Nanocomposite Polymer Electrolytes Research Articles

Preparation and characterization of new nanocomposite polymer films containing NiO nanofillers

ABSTRACTNanocomposite solid polymer films based on the poly(exo‐N‐phenyl‐7‐oxanorbornene‐5,6‐dicarboximide) (PPhONDI)/LiClO4/NiO system have been designed, and the effect of inorganic NiO nanofiller in different amounts on the film properties has been examined. The exo‐PPhONDI/LiClO4/NiO polymer system is the first solid nanocomposite polymer electrolyte film example based on a ring‐opening metathesis polymerization (ROMP) host polymer. The NiO nanoparticles were prepared by two‐step chemical syntheses, and the thermoplastic host polymer, exo‐PPhONDI, was synthesized via ROMP. Composite polymer films were prepared by the solution‐casting method. The amount of nanoparticles was varied from 1 to 15 wt % of NiO. The conductivity of the nanocomposite solid polymer systems was influenced by the NiO nanofiller concentration. The composite films based on exo‐PPhONDI ROMP polymer with the highest conductivity were achieved for the composition with 8 wt % of NiO nanofiller and 10 wt % of LiClO4 dopant. The prepared films were characterized using X‐ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy (SEM). The SEM results showed that the filler was well distributed in the polymer matrix. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45938.

Influence of TiO2 nano-particles on charge carrier transport and cell performance of PMMA-LiClO4 based nano-composite electrolytes

The plasticized PMMA-LiClO4 based solid polymer nano-composite electrolytes were prepared for different concentrations of TiO2 nano-particles using standard solution cast technique. The structure, glass transition temperature, thermal stability and particle size of these nano-composites have been studied by X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis and transmission electron microscopic analysis respectively. The complex conductivity spectra have been measured in the frequency range of 0.01 Hz–2 MHz and analyzed using random barrier model. The contribution of the electrode polarization in low frequency region and at high temperatures has been taken into account during analysis. The temperature dependence of ionic conductivity and relaxation time has been found to obey the Vogel-Tammann-Fulcher relation. A maximum ionic conductivity of ∼3.0 × 10−4 Scm−1 has been observed for the electrolyte with 1 wt% TiO2 nano-particles. The dielectric spectra have been analyzed using Havriliak-Negami function to understand the relaxation of charge carriers. The ion-ion and ion-polymer interactions have been studied using Fourier transform infrared (FTIR) spectra. Finally, the cycling performance of a coin cell of configuration graphite/PMMA-LiClO4-30 wt% PC-1wt% TiO2/LiCoO2 evaluated at 25 °C indicates suitability of the nano-composites as solid electrolytes for Li ion polymer cell.

Investigations on materials and ion transport properties of Zn2+ conducting nano-composite polymer electrolytes (NCPEs): [(90 PEO: 10 Zn(CF3SO3)2)+ x ZnO

Zn2+ conducting 2-phase Nano-Composite Polymer Electrolyte (NCPE) membranes: [(90PEO:10Zn(CF3SO3)2)+ x ZnO] have been hot-press synthesized. Solid Polymer Electrolyte (SPE) composition: [90PEO:10Zn(CF3SO3)2], identified earlier as highest conducting film with room temperature conductivity (σrt)∼ 1.09×10−6S/cm, has been used as Ist–phase host and ZnO (active) nano-particles as IInd–phase dispersoid. Filler particle concentration dependent conductivity measurement revealed Optimum Conducting Composition (OCC): [(90PEO:10Zn(CF3SO3)2)+5 ZnO] with σrt∼ 1.84×10−5S/cm. Dispersal of filler results σ-enhancement of one order. Materials property of NCPE OCC has been studied by SEM, XRD, FTIR and thermal property by DSC/TGA. Ion transport property i.e. ionic conductivity (s) and total ionic (tion)/cation (t+) transport number have been measured using different ac/dc techniques. Temperature dependent s-measurement has been done to compute activation energy (Ea) by least square linear fitting of ‘log σ - 1/T’Arrhenius plot. All-Solid-State battery has been fabricated to study cell performance under varying load conditions.

Conductivity-Relaxation Relations in Nanocomposite Polymer Electrolytes Containing Ionic Liquid.

In this study, we have used nanocomposite polymer electrolytes, consisting of poly(ethylene oxide) (PEO), δ-Al2O3 nanoparticles, and lithium bis(trifluoromethanesolfonyl)imide (LiTFSI) salt (with 4 wt % δ-Al2O3 and PEO:Li ratios of 16:1 and 8:1), and added different amounts of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesolfonyl)imide (BMITFSI). The aim was to elucidate whether the ionic liquid is able to dissociate the Li-ions from the ether oxygens and thereby decouple the ionic conductivity from the segmental polymer dynamics. The results from DSC and dielectric spectroscopy show that the ionic liquid speeds up both the segmental polymer dynamics and the motion of the Li+ ions. However, a close comparison between the structural (α) relaxation process, given by the segmental polymer dynamics, and the ionic conductivity shows that the motion of the Li+ ions decouples from the segmental polymer dynamics at higher concentrations of the ionic liquid (≥20 wt %) and instead becomes more related to the viscosity of the ionic liquid. This decoupling increases with decreasing temperature. In addition to the structural α-relaxation, two more local relaxation processes, denoted β and γ, are observed. The β-relaxation becomes slightly faster at the highest concentration of the ionic liquid (at least for the lower salt concentration), whereas the γ-relaxation is unaffected by the ionic liquid, over the whole concentration range 0-40 wt %.

Synthesis and Ionic Conductivity Studies of a New Ag+ Ion Conducting Nanocomposite Polymer Electrolytes

Synthesis and Ionic Conductivity Studies of a New Ag+ Ion Conducting Nanocomposite Polymer Electrolytes

High electrochemical performances of solid nano-composite star polymer electrolytes enhanced by different carbon nanomaterials

Here, two type of composite star polymer electrolytes enhanced by carbon nano-tube (CNT) or fullerene (C60) prepared through a solution-casting technique are investigated. The as-prepared free-standing carbon nano-composite polymer electrolyte membranes exhibit excellent comprehensive performances including high thermal stability (initial thermal degradation temperatures about 383 °C) and good electrochemical properties. However, different carbon nanomaterials bring different influence on electrochemical performances of composite polymer electrolytes. The ionic conductivity of carbon nanotube composite polymer electrolyte (HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI) is higher than that of fullerene composite polymer electrolyte. The highest ionic conductivity of HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI electrolyte can reach 1.06 × 10−5 S cm−1 at 30 °C and lithium-ion transference number reaches 0.52. In addition, two types of carbon nano-composite star polymer electrolytes both exhibit wide electrochemical window with oxidation potential above 5.2 V, good interfacial stability and interfacial compatibility. Moreover, assembled Li/LiFePO4 cells based on HBPS-(PMMA-b-PPEGMA)30/CNT/LiTFSI electrolytes possess good specific capacity with the highest value of 133 mAhh g−1, while the cells based on HBPS-(PMMA-b-PPEGMA)30/C60/LiTFSI electrolytes show a great cycle stability.

Stable cycling of lithium metal electrode in nanocomposite solid polymer electrolytes with lithium bis(fluorosulfonyl)imide

Nanocomposite solid polymer electrolytes (NSPEs) comprising lithium salt based on two representative sulfonylimide anions (i.e., bis(fluorosulfonyl)imide ([N(SO2F)2]−, FSI−) and bis(trifluoromethanesulfonyl)imide ([N(SO2CF3)2]−, TFSI−)) have been prepared by simply dissolving the corresponding lithium salt in poly(ethylene oxide) matrix in the presence of inert nano-sized Al2O3 fillers. The physicochemical and electrochemical properties of the FSI- and TFSI-based NSPEs are investigated, in terms of phase transition, ion transport behavior, chemical and electrochemical compatibility with Li metal. With the addition of nano-sized Al2O3 fillers, a significant improvement in chemical and electrochemical compatibility with Li metal has been observed in both the FSI- and TFSI-based NSPEs. Particularly, the symmetric cell using the FSI-based NSPE can be continuously cycled for >1000h at 70°C. The Li|LiFePO4 cell with the FSI-based NSPEs shows good cycling stability and capacity retention. These promising results make them attractive electrolytes for safe and stable rechargeable Li metal batteries.

Dielectric dispersion and relaxations in (PVA-PEO)-ZnO polymer nanocomposites

The organic-inorganic nanocomposite materials consisted of poly(vinyl alcohol) (PVA) and poly(ethylene oxide) (PEO) blend matrix (50/50wt%) dispersed with zinc oxide (ZnO) nanoparticles have been prepared by the aqueous solution-cast method. The dielectric dispersion and relaxation processes in these polymer nanocomposite (PNC) films (i.e., (PVA-PEO)-x wt% ZnO; x = 0, 1, 3 or 5) have been investigated over the frequency range from 20Hz to 1MHz by employing the dielectric relaxation spectroscopy (DRS). Influence of ZnO contents on the complex dielectric permittivity, electrical conductivity, electric modulus and impedance properties of these PNC materials has been explored. The dielectric permittivity and the relaxation time values corresponding to polymers cooperative chain segmental motion significantly change with the variation of ZnO contents in the PVA-PEO blend matrix at ambient temperature. The temperature dependent relaxation times and dc conductivity values of (PVA-PEO)-3wt% ZnO film have been investigated which obey the Arrhenius behaviour. The dielectric permittivity of the film as a function of temperature exhibits linear behaviour at radio frequencies and non-linear variation at lower audio frequencies. X-ray diffraction measurements confirm a huge decrease in crystalline phase of the polymer blend matrix on the addition of 1wt% ZnO nanoparticles. These PNC materials have low values of dielectric permittivity and electrical conductivity which confirm their suitability as novel flexible-type polymer nanodielectric for the insulation in microelectronic devices, whereas the fast chain segmental dynamics and high amorphous phase reveal these materials as a potential candidate for the preparation of nanocomposite solid polymer electrolytes.

Effects of different inorganic nanoparticles on the structural, dielectric and ion transportation properties of polymers blend based nanocomposite solid polymer electrolytes

Nanocomposite solid polymer electrolyte (NSPE) films consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) blend (50/50wt%) as host polymer matrix with 20wt% lithium perchlorate (LiClO4) as dopant salt and 3wt% inorganic nanoparticles (i.e., Al2O3, SiO2, SnO2 or ZnO) as filler have been prepared by solution cast method followed by melt-press technique. The X-ray diffraction (XRD) study confirms that the electrolyte films without nanofiller and with Al2O3 and SiO2 nanofillers have predominantly amorphous structures, whereas the characteristic diffraction peaks of SnO2 and ZnO crystallites are observed in the respective NSPEs. Fourier transform infra-red (FTIR) spectra of these NSPE films confirm the formation of ion-dipolar coordination between the functional groups of polymers and the lithium ions throughout the material which completely suppressed the crystalline region absorption peaks of the PEO. The metal oxides of the nanoparticles mainly exhibit van der Waals type interaction with the polymers chains and the ions in the NSPE materials. Effects of a lithium salt as a dopant and the nanoparticles as fillers on the crystalline phase and thermal behaviour of PEO–PMMA blend in these electrolyte materials have also been examined by their differential scanning calorimetry (DSC) measurements.Dielectric and electrical dispersion behaviour of the NSPE films have been characterized by employing dielectric relaxation spectroscopy (DRS) over the frequency range from 20Hz to1MHz and at temperatures 27, 35, 45 and 55°C. The single relaxation peak appeared in the dielectric loss tangent spectra of these electrolytes confirms the ion-dipolar coordinated coupled cooperative chain segmental motion of the PEO and PMMA macromolecules. Lowering in the values of dielectric polarization strength and ionic conductivity has been observed for all the NSPE films as compared to that of the SPE film without nanofiller. A linear correlation between the crystallite sizes of different nanofillers and the dielectric permittivity of NSPE materials has been revealed. It is found that the cooperative polymers chain segmental dynamics becomes slower with the dispersion of nanoparticles in the ion-dipolar complexes which causes a decrease of ionic conductivity of the NSPE films. The correlation observed between the dielectric relaxation time and the ionic conductivity confirms that the ions transport occurs by intra- and inter-chain hopping in these PEO–PMMA blend based electrolytes. Temperature dependent values of relaxation time and dc ionic conductivity of the electrolyte films obey the Arrhenius relation and their activation energies are found in the range 0.22eV to 0.40eV which differ with the types of inorganic nanoparticles dispersed in the NSPEs. The comparative results confirm that the polymers chain segmental dynamics mask the effect of amorphous phase of these materials which contributes in the lithium ions transportation and their mobility. Linear correlation observed between the dielectric permittivity and ionic conductivity values of these NSPEs suggests that the strength of dielectric polarization also plays an important role for the ion transportation process in the solid ion-dipolar complexes. The room temperature ionic conductivity values of these NSPE films are found of the order of 10−5Scm−1 which confirms their suitability as potential candidates in the design and development of all-solid-state devices including the rechargeable lithium-ion batteries. Finally, these experimental results explain in depth the fundamental issues of nanomaterials science that confront the use of various kind of inorganic nanoparticles in the preparation of NSPEs, and the dependence of their ion transportation process on the amorphous phase, dielectric permittivity and the cooperative polymers chain segmental motion, especially for the polymers blend based electrolytes.

Polyethylene oxide-based nanocomposite polymer electrolytes for redox capacitors

In this work, the use of a polyethylene oxide-based nanocomposite polymer electrolyte (NCPE) in a redox capacitor with polypyrrole electrodes has been studied. To the best of our knowledge, not much work has been reported in the literature on redox capacitors fabricated using NCPEs. The composition of the polyethylene oxide (PEO)-based NCPE was fine tuned to obtain films with the highest ionic conductivity. They were mechanically stable to handle for any purpose without damaging the film. The optimized composition was {[(10PEO:NaClO4) molar ratio]: 75 wt.% propylene carbonate (PC)}: 5 wt.% TiO2. This electrolyte film showed an ambient temperature ionic conductivity of 5.42 × 10−3 S cm−1. It was employed in a redox capacitor with polypyrrole electrodes polymerized in the presence of sodium perchlorate in non-aqueous medium. Performance of the redox capacitors were observed using cycling voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge discharge test. It was possible to observe a satisfactory capacitive behavior in the range 58–83 F/g. Further, the redox capacitors had the ability to retain for continuous charge discharge processes.

Specific features of the synthesis and the physicochemical properties of nanocomposite polymer electrolytes based on poly(ethylene glycol) diacrylate with the introduction of SiO2

The specific features of the synthesis and the physicochemical properties of new nanocomposite polymer electrolytes (NPE) based on poly(ethylene glycol) diacrylate, a liquid electrolyte, and silicon dioxide were studied. The kinetics of polymerization of the system in question were studied by isothermal calorimetry and the optimal conditions for the hardening of the NPE were selected. The dependence of the conductivity of the electrolyte samples on the amount of SiO2 nanopowder introduced, the presence of preliminary ultrasonic treatment of the nanocomposite mixture before the synthesis, and the storage duration of the samples was studied using the electrochemical impedance method. The maximum conductivity (4.3•10–3 S cm–1 at 20 °C) was observed for samples without preliminary treatment with the introduction of 6 wt.% of SiO2 and for the samples after ultrasonic treatment with 8 wt.% of SiO2. The electrolyte films with the optimal SiO2 content of 4 wt.% maintained their properties for 24 months.

Optical and dielectric properties of PVP based composite polymer electrolyte films

Solid polymer electrolyte films were prepared by adding Al2O3 particles to poly(vinylpyrrolidone)-MgCl2 ∙ 6H2O salt using solution cast technique. Various analytical techniques have been applied to characterize the prepared polymer films such as XRD, SEM, UV–Vis spectroscopy and AC conductivity. The structural analysis of pure poly(vinylpyrrolidone) complexed with MgCl2 ∙ 6H2O salt showed orthorhombic lattice structure indicating its semi-crystalline nature. SEM analysis reveals the heterogeneous phase of nanocomposite polymer electrolyte systems. The conductivity of Al2O3 doped poly(vinylpyrrolidone) based solid polymer electrolyte was found to be 1.22 × 10–6 S/cm at room temperature for 85: 15 weight composition. Electrochemical cell has been fabricated with the configuration Mg+/(PVP + MgCl2 ∙ 6H2O + Al2O3)/(I2 + C + electrolyte) and its discharge characteristics were studied for a constant load of 100 kΩ. Various cell parameters such as open-circuit voltage, short circuit current, energy density and power density were calculated for the prepared samples.

Performance enhancement of poly (vinylidene fluoride-co-hexafluoro propylene)/polyethylene oxide based nanocomposite polymer electrolyte with ZnO nanofiller for dye-sensitized solar cell

Nanocomposite polymer electrolytes (NCPEs) were prepared by blending poly (vinylidene fluoride-co-hexafluoro propylene) copolymer (PVdF-HFP) and polyethylene oxide (PEO) polymers and incorporation of ZnO inorganic nanofiller (PVdF-HFP:PEO:EC:PC:NaI:I2:ZnO). The highest ionic conductivity value of 8.36 mS cm−1 was recorded when 3 wt.% of ZnO inorganic nanofiller was incorporated into the NCPE system. Temperature-dependant ionic conductivity behaviour of NCPEs was analysed and proven to follow the Arrhenius thermal activated model. Structural studies of NCPEs were carried out using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. NCPEs were used to fabricate Dye-sensitized solar cells (DSSCs). Enhancements in the solar light to electricity conversion efficiency (η) of DSSCs were observed in the presence of ZnO inorganic nanofiller in the NCPE system and NCPE with 3 wt.% ZnO represented the highest η of 7.33% under full sun irradiation.

Synthesis and characterization of ion transport behavior in Cu2+-conducting nano composite polymer electrolyte membranes

Synthesis and characterization of ion transport behavior in Cu2+-conducting nano composite polymer electrolyte (NCPE) films: [90PEO: 10Cu(CF3SO3)2] + x CuO have been reported. NCPE films have been formed by hot-press casting technique using solid polymer electrolyte (SPE) film composition: [90PEO: 10Cu(CF3SO3)2] as 1st-phase host and nanoparticles of CuO in varying wt.(%) as 2nd-phase active filler. SPE: [90PEO: 10Cu(CF3SO3)2] was identified earlier as highest conducting film with room temperature conductivity (σrt) ~ 3.0 x 10−6 S cm−1, which is three orders of magnitude higher than that of pure polymer host PEO with σrt ~ 3.2 × 10−9 S cm−1. Filler particle concentration dependent conductivity study revealed NCPE film: [90PEO: 10Cu(CF3SO3)2] + 3%CuO as optimum conducting composition (OCC) exhibiting σrt ~ 1.14 × 10−5 S cm−1. Hence, by the fractional dispersal of 2nd-phase active filler into 1st-phase SPE host, σ-enhancement of approximately an order of magnitude has further been obtained. Ion transport behavior in NCPE OCC film has been characterized in terms of basic ionic parameters viz. ionic conductivity (σ), total ionic transference (tion)/cationic (t+) numbers. Temperature dependent conductivity measurement has also been done to explain the mechanism of ion transport and to compute activation energy (Ea). Materials characterization and hence, confirmation of complexation of salt in polymeric host and/or dispersal of filler particles in SPE host have been done by scanning electron microscopy (SEM), energy dispersive x-ray spectrometer (EDS), x-ray diffraction (XRD), Fourier transform infra-red (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). All-solid-state battery in the cell configuration: Cu (Anode) || SPE host/NCPE OCC film || C + I2 + Electrolyte) (Cathode) has been fabricated and cell performance has been studied under two load resistances viz. 60 and 100 kΩ. Each NCPE cell gave on an open circuit voltage (OCV) ~ 0.68 V. Some important battery parameters have also been evaluated from the plateau regions of cell potential discharge profiles.

Optical and Electrical Characteristics of Silver Ion Conducting Nanocomposite Solid Polymer Electrolytes Based on Chitosan

Optical and electrical properties of nanocomposite solid polymer electrolytes based on chitosan have been investigated. Incorporation of alumina nanoparticles into the chitosan:silver triflate (AgTf) system broadened the surface plasmon resonance peaks of the silver nanoparticles and shifted the absorption edge to lower photon energy. A clear decrease of the optical bandgap in nanocomposite samples containing alumina nanoparticles was observed. The variation of the direct-current (DC) conductivity and dielectric constant followed the same trend with alumina concentration. The DC conductivity increased by two orders of magnitude, which can be attributed to hindrance of silver ion reduction. Transmission electron microscopy was used to interpret the space-charge and blocking effects of alumina nanoparticles on the DC conductivity and dielectric constant. The ion conduction mechanism was interpreted based on the dependences of the electrical and dielectric parameters. The dependence of the DC conductivity on the dielectric constant is explained empirically. Relaxation processes associated with conductivity and viscoelasticity were distinguished based on the incomplete semicircular arcs in plots of the real and imaginary parts of the electric modulus.

Effect of intercalated and exfoliated montmorillonite clay on the structural, dielectric and electrical properties of plasticized nanocomposite solid polymer electrolytes

Abstract Plasticized nanocomposite solid polymer electrolyte (PNSPE) films, consisted of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) polymer blend matrix (50/50 wt%) with lithium tetrafluoroborate (LiBF4) as dopant ionic salt (10 wt%), ethylene carbonate (EC) as plasticizer (10 wt%) and montmorillonite (MMT) clay as nanofiller (3 wt%), have been prepared by classical solution-cast (SC) and the ultrasonic-microwave irradiated (US–MW) solution-cast methods. X–ray diffraction (XRD) study confirms that these PNSPE films are predominantly amorphous and contain very small amount of PEO crystallites. The SC method prepared PNSPE film bears highly ordered intercalated MMT structures, whereas, the US–MW method prepared PNSPE film has large amount of disordered exfoliated MMT structures. Dielectric relaxation spectroscopy (DRS) from 20 Hz to 1 MHz has been employed for characterization of complex dielectric permittivity, alternating current electrical conductivity and complex impedance spectra of the films. Three relaxation processes corresponding to the electric double layers dynamics, polymer chain segmental motion and ionic conductivity have been explored. It has been observed that the dielectric and electrical properties of the PNSPE films change notably with the film preparation methods. Results reveal that the exfoliated MMT decreases the dielectric polarization and creates hindrance to the polymer chain segmental dynamics which causes decrease of ionic conductivity in comparison to the ion-dipolar complexes containing intercalated MMT. The room temperature dc ionic conductivity of the PNSPE films have been found about 10−5 S cm−1, which confirms these materials as potential candidate for design and development of flexible-type all-solid-state lithium-ion conducting electrochromic devices.

Ionic conductivity, FTIR and thermal studies of nano-composite plasticized proton conducting polymer electrolytes

Ionic conductivity of polymer electrolytes obtained by complexation of trifluoromethanesulfonic acid (HCF3SO3) (triflic acid) with polyethylene oxide (PEO) has been found to increase with the addition of dimethylacetamide (DMA) as plasticizer. The increase in conductivity has been explained to be due to dissociation of ion aggregates with the addition of plasticizer, which has also been supported by FTIR studies. Plasticized polymer electrolytes have high ionic conductivity but not show better mechanical properties. Nano-sized fumed silica (SiO2) is added to improve its mechanical strength alongwith an increase the ionic conductivity of plasticized polymer electrolytes. Maximum ionic conductivity of plasticized nano-composite polymer electrolytes of 8.14×10−3Scm−1 at room temperature has been observed for the composition PEO+8wt% HCF3SO3+50wt% DMA+3wt% SiO2. X-ray diffraction studies of polymer electrolytes suggests that the amorphous content increases with the addition of plasticizer and nano-filler, which is in agreement with the conductivity results. The small change in conductivity over 30–130°C temperature range suggests that these electrolytes are suitable for their use in device applications like fuel cells, supercapacitors, sensors, separators and other electrochromic devices. DSC/TGA studies show that these nano-composite plasticized polymer electrolytes possess good thermal properties alongwith high conductivity.

Conductivity enhancement in SiO2 doped PVA:PVDF nanocomposite polymer electrolyte by gamma ray irradiation

Nanocomposite polymer electrolyte has been irradiated with 15GyGamma rays. Exposure of gamma radiation caused scissoring and crosslinking of polymer chains thereby increasing amorphous phase of the polymer matrix because of which the ionic conductivity has been enhanced. Ionic conductivity of irradiated nanocomposite polymer electrolyte is enhanced to 9.4×10−4Scm−1 at 303K compared to un-irradiated system (σ∼1.7×10−4Scm−1). Temperature dependence of ionic conductivity of both un-irradiated and irradiated systems obeys VTF relation. Frequency and temperature dependence of dielectric and modulus of both systems have been analyzed. The ionic transference number of polymer electrolyte has been calculated by Wagner’s polarization technique and it confirms that conducting species are predominantly due to ions in both systems.

Temperature dependent ionic conductivity and cell performance studies of hot-pressed nanocomposite polymer electrolytes

Abstract Temperature dependent ionic conductivity measurement of a new K + ion conducting nano-composite polymer electrolytes (NCPEs): (1−x) [70PEO:30KBr]+x SiO 2, where 0 wt%, are reported. The present NCPEs have been synthesized using a recently developed hot-press technique in place of the traditional solution cast method. Two orders of conductivity enhancement have been achieved in the present NCPE composition: [95(70PEO:30KBr)+ 5SiO 2], after the nano filler SiO2 dispersion and this composition has been used as an electrolyte for the preparation of a new solid state polymeric cell. The cell potential discharge characteristics have been studied at different temperatures and various load conditions. The ionic transference number (tion) of the present system has also been calculated with the help of transient ionic current (TIC) method at different temperatures.

Development of Solid Nanocomposite Polymer Electrolyte to Enable Lithium Metal Anode Safely Cycling for High Energy Battery Application

NASA’s future missions demand advanced batteries with higher energy density, smaller volume, lighter weight and safer operation. Current state-of-the-art lithium-ion batteries (LIBs) reach the specific energy capacity limits (<250 Wh/kg), which is unable to meet the NASA’s future energy goals (>400 Wh/kg), and also pose safety issues due to using the liquid flammable electrolyte. There are intense on-going developmental activities to increase energy density. Lithium (Li)-metal based battery chemistry has the potential to achieve high-energy goals (>400 Wk/kg) to meet NASA’s future mission’s energy requirements. However, the cycle ability and safety of Li metal as anode are challenging because of morphology change and/or Li dendrite growth. Solid polymer electrolyte enhances lithium metal-based battery technology by replacing the liquid electrolyte for safety and flexible of design. However, solid polymer electrolyte has problems of low ionic conductivity (<10-3 S/cm) at ambient temperature, and compatibility issues with lithium metal anode, which act as a barrier for the practical application. Solid polymer nanocomposite electrolyte has been developed to help improve ionic conductivity, provide good compatibility with the Li electrode and mitigate the electrolyte/Li metal interfacial issue. It is a promising approach to enhance Li metal-based battery technology. In this presentation, we will present the result of solid polymer nanocomposite electrolyte to enable Li metal anode safe cycling and for high-energy battery application.