Blend Electrolytes Research Articles

The H+ ion transport study in polymer blends incorporated with ammonium nitrate: XRD, FTIR, and electrical characteristics

The present study gained insights into H+ ion transport through non-destructive techniques. The XRD outcome reveals that poly(2-ethyl-2-oxazoline) (POZ) reduced the crystalline phase of chitosan (CS) effectively. Films of ion-conducting polymer blend electrolytes were created from CS:POZ complexed with ammonium nitrate (NH4NO3) as an H+ supplier by using the solution casting method. X-ray diffraction was used to study the structural alterations that occurred. The degrees of crystallinity were estimated from the deconvoluted XRD pattern. Measurement of electrical impedance was carried out for the electrolytes. From FTIR measurement, free ion and ion pair values were calculated. Several ion transport parameters (ITP), such as number density (n), ionic mobility (μ), and diffusion coefficient (D), were determined. It was found that the maximum conductivity was 3.87 × 10−6 S cm−1 at 30 percent NH4NO3. The DC conductivity pattern changes linearly with temperature. Dielectric and electric modulus were studied in detail. It was discovered that the loss tangent peak transferred to a upper side of frequency when the salt concentration was increased. Long-range conductivity relaxation was seen in the Mi spectra. The lack of a full semicircle arc on the Argand figure suggested non-Debye ion dynamics. The observed AC conductivity (σac) spectra showed three different zones. In the high-frequency range, the σac value follows a power law (σac=Aωs).

Investigation on conductivity and optical properties for blend electrolytes based on iota-carrageenan and acacia gum with ethylene glycol

Investigation on conductivity and optical properties for blend electrolytes based on iota-carrageenan and acacia gum with ethylene glycol

Electrochemical and Ion Transport Studies of Li+ Ion-Conducting MC-Based Biopolymer Blend Electrolytes.

A facile methodology system for synthesizing solid polymer electrolytes (SPEs) based on methylcellulose, dextran, lithium perchlorate (as ionic sources), and glycerol (such as a plasticizer) (MC:Dex:LiClO4:Glycerol) has been implemented. Fourier transform infrared spectroscopy (FTIR) and two imperative electrochemical techniques, including linear sweep voltammetry (LSV) and electrical impedance spectroscopy (EIS), were performed on the films to analyze their structural and electrical properties. The FTIR spectra verify the interactions between the electrolyte components. Following this, a further calculation was performed to determine free ions (FI) and contact ion pairs (CIP) from the deconvolution of the peak associated with the anion. It is verified that the electrolyte containing the highest amount of glycerol plasticizer (MDLG3) has shown a maximum conductivity of 1.45 × 10−3 S cm−1. Moreover, for other transport parameters, the mobility (μ), number density (n), and diffusion coefficient (D) of ions were enhanced effectively. The transference number measurement (TNM) of electrons (tel) was 0.024 and 0.976 corresponding to ions (tion). One of the prepared samples (MDLG3) had 3.0 V as the voltage stability of the electrolyte.

Study of MC:DN-Based Biopolymer Blend Electrolytes with Inserted Zn-Metal Complex for Energy Storage Devices with Improved Electrochemical Performance.

Stable and ionic conducting electrolytes are needed to make supercapacitors more feasible, because liquid electrolytes have leakage problems and easily undergo solvent evaporation. Polymer-based electrolytes meet the criteria, yet they lack good efficiency due to limited segmental motion. Since metal complexes have crosslinking centers that can be coordinated with the polymer segments, they are regarded as an adequate method to improve the performance of the polymer-based electrolytes. To prepare plasticized proton conducting polymer composite (PPC), a simple and successful process was used. Using a solution casting process, methylcellulose and dextran were blended and impregnated with ammonium thiocyanate and zinc metal complex. A range of electrochemical techniques were used to analyze the PPC, including transference number measurement (TNM), linear sweep voltammetry (LSV), cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The ionic conductivity of the prepared system was found to be 3.59 × 10−3 S/cm using the EIS method. The use of glycerol plasticizer improves the transport characteristics, according to the findings. The carrier species is found to have ionic mobility of 5.77 × 10−5 cm2 V−1 s−1 and diffusion coefficient of 1.48 × 10−6 cm2 s−1 for the carrier density 3.4 × 1020 cm−3. The TNM revealed that anions and cations were the predominant carriers in electrolyte systems, with an ionic transference value of 0.972. The LSV approach demonstrated that, up to 2.05 V, the film was stable, which is sufficient for energy device applications. The prepared PPC was used to create an electrical double-layer capacitor (EDLC) device. The CV plot exhibited the absence of Faradaic peaks in the CV plot, making it practically have a rectangular form. Using the GCD experiment, the EDLC exhibited low equivalence series resistance of only 65 Ω at the first cycle. The average energy density, power density, and specific capacitance values were determined to be 15 Wh/kg, 350 W/kg, and 128 F/g, respectively.

Design of proton conducting solid biopolymer blend electrolytes based on chitosan‐potato starch biopolymers: Deep approaches to structural and ion relaxation dynamics of H+ ion

AbstractThe need for flexible energy storage devices for advanced technologies has encouraged researchers to focus on environmental‐friendly biopolymers. In this work, chitosan (CS) and potato starch (PS) biopolymers are blended to prepare proton conducting solid electrolytes. Based on the X‐ray diffraction (XRD) inspection, the most amorphous blended film with the lowest crystallinity degree was selected to prepare polymer electrolytes. The variation in Fourier‐transform infrared spectroscopy (FTIR) bands were used to investigate the occurrence of interactions among the ammonium thiocyanate (NH4SCN) salt and CS:PS polymer blends. The experimental results of electrochemical impedance spectroscopy (EIS) were simulated with electrical equivalent circuit (EEC) modeling to determine the circuit elements. The highest value of S cm−1 was recorded for the sample included 40 wt.% of dopant salt. The dielectric analyses were helpful in separating the regions ascribed to electrode and molecular polarizations. The combination of circuit elements achieved from the EEC modeling and Koops phenomenological interpretation is used to understand the behavior of the loss tangent (tanδ) pattern. The AC conductivity pattern followed Jonscher's power law. The relaxation dynamics interrelated with ions is explained using electric modulus approaches. The peaks hidden in the dielectric loss () spectra, were manifested in the imaginary part of electric modulus () pattern. The ‐ patterns were used to shed light on the coupling between ionic motion and polymer chain dynamics.

Impedance Spectroscopy, AC Conductivity, and Conduction Mechanism of Iron(II) Chloride/Polyvinyl Alcohol/Polyvinylpyrrolidone Polymer Blend

Polymer blend electrolytes have been prepared using the casting technique. The electrolyte is composed of two polymers polyvinyl alcohol (PVA)/polyvinylpyrrolidone (PVP)) with a fixed ratio (50 : 50) loaded with varied ratios of FeCl2 (0.5, 1, and 2 wt.%). The impedance analysis indicates that the AC conductivity increased as the temperature was following the power law. Nyquist plots for pure and blend composite samples present depressed semicircles at all temperatures. The conduction mechanism of the pure blend sample was based on a hopping mechanism, whereas the ionic conduction was applied to the blend composite sample. The activation energy for blend and blend composite samples was determined, and the two activation regions appeared for blend electrolyte samples. The results indicate a significant improvement in the electrical behavior of the polymeric blend (PVA/PVP) by adding a small weight percentage of FeCl2 salt to the blend samples.

Critical Percolation Threshold for Solvation Site Connectivity in Polymer Electrolytes Mixtures

To address the tradeoff between mechanical strength and Li+ conductivity in Poly(Ethylene Oxide) (PEO)-based electrolytes, a rigid nonconductive polymer is frequently added to the electrolyte via blending or copolymerization. The ionic conductivity of mixed PEO electrolytes is generally lower than that of unmixed PEO electrolytes. The suppressed ionic conductivity is attributed to the reduced segmental mobility and connectivity of the conductive PEO cites. Most experimental systems make it difficult to decouple the two mechanisms and accurately examine their impact on conductivity. We compare two symmetric polymer mixtures (50:50 wt%): a miscible polymer blend PEO/PMMA and a disordered block copolymer (BCP) PEO-b-PMMA, both with the same amount of Li salt. Because their chemical and physical properties are the same, changes in ionic conductivity can be attributed solely to local changes in PEO network connectivity. We discover that the mixtures' immediate Li+ solvation sites (<5 Å) are identical to those of unmixed PEO electrolytes. The presence of non-conducting PMMA near the PEO, on the other hand, causes local concentration changes at longer range scales. The BCP is more mixed than the blend electrolyte at these length scales, resulting in a factor of two drop in conductivity. To that end, we propose a quantitative computational model that considers Li+ transport within and across PEO clusters at the appropriate length scales. This new understanding of network connectivity in polymer electrolyte mixtures is critical for the design of future multiphase polymer electrolyte systems.

The Influence of Polar Functional Groups in Hot-Melt Extruded Polymer Blend Electrolytes for Solid-State Lithium Batteries

Following the COP26 Summit in November 2021, more than hundred countries pledged to reach zero-emission by 2070 at the latest and the major car manufacturers committed to selling only electric vehicles by 2040. Currently, lithium-ion batteries (LIBs) are among the most widely used storage systems because of their high energy and power densities and long lifespan.1 The early LIBs are composed of intercalation electrodes, electronically isolated by an ion-conducting organic liquid electrolyte. However, the use of liquid electrolytes presents some disadvantages – especially in regard to consumer safety – related to short-circuits and potential leakages of the flammable liquid solvent. Moreover, in the case of lithium metal batteries, the combination of a liquid electrolyte and a high-capacity lithium metal anode leads to the uncontrolled deposition of lithium during the reduction, forming dendrites between the electrodes. A promising way to avoid this instability and improve battery safety is to replace the liquid electrolyte with an ion-conducting solid electrolyte.2 Among them, solid polymer electrolytes (SPEs) represent one of the most attractive alternatives due to their capacity to effectively conduct ions and higher mechanical resistance than their liquid counterparts.3 An important criterion for selecting polymers for use in SPEs is their ability to dissolve lithium salts through polar functional groups. Salt dissolution results in the replacement of ion-ion interactions in the lithium salt, with ion-dipole interactions in the polymer. The transport mechanisms of these ion-conducting materials differ from those of liquid electrolytes. Cation transport in polymer involves two steps which are considered to be dissociated or not, depending on the model chosen (Arrhenius or Vogel-Fulcher-Tammann, respectively). The application of one of these models provides interesting information on the ionic mobility dynamics in SPEs and, in particular, on the interplay between ionic jumps and polymer chain mobility. In the Arrhenius model, ionic jumps occur between coordinating sites, without taking into account the influence of segmental relaxation. Conversely, the VTF equation implies a strong relationship between these parameters. According to previous studies, higher segmental motions in the amorphous phase of polymers mainly provide ionic transport, which explains the limited ionic conductivity of SPEs at ambient temperature (less than 10-5 S/cm).Another major limitation of SPEs is primarily related to their dual role as electrolyte and binder in composite electrodes, which requires contradictory requirements to be met. Indeed, SPEs must have both sufficient flexibility to allow good interfacial contact between the electrode components and sufficient rigidity to limit short circuits.Polymer blending has emerged as an economic and effective technique to develop new SPEs which may simultaneously combine properties of each polymer and control the intrinsic properties of the resulting blend by adjusting the formulation.4 Moreover, polymer blends can be obtained by a solvent-free processing method, which reduce SPE toxicity and production time (no solvent evaporation). However, polymer blending makes both the salt dissociation processes and the ionic transport more difficult to understand as both polymers can dissolve lithium salts with their polar functional groups. Each polymer has different ionic transport properties depending on its architecture and thermal properties. Currently, no systematic survey comparing the ability of polymers with various functional groups to dissolve lithium salts in blends has thus far been conducted.In this presentation, we will discuss the salt dissociation ability of polar functional groups in various polymer blend SPEs. These groups are limited to those that are most commonly present in SPEs : ether, nitrile, carbonate, ester, alcohol and amide.5 The blends presented have been obtained by extrusion, which allows the effect of solvents on salt/polymer interactions to be neglected. In this work, coupled FTIR, EDX and 7Li NMR analyses allow the interactions between LiTFSI and the polymer blends to be determined with a good degree of certainty. Our original study combines experimental and theoretical approaches to determine effects of polymers’ lithium salt solvating ability on polymer blend electrolyte properties and represents an advancement in understanding and optimizing polymer selection for SPEs, used in lithium-ion batteries. References Xie, W., Liu, X., He, R., Li, Y., Gao, X., Li, X., Peng, Z., Feng, S., Feng, X. and Yang, S. Journal of Energy Storage 2020, 32, 101837.Chen, R., Qu, W., Guo, X., Li, L. and Wu, F. Materials Horizons 2016, 3, 487-516.Gray, F. M. Solid polymer electrolytes, VCH New Tork 1991.Caradant, L., Lepage, D., Nicolle, P., Prébé, A., Aymé-Perrot, D. and Dollé, M. ACS Applied Polymer Materials 2020, 4943-4951.Caradant, L., Verdier, N., Foran, G., Lepage, D., Prébé, A., Aymé-Perrot, D. and Dollé, M. ACS Applied Polymer Materials 2021. Figure 1

Stable Formulations for the Lithium and Sodium Metal Interfaces in Alkali Metal-Oxygen Batteries

The high reactivity of both positive and negative interfacial regions in metal-oxygen (M-O2) batteries leads to a variety of parasitic degradation reactions that reduce reversibility on charge/discharge and can lead to rapid cell failure. To reversibly access the high theoretical specific energies these chemistries promise (3456 and 1602 Wh·kg-1 for Li-O2 and Na-O2, respectively), reducing charging overpotentials and the design of new electrode and electrolyte materials with improved stabilities are key targets. Considering the M|electrolyte interface, where decomposition reactions and dendrite formation generates severe safety concerns as well as reduced cycling stabilities, surface protection of the alkali metal anode by pre-treatment techniques or additive formulation has been among the more successful methodologies.1 In this work, we present a formulation strategy targeting enhanced cycling stabilities of the metal anode in M-O2 cells. Initially demonstrated in the Li-O2 chemistry, we report on an in-depth investigation into the electrochemical performance and the spectroscopic and diffusional properties of ternary ionic liquid (IL)-molecular solvent blend electrolytes.2 By introduction of the IL and exploring a wide formulation range (Figure 1a), we attain significant enhancements in the stability of practically-relevant electrolyte materials that otherwise fail rapidly at alkali metal anodes (Figure 1b), achieving the highest Coulombic efficiencies for Li plating/stripping in this solvent. The optimized formulations consequently displayed enhanced performances in Li-O2 full cells and ex situ characterization of Li surfaces also revealed the suppression of dendrite formation and important changes in the solid electrolyte interphase as a result of modulating solvent reactivity. Using Raman spectroscopy and diffusional analyses, we relate this closely to the local solvation environments involving the reactive solvent component in optimized formulations and, therefore, elucidate critical solvent/Li-salt ratios for improved stability.By understanding key shifts in Raman spectra relating to solvation effects in concentrated Li formulations, and how this modulates cycling performances, we further demonstrate the applicability of this relationship and formulation strategy to the Na-O2 battery chemistry. Therein, the Na metal interface is comparably more reactive and, therefore, presents greater stability challenges, with decomposition reactions in non-optimized formulations more rapidly causing plating and stripping at the anode to fail. However, we demonstrate the plating/stripping of Na (Figure 1c) and cycle lifetime in Na-O2 cells can be hugely improved by applying the above strategy and understandings of critical solvation interactions to equivalent formulations based on Na-salts. Y. Yu, G. Huang, J.-Z. Wang, K. Li, J.-L. Ma, and X.-B. Zhang, Adv. Mater. (Weinheim, Ger.), 32 (38), 2004157 (2020). A. R. Neale, R. Sharpe, S. R. Yeandel, C.-H. Yen, K. V. Luzyanin, P. Goddard, E. A. Petrucco, and L. J. Hardwick, Adv. Funct. Mater., 31 (27), 2010627 (2021). Figure 1. (a) Ternary plot highlighting the changes in stability of Li/Na metal anode cycling as a function of the studied formulation ranges and example voltage profiles of symmetric (b) Li|Li cells and (c) Na|Na cells with non-optimized (navy/purple) and optimized (orange) electrolyte formulations. Figure 1

Phase Behavior and Ionic Conductivity of Blended, Ion-Condensed Electrolytes with Ordered Morphologies

In this study, the amphiphilic salt lithium trifluoromethanesulfonylimide octadecane (C18LiTFSI) was used as a basis to investigate the effects of anion density and cation coordination sites within blended electrolytes with strong ionic aggregation. C18LiTFSI was previously reported as a single-component, ion-condensed electrolyte with a wide layered liquid crystalline phase regime. Three additive molecules with varyingly sized polar sulfonyl groups attached to an octodecane-tail were synthesized and mixed with C18LiTFSI. The thermal properties, morphology, and ionic conductivity of the blended electrolytes were characterized. It was found that the blended electrolytes exhibited layered liquid crystalline morphology over a narrower temperature range than the pure salt, and the ionic conductivity of the blended liquid crystalline electrolytes were generally lower than that of the pure salt. Surprising, the additives were found to have the greatest effect on the bulk ionic conductivity of the semicrystalline phase of the electrolytes. Addition of minor fractions of methylsulfonyloctadecane to C18LiTFSI resulted in increases in conductivity of over two orders of magnitude at room temperature, while addition of ethylsulfonyloctadecane or isopropylsulfonyloctadecane with the larger head group resulted in decreased ionic conductivity over the entire composition space and temperature range investigated.

Magnesium ion conducting free-standing biopolymer blend electrolyte films for electrochemical device application

Solid polymer blend electrolyte films composed of 70 wt.% of chitosan (CS) and 30 wt.% of methylcellulose (MC) were prepared with different weight percentages of MgCl2 by solution casting method. FTIR analysis demonstrated the interactions between blend and MgCl2, XRD study revealed the amorphous nature of the films. Thermogravimetric analysis (TGA) was carried out to study the thermal stability. Electrical impedance spectroscopy (EIS) study showed that the bulk resistance decreased with increasing salt concentration and is due to the influence of carrier concentration. From EIS measurement, the highest value of DC conductivity at ambient temperature (30 °C) was found to be 2.75 × 10−3 Scm−1 for the sample containing 30 wt.% of MgCl2. The voltage stability window of the highest conducting film was found to be 3.86 V. The total ionic transference number was found to be 0.98. Finally, the highest conducting polymer electrolyte was employed to construct a primary magnesium ion battery.

Insights into ion transport in biodegradable solid polymer blend electrolyte based on FTIR analysis and circuit design

This study reports the use of the solution casting method to prepare a biodegradable polymer blend electrolyte composed of chitosan (CS) and potato starch (PS). Different concentrations of potassium thiocyanate (KSCN) salt as an ionic provider were added to the CS:PS host. The results of X-ray diffraction (XRD) revealed a substantial reduction in the crystalline phase of the host polymers of up to 40 wt% of the added KSCN salt. Fourier transform infrared (FTIR) spectroscopy was used to detect microstructural modifications to the films to explore the complexation between the blended polymer chains and ions of the salt. Deconvoluted FTIR spectra were used to compute the free ions, contact ion pairs, and ion aggregates, which were then used as a sensitive method to determine the parameters of ion transport, including mobility (μ), carrier density (n), and the diffusion coefficient (D). Electrochemical impedance spectroscopy (EIS) was used based on electrical equivalent circuit modeling to study the electrical properties of the electrolyte films. A circuit design for each electrolyte was presented based on the curves of fitting of the EIS data. The parameters associated with elements of the circuit were of significant interest, especially for determining the conductivity of the films. The sample with the highest KSCN concentration of 50 wt% exhibited a reduction in conductivity due to the formation of ion pairs, the recrystallization of salt, and a decline in the amorphous fraction of the system, which was also visualized from its surface morphology by using an optical microscope. An analysis of properties of the dielectric manifested an enhancement upon the addition of salt, with characteristics of dispersive relaxation that verified the non-Debye behavior of the solid polymer electrolyte films. This behavior was further confirmed through the appearance of a distorted arc in the Argand plot. A decrease in the relaxation time was noted with the addition of salt, where this was in agreement with the results of EIS and AC conductivity measurements. An examination of the electric modulus revealed the process of viscoelastic relaxation whereby ion hopping was supported by coupling with segmental chain dynamics.

Hole transport and current–voltage characteristics of PEO/PVP/cobalt nitrate polymer blend electrolytes

AbstractHole transport properties and Current–Voltage characteristics of the single‐layer device in an inverted structure were investigated with spin‐coated PEO/PVP/Cobalt nitrate polyblend electrolyte film as an active layer. A strong correlation between morphology and ionic conductivity was confirmed through XRD, DSC‐TGA, SEM and fluorescence spectroscopic techniques. The optical band gap values are in good agreement with the electrochemical band gap. Schottky diode measurements confirmed the formation of p‐type semiconductors with PEO/PVP bulk films with cobalt nitrate as a dopant at room temperature. The I‐V characteristics are strongly dependent on the salt concentration in the polymer blend. The parameters of diodes such as barrier height, saturation current, and charge carrier concentration were calculated from I‐V characteristics. From C‐V characteristics a charge carrier concentration in the range of 1022 cm−3 was obtained for the highest concentration of cobalt nitrate salt in the PEO/PVP blend. A very low energy barrier for hole injection at the anode ΔEh = 0.28 eV was observed.

Structural and energy storage behavior of ion conducting biopolymer blend electrolytes based on methylcellulose: Dextran polymers

Biodegradable polymer electrolyte has attracted significant attention from both economic and environmental perspectives. This study reports the preparation and analysis of plasticized methylcellulose (MC)-dextran (DN)-ammonium iodide (NH4I) bio-based polymer electrolytes with high ion transport properties using solution casting method.It was discovered that when the glycerol concentrations increased, the FTIR bands changed and dropped in their intensities, revealing good complexation between electrolyte constituents. The glycerol inclusion improved the ionic conductivity up to (3.24 × 10−4) S/cm, according to impedance spectroscopy (EIS). The EEC simulation has been employed to study the electrolyte circuit components further. Transference number measurement (TNM) was used to calculate both transport ion (tion) and electron (tel) values, which were found to be 0.952 and 0.048, respectively. The most conducting sample was found to be stable up to 2 V. Various techniques, such as cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) were utilized to examine the properties of the assembled EDLC device. At the initial cycle, the designed EDLC had a specific capacitance (Cspe) value of ∼ 44F/g, with an energy density of ∼ 4.9 Wh/kg and a power density of ∼ 500 W/kg.

Polysiloxane‐Based Single‐Ion Conducting Polymer Blend Electrolyte Comprising Small‐Molecule Organic Carbonates for High‐Energy and High‐Power Lithium‐Metal Batteries

AbstractSingle‐ion conducting polymer electrolytes are considered particularly attractive for realizing high‐performance solid‐state lithium‐metal batteries. Herein, a polysiloxane‐based single‐ion conductor (PSiO) is investigated. The synthesis is performed via a simple thiol‐ene reaction, yielding flexible and self‐standing polymer electrolyte membranes (PSiOM) when blended with poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP). When incorporating 57 wt% of organic carbonates, these polymer membranes provide a Li+ conductivity of &gt;0.4 mS cm−1 at 20 °C and a wide electrochemical stability window of more than 4.8 V. This excellent electrochemical stability allows for the highly reversible cycling of symmetric Li||Li cells as well as high‐energy Li||LiNi0.6Mn0.2Co0.2O2 (NMC622) and Li||LiNi0.8Mn0.1Co0.1O2 (NMC811) cells for several hundred cycles at relatively high discharge and charge rates. Remarkably, Li||NMC811 cells with high mass loading cathodes provide more than 76% capacity retention at a high current density of 1.44 mA cm−2, thus rendering this polymer electrolyte suitable for high‐performance battery applications.

Graphene oxide induced high dielectricity in CS/PMMA solid polymer electrolytes and the enhanced specific capacitance with Ag decorated MnCoFeO4 nanoparticles anchored graphene sheets in hybrid solid-state supercapacitors

Enhanced specific capacitance with silver decorated manganese cobalt ferrite (MnCoFeO4) nanoparticles anchored onto graphene sheets as an electrode and graphene oxide (GO) grafted chitosan (CS)/ polymethyl methacrylate (PMMA) as solid electrolytes in hybrid solid-state supercapacitors has been reported here. GO doped CS/PMMA blended solid electrolytes exhibit high ionic conductivity (∼4.5 × 10−3 S/cm) and dielectric constant (∼4018) at room temperature. Thermal analysis suggests a significant reduction in crystallinity in GO grafted CS/PMMA electrolytes. The scaling of the ac conductivity and dielectric constant suggests that the relaxation phenomenon is independent of the CS/PMMA blending compositions but dependent on the GO doping. The interaction between Li+cation and the amide functional group is weakened remarkably on grafting the electrolytes with GO. An effective specific capacitance of ∼294 Fg−1 is obtained with Ag decorated MnCoFeO4 nanoparticles anchored onto rGO electrode which is ∼2.5 times enhanced compared to that with MnCoFeO4 electrode.

Development of Flexible Plasticized Ion Conducting Polymer Blend Electrolytes Based on Polyvinyl Alcohol (PVA): Chitosan (CS) with High Ion Transport Parameters Close to Gel Based Electrolytes.

In the current study, flexible films of polyvinyl alcohol (PVA): chitosan (CS) solid polymer blend electrolytes (PBEs) with high ion transport property close enough to gel based electrolytes were prepared with the aid of casting methodology. Glycerol (GL) as a plasticizer and sodium bromide (NaBr) as an ionic source provider are added to PBEs. The flexible films have been examined for their structural and electrical properties. The GL content changed the brittle and solid behavior of the films to a soft manner. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) methods were used to examine the structural behavior of the electrolyte films. X-ray diffraction investigation revealed that the crystalline character of PVA:CS:NaBr declined with increasing GL concentration. The FTIR investigation hypothesized the interaction between polymer mix salt systems and added plasticizer. Infrared (FTIR) band shifts and fluctuations in intensity have been found. The ion transport characteristics such as mobility, carrier density, and diffusion were successfully calculated using the experimental impedance data that had been fitted with EEC components and dielectric parameters. CS:PVA at ambient temperature has the highest ionic conductivity of 3.8 × 10 S/cm for 35 wt.% of NaBr loaded with 55 wt.% of GL. The high ionic conductivity and improved transport properties revealed the suitableness of the films for energy storage device applications. The dielectric constant and dielectric loss were higher at lower frequencies. The relaxation nature of the samples was investigated using loss tangent and electric modulus plots. The peak detected in the spectra of tanδ and M” plots and the distribution of data points are asymmetric besides the peak positions. The movements of ions are not free from the polymer chain dynamics due to viscoelastic relaxation being dominant. The distorted arcs in the Argand plot have confirmed the viscoelastic relaxation in all the prepared films.

Studies of Circuit Design, Structural, Relaxation and Potential Stability of Polymer Blend Electrolyte Membranes Based on PVA:MC Impregnated with NH4I Salt.

This work presents the fabrication of polymer electrolyte membranes (PEMs) that are made of polyvinyl alcohol-methylcellulose (PVA-MC) doped with various amounts of ammonium iodide (NH4I). The structural and electrical properties of the polymer blend electrolyte were performed via the acquisition of Fourier Transform Infrared (FTIR) and electrical impedance spectroscopy (EIS), respectively. The interaction among the components of the electrolyte was confirmed via the FTIR approach. Electrical impedance spectroscopy (EIS) showed that the whole conductivity of complexes of PVA-MC was increased beyond the addition of NH4I. The application of EEC modeling on experimental data of EIS was helpful to calculate the ion transport parameters and detect the circuit elements of the films. The sample containing 40 wt.% of NH4I salt exhibited maximum ionic conductivity (7.01 × 10−8) S cm−1 at room temperature. The conductivity behaviors were further emphasized from the dielectric study. The dielectric constant, ε’ and loss, ε’’ values were recorded at high values within the low-frequency region. The peak appearance of the dielectric relaxation analysis verified the non-Debye type of relaxation mechanism was clarified via the peak appearance of the dielectric relaxation. For further confirmation, the transference number measurement (TNM) of the PVA-MC-NH4I electrolyte was analyzed in which ions were primarily entities for the charge transfer process. The linear sweep voltammetry (LSV) shows a relatively electrochemically stable electrolyte where the voltage was swept linearly up to 1.6 V. Finally, the sample with maximum conductivity, ion dominance of tion and relatively wide breakdown voltage were found to be 0.88 and 1.6 V, respectively. As the ions are the majority charge carrier, this polymer electrolyte could be considered as a promising candidate to be used in electrochemical energy storage devices for example electrochemical double-layer capacitor (EDLC) device.

Fabrication of a PEO-PVDF blend based polymer composite electrolyte with extremely high ionic conductivity via the addition of LLTO nanowires

In this study, fast ionic conductor electrospun Li0.33La0.55TiO3 (LLTO) nanowires were added to the PEO-PVDF blend electrolyte. We then investigated the effect of nanowire diameter and weight percentage on ionic conductivity, mechanical properties, and electrolyte performance. The results indicated that polymer composite electrolytes containing 88 nm diameter nanowires exhibited a higher ionic conductivity than those containing 161 nm or 238 nm diameter nanowires. By adding LLTO nanowires with a diameter of 238 nm, the electrochemical potential window increased to at least 4.87 V. The stability of composite polymer electrolytes containing nanowires with a diameter of 88 nm was greater than that of composite polymer electrolytes containing nanowires with a diameter of 238 nm. By adding 8 wt% LLTO nanowires with a diameter of 88 nm to the PEO-PVDF blend electrolyte, the thermal stability and ionic conductivity increased to 450 °C and 6.02 mS.cm−1, respectively.

Cornstarch/polyvinylpyrrolidone based proton conducting biocompatible polymer blend electrolyte for long life battery

Cornstarch/polyvinylpyrrolidone based proton conducting biocompatible polymer blend electrolyte for long life battery