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In this study, polymer blends of polythiophene (PTH) and poly(vinylidene fluoride) (PVDF) are investigated by focusing on their structural and electrochemical characteristics. These blends displayed immiscibility confirmed through field emission scanning electron microscopy (FE‐SEM) and interaction assessments. PTH's role as a plasticizer is evident, diminishing crystallinity. A rise in PTH level led to a lower glass transition temperature and a higher melting point, suggesting reduced intermolecular forces and increased polymer chain flexibility. Conversely, a dispersed phase presence elevated the melting point, restricting chain movement and crystallization. The thermal properties of blends are enhanced by increased PTH content. Applying the Vogel–Tammann–Fulcher model to ionic conductivity measurements, it observed a direct relationship between temperature and free volume, impacting conductivity and ion transport numbers. Certain materials exhibit increased activation energies, indicating substantial thermodynamic barriers to local motion. Higher PTH content within the PVDF matrix notably increased the lithium ion transfer number from 0.22 to 0.71, a change tied to the C–S–C structure of polythiophene. However, elevated PTH levels also led to diminished negative charge transfer and ionic conductivity in the PTH‐PVDF blend compared to pure PVDF, likely due to an ionic conduction hindrance. [ABSTRACT FROM AUTHOR]

Solid‐state nanopore gating inspired by biological ion channels is gaining increasing traction due to a large range of applications in biosensing and drug delivery. Integration of stimuli‐responsive molecules such as poly(N‐isopropylacrylamide) (PNIPAM) inside nanopores can enable temperature‐dependent gating, which so far has only been demonstrated using external heaters. In this work, plasmonic resonators are combined inside the nanopore architecture with PNIPAM to enable optical gating of individual or multiple nanopores with micrometer resolution and a switching speed of a few milliseconds by thermo‐plasmonics effects. A temperature change of 40 kelvin per millisecond is achieved and demonstrates the efficacy of this method using nanopore ionic conductivity measurements that enable selective activation of individual nanopores in an array. Moreover, the selective gating of specific nanopores in an array can set distinct ionic conductance levels: low, medium, and high (i.e., “0,” “1,” and “2”), which can be exploited for logical gating with optical signal control. Such selective optical gating in nanopore arrays marks a breakthrough in nanofluidics, as it paves the way toward smart devices that offer multifunctional applications including biosensing, targeted drug delivery, and fluidic mixing. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells were fabricated with a polyethylene oxide (PEO)-based quasi-solid (gel) electrolyte consisting of the ionic liquid 1-hexil-3-methylimidazoliym iodide (HMII), and tetrapropyl ammonium iodide (Pr4N+I−) as the two iodide salts with two dissimilar cations. Titanium dioxide powder (TiO2) (P-25) was added to the polymer electrolyte to enhance the iodide ion conductivity further by the nanofiller effect. The electrolyte and the solar cells were characterized by ionic conductivity and impedance measurements, DC polarization test, and current-voltage measurements. The maximum ionic conductivity of 6.95 × 10−3 S cm−1 at 30 °C was exhibited by the electrolyte composition with a 5 wt% TiO2 nanofiller concentration, and the activation energy of this electrolyte was 0.181 eV. The solar cell with this conductivity-optimized gel electrolyte had the highest short-circuit photocurrent of 8.72 mA cm−2 and the highest efficiency of 4.04% with an open-circuit voltage of 685.4 V and a fill factor of 67.6%. The addition of TiO2 nanofiller to the PEO-based gel polymer electrolyte has increased the electron recombination lifetime in the TiO2 photoanode from 2.23 ms for the TiO2 nanofiller-free electrolyte to 33.84 ms for the filler-added electrolyte. The enhancement of the solar cell efficiency is attributed to the mixed cation effect and the diffusion-mediated ionic conductivity increase due to the presence of the TiO2 nanofiller. [ABSTRACT FROM AUTHOR]

The increasing global demand for cement significantly impacts greenhouse gas emissions and resource consumption, necessitating sustainable alternatives. This study investigates fresh geopolymer (GP) pastes incorporating 20 wt.% of five industrial wastes—suction dust, red mud from alumina production, electro-filter dust, and extraction sludges from food supplement production and from partially stabilized industrial waste—as potential replacements for traditional cement. Consistent synthesis methods are used to prepare the geopolymers, which are characterized for their physicochemical, mechanical, and biological properties. Ionic conductivity and pH measurements together with integrity tests, thermogravimetry analysis (TGA), and leaching analysis are used to confirm the stability of the synthesized geopolymers. Fourier-transform Infrared (FT-IR) spectroscopy is used to follow geopolymerization occurrences. Results for ionic conductivity, pH, and integrity revealed that the synthesized GPs were macroscopically stable. TGA revealed that the main mass losses were ascribable to water dehydration and to water entrapped in the geopolymer networks. Only the GP filled with the powder of the red mud coming from alumina production experienced a mass loss of 23% due to a partial waste degradation. FT-IR showed a red shift in the main Si-O-(Si or Al) absorption band, indicating successful geopolymer network formations. Additionally, most of the GPs filled with the wastes exhibited higher compressive strength (37.8–58.5 MPa) compared to the control (22 MPa). Only the GP filled with the partially stabilized industrial waste had a lower mechanical strength as its structure was highly porous because of gas formation during geopolymerization reactions. Despite the high compressive strength (58.5 MPa) of the GP filled with suction dust waste, the concentration of Sb leached was 25 ppm, which limits its use. Eventually, all samples also demonstrated effective antimicrobial activity against Escherichia coli and Staphylococcus aureus due to the alkaline environment and the presence of metal cations able to react with the bacterial membranes. The findings revealed the possibility of recycling these wastes within several application fields. [ABSTRACT FROM AUTHOR]

This study investigated the influence of variations in the mixing ratio of ethylene carbonate (EC) to ethyl methyl carbonate (EMC) on the composition and effectiveness of the solid electrolyte interphase (SEI) in lithium-metal batteries. The SEI is crucial for battery performance, as it prevents continuous electrolyte decomposition and inhibits the growth of lithium dendrites, which can cause internal short circuits leading to battery failure. Although the properties of the SEI largely depend on the electrolyte solvent, the influence of the EC:EMC ratio on SEI properties has not yet been elucidated. Through electrochemical testing, ionic conductivity measurements, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, the formation of Li2CO3, LiF, and organolithium compounds on lithium surfaces was systematically analyzed. This study demonstrated that the EC:EMC ratio significantly affected the SEI structure, primarily owing to the promotion of the formation of a denser SEI layer. Specifically, the ratios of 1:1 and 1:3 facilitated a uniform distribution and prevalence of Li2CO3 and LiF throughout the SEI, thereby affecting cell performance. Thus, precise control of the EC:EMC ratio is essential for enhancing the mechanical robustness and electrochemical stability of the SEI, thereby providing valuable insights into the factors that either enhance or impede effective SEI formation. [ABSTRACT FROM AUTHOR]

This research focused on the development of anion exchange membrane electrolytes suitable for direct methanol alkaline fuel cells (DMAFC) by employing a straightforward blending and solution casting process complemented by subsequent heat treatment. Tartaric acid (TA) was employed as a cross‐linking agent to enhance the heat resistance and structural integrity of the PVA matrix. The distinctive attributes of the PT (PVA and tartaric acid blend) samples, including water absorption and swelling capacity, were comprehensively investigated with respect to variations in both TA content (expressed as wt. % relative to the PVA matrix) and alterations in the duration of thermal treatment. Cross‐link formation between the polymer chains and TA was determined using FTIR analysis. The samples were subjected to comprehensive analysis, encompassing the determination of crystallinity via X‐ray diffraction (XRD), assessment of thermal stability using thermogravimetric analysis (TGA), investigation of morphology through scanning electron microscopy (SEM), and measurement of ionic conductivity using AC Impedance spectroscopy. The methanol permeability was measured to determine the selectivity values of the membranes. Subsequently, within the DMAFC system, the performances of the PT30‐3, PT40‐2, and PT40‐3 membranes, which exhibited the highest selectivities, were assessed. The contribution of the crosslinking process to the resistance of the membranes to oxidative conditions, as represented by the Fenton solution, was evaluated to assess the chemical stability of the membranes. The maximum power densities for PT30‐3 and PT40‐3 membranes reached 15.29 and 12.53 mW/cm2 at 30°C, respectively. These figures exhibited a notable increase, reaching 32.73 mW/cm2 for PT30‐3 and 31.72 mW/cm2 for PT40‐3 when the temperature was elevated to 60°C. This study confirmed that the crosslinking strategy using TA assisted by thermal treatment is very simple and competitive compared with other techniques reported in the literature. PT membranes are promising candidates for commercialization and utilization in DMAFC owing to their environment‐friendly nature, cost‐effectiveness, and high efficiency. Highlights: TA cross‐linking improved the thermal and dimensional stability of PVA.The PT membrane properties varied with TA content and thermal treatment time.Some electrolytes in this study outperformed those previously reported for DMAFC.PT membranes offer efficiency, cost‐effectiveness, and eco‐friendliness for DMAFCs. [ABSTRACT FROM AUTHOR]

As a new approach, biodegradable solid polymer blend polymer electrolytes are prepared using a synthetic polymer Poly [vinyl pyrrolidone] (PVP) and a biopolymer Starch with constant amount of Ammonium ceric nitrate. The Biopolymer starch is used to enhance the biodegradability of the polymer membranes. The polymer electrolytes are prepared by solution casting method using deionized water as solvent. The prepared electrolytes are analyzed with structural, vibrational, electrical and electrochemical behavior by using different characterization techniques. The amorphous nature of the blend polymer electrolytes has been confirmed by X-Ray diffraction (XRD) analysis. PVP/cassava starch/ammonium ceric nitrate polymer electrolyte shows high amorphous nature. In FTIR study, polymers-salt complexation and molecular vibrations are observed in the electrolytes. The ionic conductivity and dielectric measurement of the electrolytes are carried out by impedance spectroscopy. The maximum ionic conductivity of 8.1 × 10−6 S/cm is observed at room temperature for 80% PVP: 20% cassava starch: 2% ammonium ceric nitrate (ACN) system. The dielectric properties of the prepared polymer electrolytes are also analyzed. The electrolyte having higher ionic conductivity is tested with cyclic voltammetry (CV) and linear sweep voltammetry (LSV) studies that reveal the electrochemical properties and range of potential window of the polymer electrolyte. [ABSTRACT FROM AUTHOR]

The article highlights the development of fluorinated porous frameworks for sodium metal batteries, addressing dendrite-related issues and improving energy density through reduced sodium consumption in the interphase design. This innovative approach demonstrates enhanced stability and performance, offering a potential solution for practical deployment of metal batteries.

The dynamical properties of four protic ionic liquids, based on the ethyltriazolium ([C 2 HTr 124 ]) and the ethylimidazolium ([C 2 HIm]) cation, were investigated. The associated anions were the triflate ([TfO]) and the bistriflimide ([TFSI]). Ionic conductivity values and self-diffusion coefficients were measured and discussed, extending the discussion to the concept of fragility. Furthermore, in order to allow the measurement of the ionic conductivity of very small volumes (<0.5 mL) of ionic liquid under an inert and dry atmosphere, a new setup was developed. It was found that the cation nature strongly affected the transport properties, the [C 2 HTr 124 ] cation resulting in slower dynamics than the [C 2 HIm] one. This was concluded from both conductivity and diffusivity measurements while for both properties, the anion had a lesser effect. By fitting the conductivity data with the Vogel–Fulcher–Tammann (VFT) equation, we could also estimate the fragility of these ionic liquids, which all fell in the range of very fragile glass-forming materials. Finally, the slower dynamics observed in the triazolium-based ionic liquids can be rationalized by the stronger interactions that this cation establishes with both anions, as deduced from the frequency analysis of relevant Raman signatures and density functional theory (DFT) calculations. [ABSTRACT FROM AUTHOR]

The aim of this research was to evaluate the possibility of reusing waste foundry sands derived from the production of cast iron as a secondary raw material for the production of building materials obtained both by high-temperature (ceramic tiles and bricks) and room-temperature (binders such as geopolymers) consolidation. This approach can reduce the current demand for quarry sand and/or aluminosilicate precursors from the construction materials industries. Samples for porcelain stoneware and bricks were produced, replacing the standard sand contained in the mixtures with waste foundry sand in percentages of 10%, 50%, and 100% by weight. For geopolymers, the sand was used as a substitution for metakaolin (30, 50, 70 wt%) as an aluminosilicate precursor rather than as an aggregate to obtain geopolymer pastes. Ceramic samples obtained using waste foundry sand were characterized by tests for linear shrinkage, water absorption, and colorimetry. Geopolymers formulations, produced with a Si/Al ratio of 1.8 and Na/Al = 1, were characterized to evaluate their chemical stability through measurements of pH and ionic conductivity, integrity in water, compressive strength, and microstructural analysis. The results show that the addition of foundry sand up to 50% did not significantly affect the chemical-physical properties of the ceramic materials. However, for geopolymers, acceptable levels of chemical stability and mechanical strength were only achieved when using samples made with 30% foundry sand as a replacement for metakaolin. [ABSTRACT FROM AUTHOR]

Polymeric ionic liquids (PILs) are an emerging class of materials which have attracted considerable attention as solid‐state electrolytes because they combine the attractive properties of ionic liquids with the mechanical features of polymers. This paper presents a new method for the synthesis and characterization of stretchable and highly ionically conducting membranes and their subsequent use in truly all‐solid‐state, flexible, and soft electroactive devices. Linear conductive PIL and reinforcing poly(ethylene oxide) (PEO) network are first intimately entangled during the synthesis of a semi‐interpenetrating polymer network (semi‐IPN). Polymerization kinetics, thermomechanical properties, as well as ionic conductivity measurements reveal that for the 60:40 wt ratio of PEO:PIL a true synergy of the properties of both polymer partners is achieved, with ionic conductivities up to 8.7 × 10−5 S cm−1 at 30 °C and elongations at break greater than 100%, being both superior to each partners taken separately. The performances of these semi‐IPNs as central membranes in all‐solid‐state electrochemical microdevices, composed of three self‐supported and flexible layers, namely poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/semi‐IPN membrane/PEDOT:PSS, are successfully demonstrated. Their testing as liquid‐free ionic actuators and liquid‐free piezoionic sensors undoubtfully proves that electromechanical and mechanoelectrical responses of these all‐solid‐state microdevices can reach performances identical to that of "classical" ionic liquid‐filled systems. [ABSTRACT FROM AUTHOR]

Non‐crystalline lithium oxonitridophosphate (LiPON) is used as solid electrolyte in all‐solid‐state batteries. Crystalline lithium oxonitridophosphates are important model structures to retrieve analytical information that can be used to understand amorphous phases better. The new crystalline lithium oxonitridophosphate Li5+xP2O6−xN1+x was synthesized as an off‐white powder by ampoule synthesis at 750–800 °C under Ar atmosphere. It crystallizes in the monoclinic space group P21/c with a=15.13087(11) Å, b=9.70682(9) Å, c=8.88681(7) Å, and β=106.8653(8)°. Two P(O,N)4 tetrahedra connected by an N atom form the structural motif [P2O6−xN1+x](5+x)−. The structure was elucidated from X‐ray diffraction data and the model corroborated by NMR and infrared spectroscopy, and elemental analyses. Measurements of ionic conductivity show a total ionic conductivity of 6.8×10−7 S cm−1 at 75 °C with an activation energy of 0.52±0.01 eV. [ABSTRACT FROM AUTHOR]

Alkali activated binders, based on an aluminosilicate powder that is activated by an alkaline solution, have been proven to encapsulate a wide number of different wastes, both in the form of liquids and solids. In this study, we investigated the effect that the addition of a spent abrasive powder, mainly composed of corundum grains (RC), had on the mechanical, physical, and chemical properties of metakaolin-based geopolymers. The waste was introduced into the geopolymer matrix as a substitute for metakaolin, or added as a filler to the geopolymeric paste. The 3D cross-linking of the geopolymer structure, with and without the presence of the corundum, was investigated via Fourier transform infrared spectroscopy, X-ray diffraction, and ionic conductivity measurements of the eluate that was produced after 24 h of immersion of the sample in water. The RC powder did not significantly modify the matrix reticulation but increased densification, as observed with scanning electron microscopy, and there was increased resistance to compression by 10 wt% addition of RC, and also when added to the paste as a filler at 20 wt%. [ABSTRACT FROM AUTHOR]

In the present research work, films of pure PMMA, pure PVDF-HFP, PMMA : PVDF-HFP : NaClO4 polymer blend electrolyte, and different concentrations of TiO2 nanoparticles doped PMMA : PVDF-HFP : NaClO4 polymer electrolytes have been prepared with the help of solution casting technique. The research work attempted to fabricate dye sensitized Solar (DSS) cell using best TiO2 nanoparticles doped thin film. Properties like structural, morphological, optical and conductivity of all the prepared thin films have been investigated through different characterization techniques such as XRD, SEM, FTIR, and AC conductivity respectively. From the results of XRD and SEM of these films, established dominant amorphous nature at 12 wt % of TiO2 nanoparticles doped PMMA : PVDF-HFP : NaClO4 thin film. The interaction/complexation of TiO2 nanoparticles with polymers and salt is observed from IR spectra of vibrational bands. Ionic conductivity measurements of the films have been carried out using AC impedance spectro-scopy, and the optimum conductivity value was found at 1.12 × 10–3 S/cm. Finally, dye sensitized Solar (DSS) cell has been constructed using the best polymer electrolyte i.e. 12 wt % of TiO2 nanocomposition PMMA : PVDF-HFP : NaClO4, further fill factor and efficiency are calculated and reported as 0.853 and 8.29% respectively. The features of the developed DSS cell have been shown to be stable and exhibit remarkable potential in solar cells. [ABSTRACT FROM AUTHOR]

This study investigates the impact of ionic liquid, 1-methylimidazolium tetrafluoroborate (IL) and graphene oxide (GO) on the performance of chitosan/polyvinyl alcohol (CS/PVA)-based composite electrolytes. Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) confirm the successful incorporation of IL and GO, affecting the structural and morphological properties of the electrolytes. Thermogravimetric analysis (TGA) reveals enhanced thermal stability in GO-doped samples, with increased residual weight at high temperatures, while IL addition leads to higher initial weight loss due to its hygroscopic nature. Ionic conductivity measurements demonstrate that the CS/PVA/IL-GO(4.0) composite achieves the highest proton conductivity of 1.76 × 10−3 S/m at 300 K and 1 MHz, surpassing other samples and aligning with top values reported in literature. Dielectric studies show a significant increase in dielectric constant to 9.55 × 104 at 300 K and 20 Hz for CS/PVA/IL-GO(4.0), attributed to enhanced dipole alignment and polarization effects. The loss tangent analysis indicates the shortest relaxation time of 2.07 × 10−4 s for CS/PVA/IL-GO(4.0), correlating with its superior proton conductivity. These findings highlight the potential of CS/PVA/IL-GO electrolytes for advanced energy storage and conversion applications, suggesting further research into GO dispersion and long-term stability for optimized performance in practical devices. [ABSTRACT FROM AUTHOR]

In this work, the stability issues associated with liquid electrolyte-based dye-sensitized solar cells (DSSC) have been addressed by introducing polymer gel electrolytes. The synergistic combination of polyvinylidene fluoride (PVDF) and polyvinylpyrrolidone (PVP) has been achieved through solution blending. Ionic conductivity measurements, scanning electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy have been employed for analysis. Optimal cohesiveness was observed at PVP concentrations exceeding 40 %, with the best outcomes achieved at a 50 % PVDF-PVP weight ratio. The electrolyte solution, comprising the polymer blend, suitable solvents, and iodine-based salts, exhibits peak conductivity (2.33 mScm⁻1) at a 10 % salt content. DSSCs utilizing the PVDF & PVP polymer blend gel electrolytes demonstrate enhanced durability and maintained efficiency at 5.43 %, exhibiting only a modest 12 % reduction compared to liquid electrolyte counterparts. Over two weeks, the fabricated DSSCs exhibited consistent photovoltaic performance, while conventional cells experienced significant declines in short-circuit current (36 %) and open-circuit voltage (33.33 %). This study signifies a promising advancement in solar cell technology, showcasing improved stability and performance in DSSCs using conductive polymer blend gel electrolytes. • PVDF and PVP were solution-blended to optimize polymer characteristics and analyzed for conductivity and other properties. • Optimal cohesiveness occurred at PVP > 40%, with the best results at a 50% PVDF-PVP weight ratio. • The research achieved peak gel electrolyte conductivity (2.33 mScm⁻¹) at 10% salt content in the polymer blend. • The optimized gel electrolyte boosted DSSCs to 5.43% efficiency, only 12% lower than liquid electrolyte cells. • Gel-electrolyte DSSCs endured better over two weeks, showing promise for solar tech advancement. [ABSTRACT FROM AUTHOR]

We proposed a thermoresponsive light scattering device that utilizes the surface behavior between polyimide and an ionic liquid-water mixture exhibiting lower critical solution temperature (LCST)-type phase separation. The LCST behavior for an ionic liquid device utilizing the polyimide with and without alkyl side chains was investigated. In the here-reported ionic liquid device that utilized the polyimide with alkyl side chains, [nBu4P][CF3COO] droplets were generated by phase separation—they were predominantly formed at the alkyl surface by a surface pinning effect. A stable transmittance in the opaque state could be obtained with this device. In contrast, an ionic liquid device using polyimide without alkyl side chains deteriorated transmittance in the opaque state because there was no surface pinning effect. Additionally, the viewing angle, contrast ratio, and heat cycle testing of this ionic liquid device with polyimide with alkyl side chains were also investigated. The results indicated that no parallax was obtained and that the ionic liquid device has a stable transmittance (verified by heat cycle testing). This unique device is expected to find use in the smart window applications that are activated by temperature changes. [ABSTRACT FROM AUTHOR]

This work provides a comprehensive evaluation of the effect of the cation alkyl side chain length of the 1-alkyl-3-methylimidazolium chloride series ([CnC1im]Cl, n = 2-14) of ionic liquids (ILs) on their capability to form aqueous biphasic systems (ABSs) with salts and self-aggregation derived properties. The liquid-liquid phase behavior of ternary systems composed of [CnC1im]Cl, water, and K3PO4 or K2CO3 and the respective Setschenow salting-out coefficients (ks), a quantitative measure of the two-phase formation ability, were determined. An odd-even effect in the ks values along the number of methylene groups of the longest IL cation alkyl side chain was identified for the ABS formed by K2CO3, a weaker salting-out agent where the phenomenon is clearly identified. In general, cations with even alkyl side chains, being likely to display higher molar volumes, are more easily salted-out and thus more prone to undergo phase separation. The odd-even effect in the ks values is, however, more significant in ILs up to n = 6, where the nanostructuration/nanosegregation of ILs plays a less relevant role. Still, with the [CnC1im]Cl (n = 7-14) series of ILs, an odd-even effect was also identified in the ILs’ ionization degree, molar conductivity, and conductivity at infinite dilution. In summary, it is shown here that the ILs’ odd-even effect occurs in IL aqueous solutions and not just in neat ILs, an already well-established phenomenon occurring in a series of ILs’ properties described as a result of the orientation of the terminal methyl groups to the imidazolium ring cation and consequent effect in the ILs’ cohesive energy. [ABSTRACT FROM AUTHOR]

Dielectric relaxation spectra of three members of the alkylammonium formate family of protic ionic liquids (PILs), namely, ethylammonium formate (EAF), n-butylammonium formate (BuAF), and n-pentylammonium formate (PeAF), as well as the pseudo-PIL triethylamine + formic acid (molar ratio 1:2; TEAF) have been studied over a wide frequency (50 MHz to 89 GHz) and temperature range (5–65 °C), complemented by measurements of their density, viscosity, and conductivity. It turned out that the dominating relaxation of EAF, BuAF, and PeAF arises from both cation and anion reorientations which are synchronized in their dynamics due to hydrogen bonding. Amplitudes and relaxation times of this mode reflect the—compared to nitrate—different nature of H bonding between the formate anion and ethylammonium cation, as well as increasing segregation of the PIL structure into polar and non-polar domains. The TEAF data suggest that its dominating relaxation is due to the rotation of the complex triethylamine⋅(formic acid)2 in which no significant proton transfer to an ion pair occurred. Weak dissociation of this complex into ions was postulated to account for the high conductivity of TEAF. [ABSTRACT FROM AUTHOR]

We study generic properties of poly(ionic liquid)s (PILs) via coarse-grained molecular dynamics simulations in bulk solution and under confinement. The influence of different side chain lengths on the spatial properties of the PIL systems and on the ionic transport mechanism is investigated in detail. Our results reveal the formation of apolar and polar nanodomains with increasing side chain length in good agreement with previous results for molecular ionic liquids. The ion transport numbers are unaffected by the occurrence of these domains, and the corresponding values highlight the potential role of PILs as single-ion conductors in electrochemical devices. In contrast to bulk behavior, a pronounced formation of ion conductivity channels in confined systems is initiated in close vicinity to the boundaries. We observe higher ion conductivities in these channels for increasing PIL side chain lengths in comparison with bulk values and provide an explanation for this effect. The appearance of these domains points to an improved application of PILs in modern polymer electrolyte batteries. [ABSTRACT FROM AUTHOR]

Ionic liquid electrolytes with high alkali salt concentrations have displayed some excellent electrochemical properties, thus opening up the field for further improvements to liquid electrolytes for lithium or sodium batteries. Fundamental computational investigations into these high concentration systems are required in order to gain a better understanding of these systems, yet they remain lacking. Small phosphonium-based ionic liquids with high concentrations of alkali metal ions have recently shown many promising results in experimental studies, thereby prompting us to conduct further theoretical exploration of these materials. Here, we conducted a molecular dynamics simulation on four small phosphonium-based ionic liquids with 50 mol. % LiFSI salt, focusing on the effect of cation structure on local structuring and ion diffusional and rotational dynamics—which are closely related to the electrochemical properties of these materials. [ABSTRACT FROM AUTHOR]

Equimolar mixtures of glymes and organic lithium salts are known to produce solvate ionic liquids, in which the stability of the [Li(glyme)]+ complex plays an important role in determining the ionic dynamics. Since these mixtures have attractive physicochemical properties for application as electrolytes, it is important to understand the dependence of the stability of the [Li(glyme)]+ complex on the ion dynamics. A series of microsecond molecular dynamics simulations has been conducted to investigate the dynamic properties of these solvate ionic liquids. Successful solvate ionic liquids with high stability of the [Li(glyme)]+ complex have been shown to have enhanced ion dynamics. Li-glyme pair exchange rarely occurs: its characteristic time is longer than that of ion diffusion by one or two orders of magnitude. Li-glyme pair exchange most likely occurs through cluster formation involving multiple [Li(glyme)]+ pairs. In this process, multiple exchanges likely take place in a concerted manner without the production of energetically unfavorable free glyme or free Li+ ions. [ABSTRACT FROM AUTHOR]

A new method for the solid-phase synthesis of the superionic conductor CsAg4Br2.5I2.5 is proposed, which facilitates the preparation of a single-phase product. The thermal behavior of CsAg4Br2.5I2.5 in the temperature range from –160 to +190°С was studied by differential scanning calorimetry, and the absence of polymorphous transitions was confirmed; the only first-order phase transition is observed near 177°C and corresponds to the incongruent melting of the solid electrolyte. It is shown that the dense ceramics can be obtained from CsAg4Br2.5I2.5 powder by pressing at room temperature; the optimal value of pressure is determined. Studies of the electrical transport characteristics of CsAg4Br2.5I2.5 included measurements of the ionic conductivity by the four-probe method in the range of –60...+120°C and an assessment of the electronic component of the conductivity by the Hebb–Wagner method. The contribution of electron transfer is shown to be negligibly small (~10–9 S cm–1), and the ionic conductivity is close to that of the well-known superionic conductor RbAg4I5 and is characterized by a low activation energy (10.3 kJ mol–1). The oxidation potential determined by the stepwise polarization method is 0.78 V, which is noticeably higher than that of RbAg4I5. The absence of first-order phase transitions at temperatures below the melting point, combined with high ionic conductivity, makes the CsAg4Br2.5I2.5 compound more attractive for low-temperature applications, and the increased electrochemical stability makes it more attractive for use in chemical power sources as compared to RbAg4I5. [ABSTRACT FROM AUTHOR]

Polymer electrolyte membrane (PEM) fuel cells have the potential to reduce our energy consumption, pollutant emissions, and dependence on fossil fuels. To achieve a wide range of commercial PEMs, many efforts have been made to create novel polymer-based materials that can transport protons under anhydrous conditions. In this study, cross-linked poly(vinyl) alcohol (PVA)/poly(ethylene) glycol (PEG) membranes with varying alumina (Al2O3) content were synthesized using the solvent solution method. Wide-angle X-ray diffraction (XRD), water uptake, ion exchange capacity (IEC), and proton conductivity were then used to characterize the membranes. XRD results showed that the concentration of Al2O3 affected the degree of crystallinity of the membranes, with 0.7 wt.% Al2O3 providing the lowest crystallinity. Water uptake was discovered to be dependent not only on the Al2O3 group concentration (SSA content) but also on SSA, which influenced the hole volume size in the membranes. The ionic conductivity measurements provided that the samples were increased by SSA to a high value (0.13 S/m) at 0.7 wt.% Al2O3. Furthermore, the ionic conductivity of polymers devoid of SSA tended to increase as the Al2O3 concentration increased. The positron annihilation lifetimes revealed that as the Al2O3 concentration increased, the hole volume content of the polymer without SSA also increased. However, it was densified with SSA for the membrane. According to the findings of the study, PVA/PEG/SSA/0.7 wt.% Al2O3 might be employed as a PEM with high proton conductivity for fuel cell applications. [ABSTRACT FROM AUTHOR]

Green resources for lithium‐based batteries excite many researchers due to their eco‐friendly nature. In this work, a sustainable bio‐based solid‐state electrolyte was developed based on carbonated soybean oil (CSBO), obtained by organocatalyzed coupling of CO2 to epoxidized soybean oil. CSBO coupled with lithium bis(trifluoromethanesulfonyl)imide salt on a bio‐based cellulose separator resulted in free‐standing membranes. Those membranes on electrochemical measurements exhibited ionic conductivity of around 10−3 S cm−1 at 100 °C and around 10−6 S cm−1 at room temperature with wide electrochemical stability window (up to 4.6 V vs. Li/Li+) and transference number up to 0.39 at RT. Further investigations on the galvanostatic charge‐discharge of LiFePO4 cathodes with CSBO‐based electrolyte membranes and lithium metal anodes delivered the gravimetric capacity of 112 and 157 mAh g−1 at RT and 60 °C, respectively, providing a promising direction to further develop bio‐based solid electrolytes for sustainable solid‐state lithium batteries. [ABSTRACT FROM AUTHOR]

Over the years, many materials have been used to restore buildings, paintings, ceramics, and mosaic pieces exhibiting different types of dyes and colour hues. Recently, geopolymers have been used for restoration purposes owing to their high chemical and mechanical resistance. In this work, white metakaolin was used to obtain white geopolymers, cured at 25 and 40 °C, as bulk materials to be coloured with synthetic organic dyes, i.e., bromothymol blue, cresol red, phenolphthalein, and methyl orange. These dyes were added during the fresh paste preparation to obtain dyed geopolymeric solids. Ionic conductivity and pH measurement confirmed the chemical stability of the consolidated materials, while FT-IR analyses were used to follow the geopolymerisation occurrences at different ageing times (from 7 to 56 days). Finally, the colour hues and properties were assessed in the CIELAB colour space before and after immersion in water. [ABSTRACT FROM AUTHOR]

CaSn(OH)6 thermolysis products have been characterized by thermal analysis, X-ray diffraction, IR spectroscopy, low-temperature nitrogen adsorption measurements, and electron microscopy. Ionic conductivity measurements for CaSnO3–SnO2–CsNO2 composites suggest that calcium stannate is potentially attractive for use as a heterogeneous additive to composite solid electrolytes. [ABSTRACT FROM AUTHOR]

Poly (ethylene oxide) based sodium ion conducting solid polymer electrolytes films (salt NaCH3COO) with varying amounts of an ionic liquid, 1-ethyl 3-methylimidazolium thiocyante were prepared by solution-cast method. All the prepared samples were characterized in detail for their ion transport characteristics at room temperature and temperature dependent behavior as well using electrochemical impedance spectroscopy. The measurement of ionic conductivity shows the many fold enhancement due the incorporation of ionic liquid in the polymer electrolyte matrix. The charge carrier density and mobility of charge carriers has been calculated and used for explaining the conductivity variations in these films. The increase in conductivity has been explained in terms of plasticization effect of ionic liquid and number of charge carriers per unit volume of electrolyte. [ABSTRACT FROM AUTHOR]

CaSn(OH)6 thermolysis products have been characterized by thermal analysis, X-ray diffraction, IR spectroscopy, low-temperature nitrogen adsorption measurements, and electron microscopy. Ionic conductivity measurements for CaSnO3–SnO2–CsNO2 composites suggest that calcium stannate is potentially attractive for use as a heterogeneous additive to composite solid electrolytes. [ABSTRACT FROM AUTHOR]

The article discusses All-solid-state batteries are a potential game changer in the energy storage market; however, their practical employment has been hampered by premature short circuits caused by the lithium dendritic growth through the solid electrolyte. Here, we demonstrate that a rational layer-by-layer strategy using a lithiophilic and electron-blocking multilayer can substantially enhance the performance/stability.

Water-in-salt electrolytes - WISEs - are prevailing thanks to their compelling extended voltage window due to the reduced free water molecules at the electrode interface. However, as has been reported elsewhere, free-water content still can be reduced further. In our previous work, an unstable phenomenon of solid electrolyte interphase (SEI) and salt precipitation/dissolution issue were revealed. Herein, we propose a novel approach in order to alleviate those issues using poly(ethylene glycol) diglycidyl ether (PDE) as an additive. Indeed, upon mixing LiTFSI, water and PDE at high concentrations, we observed a ring-opening reaction of PDE that was confirmed via Raman spectroscopy, FTIR and ionic conductivity measurements. These crosslinked networks could also increase the solubility limits of LiTFSI in water, which was identified by adding more LiTFSI or LiOTf. Differential scanning calorimetry (DSC) measurement demonstrated that these crosslinked electrolytes effectively suppress the crystallization of water molecules with the WISE. Linear sweep voltammetry (LSV) measurements revealed that these novel crosslinked electrolytes considerably reduce free water content which effectively drives the HER to more negative potentials. More significantly, the SEI formed with these novel electrolytes remains present and stable on the electrode surface after a resting period of 1 h. Our work herein offers a new approach to tackling SEI instability and precipitation/dissolution issues. [ABSTRACT FROM AUTHOR]

Electrically conductive nanoporous membranes represent a class of stimuli–responsive materials, which selectivity/permeability characteristics can be adjusted by varying the surface potential. In this work, we perform a comprehensive theoretical and experimental study of ionic conductivity of such membranes. The 2D Space charge and 1D Uniform potential models are used to describe the ion transport through a cylindrical nanopore. The calculations show that the imposed electric field polarizes the conductive surface, which results in the continuous variation of electronic surface charge from positive to negative along the nanopore. A higher concentration of cations (anions) is observed at negatively (positively) charged part of the nanopore. The increase of charge carries concentration due to polarization effect results in the enhancement of ionic conductivity with increasing the voltage difference. The corresponding current–voltage curves are non-linear. The enhancement can reach a few orders of magnitude at low salt concentrations, but becomes much smaller at high concentrations. The presence of chemical charge has a screening effect on the interaction of electric field with the electronic charge on the nanopore surface, and reduces the conductivity enhancement. A novel analytical solution is derived for the dependence of ionic current on the Stern layer capacitance, salt concentration, and the applied potential difference. The theoretical predictions are first confirmed by the ionic conductivity measurements in porous anodic alumina membranes with carbon nanotubes inside the pores. The experimental data are approximated by the 1D Uniform potential model curves using chemical charge as a fitting parameter. Strong enhancement of ionic conductivity (more than 6 times) and the corresponding non-linear dependence of current on the applied voltage is experimentally registered at low KCl concentrations (0.1 – 10 mM) with increasing the voltage difference. [Display omitted] [ABSTRACT FROM AUTHOR]

Over the years, several materials have been used for restoration purposes, with different types of dyes and colour hues. Recently, some researchers have proposed geopolymers (GPs) or amorphous aluminosilicate polymers for these purposes. In this work, an alcohol-based grape marc extract (GME, obtained via dark maceration assisted with ultrasound) was used as a natural dyeing agent for metakaolin-based GPs. The geopolymerisation occurrence was assessed by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction analysis, while the colour of the resulting material was determined through the colorimetric analysis in the L*a*b* colour space. Additionally, the thermal stability of GME and GPs was investigated by thermogravimetry coupled with FT-IR spectroscopy. The microstructure, the reticulation stability, and the antimicrobial activity of GPs were examined through the scanning electron microscopy, the pH and ionic conductivity measurements, integrity, and mass loss tests. Overall, a coloured geopolymer with suitable thermal, antimicrobial, and mechanical properties was obtained, justifying its potential use in restoration or, more generally, in the construction field.Graphical abstract: Over the years, several materials have been used for restoration purposes, with different types of dyes and colour hues. Recently, some researchers have proposed geopolymers (GPs) or amorphous aluminosilicate polymers for these purposes. In this work, an alcohol-based grape marc extract (GME, obtained via dark maceration assisted with ultrasound) was used as a natural dyeing agent for metakaolin-based GPs. The geopolymerisation occurrence was assessed by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction analysis, while the colour of the resulting material was determined through the colorimetric analysis in the L*a*b* colour space. Additionally, the thermal stability of GME and GPs was investigated by thermogravimetry coupled with FT-IR spectroscopy. The microstructure, the reticulation stability, and the antimicrobial activity of GPs were examined through the scanning electron microscopy, the pH and ionic conductivity measurements, integrity, and mass loss tests. Overall, a coloured geopolymer with suitable thermal, antimicrobial, and mechanical properties was obtained, justifying its potential use in restoration or, more generally, in the construction field. [ABSTRACT FROM AUTHOR]

Sodium alginate/krill protein/polyacrylamide (SA/AKP/PAM) hydrogel with "covalent bond―ion complex―hydrogen bond" multi-network structure was prepared by covalent cross-linking and complexion ion crosslinking using SA, AKP, and acrylamide (AM) as raw materials. The effects of ion species (Fe3+, Ba2+, Sr2+, Ca2+, and Zn2+) on the structure, morphology, and properties of multi-network hydrogels were studied in detail. The results showed that the mechanical strength of ionic cross-linked hydrogels increased significantly. The compressive strength of Fe3+ cross-linked hydrogels was 5.56 MPa, 16.13 times that of non-ionic crosslinked hydrogels. The results of ionic conductivity measurements showed that hydrogels had significant ionic conductivity and were sensitive to external forces. Interestingly, the hydrogel can be used as a capacitive pen in mobile phone writing, painting and dialing numbers. Moreover, ionic cross-linked hydrogels had a unique three-dimensional porous structure with gradient distribution, excellent shape memory effect, and good biocompatibility. Fe3+, Ba2+, Sr2+, and Ca2+ cross-linked hydrogels were nontoxic and conducive to the adhesion and growth of Schwann cells. These excellent properties of ionic cross-linked SA/AKP/PAM hydrogels have broad applications prospects in flexible electronic devices, sensors, soft electronic skins, and tissue engineering. • The SA/AKP/PAM multi-network hydrogels were developed based on chemical cross-linking and physical cross-linking. • The gradient porous structure hydrogel was prepared based on the difference in mass transfer rate assisted insulating layer. • Hydrogels exhibit good functionalities such as ion conductivity, strain sensitivity, capacitance, and shape memory effect. • Adjust the biocompatibility of hydrogels through simple ion introduction. • The type of ions had a significant influence on the structure and performance of the hydrogel. [ABSTRACT FROM AUTHOR]

Summary: The application of hydrocarbon‐based polymer electrolyte membranes as an alternative to Nafion membranes for vanadium redox‐flow batteries (VRFBs) has been investigated. Ionic conductivity measurements and the crossover characteristics of vanadyl ions (VO2+), as well as durability testing against V5+ in H2SO4 solution, were performed to investigate the applicability of sulfonated poly(ethersulfone) (S‐PES) membranes with high molecular weight to VRFB. The diffusion coefficient of V4+ in S‐PES was lower than that in Nafion, and the ionic conductivity was comparable to that of Nafion in S‐PES with an ion‐exchange capacity (IEC) of 1.5 meq/g. A durability evaluation of V5+ with high oxidizing power indicated that it was extremely stable compared to the sulfonated poly(etheretherketone). It was clarified that by setting the IEC to an appropriately high value and reducing the membrane thickness, the membrane characteristics can be made comparable to those of Nafion. Finally, a VRFB test was performed using S‐PES with controlled IEC and membrane thickness, whereby the high molecular weight S‐PES was shown to have relatively good performance comparable to Nafion. [ABSTRACT FROM AUTHOR]

Two new ternary thiogallates in the A5GaS4 (A = Li (I) and Na (II)) series have been synthesized for the first time employing a gas passing route using oxide precursors and a high temperature solid state route using stoichiometric combinations of elements, respectively. Li5GaS4 crystallizes in the P21/m space group and the structure is built up of layers of corner sharing tetrahedra of LiS4 and GaS4 stacked along the a-axis and the octahedrally coordinated Li ions residing in the interlayer space. Na5GaS4 crystallizes in the Pbca space group and the structure consists of isolated (GaS4)5− tetrahedra held together by charge balancing sodium ions in distorted tetrahedral and octahedral coordination geometries. Measurements of ionic conductivity of the compounds showed room temperature ionic conductivities of 1.8 × 10−7 and 4.0 × 10−7 S cm−1 with activation energies of 0.54 and 0.28 eV, respectively, for I and II. Density functional theory calculations show close agreement in structural parameters with the measured data and predict band gaps of 2.75 eV (I) and 2.70 eV (II). Single point hybrid functional calculations result in band gaps of 3.95 and 3.65 eV correspondingly, in better agreement with the experimental value of ∼4.1 eV for both. Bond valence energy landscape maps suggest the absence of any suitable diffusion path for Li in Li5GaS4. On the other hand, BVEL maps of Na5GaS4 confirm that the tetrahedrally coordinated Na ions are responsible for ionic conduction, whereas the involvement of octahedrally coordinated Na ions in the conduction process could not be discerned. [ABSTRACT FROM AUTHOR]

The focus of this research is to investigate of the possibility of reusing mineral wastes and by-products from mining processes to produce more sustainable binders in large amounts. A mining by-product consisting of halloysite (approximately 48 wt%) was used to produce dense alkali activated solids. Attention was paid to the influence of temperature on the geopolymerisation process in terms of the microstructural characteristics of the samples obtained. The challenge was to alkali activate the clay as received without any firing pre-treatment. The fresh paste of untreated clay was cured at 50% relative humidity (RH%) at different temperatures: 40, 60, and 70 °C. The halloysite-bearing powder (HC) was then mixed with a low-quartz sand, a second by-product of the mining industry, to achieve higher chemical stability. The results showed a clear difference in chemical stability for samples containing sand compared to those without sand. Low percentages of metakaolin (5–15%) were also added to the same formulations to improve the chemical and physical properties of the samples and to reduce the curing time. For mixtures consisting of untreated clay and sand only NaOH was added as alkaline activator. The effect of curing temperature, curing time and addition of metakaolin (MK) on the microstructure of the geopolymers was analysed by different techniques: measurement of pH and ionic conductivity of the eluate of the chemical stability test in water, X-ray diffraction (XRD), scanning electron microscopy (SEM), bulk density, and compressive strength. Finally, a statistical approach was adopted to rationalise the effect of the curing conditions on the consolidation of the fresh pastes of samples with the untreated HC, sand and metakaolin. To test whether the parameters of the curing process, as well as the MK addition had an influence on the values of the ionic conductivity of the eluate from water sinking and/or the density of the solid final product, a 3-way ANOVA followed by Tukey-Kramer post hoc tests (p < 0.05) were performed. To further investigate the interaction between preparation parameters and the material properties, we also built a Generalized Linear model that provided an equation to predict the final results. Overall, we found that the addition of MK significantly reduced the conductivity while only marginally increasing the density of the material. This effect was extremely temperature-dependent, and it disappeared at 70 °C. In conclusion, it has been demonstrated how the addition of fillers, an easily controllable industrial step, can maximise the performance of the consolidated material, rather than controlling the curing time and temperature conditions. • An halloysitic mining by-product was alkali-activated to obtain a solid material at 40 to 60 °C. • Best results were achieved with the addition of 42–50 wt% sand and 5–15 wt% of metakaolin. • The use of sole NaOH 8 M as activator solution is an advantage in terms of sustainability. • Curing temperature affected microstructure and performance starting from 3 curing days. • Statistical approach proved a significant contribution of increment of MK on reticulation. [ABSTRACT FROM AUTHOR]

Novel bone substitutes such as highly porous ceramic scaffolds can serve as platforms for delivering active molecules. A common problem is to control the release of the drug, therefore, it is beneficial to use a drug-functionalized polymer coating. In this study, β-tricalcium phosphate-based porous scaffolds were obtained and coated with diclofenac-functionalized biopolymer – poly(3-hydroxyoctanoate) – P(3HO). To the best of our knowledge, studies using P(3HO) as a component in ceramic-polymer based drug delivery system for bone tissue regeneration have not yet been reported. Presented materials were comprehensively investigated by various techniques such as powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, hydrostatic weighing and compression tests, pH and ionic conductivity measurements, high-performance liquid chromatography and in vitro cytotoxicity studies. The obtained diclofenac-loaded composite was not only characterised by controlled and sustained drug release, but also possessed improved mechanical properties. Moreover, the precipitation of apatite-like forms on its surface was observed after incubation in simulated body fluid, which indicates its bioactive potential. After 24 hours no cytotoxic effect on MC3T3-E1 mouse preosteoblastic cells was confirmed using indirect cytotoxicity studies. Thus, this promising multifunctional composite scaffold can be a promising candidate as an anti-inflammatory drug-delivery system in bone tissue engineering. [ABSTRACT FROM AUTHOR]

Anion exchange membranes (AEMs) are one of the core components of AEM fuel cells. A series of poly(vinyl alcohol)/polyquaternium‐10 (PVA/PQ‐10) AEMs with semi‐interpenetrating networks (s‐IPNs) are prepared by a simple solution‐casting method using glutaraldehyde (GA) as a cross‐linking agent. Subsequently, the prepared PVA/PQ‐10 cross‐linked membranes are characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, mechanical analysis, water uptake and swelling ratio tests, ion exchange capacity (IEC) tests, ionic conductivity measurements, and oxidative/alkaline stability tests. The effects of the mass ratio of PVA and PQ‐10 and the amount of cross‐linking agent GA on the performance of the PVA/PQ‐10 cross‐linked membranes are systematically explored. The results show that the cross‐linked PVA/PQ‐10 AEMs have high IEC and low water uptake and swelling ratio, and its maximum ionic conductivity can reach 79.37 mS cm–1 at 80 °C. In addition, the PVA/PQ‐10 cross‐linked membrane has good oxidative and alkaline stability under optimal preparation conditions. These results may provide valuable insights toward more effective scheme designs and new, simple preparation methods for AEMs with s‐IPN structures. [ABSTRACT FROM AUTHOR]

Dion–Jacobson (DJ)‐type quasi‐two‐dimensional perovskites exhibit improved stabilities than their 3D counterparts but meanwhile limited charge transport properties. Knowledge to manipulate the crystal orientation and crystallinity is the primary issue for DJ perovskite with high power conversion efficiencies (PCEs). Herein, the nucleation of DJ perovskite films is divided into three stages and the formation of PbI2–N,N‐dimethylformamide (DMF)‐based solvated phase (PDS) is highlighted as the initial stage. For the first time, it is demonstrated that regulating the amount of PDS precipitation in stage I by MACl additive is the key to ensure the downward growth of DJ perovskites with out‐of‐plane orientation and high crystallinity in stage III, which is valid for DJ perovskites with different bukly organic cations including p‐phenylenediamine (PPD), p‐xylylenediamine (PXD), and propane‐1,3‐diammonium (PDA). For (PXD)(MA)2Pb3I10‐based perovskite solar cells, the PDS engineering lead to a dramtically improved PCE from 1.2% to 15.6%. Moreover, based on temperature‐dependent ionic conductivity measurement, it is confirmed that the ion migration in DJ perovskite films is efficiently suppressed, despite the possible coexisting 3D perovskite phase. The unencapsulated PXD‐based DJ perovskite devices retain over 90% efficiencies after 700 h of continuous illumination or 1500 h of storage in glove box. [ABSTRACT FROM AUTHOR]

In this work, we introduce a new design of the interdigitated electrode (IDE) for the measurement of conductivity of ionomer thin film on the planar carbon surface, which is relevant to many electrochemical systems including fuel cells. The design is an advancement over commonly used SiO2 substrate based IDE, previously employed for Nafion thin film conductivities. Electrochemical impedance spectroscopy technique was applied to measure the conductivity of 55 nm thick Nafion film on carbon surface. Through complementary modeling work using equivalent circuit, we identify that the competition between the double layer capacitances at ionomer/carbon and ionomer/electrode interfaces can mask the conventionally observed high-to-medium impedance arc observed for Nafion films on SiO2 substrate. This problem can be circumvented by using electrochemically active Pt electrode in hydrogen environment. Hence, this systematic study describes a method to determine the thin film conductivity on carbon substrate. [ABSTRACT FROM AUTHOR]

This study is based on reversible Solid Oxide Cells (rSOCs) numerical and experimental analysis. To increase the cell application and accommodate a variety of excellent materials to be adopted in this innovation, the operating temperatures has to be lowered. Porosity control is used to substitute the high operating temperatures. Pretreatment and sintering procedures are used to adjust a button cell porosity. Experimental results include property measurements for porosity and ionic conductivity to understand the cell performance. A cell sintered at 1400 °C with 36.2% porosity renders superior results compared to the other conditions. Improved performance has been noted on 40-30% porosity decrease. COMSOL Multiphysics is used to simulate the experimental procedures. Butler–Volmer equation is implemented to predict the cell current density distribution, and Modified Stefan-Maxwell diffusion model incorporating Knudsen diffusion equation has been used for multicomponent diffusion. Image 1 [ABSTRACT FROM AUTHOR]

The present study investigated thermo-mechanical behaviour of A-site deficient perovskites Li 3 x La 1/3- x TaO 3 (LLTaO) and Li 3 x La 1/3- x NbO 3 (LLNbO) with x = 0.00 to 0.06 as a function of temperature by means of thermo-mechanical analysis. LLTaO for all compositions exhibits an orthorhombic-tetragonal phase transition around 200 K, above which it has a tetragonal phase. As the temperature increases from 200 K to 400 K, the linear expansion coefficient shows a slight decrease for all the compositions, followed by a constant value of ~3 × 10−6 K−1 above 400 K regardless of x. On the other hand, LLNbO has an orthorhombic phase for x ≤ 0.02 and the tetragonal for x ≥ 0.04 at room temperature. The linear expansion coefficient of LLNbO with x ≤ 0.02 shows a peak around 470 K, which can be attributed to an orthorhombic-tetragonal phase transition. In addition, the expansion coefficient of LLNbO with x ≥ 0.02 significantly increases as the temperature rises from 200 K to 400 K, followed by a plateau and a relatively abrupt decrease after reaching a temperature above 600 K. Additional ionic conductivity measurement of LLNbO suggested that the inconstant expansion behaviour could be attributed to the lithium-ion motion. [ABSTRACT FROM AUTHOR]

New organic–inorganic nanocomposites based on PVA, SiO2 and SSA were prepared in a single step using a solution casting method, with the aim to improve the thermomechanical properties and ionic conductivity of PVA membranes. The structure, morphology, and properties of these membranes were characterized by Raman spectroscopy, small- and wide-angle X-ray scattering (SAXS/WAXS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), water uptake (Wu) measurements and ionic conductivity measurements. The SAXS/WAXS analysis showed that the silica deposited in the form of small nanoparticles (∼ 10 nm) in the PVA composites and it also revealed an appreciable crystallinity of pristine PVA membrane and PVA/SiO2 membranes (decreasing with increasing silica loading), and an amorphous structure of PVA/SSA and PVA/SSA/SiO2 membranes with high SSA loadings. The thermal and mechanical stability of the nanocomposite membranes increased with the increasing silica loading, and silica also decreased the water uptake of membranes. As expected, the ionic conductivity increased with increasing content of the SSA crosslinker, which is a donor of the hydrophilic sulfonic groups. Some of the PVA/SSA/SiO2 membranes had a good balance between stability in aqueous environment (water uptake), thermomechanical stability and ionic conductivity and could be potential candidates for proton exchange membranes (PEM) in fuel cells. [ABSTRACT FROM AUTHOR]

Low‐melting‐point solid‐state electrolytes (SSE) are critically important for low‐cost manufacturing of all‐solid‐state batteries. Lithium hydroxychloride (Li2OHCl) is a promising material within the SSE domain due to its low melting point (mp < 300 °C), cheap ingredients (Li, H, O, and Cl), and rapid synthesis. Another unique feature of this compound is the presence of Li vacancies and rotating hydroxyl groups which promote Li‐ion diffusion, yet the role of the protons in the ion transport remains poorly understood. To examine lithium and proton dynamics, a set of solid‐state NMR experiments are conducted, such as magic‐angle spinning 7Li NMR, static 7Li and 1H NMR, and spin‐lattice T1(7Li)/T1(1H) relaxation experiments. It is determined that only Li+ contributes to long‐range ion transport, while H+ dynamics is constrained to an incomplete isotropic rotation of the OH group. The results uncover detailed mechanistic understanding of the ion transport in Li2OHCl. It is shown that two distinct phases of ionic motions appear at low and elevated temperatures, and that the rotation of the OH group controls Li+ and H+ dynamics in both phases. The model based on the NMR experiments is fully consistent with crystallographic information, ionic conductivity measurements, and Born–Oppenheimer molecular dynamic simulations. [ABSTRACT FROM AUTHOR]

We study ion dissociation in four aqueous 1-alkyl-3-methyl-imidazolium chloride ([amim][Cl]) (where a = alkyl) ionic liquids (ILs) focusing on the effects of microstructure formation. We calculate ion dissociation using precise density, viscosity, and ionic conductivity measurements taken in this work as well as values reported by Rogac et al. (M. Bešter-Rogač, M. V. Fedotova, S.E. Kruchinin, and M. Klähn, Mobility and association of ions in aqueous solutions: The case of imidazolium based ionic liquids, Phys. Chem. Chem. Phys. 18, 28594–28605 (2016); R. Toma, A. Tot, J. Kuhar, and M. Be, Interactions in aqueous solutions of imidazolium chloride ionic liquids [C n mim][Cl] (n=0, 1, 2, 4, 6, 8) from volumetric properties, viscosity B-coefficients and molecular dynamics simulations, 254, 267–271 (2018)) in conjunction with our estimation framework presented previously (O. Nordness, L.D. Simoni, M.A. Stadtherr, and J.F. Brennecke, Characterization of Aqueous 1-Ethyl-3-Methylimidazolium Ionic Liquids for Calculation of Ion Dissociation, J. Phys. Chem. B 123, 1348–1358 (2019); L.D. Simoni, Predictive Modeling of Fluid Phase Equilibria for Systems Containing Ionic Liquids (University of Notre Dame, Notre Dame, IN, 2009)). We first consider ion dissociation at dilute IL concentrations below the critical aggregate concentrations (cac). We introduce a combined Stokes radii term calculated from limiting molar conductivity data, which more accurately estimates ion dissociation in dilute IL systems than radii estimated from a group contribution method. Incorporating the new radii term in the existing model, we study ion dissociation across a wide IL concentration range. Even if prior knowledge of aggregation were not available, as is the case for aqueous [amim][Cl] systems, aggregation is apparent from this analysis because the increased viscous forces of microstructure formation lead to unrealistic estimates of ion dissociation. [ABSTRACT FROM AUTHOR]

Ionic conductivity and molar volume measurements were performed on H2O ice at high pressure (P) and temperature (T) in a resistive-heated diamond anvil cell. The conductivity data obtained at P = 20-62 GPa, T = 304-930 K are well fitted with a single Arrhenius equation. Isothermal volume measurements at T = 873 K, P = 30-101 GPa indicate that H2O ice undergoes phase transitions at P = 50 GPa and 53 GPa due to hydrogen-bond symmetrization. Combining these results, we suggest that the conduction mechanism does not change with pressure-induced hydrogen-bond symmetrization. Along the Arrhenius behavior of conductivity data, the experimental evidence for superionic conduction (>10-1 S/cm) was found at T = 739 K, P = 56 GPa and T = 749 K, P = 62 GPa, which is significantly low temperature compared with earlier theoretical estimates resorted to the observation of a drastic rise of the melting curve. We infer that the sudden increase of the melting temperature is not related to the onset of superionic conduction, but is attributed to the phase change regarding to the symmetrization. [ABSTRACT FROM AUTHOR]

In this study, two known double borates (Na 3 Sc 2 (BO) 3 , Na 3 Sc(BO 3) 2) were synthesized by solid state reactions, and their crystal structures were confirmed using the Rietveld method. The melting points of Na 3 Sc 2 (BO) 3 and Na 3 Sc(BO 3) 2 at 1003 °C and 1069°С, respectively, were measured through thermal analysis. The presence of BO 3 groups in the crystal structures of the both borates has been confirmed by IR spectroscopy. The thermal expansion was characterized by HTXRD. It was found, that the thermal expansion of Na 3 Sc(BO 3) 2 is anisotropic: the maximum expansion is observed along the c -axis (α 33 = 179 × 10−6°C−1), while the minimum — in the b -direction (α 22 = 35 × 10−6 °C−1) and in the tensor α 11 -axis direction (α 11 = 31 × 10−6 °C−1), which is caused by the orientation of BO 3 groups. The results of shear strain calculations are also presented. In the entire investigated temperature interval, the unit cell of Na 3 Sc 2 (BO 3) 3 demonstrate expansion in the (ab) plane (α a = 10 × 10−6°C−1) while exhibiting compression in the c -direction (α c = −6 × 10−6 °C−1). In this work, we have successfully performed theoretical estimations of the activation energy and ion transport pathways of the studied borates. This analysis was conducted using valence-based energy maps (BVE), which predict predominantly three-dimensional conductivity. The theoretical calculations were confirmed by ionic conductivity experimental measurements. The conductivity of Na 3 Sc 2 B 3 O 9 and Na 3 ScB 2 O 6 at 973 K reached 1.3 × 10−3 Sm/cm (E a = 0.6 eV) and 1.1 × 10−3 Sm/cm (E a = 0.7 eV), respectively. [Display omitted] • The Na 3 Sc 2 (BO) 3 and Na 3 Sc(BO 3) 2 were synthesized by solid state reactions. • Their crystal structures were confirmed using the Rietveld method. • A DSC study of the Na 3 Sc 2 (BO) 3 and Na 3 Sc(BO 3) 2 revealed the melting points at 1003°C and 1069°С, respectively. • The thermal expansion of Na 3 Sc(BO 3) 2 is anisotropic: the maximum expansion is observed along the c -axis. • The unit cell of Na 3 Sc 2 (BO 3) 3 demonstrate expansion in the ab plane, while exhibiting compression in the c -direction. • The conductivity of Na 3 Sc 2 B 3 O 9 and Na 3 ScB 2 O 6 at 973 K reached 1.3 × 10–3 Sm/cm and 1.1 × 10–3 Sm/cm, respectively [ABSTRACT FROM AUTHOR]

• Impact of temperature on binary electrolyte-based Li-O2 battery is investigated. • Binary electrolyte comprises of room temperature ionic liquid and organic solvent. • Viscosity, ionic conductivity, reaction, and evaporation rates are also studied. • Binary electrolyte outperforms pure electrolytes at all operating temperatures. Awaiting a breakthrough, the Li-oxygen battery (LOB) is considered a promising candidate to meet the high energy demands in the future. Among various critical challenges which hamper its development, the mystery of the electrolyte with optimal properties remains unsolved to this day. In this study, we comprehensively investigated the effects of operating temperature (20C, 40 °C and 60 °C) on the electrochemical performance of LOBs incorporated with room temperature ionic liquid (RTIL) and organic solvent binary electrolyte. We designed and investigated 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C 2 C 1 im ][Tf 2 N]) RTIL and dimethyl sulfoxide (DMSO) organic solvent at various volume ratios ((4:1), (1:1), (1:4)). Among the binary electrolytes, ([C 2 C 1 im ][Tf 2 N]/DMSO (1:4)) delivered the highest discharge capacities of 3.70 Ah g − 1 (20 °C), 4.0 Ah g − 1 (40 °C) and 3.65 Ah g − 1 (60 °C) as compared with pure [C 2 C 1 im][Tf 2 N] and DMSO. Cycling stability tests showed superior stability of the binary electrolyte ([C 2 C 1 im ][Tf 2 N]/DMSO (1:4)) irrespective of the operating temperature. From viscosity and ionic conductivity measurements (at 20–60 °C), [C 2 C 1 im][T f 2 N]/DMSO (1:4) exhibited the highest ionic conductivity and the lowest viscosity compared with other binary electrolytes (even with pure electrolytes) at any given temperature. Cyclic voltammetry (CV) tests revealed the highest reaction rates for [C 2 C 1 im][T f 2 N]/DMSO (1:4) binary electrolytes than pure electrolytes. The superior performance of [C 2 C 1 im][T f 2 N]/DMSO (1:4) binary electrolyte was ascribed to enhanced stability against reactive intermediate species during oxygen reduction reaction (ORR), increased ionic conductivity, low viscosity (comparable with organic electrolytes), improved oxygen solubility, and relatively low evaporation rates. [ABSTRACT FROM AUTHOR]