Preparation and ionic conductivity of solid polymer electrolyte based on polyacrylonitrile‐polyethylene oxide

The transparent and flexible solid polymer electrolytes (SPEs) were fabricated from polyacrylonitrile‐polyethylene oxide (PAN‐PEO) copolymer which was synthesized by methacrylate‐headed PEO macromonomer and acrylonitrile. The formation of copolymer is confirmed by Fourier‐transform infrared spectroscopy (FTIR) measurements. The ionic conductivity was measured by alternating current (AC) impedance spectroscopy. Ionic conductivity of PAN‐PEO‐LiClO₄ complexes was investigated with various salt concentration, temperatures and molecular weight of PEO (Mn). And the maximum ionic conductivity at room temperature was measured to be 3.54 × 10^?4 S/cm with an [Li⁺]/[EO] mole ratio of about 0.1. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 461–464, 2006     

Morphological,infrared, and ionic conductivity studies of poly(ethylene oxide)–49% poly(methyl methacrylate) grafted natural rubber–lithium perchlorate salt based solid polymer electrolytes

The potential of poly(ethylene oxide) (PEO) and 49% poly(methyl methacrylate) grafted natural rubber (MG49) as a polymer host in solid polymer electrolytes (SPE) was explored for electrochemical applications. PEO–MG49 SPEs with various weight percentages of lithium perchlorate salt (LiClO₄) was prepared with the solution casting technique. Characterization by scanning electron microscopy, Fourier transform infrared spectroscopy, and impedance spectroscopy was done to investigate the effect of LiClO₄ on the morphological properties, chemical interaction, and ionic conductivity behavior of PEO–MG49. Scanning electron microscopy analysis showed that the surface morphology of the sample underwent a change from rough to smooth with the addition of lithium salts. Infrared analysis showed that the interaction occurred in the polymer host between the oxygen atom from the ether group (C? O? C) and the Li⁺ cation from doping salts. The ionic conductivity value increased with the addition of salts because of the increase in charge carrier up to the optimum value. The highest ionic conductivity obtained was 8.0 × 10^?6 S/cm at 15 wt % LiClO₄. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effect of silicone dioxide and poly(ethylene glycol) on the conductivity and relaxation dynamics of poly(ethylene oxide)–silver triflate solid polymer electrolyte

The conducting and relaxation dynamics of Ag⁺ ions in poly(ethylene oxide) (PEO)–silver triflate (AgCF₃SO₃) solid polymer electrolytes (SPEs) containing nanosize SiO₂ filler and poly(ethylene glycol) (PEG) as a plasticizer were studied in the frequency range 10 Hz to 10 MHz and in the temperature range 303–328 K. The comparatively lower conductivity of the plasticized (PEG) PEO–AgCF₃SO₃–SiO₂ nanocomposite electrolyte system was examined by analysis of the Fourier transform infrared (FTIR) spectroscopy and conductivity data. The electric modulus (M″) properties of the SPE systems were investigated. A shift of the M″ peak spectra with frequency was found to depend on the translation ion dynamics and the conductivity relaxation of the mobile ions. The value of the conductivity relaxation time was observed to be lower for the PEO–AgCF₃SO₃ system only with nanofiller SiO₂. The scaling behavior of the M″ spectra showed that the dynamical relaxation processes was temperature-independent in the PEO–AgCF₃SO₃ and PEO–AgCF₃SO₃–SiO₂–PEG polymer systems, whereas they were temperature-dependent for the PEO–AgCF₃SO₃–SiO₂ system. However, the relaxation processes of all of theses systems were found to be dependent on their respective compositions. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Nanocomposite polymer electrolytes for solid-state lithium-ion batteries with enhanced electrochemical properties

Solid-state polymer electrolytes (SPEs) have attracted significant attention owing to their improvement in high energy density and high safety performance. However, the low lithium-ion conductivity of SPEs at room temperature restricts their further application in lithium-ion batteries (LIBs). Herein, we propose a novel poly (ethylene oxide) (PEO)-based nanocomposite polymer electrolytes by blending boron-containing nanoparticles (BNs) in the PEO matrix (abbreviated as: PEO/BNs NPEs). The boron atom of BNs is sp²-hybridized and contains an empty p-orbital that can interact with the anion of lithium salt, promoting the dissociation of the lithium salts. In addition, the introduction of the BNs could reduce the crystallinity of PEO. And thus, the ionic conductivity of PEO/BNs NPEs could reach as high as 1.19 × 10⁻³ S cm⁻¹ at 60°C. Compared to the pure PEO solid polymer electrolyte (PEO SPEs), the PEO/BNs NPEs showed a wider electrochemical window (5.5 V) and larger lithium-ion migration number (0.43). In addition, the cells assembled with PEO/BNs NPEs exhibited good cycle performance with an initial discharge capacity of 142.5 mA h g⁻¹ and capacity retention of 87.7% after 200 cycles at 2 C (60°C).     

Synthesis of high molecular weight polyoxyethylene with a quaternary catalyst and study of its conductive blends with poly(2‐vinyl pyridine)

High molecular weight polyoxyethylene (PEO) was synthesized by using a quaternary catalyst composed of triisobutyl aluminum, phosphoric acid, water, and N,N‐dimethylaniline (DMA). Optimum synthesis conditions and some properties of the product were studied. This catalyst showed high activity and the molecular weight of the polyoxyethylene obtained can approach one million. The activity of polymerization mainly depends upon the composition of catalyst. The optimum composition is as follows: i‐Bu₃Al:H₃PO₄:H₂O:DMA = 1 : 0.17 : 0.17 : 0.10–0.15 (molar ratio).The active centers of the catalyst was thus proposed. The high molecular weight PEO synthesized by this catalyst was blended with poly(2‐vinyl pyridine) (PVP) and then doped with LiClO₄ and TCNQ to obtain a conductive elastomeric material. Ionic, electronic, and mixed (ionic–electronic) conductivities of blends were investigated. At a Li/EO molar ratio of 0.1 and a TCNQ/VP molar ratio of 0.5, the mixed conductivity of the blend of PEO/PVP/LiCIO₄/TCNQ is higher than the sum of ionic conductivity of PEO/PVP/LiCIO₄ and electronic conductivity of PEO/PVP/TCNQ, when the weight ratio of PEO to PVP is 6/4 or 5/5. It can reach 4 × 10^?6 S/cm at room temperature. Differential scanning calorimetry, thermal gravimetric analysis, and the appearance of the blend showed that both TCNQ and LiClO₄ can complex with PEO and PVP, thus enhancing the compatibility between PEO and PVP. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Nanocomposite solid polymer electrolytes based on polyethylene oxide,modified nanoclay,and tetraethylammonium tetrafluoroborate for application in solid‐state supercapacitor

Nanocomposite solid polymer electrolytes (SPEs) have been prepared from polyethylene oxide (PEO), organically modified nanoclay (MNclay), and tetraethylammonium tetrafluoroborate (TEABF₄) salt. The concentration of the salt has been varied in the respective SPE, wherein PEO/MNclay ratio was kept constant. It has been proposed that three types of complex formation could be operative in the SPEs due to the interactions among PEO, MNclay, and the salt. The complex formation mechanism has been postulated on the basis of X‐ray diffraction (XRD) analysis, transmission electron microscopic (TEM) observation, differential scanning calorimetric (DSC) analysis, and polarized optical microscopic (POM) observation. ‘Complex 1’ and ‘complex 3’ formation could be involved in the crystalline phase as indicated by DSC and XRD analyses, whereas ‘complex 2’ formation might be restricted in the amorphous phase as suggested by TEM observation. The ionic conductivity of the SPEs has been correlated with the results obtained from XRD, DSC, and POM analyses. The formation of complex 1 and complex 2 could be responsible for the increase in the ionic conductivity, whereas complex 3 formation might decrease the ionic conductivity. An activated carbon‐based supercapacitor has been fabricated using SPEs and characterized by cyclic voltammetry, galvanostatic ‘charge–discharge’ behavior, and impedance spectroscopic analysis. POLYM. ENG. SCI., 55:1536–1545, 2015. © 2015 Society of Plastics Engineers     

Hyperbranched Poly(Glycidol)-Grafted Silica Nanoparticles for Enhancing Li-Ion Conductivity of Poly(Ethylene Oxide)

Silica nanoparticles bearing hyperbranched polyglycidol (hbP) grafts are synthesized and blended with poly(ethylene oxide) (PEO) for the fabrication of composite solid polymer electrolytes (SPEs) for enhancing Li-ion conductivity. Different batches of hbPs are prepared, namely, the 5th, 6th, and 7th with increasing molecular weights using cationic ring-opening polymerization and grafted the hbPs onto the silica nanoparticles using quaternization reaction. The effect of end functionalization of hbP-grafted silica nanoparticles with a nitrile functional group (CN–hbP–SiO₂) on the ionic conductivity of the blends with PEO is further studied. High dipole moments indicate polar nature of nitriles and show high dielectric constants. Among all the hbPs, the 6th-batch CN–hbP–SiO₂ nanoparticles exhibit better ionic conductivity on blending with PEO showing ionic conductivity of 2.3 × 10⁻³ S cm⁻¹ at 80 °C. The blends show electrochemical stability up to 4.5 V versus lithium metal.     

Influence of molar mass on the thermal properties,conductivity and intermolecular interaction of poly(ethylene oxide) solid polymer electrolytes

The sample preparation pathway of solid polymer electrolytes (SPEs ) influences their thermal properties, which in turn governs the ionic conductivity of the materials especially for systems consisting of a crystallizable constituent. Majority of poly(ethylene oxide) (PEO)‐based SPEs with molar masses of PEO well above 10⁴ g mol^?1 (where PEO is crystallizable and should reach an asymptote in thermal behaviour) display molar mass dependence of the thermal properties and ionic conductivities in non‐equilibrium conditions, as reported in the literature. In this study, PEO of different viscosity‐molar masses (M _η = 3 × 10⁵, 6 × 10⁵, 1 × 10⁶, 4 × 10⁶ g mol^?1) and LiClO₄ salt (0 to 16.7 wt%) were used. The SPEs were thermally treated under inert atmosphere above the melting temperature of PEO and then cooled down for subsequent isothermal crystallization for sufficient experimental time to develop morphology close to equilibrium conditions. The thermal properties (e.g. glass transition temperature, melting temperature, crystallinity) according to differential scanning calorimetry and the ionic conductivity obtained from impedance spectroscopy at room temperature (σ _DC ～ 10^?6 S cm^?1) demonstrate insignificant variation with respect to the molar mass of PEO at constant salt concentration. These findings are in agreement with the PEO crystalline structures using X‐ray diffraction and ion ? dipole interaction by Fourier transform infrared results. © 2017 Society of Chemical Industry     

Composite alkaline polymer electrolytes and its application to nickel-metal hydride batteries

In order to enhance the ionic conductivity of polyethylene oxide (PEO)-KOH based alkaline polymer electrolytes, three types of nano-powders, i.e., TiO₂, β-Al₂O₃ and SiO₂ were added to PEO-KOH complex, respectively, and the corresponding composite alkaline polymer electrolytes were prepared. The experimental results showed that the prepared polymer electrolytes exhibited higher ionic conductivities at room temperature, typically 10⁻³ S cm⁻¹ as measured by ac impedance method, and good electrochemical stability. The electrochemical stability window of ca. 1.6 V was determined by cyclic voltammetry with stainless steel blocking electrodes. The influence of the film composition such as KOH, H₂O and nano-additives on ion conductivity was investigated and explained. The temperature dependence of conductivity was also determined. In addition, polyvinyl alcohol (PVA)-sodium carboxymethyl cellulose (CMC)-KOH alkaline polymer electrolytes were obtained using solvent casting method. The properties of the polymer electrolytes were characterized by ac impedance, cyclic voltammetry and differential thermal analysis methods. The ionic conductivity of the prepared PVA-CMC-KOH-H₂O electrolytes can reach the order of 10⁻² S cm⁻¹. The effect of CMC addition on the alkaline polymer electrolytes was also explained. The experimental results demonstrated that the PVA-CMC-KOH-H₂O polymer electrolyte could be used in Ni/MH battery.     

Preparation of porous carbons from petroleum coke by different activation methods

Porous carbons were prepared from Shengli petroleum coke (SPC) and Minxi petroleum coke (MPC) by different activation methods with H₂O, KOH and/or KOH+H₂O as active agents. The porous carbons were characterized by nitrogen adsorption at 77 K. It has been found that activation method and component of petroleum coke, of which different kinds of transitional metals on petroleum coke are crucial for preparing high quality porous carbons. Under the identical experimental conditions, the co-activation with KOH and H₂O as active agents in the same activation process, which has been rarely reported in literature, is the easiest method for the preparation of porous carbons with high surface area. The sequence of active agents in terms of difficulty in the preparation of porous carbons with high surface area is as follows: KOH+H₂O>KOH>H₂O. A drawback of KOH+H₂O activation in the preparation of porous carbon in this work is found to be its low carbon yield in comparison to KOH activation. Compared with the SPC coke, the MPC coke with higher contents of transitional metal and carbon and lower content of nitrogen is more suitable for making high surface area porous carbons, which is believed to be mainly due to the difference in the contents of transitional metals. Porous carbon with surface area around 2500–3000 m²/g and carbon yield about 25–30% has been obtained from MPC coke by KOH+H₂O activation with less KOH and shorter activation time in comparison to the traditional methods.     

Preparation of core–shell particles by dispersion polymerization with a poly(ethylene oxide) macroazoinitiator

A macroazoinitiator (MAI) containing a poly(ethylene oxide) (PEO) block was used with a methyl methacrylate monomer to prepare polymer particles in ethanol/H₂O solutions. The effects of the monomer/MAI ratio (RMI) and H₂O content in the solutions on the molecular weight, particle diameters, and chemical structure of the resulting polymer particles were investigated. The reaction mixtures showed three kinds of states, which were milky colloid solutions, macrogels and/or precipitations, and clear solutions. The colloid solutions were obtained in the solutions with an H₂O content of about 50–90 vol % and a RMI of 20–400. In the colloid solutions, core–shell nanospheres consisting of PEO shells and poly(methyl methacrylate) (PMMA) cores were predominantly obtained. In the specific conditions close to the area of gel and/or precipitation formation, particles connected about 0.5–5 μm in length were obtained. Multiblock copolymers nanospheres tended to be obtained with lower RMIs, and PMMA‐PEO‐PMMA tri‐bloc and/or PMMA‐PEO di‐block copolymer nanospheres were obtained with higher RMIs. The solubility of the monomer and the generated polymer in solutions may have affected the polymerization development and the state of the products. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Influences of Bentonite on conductivity of composite solid alkaline polymer electrolyte PVA-Bentonite-KOH-H2O

The influence of the dopant Bentonite, on the ionic conductivity of the PVA-KOH-H₂O alkaline solid polymer electrolyte (ASPE) is studied. The results show that the addition of Bentonite has both positive and negative effects on the ionic conductivity of ASPE. At lower KOH and H₂O contents, the addition of Bentonite can break the continuous ion conducting phase of the ASPE, and therefore decrease the ASPE conductivity. However, the addition of Bentonite can also increase the KOH content in PVA matrix. This greatly increases the conductivity of the ASPE especially at higher water content. A highest ionic conductivity of 0.11 S cm⁻¹ is reached at room temperature. A maximum ionic conductivity value is observed at relative lower water content for different amount of Bentonite-doped ASPE. The temperature dependence of the ionic conductivity is of the Arrhenius type. The ion transfer activation energy Ea, in the order of 4-6 kJ mol⁻¹, heavily depends on the Bentonite content. XRD and SEM tests show that PVA in the Bentonite-doped ASPE is of amorphous structure, and there are lots of interspaces in the composite ASPE inner structure. The composite electrolyte has good electrochemical stability window and good charged-discharge property in secondary Zn-Ni cells at low charge-discharge rate.     

Lithium sulfonated styrene oligomer (LiSSO) as a new class of lithium salt for polymer electrolytes

Summary   A new class of lithium salt with single-ionic characteristics, lithium sulfonated styrene oligomer (LiSSO) [(CH₂CHC₆H₅)₇-(CH₂CHC₆H₄SO₃ ⁻Li⁺)₂], was synthesized and its complex with poly(ethylene oxide) (PEO) was prepared. The maximum ionic conductivity of the PEO/LiSSO complex at 65°C was 2.1×10⁻⁴S/cm at a salt concentration of [Li⁺]/[EO] = 0.20. The lithium cationic transference number (t ₊) of the PEO/LiSSO complex was found to be 0.95, and the polymer electrolyte was electrochemically stable up to 6.2V. Received: 2 April 2001/Revised version: 30 July 2001/Accepted: 30 July 2001     

Influences of doping approach on conductivity of composite alkaline solid polymer electrolyte PVA–HA–KOH–H2O

Hydroxyapatite (HA) was selected as dopant and synthesized by a sonochemical method in this study. PVA–HA–KOH–H₂O composite alkaline solid polymer electrolyte (ASPE) was prepared by solution casting method. Two different doping routes, i.e., the physical mixing (PM) and in situ synthesis (ISS) were considered. The influences of the ASPE composition such as HA content, KOH content and water content on the conductivity were investigated. The ASPE prepared by ISS route has a porous structure which is important for ion transfer. Accordingly, the conductivity of the ASPE prepared by ISS is higher than that of by PM. A highest conductivity of about 0.1 S/cm is reached for ASPE prepared by ISS route at 70% water content for m(PVA):m(KOH):m(HA) = 10:14:10 system, higher than that of by PM route, 0.08 S/cm. The nickel/zinc cell shows better electrochemical properties assembled with the ASPE prepared by ISS approach than by PM approach.     

A novel CuI-based iodine-free gel electrolyte for dye-sensitized solar cells

A novel CuI-based iodine-free gel electrolyte using polyethylene oxide (PEO, MW = 100,000) as plasticizer and lithium perchlorate (LiClO₄) as salt additive was developed for dye-sensitized solar cells (DSSCs). Such CuI-based gel electrolyte can avoid the problems caused by liquid iodine electrolyte and has relative high conductivity and stability. The effects of PEO and LiClO₄ concentrations on the viscosity and ionic conductivity of the mentioned iodine-free electrolyte, as well as the performance of the corresponding quasi solid-state DSSCs were investigated comparatively. Experimental results indicate that the performance of DSSCs can be dramatically improved by adding LiClO₄ and PEO, and there are interactions (Li⁺–O coordination) between LiClO₄ and PEO, these Li⁺–O coordination interactions have important influence on the structure, morphology and ionic conductivity of the present CuI-based electrolyte. Addition of PEO into the electrolyte can inhibit the rapid crystal growth of CuI, and enhance the ion and hole transportation property owing to its long helix chain structure. The optimal efficiency (2.81%) was obtained for the quasi solid-state DSSC fabricated with CuI-based electrolyte containing 3 wt% LiClO₄ and 20 wt% PEO under AM 1.5 G (1 sun) light illumination, with a 116.2% improvement in the efficiency compared with the cell without addition of LiClO₄, indicating the promising application in solar cells of the present CuI-based iodine-free electrolyte.     

Effects of solvents on thermoelectric performance of PANi/PEDOT/PSS composite films

Organic thermoelectric materials based on conducting polymers, especially for polyaniline (PANi) and poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), have attracted great concern due to their tunable electron transport properties by controlling doping level. Here, the solvent effects of deionized H₂O and NH₃·H₂O were investigated on the electrical conductivity and Seebeck coefficient of PANi/PEDOT/PSS composite films. The introduction of PEDOT/PSS can not only effectively improve the quality of pure PANi film, but also enhance the electrical conductivity of PANi film. The different volumes of deionized H₂O as dilution have a great influence on the electrical conductivity of PANi/PEDOT/PSS composite thin film with a maximum electrical conductivity value of 63.5 S cm^?1, which is much higher than pure PANi and pristine PEDOT/PSS. The introduction of NH₃·H₂O shows a positive effect on Seebeck coefficient with a large decline on electrical conductivity of PANi/PEDOT/PSS. The Raman spectroscopy, scanning electron microscopy (SEM), and UV-vis spectroscopy were used to obtain the morphology and structure information of PANi/PEDOT/PSS.     

Effects of the electrolyte content on the electrical permittivity,thermal stability,and optical dispersion of poly(vinyl alcohol)–cesium copper oxide–lithium perchlorate nanocomposite solid‐polymer electrolytes

Solid‐polymer electrolytes (SPEs) in the form of poly(vinyl alcohol) (PVA) doped with various amounts (5, 10, and 15 wt %) of lithium perchlorate trihydrate (LiClO₄·3H₂O) and 2 wt % cesium copper oxide (Cs₂CuO₂) nanoparticles were fabricated by a solvent intercalation method. The obtained nanocomposites were evaluated for their chemical structure and microstructural and morphological behaviors via Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy methods, respectively. The obtained dielectric behaviors, alternating‐current conductivity, dielectric modulus, and dielectric relaxation of the SPEs depended on the volume fraction of the electrolyte. Linear behavior of the current–voltage characteristics for all of the SPE films was observed with a slight deviation at a higher voltage. The thermal behaviors of the PVA–Cs₂CuO₂–LiClO₄ films were evaluated by differential scanning calorimetry and thermogravimetric analysis. The refractive index, band‐gap energy, and optical dispersion were examined with UV–visible spectroscopy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45852.     

Aggregate formation in poly(ethylene oxide) solutions

Static light scattering and viscosity measurements were performed on different molecular weight poly (ethylene oxide) to see the formation of aggregates in its dilute solutions. Viscosity measurements were carried out for PEO samples in water and methanol at 20–45°C and in chloroform at 20–30°C. Using Huggin's equation, the viscosity plots showed distinct upward curvature indicating the presence of aggregates in both PEO/H₂O and PEO/CH₃OH solutions The [η] values for PEO/H₂O and PEO/CH₃OH system were 2–4 times as large as observed for other linear flexible polymers in good solvents thus showing extensive coil swelling/aggregation. This is also apparent from the exponent a values of the Mark–Houwink–Sakurada equation. Light Scattering results using Zimm method showed that aggregation occurred in low molecular weight samples; however, in higher molecular weight samples there was a little evidence for aggregation both in water and methanol. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2578–2583, 2006     

Poly(ester)s and poly(amide)s with fluorene and diphenyl-silane units in the main chain: Effects of iodine doping on the structure and electrical conductivity

Intramolecular charge transfer interaction between the electron donor and electro acceptor units within the polymeric structure and its optoelectronic properties were studied. The monomer, 9H-fluorene-2,7-dicarboxylic acid, was prepared from 9H-fluorene-2,7-dicarbonitrile using CuCN/N,N-dimethylformamide followed by the decomposition of the complex with FeCl₃x6H₂O in HCl and KOH/H₂O. The formation of two new classes of polymers was reported at different reaction times. The poly(ester) (PEF) was synthesized by the reaction of the diacid monomer with bis(4-hydroxiphenyl)diphenylsilane using tosyl chloride/pyridine/dimethylformamide system as condensing agent. Alternatively, the poly(amide) (PAF) was synthesized by the direct polycondensation of the diacid monomer and bis(4-aminophenyl)diphenylsilane in N-methyl-2-pyrrolidine solution containing dissolved calcium chloride. The resulting new polymers were obtained in good yields and were characterized by FTIR, NMR (¹H, ¹³C, and ²⁹Si), ESI, Raman, UV (optical gap) and fluorescence spectroscopy. The thermal properties were characterized by DSC and TGA. The electrical conductivity of the polymers was measured before and after exposure to iodine vapor, utilizing films of different thickness. Ellipsometric studies were used for the determination of the film thickness. Morphological differentiation was carried out by SEM-EDX analysis. Oxidation of the polymer films of low thickness decreased their conductivities, mainly due to the small structural changes. For a polymeric sample with a higher thickness, the doping process slightly increased the conductivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Crystallinity,ion conductivity,and thermal and mechanical properties of poly(ethylene oxide)–illite nanocomposites with exfoliated illite as a filler

Illite particles were exfoliated by the intercalation and subsequent deintercalation of dimethyl sulfoxide (DMSO) in the interlayer of illite, and the exfoliated illite particles were used to prepare a novel poly(ethylene oxide) (PEO)–illite nanocomposite. The resulting exfoliated illite and PEO–illite nanocomposites were characterized by X‐ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry, ion conductivity testing, thermogravimetry analysis, and mechanical testing. The XRD results showed that the acid treatment of illite to exchange K⁺ in the interlayer of illite with H⁺ was a necessary condition for the DMSO intercalation. SEM micrographs confirmed the exfoliation of the illite particles in the process of DMSO deintercalation from the interlayer of the illite–DMSO intercalation complex. A good dispersion of exfoliated illite in the PEO matrix was also confirmed. A gradual decrease in the PEO crystallinity in the PEO–illite nanocomposites was observed with increasing exfoliated illite concentration. The ion conductivity of the nanocomposites gradually increased with the filler content and reached 3.21 × 10⁻⁵ S/cm at an illite concentration of 20 wt %. The formation of an amorphous region around the exfoliated illite was beneficial for Li⁺‐ion conduction. The ion conductivity significantly increased when the amorphous regions were connected to each other to form a conducting path for Li⁺ ions with a high filler concentration of greater than 10 wt %. Meanwhile, the thermooxidative stability and mechanical properties of the PEO–illite nanocomposites were also enhanced when exfoliated illite was introduced into the polymer matrix. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44226.