Transference Number Measurements Research Articles

Tamarind seed polysaccharide biopolymer membrane for lithium-ion conducting battery

Solid biopolymers have gained much attention in the development of polymer electrolytes due to its biocompatibility, film-forming nature, and non-toxicity. In the present work, biopolymer membrane has been prepared using tamarind seed polysaccharide (TSP) as host polymer and various concentrations of lithium chloride (LiCl) salt as dopant by solution casting technique. The prepared biopolymer electrolyte has been characterized by XRD, FTIR, differential scanning calorimetry (DSC) analysis, AC impedance spectroscopy analysis, and transference number measurement. XRD analysis has been done to investigate the amorphous/crystalline nature of the polymer membrane. The highest amorphous nature has been found for 1 g of TSP with 0.4 g LiCl. FTIR spectrum analysis confirms the complex formation between TSP biopolymer with LiCl. From AC impedance conductivity analysis, the maximum ionic conductivity is of the order of 6.7 × 10−3 S cm−1 at room temperature for 1 g TSP with 0.4 g LiCl, whereas for pure TSP biopolymer membrane, the ionic conductivity is of the order of 5.48 × 10−7 S cm−1. The glass transition temperature for the highest conducting biopolymer membrane for the composition of 1 g TSP: 0.4 g LiCl has been found to be 44.25 °C using the DSC technique. Employing the maximum conducting biopolymer membrane, a lithium-ion conducting battery has been fabricated and its discharge characteristics have been studied.

A study on blend polymer electrolyte based on poly(vinyl alcohol)-poly (acrylonitrile) with magnesium nitrate for magnesium battery

Studies on magnesium ion conducting blend polymer electrolyte (BPE) at room temperature are reported. BPE films of optimized 92.5PVA:7.5PAN ratio in view of its maximum conductivity with various concentrations of magnesium salt—Mg(NO3)2—of different molar mass percentages (0.1, 0.2, 0.3, and 0.4 m.m.%) have been prepared using solution-casting technique with dimethylformamide (DMF) as solvent. The promising characteristic features of these films have been studied. Possible conformational changes in the polymer host 92.5PVA:7.5PAN due to Mg(NO3)2 entrapment have been investigated by FTIR and XRD analysis. The composition 92.5PVA:7.5PAN:0.3 m.m.% Mg(NO3)2 offers maximum electrical conductivity of 1.71 × 10−3 S/cm at room temperature. The σ values follow the Arrhenius equation, and the activation energy for the optimized composition is 0.36 eV. The variations in glass transition temperature have been found using differential scanning calorimeter. Mg2+ ion conduction in the BPE film is confirmed using transference number measurement and cyclic voltammetry. The transport number of the Mg2+ ion is 0.30. Using linear sweep voltammetry, the electrochemical stability window for the highest BPE has been measured. Primary magnesium battery has been constructed using the maximum conducting membrane, and its output characteristics have been studied.

Large tunable photoeffect on ion conduction in halide perovskites and implications for photodecomposition

In the same way as electron transport is crucial for information technology, ion transport is a key phenomenon in the context of energy research. To be able to tune ion conduction by light would open up opportunities for a wide realm of new applications, but it has been challenging to provide clear evidence for such an effect. Here we show through various techniques, such as transference-number measurements, permeation studies, stoichiometric variations, Hall effect experiments and the use of blocking electrodes, that light excitation enhances by several orders of magnitude the ionic conductivity of methylammonium lead iodide, the archetypal metal halide photovoltaic material. We provide a rationale for this unexpected phenomenon and show that it straightforwardly leads to a hitherto unconsidered photodecomposition path of the perovskite.

Measurement of Transference Number of Polythiophene -Poly(Ethylene Oxide) Polymer Composite

Measurement of Transference Number of Polythiophene -Poly(Ethylene Oxide) Polymer Composite

Comprehensive studies on polymer electrolyte and dye-sensitized solar cell developed using castor oil-based polyurethane

Comprehensive characterization of new polymer electrolyte system prepared using polyurethane derived from castor oil polyol was undertaken. The castor oil polyol was synthesized via transesterification and reacted with 4,4′-diphenylmethane diisocyanate to form polyurethane. Polyurethane electrolyte films were prepared by addition of sodium iodide in different weight percentage with respect to the weight of the polymer. The electrolyte films were analyzed using Fourier transform infrared spectroscopy, dynamic mechanical analysis, electrochemical impedance spectroscopy, transference number measurement, and linear sweep voltammetry. Fourier transform infrared spectroscopy results confirmed the complexation between polymer and salt. Tan delta peak observed in the tan δ–temperature curve plotted using data obtained from dynamic mechanical analysis indicated that the glass transition temperature of polyurethane decreased with the addition of sodium iodide. The highest conductivity of 4.28 × 10−7 S cm−1 was achieved for the film with 30 wt% of sodium iodide. The performances of dye-sensitized solar cell using the electrolyte systems were analyzed in terms of short-circuit current density, open-circuit voltage, fill factor, and energy conversion efficiency. The polymer electrolyte with 30 wt% sodium iodide showed the best performance with energy conversion efficiency of 0.80%.

Preparation and characterization of blend polymer electrolyte film based on poly(vinyl alcohol)-poly(acrylonitrile)/MgCl2 for energy storage devices

The development of magnesium electrolytes for battery applications has been the demand for electrochemical devices. To meet such demand, in this work solid blend polymer electrolytes were prepared using polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) (92.5PVA:7.5PAN) as host polymer, magnesium chloride (MgCl2) of different molar mass percentage (m.m.%) (0.1, 0.2, 0.3, 0.4, 0.5, and 0.6%) as salt and dimethylformamide (DMF) as solvent. Structural, vibrational, thermal, electrical, and electrochemical properties of the prepared electrolytes were investigated using different techniques such as X-ray diffraction pattern, FTIR spectroscopy analysis, differential scanning calorimetry (DSC), AC impedance measurement, and transference number measurement. X-ray diffraction studies confirm the minimum volume fraction of crystalline phase for the polymer electrolyte with 0.5 m.m.% of MgCl2. FTIR confirms the complex formation between host polymer and salt. DSC analysis proves the thermal transition of the prepared films are affected by salt concentration. The optimized material with 0.5 m.m.% of MgCl2 offers a maximum electrical conductivity of 1.01 × 10−3 S cm−1 at room temperature. The Mg2+ ion conduction in the blend polymer electrolyte is confirmed from transference number measurement. Electrochemical analysis demonstrates the promising characteristic of these polymer films suitable as electrolytes for primary magnesium batteries. Output potential and discharge characteristics have been analyzed for primary magnesium battery which is constructed using optimized conducting electrolyte.

Structural and electrical properties of Bi3Y0.9W0.1O6.15-La0.8Sr0.2MnO3 (BiYWO-LSM) composites

Electrical conductivity and structural behavior in Bi3Y0.9W0.1O6.15-La0.8Sr0.2MnO3 (BiYWO-LSM) composite cathodes for intermediate temperature solid-oxide fuel cells (IT-SOFCs) have been investigated. The ionically conducting component (BiYWO) was selected as it not only exhibits high oxide ion conductivity at intermediate temperatures, but also shows good long-term stability. The LSM component is a well-known electronic conductor, commonly used for SOFC cathodes and also shows high interfacial polarization effects. Both composite components exhibit similar thermal expansion coefficients. Composites of different molar ratios of components were prepared by sintering the components together at 850°C. Electrical behavior was studied by a.c. impedance spectroscopy and transference number measurements were used to determine the ionic and electronic contributions to total conductivity. Percolation type behavior was observed for total conductivity and the percolation threshold value was determined to be in the bismuth rich region of the compositional range, due to the significant difference in the grain sizes of the two components. Ionic and electronic components of the total conductivity at, above and below the percolation threshold are discussed. Stability measurements on a composition close to the percolation threshold show some degree of conductivity decay on prolonged annealing at 650°C, which is partly recoverable on heating to higher temperatures.

Incorporation of NH4Br in Tamarind Seed Polysaccharide biopolymer and its potential use in electrochemical energy storage devices

Abstract Novel proton conducting biopolymer Tamarind Seed Polysaccharide complexed with different concentrations of ammonium bromide have been prepared and characterized. The increase in amorphous nature of the sample has been confirmed by structural analysis. The complex formation between biopolymer and salt has been confirmed by vibrational analysis. The glass transition temperature values of the biopolymer membranes have been found by Differential Scanning Calorimetry analysis. The maximum ionic conductivity 1.58 × 10 −3 S cm −1 is observed for 1 g TSP: 0.4 g NH 4 Br by impedance analysis. The conducting ions in the polymer network have been confirmed by transference number measurement. A simple battery has been fabricated with good stability of 1.54 V as open circuit voltage. The red light emitting diode has been activated by the battery constructed with the highest ionic conductivity membrane.

Influence of nano-sized fumed silica on physicochemical and electrochemical properties of cellulose derivatives-ionic liquid biopolymer electrolytes

Nanocomposite biopolymer electrolyte was prepared by solution-casting technique. Carboxymethyl cellulose from kenaf bast fibre, ammonium acetate, (1-butyl)trimethyl ammonium bis(trifluoromethylsulfonyl)imide ionic liquid and silica nanofiller was used to prepare the biopolymer electrolyte samples. The films were characterized by Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, scanning electron microscopy, transference number measurement and linear sweep voltammetry. The interactions of doping salt, ionic liquid and inorganic nanofiller with the host biopolymer were confirmed by FTIR study. The highest conductivity achieved was 8.63 × 10−3 S cm−1 by the incorporation of 1 wt% of SiO2 at ambient temperature. The electrochemical stability of the highest conducting sample was stable up to 3.4 V, and the ion transference number in the film was 0.99.

Impact of acceptor-type substitution on electrical transport properties of zircon-type EuVO4

Magnesium-substituted europium vanadate ceramics, MgxEuVO4±δ (x=0–0.5), were prepared by solid state method and characterized by XRD, SEM/EDS, dilatometry, UV–vis spectroscopy, impedance spectroscopy, and measurements of oxygen-ion transference numbers (to¯). Magnesium was found to substitute preferentially into vanadium sublattice of zircon-type EuVO4 with limited solubility of ∼5at.%. Additions of magnesium increase slightly coefficients of thermal expansion (3.2–6.0ppm/K at 150–400°C) and have negligible effect on the optical properties. Undoped EuVO4 is predominantly an oxygen-ionic conductor with to¯=0.96–0.99 at 700–900°C under oxidizing conditions. Acceptor-type substitution suppresses total conductivity and oxygen-ionic transport. The variations of electrical transport properties are discussed in terms of interstitial oxygen diffusion in the parent EuVO4 and oxygen vacancy diffusion in Mg-substituted vanadate. Humidified atmosphere has negligible impact on the electrical properties of substituted ceramics but results in increased electrical conductivity of EuVO4 indicating a protonic contribution to the total electrical transport.

Effect of lithium salt on physicochemical properties of P(MMA-co-EMA) based copolymer electrolytes for dye-sensitized solar cell application

In the present work, free standing films of methyl methacrylate and ethyl methacrylate complexed with different weight ratios of lithium iodide salt were successfully prepared via solution casting technique. Fourier transform infrared spectroscopy showed that the interaction between lithium ion and oxygen atoms occurred at carbonyl and ether group of the host copolymer. The incorporation of 20 wt% lithium iodide optimized the ambient temperature conductivity of the electrolyte up to 1.3 × 10−6 S cm−1. The glass transition temperature and activation energy decreased with increase in ionic conductivity which can be explained by the increase of segmental motion in polymer matrix resulting in enhancement of ion mobility. The majority of ions in this copolymer systems were anions as confirmed from lithium transference number measurements. The dye-sensitized solar cell fabricated using the highest conducting film exhibited photovoltaic response efficiency of 0.45%.

Structural, thermal and electrical properties of polyvinyl alcohol/poly(vinyl pyrrolidone)–sodium nitrate solid polymer blend electrolyte

Sodium ion conducting solid polymer blend electrolyte thin films have been prepared by using polyvinyl alcohol (PVA)/poly(vinyl pyrrolidone) (PVP) with NaNO3 by solution cast technique. The prepared films were characterized by various methods. The complexation of the salt with the polymer blend was identified by X-ray diffraction (XRD) and Fourier transforms infrared spectroscopy (FTIR), Differential scanning calorimetry was used to analyze the thermal behavior of the samples, and the glass transition temperature is low for the highest conducting polymer material. The scanning electron microscopy gives the surface morphology of the polymer electrolytes. The frequency and temperature dependent of electrical conductivities of the films were studied using impedance analyzer in the frequency range of 1 Hz to 1 MHz. The highest electrical conductivity of 50PVA/50PVP/2 wt% NaNO3 concentration has been found to be 1.25 × 10−5 S cm−1 at room temperature. The electrical permittivity of the polymer films have been studied for various temperatures. The transference number measurements showed that the charge transport is mainly due to ions than electrons. Using this highest conducting polymer electrolyte, an electrochemical cell is fabricated and the parameters of the cells are tabulated.

Mg-ion conducting blend polymer electrolyte based on poly(vinyl alcohol)-poly (acrylonitrile) with magnesium perchlorate

Research on magnesium battery has gained momentum in recent years due to its high stability and hazardous free nature. For such batteries solid polymer electrolyte films have been prepared using blend polymer technique with the polymers polyvinyl alcohol (PVA) & polyacrylonitrile (PAN) (92.5PVA:7.5PAN) and Mg(ClO4)2 of different molar mass percentage (m.m.%) as 0.05%,0.1%,0.15%,0.2%,0.25% and 0.3% by solution casting technique using DMF as solvent. The XRD results confirms that the incorporation of magnesium salt (Mg(ClO4)2) which reduces the crystallinity of blend polymer (92.5PVA:7.5PAN). FTIR has been carried out to study the complex formation between the blend polymer and salt. AC impedance spectroscopy has been used to examine the ionic conductivity and dielectric behaviour of the blend polymer electrolyte (BPE). The maximum ionic conductivity of 2.96×10−4S/cm has been observed for the sample 92.5PVA:7.5PAN:0.25m.m.% Mg(ClO4)2 at room temperature for which the activation energy measured is minimum (0.21eV). Electrochemical studies show that highest conducting BPE has the highest electrochemical stability. Transference number measurement confirms that the conducting species are Mg2+ ion. Primary magnesium battery has been constructed with maximum conducting electrolyte system and its discharge characteristics have been studied.

Synthesis and characterization of dextrin-based polymer electrolytes for potential applications in energy storage devices

An attempt has been made to synthesise a new proton conducting polymer electrolyte using the biopolymer dextrin doped with ammonium thiocyanate salts using solution casting technique. The complexation has been studied using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The differential scanning calorimetry (DSC) thermograms of dextrin with NH4SCN showed that Tg value increases with respect to the increase of NH4SCN concentration. The electrical conductivity was measured using AC impedance analyser which showed that ionic conductivity increases with increase in salt concentration up to 40%. Transference number measurement was carried out to investigate the nature of the charge transport species in the polymer electrolyte. Surface morphology of the electrolytes was determined using scanning electron microscope (SEM) studies, and the chemical composition of the elements present was determined using EDAX. The proton battery was constructed with the highest conducting polymer electrolyte Dex-40%NH4SCN and its open circuit voltage with load were carried out.

The Effect of Li Ion Dissociation Level in Gel Polymer Electrolytes on Electrochemical Performance of Li-O2 Batteries

Li-O2 batteries have been recently considered as next generation of energy storage systems for electric vehicle application due to their high specific energy densities, which are comparable to gasoline [1]. Li-O2 batteries however suffer poor cycling and reachability due to a sever electrolyte decomposition [2]. It has been shown that the electrolyte decomposition by-products such as lithium carbonate species gradually cover the surface of cathodes and shuts down the batteries quickly [3]. Although many attempts have been made to overcome the detrimental formation of these carbonate species on the surface of cathode, their formation and electrolyte instability still remains a very big challenge in this filed [4]. Recently, it has been reported that tailoring the coordination of Li ion and solvent molecules in Li-O2 battery electrolytes is a promising method to improve the electrolyte stabilities [5,6]. In this study, we report that the inclusion of inorganic fillers in gel polymer electrolytes using different salt concentration can reduce the electrolyte decomposition by-products such as lithium carbonate species during the Li-O2 battery cycling. The improved electrochemical performance of Li-O2 batteries can be attributed to the interaction of filler with Li salt which in turn can tailor the interaction of Li ion and solvent molecules. To asses our hypothesis different electrochemical tests including in-depth electrochemical impedance spectroscopy, lithium transference number measurements along with other characterization methods such as Raman spectroscopy has been used. [1] G. Girishkumar, B. McCloskey, A.C. Luntz, S. Swanson, W. Wilcke, Lithium-air battery: Promise and challenges, J. Phys. Chem. Lett. 2010,1, 2193–2203. [2] B. D. McCloskey, C. M. Burke, J. E. Nichols and S. E. Renfrew, Chem. Commun., 2015, 51, 12701–12715 [3] S. A. Freunberger, Y. Chen, N. E. Drewett, L. J. Hardwick, F. Bardé and P. G. Bruce, Angew. Chemie - Int. Ed., 2011, 50, 8609–8613 [4] R. Younesi, G.M. Veith, P. Johansson, K. Edstrom, T. Vegge, Lithium salts for advanced lithium batteries: Li-metal, Li-O2, and Li-S, Energy Environ. Sci.,2015, 8, 1905–1922. [5] F. Li, T. Zhang, Y. Yamada, A. Yamada and H. Zhou, Adv. Energy Mater., 2013, 3, 532–538. [6] B. Liu, W. Xu, P. Yan, X. Sun, M. E. Bowden, J. Read, J. Qian, D. Mei, C. M. Wang and J. G. Zhang, Adv. Funct. Mater., 2016, 26, 605–613.

Effect of Prolonged Duration of Gelatinization in Starch and Incorporation with Potassium Iodide on the Enhancement of Ionic Conductivity

ABSTRACTThree systems of starch-based crust electrolytes were prepared using various gelatinization times, various weight percentages (wt%) of starch, and various wt% of starch incorporated into potassium iodide. All the samples were subjected to electrochemical impedance spectroscopy, X-ray diffraction spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and transference number measurements. Electrochemical impedance spectroscopy shows that 1.7 wt% of starch has maximized the room temperature conductivity of the electrolyte to 1.4587 × 10−4 S cm−1. The conductivity was enhanced to 4.5278 × 10−4 S cm−1 on the increment of starch’s wt% from 1.7 to 3.2. This conductivity was further enhanced to 3.4609 × 10−3 S cm−1 on the addition of 0.3 wt% of potassium iodide. The conductivity enhancement was found due to the formation of glucosyl carboxonium ions. The effect of longer heating time in gelatinization is attributed to the formation of glucosyl carboxonium ions. X-ray diffraction spectroscopy affirms the reduction in crystallinity of starch. Scanning electron microscopy analysis shows the porous morphology of starch electrolyte, and addition of potassium iodide shows the morphology of bean nuts like particles seated on the pores. Fourier transform infrared confirms the degradation of starch. Transference number measurements of the crust electrolyte shows that ions are the dominant conducting species. All the results are authenticating that the conductivity enhancement in starch-based crust electrolyte is due to starch and the addition of inorganic salts.

Biopolymer agar‐agar doped with NH4SCN as solid polymer electrolyte for electrochemical cell application

ABSTRACTA new polymer electrolyte based on the biopolymer Agar‐Agar doped with ammonium thiocyanate (NH4SCN) has been prepared and characterized by FTIR analysis, X‐ray diffraction measurements, AC impedance spectroscopy, transference number measurements, and DSC analysis. The Fourier transform infrared analysis confirms the complex formation between agar and NH4SCN. The amorphous nature of the polymer electrolyte has been revealed from X‐ray diffraction analysis. The highest ionic conductivity has been observed for the sample of composition 1:1 between Agar and NH4SCN. As a function of temperature, the ionic conductivity of this sample exhibits Arrhenius behavior increasing from 1.03 × 10−3 S cm−1 at ambient temperature to 3.16 × 10−3 S cm−1 at 343 K. The transference number has been estimated by the dc polarization method, and it has been proven that the conducting species are predominantly cations. Using the highest conductivity polymer electrolyte, solid state electrochemical cell has been fabricated and cell parameters are reported. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44702.

The effect of NH4NO3 towards the conductivity enhancement and electrical behavior in methyl cellulose-starch blend based ionic conductors

Solid polymer electrolytes based on methyl cellulose (MC)-potato starch (PS) blend doped with ammonium nitrate (NH4NO3) are prepared by solution cast technique. The interaction between the electrolyte’s materials is proven by Fourier transform infrared (FTIR) analysis. The thermal stability of the electrolytes is obtained from thermogravimetric analysis (TGA). The room temperature conductivity of undoped 60 wt.% MC-40 wt.% PS blend film is identified to be (1.04 ± 0.19) × 10−11 S cm−1. The addition of 30 wt.% NH4NO3 to the polymer blend has optimized the room temperature conductivity to (4.37 ± 0.16) × 10−5 S cm−1. Conductivity trend is verified by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and dielectric analysis. Temperature-dependence of conductivity obeys Arrhenius rule. Conductivity is found to be influenced by the number density (n) and mobility (μ) of ions. From transference number measurements (TNM), ions are found to be the dominant charge carriers.

Preparation and characterization of cellulose acetate and lithium nitrate for advanced electrochemical devices

Environmental research has the objective of finding solutions to environmental degradation. To this aim, an optimized solid bio-polymer electrolyte (BPE) based on cellulose acetate (CA) with lithium nitrate (LiNO3) has been developed to achieve the possible energy storage Li-ion batteries. CA is one of the natural polymers with very good film forming capacity. The widespread use of CA is attributed to the availability of renewable resources, non-toxic nature, low cost, and bio-compatible material. Here, we demonstrate an extremely simplest process of solution-casting technique for the development of BPE by incorporating various LiNO3 compositions (wt.%) with bio-polymer material CA. The crystalline nature of the CA with LiNO3 has been analyzed by X-ray diffraction (XRD) measurement. The bio-polymer-salt complex formation and the biopolymer-proton interactions have been investigated through Fourier transform infrared (FTIR) spectroscopy. Electrochemical impedance spectroscopy has been used to examine the ionic conductivity of the BPEs at room temperature (303 K). The highest ionic conductivity of 1.93 × 10−3S/cm has been achieved for 50CA/50LiNO3 polymer electrolyte. Electrochemical studies show that highest BPE has high electrochemical stability windows. The conducting species is found to be Li+ ion, which has been confirmed by transference number measurement (TNM). Primary lithium battery with discharge profile has been constructed for 50CA/50LiNO3. This research will help to identify a new lithium ion membrane for battery technology and other electrochemical device applications.

Structural and Ionic Transport Properties of Protonic Conducting Solid Biopolymer Electrolytes Based on Carboxymethyl Cellulose Doped with Ammonium Fluoride.

Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and transference number measurement (TNM) techniques were applied to investigate the complexation, structural, and ionic transport properties of and the dominant charge-carrier species in a solid biopolymer electrolyte (SBE) system based on carboxymethyl cellulose (CMC) doped with ammonium fluoride (NH4F), which was prepared via a solution casting technique. The SBEs were partially opaque in appearance, with no phase separation. The presence of interactions between the host polymer (CMC) and the ionic dopant (NH4F) was proven by FT-IR analysis at the C-O band. XRD spectra analyzed using Origin 8 software disclose that the degree of crystallinity (χc%) of the SBEs decreased with the addition of NH4F, indicating an increase in the amorphous nature of the SBEs. Analysis of the ionic transport properties reveals that the ionic conductivity of the SBEs is dependent on the ionic mobility (μ) and diffusion of ions (D). TNM analysis confirms that the SBEs are proton conductors.