapacitors retains 90% after 3000 charge–discharge cycles at current density of 1 A g^?1.     

Polyvinylidene fluoride‐based novel polymer electrolytes for magnesium‐rechargeable batteries with Mg(CF3SO3)2

Magnesium trifluoromethanesulfonate (Mg (CF₃SO₃)₂)‐based polymer electrolytes (PEs) have been prepared with polyvinylidene fluoride (PVdF) as a host matrix. Tetraglyme and tetrabutyl ammonium chloride (TBACl) were used as plasticizer and filler, respectively, in the matrix by solution‐casting technique. The electrolyte containing 5 wt % TBACl exhibits the conductivity of 0.442 mS cm^?1 at ambient temperature. X‐ray diffraction study reveals the amorphous nature of the PE. Linear sweep voltammetry was also performed to evaluate the decomposition potential of the electrolyte. The morphological features were analyzed by scanning electron microscope. The activation energy has also been calculated, which corroborates the ionic conductivity results. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Lithium Ion-conducting Blend Polymer Electrolyte Based on PVA–PAN Doped with Lithium Nitrate

A new blend polymer electrolyte based on poly(vinyl alcohol) and polyacrylonitrile doped with lithium nitrate (LiNO₃) has been prepared and characterized. The complexation of blend polymer (92.5 PVA:7.5 PAN) with LiNO₃ has been studied using X-ray diffraction and Fourier transform infrared spectroscopy. Differential scanning calorimetry thermograms show a decrease in glass transition temperature with the addition of salt. The maximum ionic conductivity of the blend polymer electrolyte is 1.5 × 10^?3 Scm^?1 for 15 wt% LiNO₃ doped–92.5 PVA:7.5 PAN electrolyte. The conductivity values obey Arrhenius equation. Ionic transference number measurement reveals that the conducting species are predominantly ions.     

Synthesis and characterization of novel crosslinked polyurethane–acrylate electrolyte

Flexible, transparent, and crosslinked polymer films were synthesized by polymerization of PEG‐modified urethane acrylate using a simple method. A series of novel solid polymer electrolytes and gel electrolytes were prepared based on this type of polymer film. To understand the interactions among salt, solvent, and polymer, the swelling behaviors of the crosslinked polymer in pure propylene carbonate (PC) and liquid electrolyte solutions (LiClO₄/PC) were investigated. The results showed that the swelling rate in the electrolyte solution containing moderate LiClO₄ was greater than that in pure PC. Thermogravimetric analysis (TGA) also supported the interaction between the solvent and polymer. The morphology and crystallinity of the crosslinked polymer and polymer electrolytes were studied using atomic force microscopy (AFM) and wide‐angle X‐ray diffraction (WAXD) spectroscopy. The effects of the content of the electrolyte solution on the ionic conductivity of gel electrolytes were explored. The dependence of the conductivity on the amount of the electrolyte solution was nonlinear. With a different content of the plasticizer, the ionic conduction pathway of the polymer electrolytes would be changed. The best ionic conductivity of the gel electrolytes, which should have good mechanical properties, was 4 × 10^r?3 S cm^?1 at 25°C. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 340–348, 2003     

Development and Study of Solid Polymer Electrolyte Based on Polyvinyl Alcohol: Mg(ClO4)2

Magnesium ion-conducting solid polymer electrolytes consisting of polyvinyl alcohol with magnesium perchlorate (Mg(ClO₄)₂) as electrolytic salt have been developed and their experimental investigations are reported. The solid polymer electrolytes have been prepared by well-known solution casting method using double-distilled water as a solvent. The highest room temperature conductivity of the order of 10^?4 S cm^?1 was obtained for the solid polymer electrolyte with the composition 80?mol% polyvinyl alcohol:20?mol% Mg(ClO₄)₂. The pattern of the temperature-dependent conductivity shows Arrhenius behavior. The Fourier transform infrared spectroscopy analysis confirms the complex formation of the polymer with the salt. The X-ray diffraction results reveal that the crystalline phase of polymer host has completely changed on the addition of dopant. Differential scanning calorimetry studies show a decrease in melting temperature of the polyvinyl alcohol with the increasing dopant concentration. The real part of dielectric permittivity shows a strong dispersion at lower frequencies, which implies the space charge effects arising from the electrodes. The loss tangent spectrum reveals that the jumping probability per unit time decreases with the increasing salt concentration. The total ionic transference number measured has been found to be in the range of 0.92–0.94 for all the polymer electrolyte systems. The result reveals that the conducting species are predominantly ions. The solid polymer electrolyte with highest conductivity showed an electrochemical stability of 2?V. The results obtained by cyclic voltammetry on stainless steel/solid polymer electrolyte/stainless steel, Mg/solid polymer electrolyte/Mg symmetrical cells show evidence for reversibility.     

Effect of propylene carbonate on the ionic conductivity of polyacrylonitrile‐based solid polymer electrolytes

Solid polymer electrolyte membranes consisting of polyacrylonitrile (PAN) as a host polymer, ammonium nitrate (NH₄NO₃) as a complexing salt, and propylene carbonate (PC) as a plasticizer were prepared by a solution casting technique. An increase in the amorphous nature of the polymer electrolytes was confirmed by X‐ray diffraction analysis. A shift in the glass‐transition temperature of the PAN/NH₄NO₃/PC electrolytes was observed in the differential scanning calorimetry thermograms; this indicated interactions between the polymer and the salt. The impedance spectroscopy technique was used to study the mode of ion conduction in the plasticized polymer electrolyte. The highest ionic conductivity was found to be 7.48 × 10^?3 S/cm at 303 K for 80 mol % PAN, 20 mol % NH₄NO₃, and 0.02 mol % PC. The activation energy of the plasticized polymer electrolyte (80 mol % PAN/20 mol % NH₄NO₃/0.02 mol % PC) was found to be 0.08 eV; this was considerably lower than that of the film without the plasticizers. The dielectric behavior of the electrolyte is discussed in this article. A literature survey indicated that the synthesis and characterization of ammonium‐salt‐doped, proton‐conducting polymer electrolytes based on PAN has been rare. The use of the best composition membrane (80 mol % PAN/20 mol % NH₄NO₃/0.02 mol % PC) proton battery was constructed and evaluated. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41743.     

Effect of PBMA on PVC‐based polymer blend electrolytes

Poly(vinyl chloride) (PVC)—poly(butyl methacrylate) (PBMA) blended polymer electrolytes with lithium perchlorate (LiClO₄) as the complexing salts are prepared by solution casting technique. The addition of PBMA into PVC matrix is found to induce considerable changes in physical and electrical properties of the polymer electrolytes. Addition of PBMA into PVC matrix is found to increase the conductivity by two orders of magnitude (1.108 × 10^?5 S cm^?1) when compared with that of the pristine PVC polymer electrolyte (10^?7 S cm^?1). Structural, thermal, mechanical, morphological, and polymer–salt interactions are ascertained from X‐ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), mechanical analysis, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FTIR) respectively. A thermal stability upto 250 °C is asserted from the TG/DTA analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44939.