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Lithium ion-conducting plasticized polymer electrolyte membranes were prepared using poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) as the host polymer, lithium triflate (LiTf) as the dopant salt, and ethylene carbonate (EC) as the plasticizer, with varying compositions accomplished using the solution casting technique. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses validate the presence of substantial structural alterations and the formation of a complex in the plasticized polymer electrolytes. The electrochemical impedance spectroscopy (EIS) analysis demonstrates an increase in ionic conductivity by about two orders of magnitude after the addition of EC. Estimates of ionic transference numbers derived from the direct current (DC) polarization approach indicate that charge transport in plasticized polymer electrolytes is mostly ionic. We examined the discharge characteristics of our flexible electrochemical storage device (FESD) over 25 h. The mean discharge current is 1.4 mA with a 0.04 C rating.

The micro-porous polymer electrolytes membranes(PEMs), notably electro-spun fiber mats, have been suggested to give an improved ionic conductivity. However, the mat-type PEMs have a poor mechanical and dimensional stability because of their inevitable porous nature. In this study, we suggest a new PEM system based on poly(vinylidene fluoride)(PVdF) mats, which can overwhelm such shortcomings of the porous mats by introducing another component, poly(4-vinyl pyridine)(P4VP), into the mats. The tensile strength of PVdF/P4VP membrane was considerably improved compared with that of pristine PVdF membrane under dry and wet conditions. The ionic conductivity was also improved by about 10 times than that of PVdF mat. A micro- to nano-size gap was formed at the interfaces between PVdF nanofiber and P4VP, and this may act as a channel for fast ion transportation under wet condition.

To enhance the ionic conductivity of lithium garnets, a co-doping strategy was adopted with both strontium and zirconium for ${\mathrm{\text{Li}}}_{6+y}{\mathrm{\text{La}}}_{3-y}{\mathrm{\text{Sr}}}_y{\mathrm{\text{NbZrO}}}_{12}$ ($y=0$, 0.25, 0.5, 0.75 and 1.0) (LLSNZO). By increasing the content of Sr, lithium garnet ceramics maintain cubic structure when $y$ is in the range of 0–0.75. A secondary phase of ${\mathrm{\text{SrZrO}}}_3$ appeared in the ceramic when $y=1.0$. We also studied the cross-section of lithium garnets with silver electrode. Results showed that the density of LLSNZO ceramics increased continuously against the increase of Sr content, while their total ionic conductivity enhanced initially and then reduced, with the maximum reached when $y=0.5$. It is indicated that ionic conductivity of lithium garnets is not only decided by the density but also decided by the concentration and the mobility of ${\mathrm{\text{Li}}}^{+}$.

The specific values of the conductivity $(\sigma )$ and its variation with temperature $(T)$ of 2-pentanol and 2-methyl-1-pentanol liquids doped with different concentrations of NaI (abbreviated as 2PEN-$x$NaI and 2M1PEN-$x$NaI, respectively) ($x=0\%$, 1% and 5%) are measured by the commercial equipment. The results show that whether NaI is doped or not, $\sigma$ of 2PEN-$x$NaI and 2M1PEN-$x$NaI all have a conductivity peak in the range of 300–350 K different from that of typical glass-formers of small molecules. In addition, $\sigma$ goes up with increasing $x$, and the temperature corresponding to $\sigma$ maximum increases with rising NaI content. Moreover, there is a nonlinear behavior of $\sigma$ with $x$, i.e., with rising $x$, $\sigma /x$ decreases at low-temperatures, but increases at high-temperatures. Moreover, the liquid structure and its variation with $T$ are further analyzed based on the ionic conductivity.

We have investigated the diffusion and ionic conductivity of the cubic ceria CeO₂ using the statistical moment method (SMM) in the statistical physics. The activation energy, diffusion coefficient, pre-exponential factor and ionic conductivity are derived in closed analytic forms. The SMM calculations are performed by using the Buckingham potential for the cubic ceria. The effects of the three different potential parameter sets of the Buckingham potential and influence of dipole polarization effects on activation energy, diffusion coefficient and ionic conductivity for CeO₂ are also investigated. The present analytical formulas including the anharmonic effects of the lattice vibrations give the predicted values of these quantities, which are comparable to those of the experimental values.

In this paper, we identify a yet unreported, quantum-electro-dynamic (QED) interactions induced, self-organization in aqueous solutions. We show that its characteristics conform to hitherto unexplained experimental findings, reported in the literature. Specifically, our analysis shows: (a) Solvated ions may organize into micrometer (μm) sized domains, wherein the plasma oscillations of identical ions are in-phase. (b) These liquid domains have a crystalline-like lattice structure. (c) For salt solutions, for concentrations C below a solute specific transition concentration C_trans, the ions organize into the "in-phase" domains. For C larger than C_trans, domains form wherein the plasma oscillations of the solvated ions are just coherent. Previous studies provided theoretical and experimental evidence for the "coherent" domains. However, they did not show that the "coherent" domains only exist for C > C_trans. Typically, at room temperature and pressure, C _trans is about 10^-4 M or below. (d) At C_trans, the molar electric conductivity sharply changes, i.e. for C < C_trans, the slope of the molar electric conductivity dependence on concentration is several times larger than for C > C_trans.

The temperature dependences of the conductivity and permittivity of the Ag₈GeSe₆ compound have been studied in direct and alternating electric fields. This phenomenon is associated with the process of charge accumulation at the boundary of the sample with ionic conductivity and the blocking electrode, and the formation of a double electric layer. The observed dielectric relaxation is associated with the transition of the crystal to the superionic state. It has been established that hopping conduction with a variable hopping length over localized states near the Fermi level takes place in an Ag₈GeSe₆ crystal.

To obtain high ambient ionic conductivity of solid polymer electrolyte (SPE), we introduce polymer-in-salt system with ion hopping mechanism contrary to traditional salt-in-polymer system with segmental motion mechanism. In polymer-in-salt system, the interaction between polymer and salt is important because polymer-in-salt electrolyte contains a large amount of salt. Thus, we try to solve the origin of interaction between polymer and salt by using hard/soft acid base (HSAB) principle. The SPEs are made up of two types of polymers (poly(ethylene oxide) (PEO, hard base) and poly(ethylene imine) (PEI, softer base than PEO)) and four types of salts (LiCF₃SO₃ (hard cation/hard anion), LiCl (hard cation/soft anion), AgCF₃SO₃ (soft cation/hard anion), and AgCl (soft cation/soft anion)) according to HSAB principle. In salt-in-polymer system, ionic conductivities of SPEs were affected by HSAB principle but in polymer-in-salt system, they were influenced by the ion hopping property of salt rather than the solubility of polymer for salt according to HSAB principle. The highest ionic conductivities of PEO-based and PEI-based SPEs were 5.13 × 10^-4Scm^-1 and 7.32 × 10^-4Scm^-1 in polymer-in-salt system, respectively.

Quasi-solid-state dye-sensitized solar cells were fabricated using a high molecular polymer redox electrolyte. Poly(ethylene oxide) (PEO) and Poly(vinylidenefluoride-co-hexafluoropropylene) (P(VDF-HFP)) were used to form a stable quasi-solid structure and a three-dimensional gel polymer network structure. The polymer electrolytes were composed of LiI, I₂, and DMPII in the mixture of propylene carbonate (PC) and γ-butyrolactone (GBL) with different volume ratios. A metal-free organic dye (indoline dye D102) was used as a sensitizer. The ionic conductivity of the gel polymer electrolytes was measured with Electrochemical Impedance Spectroscopy (EIS). The dependence of the ionic conductivity on the volume ratio of PC to GBL was investigated. The volume ratio of the mix solvent, weight ratio of PEO/P(VDF-HFP), and the weight ratio of TiO₂ fillers were optimized. The optimized quasi-solid-state cell exhibited an efficiency of 5.49% at full sunlight (air mass 1.5, 60 mW/cm²) irradiation.

The phenomenon of enhancement of ionic transport and electrochemical behavior of a new poly (propylene glycol) (PPG 4000)–silver triflate (AgCF₃SO₃) as a result of incorporation of varying concentrations of ZrO₂ nanoparticles have been investigated. The significant conformal changes and the strength of interactions along with chain enlargement of polymer matrix have been analyzed by means of FT-IR and DSC studies as well. From the ac impedance measurements, it is clear that the addition of filler particles favors an increase in the conductivity by more than two orders of magnitude and that the typical sample PPG₄–AgCF₃SO₃:10 wt% ZrO₂ exhibits a maximum conductivity of 2.9 × 10^-3 Scm^-1 along with the cationic transference number of 0.49 at room temperature.

An amorphous, colorless, and highly transparent star network polymer with a pentaerythritol core linking four PEG-block polymeric arms was synthesized from the poly(ethylene glycol) (PEG), pentaerythritol, and dichloromethane by Williamson reaction. FTIR and ¹H-NMR measurement demonstrated that the polymer repeating units were C[CH₂ - OCH₂O - (CH₂CH₂O)_m - CH₂O - (CH₂CH₂O)_n - CH₂O]₄. The polymer host held well mechanical properties for pentaerythritol cross-linking. The gel polymer electrolytes based on Lithium perchlorate (LiClO₄) and ethylene carbonate/propylene carbonate (EC/PC) were prepared and characterized by AC impedance spectroscopy and thermogravimetry (TG), the results showed thermal stability up to at least 150°C and ionic conductivity reaching 8.83 × 10^-4S·cm^-1 at room temperature. The gel polymer electrolytes were further evaluated in electrochromic devices (ECD) fabricated by transparent PET-ITO and electrochromic active viologen derivative films, and its excellent performance promised the usage of the gel polymer electrolytes as ionic conductor material in ECD.

A random copolymer P(VAc-MMA) was synthesized via seeded emulsion copolymerization with vinyl acetate (VAc) and methyl methacrylate (MMA) as monomers, and the polymer electrolytes comprising blend of corresponding copolymer P(VAc-MMA) as a host polymer and LiClO₄ as a dopant were prepared by solution casting technique. Performances of the synthesized copolymer and prepared polymer membrane and electrolyte were studied by FTIR, XRD, TG, DSC, mechanical testing and AC impedance. According to the study of FTIR and DSC, it was found that P(VAc-MMA) had been formed. XRD indicates that the amorphous nature in copolymer increased with increasing the ratio of VAc in monomers, resulting in expedite migration of ions. The polymer electrolytes based on P(VAc-MMA) possess excellent thermal stability, fine mechanical performance and high ionic conductivity. The maximum ionic conductivity value was found to reach 1.27 × 10^-3S · cm^-1 at 25°C. The temperature dependence of the polymer electrolyte complexes appeared to obey Arrhenius equation.

The gel-like films obtained from the homoassociation of diprotonated meso-tetrakis(4-sulfonatophenyl)porphyrin show structural changes depending on their water content, which is determined by the affinity for water of the ionic species segregated from the homoassociation process. These materials, in which NaCl or H₂SO₄ are segregated, were studied and their electrochemical behavior at several water contents was examined. The behavior of humid films was clearly different from dry films. The p_H2O value, which determines the separation between the dry and humid behavior, depends on the type of the ionic species segregated in the homoassociation. This is briefly discussed in relation to the design of humidity sensors.

A Ce-doped La_0.9MnO_3-δ sample was prepared by the Pechini route, consisting of a polymerization of citric acid and ethylene glycol, in order to prepare a phase with oxygen deficiency that can be used in fuel cell applications. To substitute a part of lanthanum by cerium, we added CeO₂ in excess to force it to react and diffuse in the perovskite. The Fourier Transformed infrared (FTIR) spectrum of the resin at 200°C has shown the formation of complex metals form and polymerized form of ethylene glycol. The X-ray diffraction (XRD) spectrum of the sample, calcined at 900°C, has revealed that the sample is mainly constituted by a deficient rhombohedra perovskite phase. The measurement of the ionic conductivity by complex impedance at room temperature has given a relatively high value, which opens up an opportunity for solid oxide fuel cell applications.

Solid polymer electrolytes comprising a blend of poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) with different concentration of potassium hydroxide (KOH) as ionic dopant were prepared using a solution–casting technique. The conductivity was enhanced to (1.5 ± 1.1) × 10^-4S cm^-1 when 40 wt.% KOH was added. The highest conductivity exhibited when 20 wt.% ethylene carbonate (EC) and 30 wt.% propylene carbonate (PC) was added into the PVA/PVP–KOH sample electrolytes. Conductivity–temperature dependence of the plasticized samples was established to obey an Arrhenian relationship with the activation energy of the order of 0.08–0.4 eV, depending on the plasticizer concentration. Electrochemical cells of Zn|PVA/PVP–KOH + EC|MnO₂ and Zn|PVA/PVP–KOH + PC|MnO₂ have been fabricated. The discharge characteristics of the cells are considered under a constant current of 1 mA. The open circuit voltage (OCV) and discharge capacity of the cells are measured.

The samples of K₂Fe₂₂O₃₄ phase were synthesized and characterized by XRD, BET, SEM-EDX and XPS. K⁺ diffusion was investigated by impedance spectroscopy, whereas the surface segregation and desorption were monitored by Kelvin Probe (changes in work function) and Species Resolved Thermal Alkali Desorption, at the temperature range of 600–1000 K. The analysis of changes in work function and desorption signals (K and K⁺) at various temperatures allowed to resolve the kinetic parameters (flux, rate constants, activation energies) of potassium diffusion, surface accumulation and desorption. Based on the obtained results, the simple, functional model of bulk and surface changes of K-β-ferrite was proposed.

The work investigates electrical properties of all-glass composite Ag⁺-ion conductors based on silver phosphate glasses. A combination of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) was used for characterization of the samples. The impedance spectroscopy (IS) was applied to determine the electrical conductivity in a wide temperature range (from -140 to +20°C). Results of the DSC studies indicate that all-glass materials prepared from the powdered glasses are bi-phasic. On the other hand their electrical properties resemble homogeneous rather than heterogeneous superionic conductors.

Variation of microstructures and ionic conductivities in (Bi₂O₃)_0.75(Y₂O₃)_0.25 (YSB) modified electrolyte of 8 mol% Y₂O₃ stabilized zirconia (8YSZ) and YSB modified codoped zirconia (ZrO₂)_0.92(Y₂O₃)_0.075(MgO)_0.005 (YSZM) is investigated in this work. The results demonstrated that a small amount of δ-YSB addition is effective in reducing the sintering temperature of 8YSZ from 1500 to 1200°C and promoting the densification rate of ceramics. Compared to 8YSZ electrolyte, it is interesting that a very limited amount of monoclinic ZrO₂ was observed due to the MgO stabilizer in YSB modified codoped zirconia electrolyte. Besides, enhancement of ionic conductivity in δ-YSB modified codoped zirconia is evidently increased by 67% in comparison to the specimen of 8YSZ electrolyte.

Solid polymer electrolytes (SPEs) based on cellulose acetate (CA) doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt are prepared by solution cast technique. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy of the polymer salt complexes are recorded in the frequency range between 400 cm^-1 and 4000 cm^-1. The shifting of carbonyl band (C=O) at 1737 cm^-1 to a lower wavenumber confirms the occurrence of complexation between the polymer and the salt. The electrochemical impedance spectroscopy (EIS) analysis discovered that the film with 25 wt.% of salt shows the highest ionic conductivity at room temperature. The change in real dielectric permittivity (ε_r) as a function of frequency at different salt concentrations which exhibits a dispersive behavior at low frequencies and decays at higher frequencies, shows the electrode polarization and space charge effect. The real modulus formalism (M_r) analysis shows that the polymer electrolytes in this work are ionic conductors.

A large number of pores and a low relative density that are frequently observed in solid electrolytes reduce severely their ionic conductivity and thus limit their applicability. Here, we report on the use of hot isostatic pressing (HIP) for ameliorating the garnet-type lithium-ion conducting solid electrolyte of Ga₂O₃-doped Li₇La₃Zr₂O${}_{12}$ (Ga-LLZO) with nominal composition of Li${}_{6.55}$Ga${}_{0.15}$La₃Zr₂O${}_{12}$. The Ga-LLZO pellets were conventionally sintered at 1075${}^{\circ }$C for 12h, and then were followed by HIP treatment at 120MPa and 1160${}^{\circ }$C under an Ar atmosphere. It is found that the HIP-treated Ga-LLZO shows an extremely dense microstructure and a significantly enhanced ionic conductivity. Coherent with the increase in relative density from 90.5% (untreated) to 97.5% (HIP-treated), the ionic conductivity of the HIP-treated Ga-LLZO reaches as high as $1.13\times 10^{-3}$S/cm at room temperature (25${}^{\circ }$C), being two times higher than that of $4.58\times 10^{-4}$S/cm for the untreated one.