Accelerating rate calorimetry studies of the reactions between ionic liquids and charged lithium ion battery electrode materials

Using accelerating rate calorimetry (ARC), the reactivity between six ionic liquids (with and without added LiPF₆) and charged electrode materials is compared to the reactivity of standard carbonate-based solvents and electrolytes with the same electrode materials. The charged electrode materials used were Li₁Si, Li₇Ti₄O₁₂ and Li_0.45CoO₂. The experiments showed that not all ionic liquids are safer than conventional electrolytes/solvents. Of the six ionic liquids tested, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EMI-FSI) shows the worst safety properties, and is much worse than conventional electrolyte. 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI) and 1-propyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide (Py13-FSI) show similar reactivity to carbonate-based electrolyte. The three ionic liquids 1-butyl-2,3-dimethylimidazolium bis(trifluoromethanesulfonyl)imide (BMMI-TFSI), 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide (Pp14-TFSI) and N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide (TMBA-TFSI) show similar reactivity and are much safer than the conventional carbonate-based electrolyte. A comparison of the reactivity of ionic liquids with common anions and cations shows that ionic liquids with TFSI⁻ are safer than those with FSI⁻, and liquids with EMI⁺ are worse than those with BMMI⁺, Py13⁺, Pp14⁺ and TMBA⁺.     

Effective influences of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIMTFSI) ionic liquid on the ion transport properties of micro-porous zinc-ion conducting poly (vinyl chloride) /poly (ethyl methacrylate) blend-based polymer electrolytes

A series of new gel polymer electrolytes (GPEs) based on different concentrations of a hydrophobic ionic liquid (IL) 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (EMIMTFSI) entrapped in an optimized typical composition of polymer blend-salt matrix [poly(vinyl chloride) (PVC) (30 wt%) / poly(ethyl methacrylate) (PEMA) (70 wt%) : 30 wt% zinc triflate Zn(CF₃SO₃)₂] has been prepared using facile solution casting technique. The AC impedance analysis has revealed the occurrence of the maximum ionic conductivity of 1.10 × 10^?4 Scm^?1 at room temperature (301 K) exhibited by the PVC/PEMA- Zn(OTf)₂ system containing 80 wt% ionic liquid. The addition of EMIMTFSI into the optimized PVC/PEMA- Zn(OTf)₂ system in different weight percentages enhances the number of free zinc ions thereby leading to enrichment of ionic conductivity. The structural and complexation behaviour of the as prepared polymer gel electrolytes was substantiated by subjecting these electrolyte films to X-ray diffraction (XRD) and Attenuated total reflectance - Fourier transformed infrared (ATR-FTIR) investigations. The wider electrochemical stability window ~ 3.23 V and a reasonable cationic transference number (t_Zn ²⁺) of 0.63 have been attained for the polymer gel electrolyte film containing higher loading of (80 wt%) ionic liquid. The development of the amorphous phase of these gel polymer electrolyte membranes with increasing ionic liquid content was observed from scanning electron microscopic (SEM) analysis. The results of the current work divulge the assurance of developing GPEs based on ionic liquids for prospective application in zinc battery systems.     

A study on polymer blend electrolyte based on PVA/PVP with proton salt

Proton-conducting polymer blend electrolytes based on PVA–PVP–NH₄NO₃ were prepared for different compositions by solution cast technique. The prepared films are investigated by different techniques. The XRD study reveals the amorphous nature of the polymer electrolyte. The FTIR and laser Raman studies confirm the complex formation between the polymer and salt. DSC measurements show decrease in T _g with increasing salt concentration. The ionic conductivity of the prepared polymer electrolyte was found by ac impedance spectroscopy analysis. The maximum ionic conductivity was found to be 1.41 × 10^?3 S cm^?1 at ambient temperature for the composition of 50PVA:50PVP:30 wt% NH₄NO₃ with low-activation energy 0.29 eV. The conductivity temperature plots are found to follow an Arrhenius nature. The dielectric behavior was analyzed using dielectric permittivity (ε*) and the relaxation frequency (τ) was calculated from the loss tangent spectra (tan δ). Using this maximum ionic conducting polymer blend electrolyte, the primary proton battery with configuration Zn + ZnSO₄·7H₂O/50PVA:50PVP:30 wt% NH₄NO₃/PbO₂ + V₂O₅ was fabricated and their discharge characteristics studied.     

Symmetric electric double-layer capacitor containing imidazolium ionic liquid-based solid polymer electrolyte: Effect of TiO2 and ZnO nanoparticles on electrochemical behavior

Poly(vinylidene fluoride-co-hexafluoropropene) (PVDF–HFP)-based polymer electrolytes embedded with 1-ethyl-3-methylimidazolium tetrafluoroborate ioniliquid have been synthesized to improve the ionic conductivity. Electric double-layer capacitors (EDLC) have been prepared using the synthesized polymer electrolytes. Inorganic oxide fillers (5 wt %) such as titanium dioxide (TiO₂) and zinc oxide (ZnO) nanoparticles have been added to polymer electrolytes to compare the electrochemical behavior of the fabricated EDLC. The intrinsic dielectric constant of nanoparticles contributes in ionic dissociation which enhances ionic conductivity of electrolytes and also controls the specific capacitance of the EDLC fabricated with these electrolytes. Physicochemical properties of polymer nanocomposites have been investigated using X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analysis, which confirms decrease of crystalline phase in host polymer PVDF–HFP. The maximum voltage stability is obtained for TiO₂-based polymer electrolyte. The high specific capacitance as well as high energy density is obtained for the EDLC cell with TiO₂-based polymer electrolyte compared to EDLC with ZnO nanoparticles-based electrolyte. EDLC cells show specific capacitance of 76.4 and 44.51% of initial specific capacitance value at 2000th cycle for ZnO and TiO₂-based polymer electrolytes, respectively. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48757.     

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.     

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.     

Thermoanalytical Investigation of Some Binary Pyrotechnic Mixtures of Ammonium Azide as Chemical Gas Generating Systems

The conventional NaN₃/oxidants gas generator pyrotechnic mixtures suffer from leaving undesirable solid residues. The presented investigation aimed to overcome this problem through mixing of NH₄N₃ particles with some metallic components, and to introduce some new gas generator pyrotechnic mixtures. In this work, volatile ammonium azide particles were initially stabilized via microencapsulation technique, and blended with Zr, Ti, ZrH₂, and TiH₂ powders to produce different gas generation mixtures. Thermal properties and kinetic parameters of these pyrotechnic mixtures were investigated by using thermal analysis (TG/DTA and DSC) techniques. The apparent activation energy (E), ΔG^#, ΔH^#, ΔS^#, and critical ignition temperature (T_b) of the ignition processes of the mixtures were obtained from the DSC experiments. Among the investigated mixtures, NH₄N₃/ZrH₂ composition was found to show desirable efficiency, and also it can be considered as a safe pyrotechnic composition for gas generation property, due to its moderate ignition temperature.     

Hydrogen bioelectrooxidation in ionic liquids: From cytochrome c3 redox behavior to hydrogenase activity

Electrochemistry of polyheme bacterial cytochrome c₃ and catalytic oxidation of hydrogen by two different bacterial [NiFe] hydrogenases were investigated for the first time in pure room-temperature ionic liquids (RTILs) as electrolyte. Direct electrochemical response of Desulfovibrio vulgaris Hildenborough cytochrome c₃ (DvH cytc₃) adsorbed at a pyrolytic graphite (PG) electrode was observed in the RTILs used in this work: 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4), 1-ethyl-3-methylimidazolium tetrafluoroborate (EmimBF4) and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EmimNTf2). The electrochemical signal differed however from that obtained in aqueous buffer, and depended on the type of RTIL. UV–vis measurements as well as transfer experiments from aqueous buffer to RTILs or RTILs to aqueous buffer strongly suggested that the protein was not denatured in the presence of RTILs. EmimNTf2, as a hydrophobic non-water-miscible RTIL, was demonstrated to stabilize the native form of DvH cytc₃. Moreover it allowed an amount of electroactive DvH cytc₃ 30-fold higher than observed in aqueous buffer. Catalytic oxidation of H₂ via Desulfovibrio fructosovorans [NiFe] hydrogenase (Df Hase) mediated by DvH cytc₃ failed however. Further investigation suggested that Df Hase could be inhibited in the presence of RTILs. Reasons for such an inhibition were explored, including the blocking up of the substrate channels. By using hyperthermophilic [NiFe] membrane-bound hydrogenase from Aquifex aeolicus (Aa Hase) an efficient direct catalytic oxidation process was obtained in mixed aqueous buffer/RTILs electrolytes, although direct H₂ oxidation was not observed in pure RTIL. Chronoamperometric experiments showed that Aa Hase could afford 80% RTILs in aqueous buffer, thus giving the opportunity of future electrolytes with uncommon and variable properties for biofuel cell design.     

Sulfonate based ionic liquid incorporated polymer electrolytes for Magnesium secondary battery

The polymer electrolytes comprising of PVdF-HFP/PVAc/Mg(ClO₄)₂ as salt based polymer blend electrolytes derived from the addition of varying amounts of 1-ethyl – 3-methylimidazolium trifluoromethane sulfonate [EMITF], as dopant were synthesized in the form of films by solution-casting method. The XRD and FTIR patterns confirm the formation of an amorphous phase and also that complex formation between the polymers, salt and ionic liquid. The SEM images show that the polymer electrolyte exhibit a enormous pores, remarkably, the maximum ionic conductivity is obtained in the case of the typical polymer system I₃ is found to be 9.122 × 10^?4 Scm^?1at 303 K.     

Poly(methyl methacrylate) based nanocomposite gel polymer electrolytes with enhanced safety and performance

The study presents preparation of poly methyl methacrylate (PMMA) based nanocomposite gel polymer electrolytes consisting of, salt lithium perchlorate (LiClO₄), plasticizer PC/DEC and different proportions of SiO₂ nanofiber by solution casting process. The effect of the composition of the electrolytes on their ionic, mechanical and thermal characteristics was investigated. Morphology of the nanocomposite electrolyte films has been observed by scanning and transmission electron microscopes. Interactions among the constituents of the composite and structural changes of the base polymer were investigated by Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques. The maximum conductivity i.e. 10^?3 Scm^?1 at room temperature is obtained with the electrolyte composition of 0.6(PMMA)-0.15(PC + DEC)-0.1LiClO₄ (wt%) containing 10 wt% SiO₂ nanofiber and the temperature dependent conductivity data of the electrolyte follows Vogel-Tamman-Fulcher (VTF) behavior.     

Growth of TiO2-based nanotubes on Ti–6Al–4V alloy

The possibility of tailoring titania nanotube films on Ti–6Al–4V alloy is investigated using electrolytes based on NH₄H₂PO₄ with the addition of different concentrations of NH₄F. Several morphologies from high aspect ratio nanotubes to barrier layers are achieved by the control of the electrolyte composition, regarding its pH and fluoride concentrations. The morphology and composition of the anodic layers were evaluated by scanning and transmission electron microscopy, Rutherford backscattering spectroscopy (RBS) and Wavelength dispersive X-ray fluorescence spectroscopy.The formation efficiency and the fluoride ions content in the nanotubes depend on the F concentration in the electrolyte. The higher concentration of fluoride ions in the electrolyte promotes an increase of the F incorporated in the nanotubes, about 12 at.% but, reduces the nanotube formation efficiency. However, no significant presence of phosphorus was detected into the films by means of the above-mentioned analytical techniques.     

Molecular beam mass spectrometry studies of nitrogen additions to the gas phase during microwave-plasma-assisted chemical vapour deposition of diamond

In-situ molecular beam mass spectrometry has been used to study the effects of nitrogen-containing gases on the gas-phase composition during microwave plasma chemical vapour deposition (CVD) of diamond. The molecular beam mass spectrometer used in this work extracts gas directly from the plasma bulk via a small sampling orifice inserted into the side of the plasma. The plasma composition was examined for a variety of nitrogen-containing gases added to a standard 1% C:H₂ feedstock. Nitrogen was added to this mixture at a carbon-to-nitrogen ratio, C:N1:1, in one of the following forms: N₂, NH₃, CH₃NH₂, or HCN. For N₂ and NH₃, the carbon source was CH₄, whereas CH₃NH₂ and HCN required no added carbon. Mass spectrometer signals from hydrocarbons, nitrogen-containing species, and the methyl radical were recorded. These were calibrated to give absolute mole fractions of the main carbon- and nitrogen-containing species present at detectable levels. The content of N₂ and NH₃ in the feed was also varied while holding the CH₄ content at 1%. Results are compared with those found during hot-filament CVD. The relevance of the measured abundance of various nitrogen-containing species in the plasma to attempts to create p-type diamond is discussed.     

PEO-imidazole ionic liquid-based electrolyte and the influence of NMBI on dye-sensitized solar cells

1-Oligo(ethylene oxide)-3-methylimidazolium iodide (PEOMImI) was synthesized and applied to dye-sensitized solar cells (DSSCs) by blending it with different 1-alkyl-3-methylimidazolium iodides used as ionic liquid electrolytes. The 1-propyl-3-methylimidazolium iodide (PMII) blend enabled the DSSC to attain a higher solar energy conversion efficiency of 4.52% under a light intensity of 100 mW cm⁻². The addition of N-methylimidazole (NMBI) to the electrolytes increased the conversion efficiency as compared to DSSCs based on NMBI-free electrolytes. The addition of both 1-allyl-3-methylimidazolium iodide (AMII) and NMBI enabled DSSCs to reach their highest solar energy conversion efficiency of 6.14% under a light intensity of 100 mW cm⁻². The ionic conductivity and diffusion coefficient of the triiodide were found to be augmented dramatically after adding NMBI, which leads to an increase in the photocurrent density. The enhancement mechanism of NMBI in the electrolyte was investigated by Raman spectroscopy and differential scanning calorimetry, and it was mainly due to the enhancement of electron exchange in electrolytes.     

Electrodeposition of nanocrystalline copper thin films from 1-ethyl-3-methylimidazolium ethylsulphate ionic liquid

Copper thin films are increasingly important as interconnectors for the creation of smaller and better performing integrated circuits and electrodeposition from ionic liquid-based electrolytes could provide a greener fabrication method for these films. The electrodeposition of copper from copper(I) and copper(II) salt solutions in a low cost, widely available ionic liquid, 1-ethyl-3-methylimidazolium ethylsulphate, was studied using a range of different deposition potentials and temperatures. Three different electrolytes containing ~0.1 M of copper(I) chloride(CuCl), copper(II) chloride (CuCl₂) and copper(II) sulphate (CuSO₄) were used. Under similar deposition conditions, the films obtained from CuCl and CuSO₄-based electrolytes presented better continuity than films obtained from CuCl₂-based electrolyte. Continuous films with a homogeneous structure were obtained by electrodeposition from CuCl and CuSO₄-based solutions at a constant potential of ?1.8 V and a temperature of 35 °C. Under similar deposition parameters, the films deposited from CuCl₂-based electrolyte presented the largest particle size, while those deposited from copper(I) chloride and CuSO₄-based solutions presented finer microstructures. X-ray diffraction analysis and energy dispersive X-ray spectroscopy showed that the deposits were crystalline and consisted mainly of copper, with traces of oxygen and sulphur resulting from residues of the ionic liquid. The films presented a nanocrystalline microstructure consisting of particles about 25 nm, aggregated in clusters.     

Control of morphology and composition of self-organized zirconium titanate nanotubes formed in (NH4)2SO4/NH4F electrolytes

We investigated the formation of self-organized zirconium titanate nanotubes by anodizing a Ti-35Zr alloy in 1 M (NH₄)₂SO₄ + 0.1-2.0 wt.% NH₄F electrolytes. The morphology and composition of the zirconium titanate nanotube are controlled by the applied electrochemical conditions. The outer diameter of nanotubes is controlled by the anodization potential in the range between 1 and 100 V (versus Ag/AgCl). Tubes with diameters from 14 to 470 nm can be grown. The nanotube length correlates with the anodic charge up to a length where significant dissolution of the nanotube layer is observed. The wall thickness, composition of the nanotubes and porosity of the nanotube layer are significantly affected by the fluoride ion concentration. The length limiting factor of the nanotube growth is found to be the diffusion of ionic species in the electrolyte.     

Highly efficient dye-sensitized solar cells: A comparative study with two different system of solvent-free binary room-temperature ionic liquid-based electrolytes

In this work, novel redox electrolytes based on poly (ethylene oxide) (PEO) were prepared using binary ionic liquid 1-methyl-3-propylimidazolium iodide (MPII) with 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) or 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF₄) to reduce the high viscosity of MPII. The addition of low viscosity ionic liquids is to overcome the low mass transportation of redox mediator faced by the single ionic liquid. Therefore, different ratios of ionic liquids were added, and their effect on the electrical properties of the ionic liquid-based gel polymer electrolytes (GPE) was observed. It was confirmed that all the system dominant by ions rather than electron. The binary ionic liquid system containing 37.5 wt.% of BMIMBF₄ showed the highest ionic conductivity of 24.2 mS cm⁻¹. Fourier-transform infrared and X-ray diffraction studies confirmed that complexation occurred between all materials. The combination of two alkyl side chain length has enhanced the efficiency of the DSSC with short-circuit current density (J_SC) of 26.81 mA cm⁻¹, open-circuit voltage (V_OC) of 0.67 V, fill factor of 44.5% and photovoltaic conversion efficiency (η) of 7.8%. This work has provided valuable insight for further stability of binary ionic liquid-based GPE compared to single ionic liquid electrolytes.     

Quasi in situ XPS study of electrochemical oxidation and reduction of highly oriented pyrolytic graphite in [1-ethyl-3-methylimidazolium][BF4] electrolytes

Highly oriented pyrolytic graphite (HOPG) electrodes were electrochemically oxidised and reduced in 1-ethyl-3-methylimidazolium tetrafluoroborate [EMIM][BF₄] electrolytes and studied by X-ray photoelectron spectroscopy (XPS). Sample preparation and transfer have been performed under inert nitrogen atmosphere in a preparation chamber directly attached to an ultra high vacuum system. After electrochemical treatment, both, the electrolyte and the electrode surface were investigated. While on the oxidised HOPG surface the core levels of the detected elements shift towards lower energies, on the reduced samples a shift towards higher binding energies is observed. These shifts refer to a Fermi level shift proving that graphite intercalation compounds were formed. Intercalation occurs together with co-intercalation of the ionic liquid. XPS analysis of the ionic liquids before and after electrochemical treatment reveals changes in electrolyte composition. The influence of impurities on electrochemical behaviour and XPS data is discussed.     

Effects of polymer matrix and salt concentration on the ionic conductivity of plasticized polymer electrolytes

Two polar polymers with different dielectric constants, poly(vinylidene fluoride) (PVDF) and poly(ethylene oxide) (PEO), were each blended with a chlorine-terminated poly(ethylene ether) (PEC) and one of the two salts, LiBF₄ and LiCF₃CO₂, to form PEC plasticized polymer electrolytes. The room-temperature ionic conductivity of the PEC plasticized polymer electrolytes reached a value as high as 10^?4 S/cm. The room-temperature ionic conductivity of the PVDF-based polymer electrolytes displayed a stronger dependence on the PEC content than did the PEO-based polymer electrolytes. In PVDF/PEC/LiBF₄ polymer electrolytes, the dynamic ionic conductivity was less dependent on temperature and more dependent on the PEC content than it was in PEO/PEC/LiBF₄ polymer electrolytes. The highly plasticized PVDF-based polymer electrolyte film with a PEC content greater than CF4 (CF4 defined as the molar ratio of the repeat units of PEC to those of PVDF equal to 4) was self-supported and nonsticky, while the corresponding PEO-based polymer electrolyte film was sticky. In these highly plasticized PVDF-based polymer electrolytes, the curves of the room-temperature ionic conductivity vs. the salt concentration were convex because the number of carrier ions and the chain rigidity both increased with increase of the salt content. The maximum ionic conductivity at 30°C was independent of the PEC content, but it depended on the anion species of the lithium salts in these highly plasticized polymer electrolytes. © 1995 John Wiley & Sons, Inc.     

Structural,electrical and electrochemical properties of polyacrylonitrile-ammonium hexaflurophosphate polymer electrolyte system

Polyacrylonitrile (PAN) based polymer electrolyte membranes complexed with Ammonium hexafluorophosphate (NH₄PF₆) with different molar concentration are prepared by solution casting method. Increase in the amorphous nature by the addition of Ammonium salt and the formation of polymer-salt complex are confirmed by X ray diffraction studies and infrared spectroscopy respectively. The glass transition temperature is measured for all membranes and it showed a lowest value for the PAN complexed with 20 mol% of NH₄PF₆. Electrical properties are studied by AC impedance spectroscopy. An ionic conductivity of the order of 10^?3 Scm^?1 is obtained for the 80 PAN / 20 NH₄PF₆ polymer electrolyte. Conductivity, dielectric and modulus spectra from the impedance data are analysed to understand the ionic transport mechanism. Transference number measurement is done to study the ionic contribution to the charge transport. A proton battery with the configuration, Zn+ ZnSO₄. 7H₂O /80 PAN / 20 NH₄PF₆ / PbO₂ +V₂O₅ has been constructed and its discharge characteristics are studied.     

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether and the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate: Preparation, physico-chemical characterization, and theoretical study

Polymer electrolytes based on poly(ethylene glycol) dimethyl ether (PEGdME) and the ionic liquid (IL) 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]PF₆) have been prepared and characterized by different techniques. Coordination of the IL by the polymer occurs mainly in the amorphous phase. This finding was correlated with previous theoretical investigations of a similar model for polymer electrolytes based on poly(ethylene oxide), PEO, and IL. It has been obtained ionic conductivity σ ∼ 10⁻³ S cm⁻¹ for the polymer electrolyte with 35 wt% of IL at 100 °C. The same order of magnitude for σ was obtained by molecular dynamics simulation of PEO/IL. This work demonstrates consistency between experimental and theoretical results for polymer electrolytes containing ionic liquids.