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The melting temperature is important for materials design because of its relationship with thermal stability, synthesis, and processing conditions. Current empirical and computational melting point estimation techniques are limited in scope, computational feasibility, or interpretability. We report the development of a machine learning methodology for predicting melting temperatures of binary ionic solid materials. We evaluated different machine-learning models trained on a dataset of the melting points of 476 non-metallic crystalline binary compounds using materials embeddings constructed from elemental properties and density-functional theory calculations as model inputs. A direct supervised-learning approach yields a mean absolute error of around 180 K but suffers from low interpretability. We find that the fidelity of predictions can further be improved by introducing an additional unsupervised-learning step that first classifies the materials before the melting-point regression. Not only does this two-step model exhibit improved accuracy, but the approach also provides a level of interpretability with insights into feature importance and different types of melting that depend on the specific atomic bonding inside a material. Motivated by this finding, we used a symbolic learning approach to find interpretable physical models for the melting temperature, which recovered the best-performing features from both prior models and provided additional interpretability. [ABSTRACT FROM AUTHOR]

Choline dihydrogen phosphate, [Chol][H2PO4], is a proton-conducting ionic plastic crystal exhibiting a complicated sequence of phase transitions. Here, we address the argument in the literature around the thermal properties of [Chol][H2PO4] using Raman and infrared microspectroscopy. The known structure of the low-temperature crystal, which contains the anti-conformer of [Chol]+ and hydrogen-bonded dimers of anions, was used to do periodic density functional theory calculations of the vibrational frequencies. Raman spectra indicate that the solid–solid transition at 20 °C is linked to a conformational change to the gauche [Chol] conformer with a concurrent local rearrangement of the anions. The distinct bands of lattice modes in the low-frequency range of the Raman spectra vanish at the 20 °C transition. Given the ease with which metastable crystals can be produced, Raman mappings demonstrate that a sample of [Chol][H2PO4] at ambient temperature can contain a combination of anti- and gauche conformers. Heating to 120 °C causes continuous changes in the local environment of anions rather than melting as suggested by a recent calorimetric investigation of [Chol][H2PO4]. The monotonic change in vibrational spectra is consistent with earlier observations of a very small entropy of fusion and no abrupt jump in the temperature dependence of ionic conductivity along the phase transitions of [Chol][H2PO4]. [ABSTRACT FROM AUTHOR]

Computing the solubility of crystals in a solvent using atomistic simulations is notoriously challenging due to the complexities and convergence issues associated with free-energy methods, as well as the slow equilibration in direct-coexistence simulations. This paper introduces a molecular-dynamics workflow that simplifies and robustly computes the solubility of molecular or ionic crystals. This method is considerably more straightforward than the state-of-the-art, as we have streamlined and optimised each step of the process. Specifically, we calculate the chemical potential of the crystal using the gas-phase molecule as a reference state, and employ the S0 method to determine the concentration dependence of the chemical potential of the solute. We use this workflow to predict the solubilities of sodium chloride in water, urea polymorphs in water, and paracetamol polymorphs in both water and ethanol. Our findings indicate that the predicted solubility is sensitive to the chosen potential energy surface. Furthermore, we note that the harmonic approximation often fails for both molecular crystals and gas molecules at or above room temperature, and that the assumption of an ideal solution becomes less valid for highly soluble substances. [ABSTRACT FROM AUTHOR]

[Display omitted] Water is considered an effective microwave absorber due to its high transmittance and frequency-dispersive dielectric constant, yet it is challenging to form it into a stable state as an absorber. Herein, we developed a water-containing microwave absorber using chemical vapor deposition (CVD), namely, the bifunctional carbon/NaCl multi-interfaces hybrid with excellent water harvesting and microwave absorption performance. Carbon/NaCl exhibits remarkable water harvesting abilities from air, exceeding 210 % of its weight in 12 h. The development of the hydrophilic/hydrophobic heterojunction interface is responsible for this outstanding performance. Additionally, the interfacial polarization provided by carbon/NaCl, along with the dipole polarization induced by the internally captured water and defects, enhances its microwave absorption. The carbon/NaCl hybrid achieved a minimum reflection loss (RL min) of −69.62 dB at 17.1 GHz with a thickness of 2.13 mm, and a maximum effective absorption bandwidth (EAB max) of 6.74 GHz at a thickness of 2.5 mm. Compared with raw NaCl (RL min of −24.5 dB, EAB max of 3.88 GHz), the RL min and EAB max values of the absorber increased by approximately 2.85 and 1.74 times. These results highlight the potential for bifunctional carbon/NaCl hybrid in applications within extreme environments, presenting a promising avenue for further research and development. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium‐ion batteries, employing solid electrolytes, offer a promising solution to address safety concerns inherent in conventional lithium‐ion batteries. Among the various types of Li‐ion solid electrolytes, LiTi2(PO4)3 (LTP) with the Na Super Ionic CONductor (NASICON) structure stands out as a particularly attractive material, despite its relatively low ionic conductivity at room temperature. One approach to enhance the performance of LTP solid electrolytes involves modifying the network size or redistributing Li cations and vacancies within the adjacent sites of the NASICON structure. Therefore, this study seeks to replace lithium ions with divalent cations, thereby increasing the concentration of vacancies, and facilitates the migration of Li+ ions between adjacent partially populated M1 sites. Introducing divalent elements not only augments vacancies in the lithium sites but also induces variations in local disorder within NASICON structures. Consequently, NASICON compounds, MIIx/2Li1−xTi2(PO4)3 (MII = Mg, Zn, and Cd), were synthesized via the sol–gel method, and their structural, microstructural, and electrical properties were thoroughly analyzed using a variety of techniques. The presence of divalent cations in the M1 site results in a reduction of symmetry and an enhancement of local disorder. A correlation between ionic conductivity and structure was established, which was linked to the disorder of lithium atoms within the structure. Electric modulus formalism was employed to explore electric relaxation, revealing that the diffusion and relaxation processes are thermally activated. [ABSTRACT FROM AUTHOR]

Barocaloric (BC) materials offer the potential for highly energy-efficient refrigeration by generating heat absorption through the effect of pressure on a solid-solid phase transition. However, very few of the known materials have the required phase transition in the temperature regions necessary for domestic refrigeration or air conditioning. We introduce organic ionic plastic crystals (OIPCs) as a new family of BC materials. OIPCs display subambient transition temperatures, so-called “colossal” entropy changes (92 to 240 joules per kilogram per kelvin), and a high sensitivity to pressure, up to 23.7 kelvin per kilobar. The BC responses achieved with these prototype OIPC-BCs are tunable through structural modification of the ions; this wide matrix of possible combinations of structure and function indicates the scope of OIPCs as a new class of material for efficient and sustainable cooling technologies. [ABSTRACT FROM AUTHOR]

BiYSZ, a Bi3+-doped yttria-stabilized zirconia with 4% molYO1.5, was synthesized using a lamellar liquid crystal template technique. The influence of different doping amounts of Bi3+ on crystal form, morphology and the ionic conductivity has been investigated in detail. In addition, the densification time of BiYSZ has been determined. Analytical techniques such as X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) have been utilized to characterize the synthesized powders. The results reveal that BiYSZ, with its stable tetragonal phase and spherical nanostructure, benefits from Bi3+ doping in 4% mol YO1.5-stabilized zirconia, leading to enhanced ionic conductivity. Notably, the optimal formulation with 3 mol% Bi3+ and 4 mol% Y3+ in yttria-stabilized zirconia reaches a maximum ionic conductivity of 7.41 × 10−5 S/cm at 500°C. This formulation also reduces the sintering temperature by 100°C compared to 4YSZ and significantly improves conductivity by an order of magnitude. [ABSTRACT FROM AUTHOR]

Crystal symmetry, which governs the local atomic coordination and bonding environment, is one of the paramount constituents that intrinsically dictate materials' functionalities. However, engineering crystal symmetry is not straightforward due to the isotropically strong covalent/ionic bonds in crystals. Layered two-dimensional materials offer an ideal platform for crystal engineering because of the ease of interlayer symmetry operations. However, controlling the crystal symmetry remains challenging due to the ease of gliding perpendicular to the Z direction. Herein, we proposed a substrate-guided growth mechanism to atomically fabricate AB′-stacked SnSe2 superlattices, containing alternating SnSe2 slabs with periodic interlayer mirror and gliding symmetry operations, by chemical vapor deposition. Some higher-order phases such as 6 R, 12 R, and 18 C can be accessed, exhibiting modulated nonlinear optical responses suggested by first-principle calculations. Charge transfer from mica substrates stabilizes the high-order SnSe2 phases. Our approach shows a promising strategy for realizing topological phases via stackingtronics. van der Waals (vdW) materials offer unique opportunities to engineer their crystal symmetry, but usually require top-down fabrication approaches. Here, the authors report a mica substrate-guided bottom-up method to grow exotic phases of SnSe2 and other vdW materials, showing tunable nonlinear optical properties. [ABSTRACT FROM AUTHOR]

Polymer electrolytes‐based batteries are suffering great degradation due to the irreversible lithium deposition and increased impedance at sub‐zero temperature, which is related with Li+ conductivity of bulk electrolyte (σBulk) and ionic conductivity of solid electrolyte interface (σSEI). Thereby, an artificial SEI layer has coated on Li anode through in situ polymerizing polyester with fluorinated porphyrin, which could accelerate Li+ desolvation and conductivity of SEI. Then, the dual‐salt eutectic polymer electrolyte tolerate is employed to accelerate Li+ transfer through optimize their solvation structure. The matching factor is calculated to evaluate the synergistic effect of σBulk and σSEI on low‐temperature Li+ mobility. Thus, homogenize the Li+ flux during Li‐plating is achieved by marching the Li+ diffusion rate (δ = 1.92), which significantly mitigate overpotential aggravation and suppress dendrite nucleation. Overall, such marching factor could provide a theoretical parameter for evaluating the low‐temperature tolerability of solid‐state lithium batteries (SSBs), which would useful for improving batteries’ durability, safety and flexibility. [ABSTRACT FROM AUTHOR]

Metal‐free ionic crystals have attracted tremendous attention for their environmental friendliness, biocompatibility, easy fabrication and structural variability. Herein, a metal‐free ionic crystal [C7H16NO][ClO4] ([C7H16NO]=1‐methyl‐4‐piperidinemethanol) with a dielectric transition at room temperature was designed and constructed. Differential scanning calorimetry (DSC) proved that there exists a reversible phase transition near room temperature at 304 K, accompanied with switchable dielectric behaviors between the low and high dielectric states. The single crystal structure show that the mechanism of such structural phase transition mainly results from the dynamic motion of perchlorate anions. The compound is further shown to exhibit remarkable luminescent properties, characterized by a prolonged lifetime of 18.6 ns. This work offers valuable insights into the construction of room temperature phase‐transition ionic crystals involved with dielectric switching and blue luminescence properties. [ABSTRACT FROM AUTHOR]

Metal‐free ionic crystals have attracted tremendous attention for their environmental friendliness, biocompatibility, easy fabrication and structural variability. Herein, a metal‐free ionic crystal [C7H16NO][ClO4] ([C7H16NO]=1‐methyl‐4‐piperidinemethanol) with a dielectric transition at room temperature was designed and constructed. Differential scanning calorimetry (DSC) proved that there exists a reversible phase transition near room temperature at 304 K, accompanied with switchable dielectric behaviors between the low and high dielectric states. The single crystal structure show that the mechanism of such structural phase transition mainly results from the dynamic motion of perchlorate anions. The compound is further shown to exhibit remarkable luminescent properties, characterized by a prolonged lifetime of 18.6 ns. This work offers valuable insights into the construction of room temperature phase‐transition ionic crystals involved with dielectric switching and blue luminescence properties. [ABSTRACT FROM AUTHOR]

The formation of cyanopyridine (CN-py) adducts of silicon tetrahalides was investigated for 3- and 4-cyanopyridine in combination with SiF4 and SiCl4. Whereas bubbling of SiF4 through toluene solutions of 3-CN-py and 4-CN-py afforded white precipitates, which should possess the respective composition SiF4(CN-py)2, addition of SiCl4 did not cause any precipitation. Upon storage of the toluene solution of SiCl4 and 4-CN-py at 6 °C for several weeks, some crystals of the composition SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) ⋅ (toluene) were obtained. The use of SiCl4 as the solvent (i.e. SiCl4 in large excess) and dissolving 4-CN-py therein gave access to a crystalline adduct of the composition SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py). 3-CN-py instead recrystallized from SiCl4 without forming an adduct with the silane. Computational analyses (B2T-PLYP level) of the single-point energy differences between starting materials SiX4 (X = F, Cl) and 'pyridine' ('pyridine' = pyridine, 3-CN-py, 4-CN-py) and their adducts SiX4('pyridine')2 revealed the tendencies toward adduct formation to decrease in the order SiF4 > SiCl4 as well as pyridine >> 4-CN-py > 3-CN-py. For SiCl4 with 4- and 3-CN-py, the energy of adduct formation (−7.0 and −5.7 kcal mol−1, respectively) is easily compensated by entropy effects at room temperature. Whereas the former explains as to why cyanopyridines and SiCl4 may co-exist without noticeable adduct formation, the crystal structures of the adducts SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) ⋅ (toluene) and SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) reveal the additional stabilization of these solids by co-crystallization with 4-cyanopyridine, which eventually enabled the isolation of the SiCl4(4-CN-py)2 moiety in a solid. Partial decomposition (hydrolysis) during attempts of recrystallization of SiF4(4-CN-py)2 and SiF4(3-CN-py)2 afforded crystals of the ionic compounds [4-CN-PyH]+[SiF5(4-CN-py)]– and [3-CN-PyH]+2[SiF6]2–, respectively. [ABSTRACT FROM AUTHOR]

Over the past 130 years, Fischer-Speier esterification has been established as the benchmark method for synthesizing esters from organic acids and alcohols. The reaction's versatility, arising from the vast combinations of starting materials and the numerous catalytic alternatives to the traditional H2SO4, has maintained its relevance, with a steady flow of publications addressing new developments. This review highlights the most significant contributions to Fischer-Speier esterification over the past five years, with a particular emphasis on mechanistic advancements and innovative catalytic systems. Both homogeneous and heterogeneous catalytic approaches are discussed, including novel catalysts leveraging hydrogen-bonding interactions and systems offering fresh insights into specific reaction mechanisms and atypical methodologies. Some of these catalytic systems, as ionic liquids or sulfonated heterogeneous catalytic precursors, reached excellent yields (>90%), e.g., in the synthesis of fatty acids methyl esters. Also, classic catalysts such as H2SO4 and para-toluen sulfonic acid were optimized for quantitative conversions (e.g., in the esterification of trans-cinnamic acid with methanol). A consistent number of catalysts was studied with model substrates (as benzoic acid in combination with methanol, ethanol, and ethylene glycol), and new activation pathways were presented. [ABSTRACT FROM AUTHOR]

This research explores the use of solid polymer electrolytes (SPEs) as a conductive medium for sodium ions in sodium‐ion batteries, presenting a possible alternative to traditional lithium‐ion battery technology. The researchers prepare SPEs with varying molecular weight ratios of polyacrylonitrile (PAN) and sodium tetrafluoroborate (NaBF4) using a solution casting method with dimethyl formamide as the solvent. Through optical absorbance measurements, we identified the PAN:NaBF4 (80:20) SPE composition as having the lowest energy band gap value (4.48 eV). This composition also exhibits high thermal stability based on thermogravimetric analysis results. Electrochemical impedance spectroscopy reveals an ionic conductivity of 1.02 × 10−4 S cm−1 for the PAN:NaBF4 (80:20) blend at ambient temperature. Additionally, linear sweep voltammetry demonstrates its good electrochemical stability up to 3.22 V. We assemble a primary sodium‐ion battery using the optimal SPE composition (Na/(PAN + NaBF4)/(I2 + C + electrolyte)). This battery achieves an open‐circuit voltage of 2.83 V and displays promising discharge performance. [ABSTRACT FROM AUTHOR]

The formation of cyanopyridine (CN-py) adducts of silicon tetrahalides was investigated for 3- and 4-cyanopyridine in combination with SiF4 and SiCl4. Whereas bubbling of SiF4 through toluene solutions of 3-CN-py and 4-CN-py afforded white precipitates, which should possess the respective composition SiF4(CN-py)2, addition of SiCl4 did not cause any precipitation. Upon storage of the toluene solution of SiCl4 and 4-CN-py at 6 °C for several weeks, some crystals of the composition SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) ⋅ (toluene) were obtained. The use of SiCl4 as the solvent (i.e. SiCl4 in large excess) and dissolving 4-CN-py therein gave access to a crystalline adduct of the composition SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py). 3-CN-py instead recrystallized from SiCl4 without forming an adduct with the silane. Computational analyses (B2T-PLYP level) of the single-point energy differences between starting materials SiX4 (X = F, Cl) and 'pyridine' ('pyridine' = pyridine, 3-CN-py, 4-CN-py) and their adducts SiX4('pyridine')2 revealed the tendencies toward adduct formation to decrease in the order SiF4 > SiCl4 as well as pyridine >> 4-CN-py > 3-CN-py. For SiCl4 with 4- and 3-CN-py, the energy of adduct formation (−7.0 and −5.7 kcal mol−1, respectively) is easily compensated by entropy effects at room temperature. Whereas the former explains as to why cyanopyridines and SiCl4 may co-exist without noticeable adduct formation, the crystal structures of the adducts SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) ⋅ (toluene) and SiCl4(4-CN-py)2 ⋅ 2 (4-CN-py) reveal the additional stabilization of these solids by co-crystallization with 4-cyanopyridine, which eventually enabled the isolation of the SiCl4(4-CN-py)2 moiety in a solid. Partial decomposition (hydrolysis) during attempts of recrystallization of SiF4(4-CN-py)2 and SiF4(3-CN-py)2 afforded crystals of the ionic compounds [4-CN-PyH]+[SiF5(4-CN-py)]– and [3-CN-PyH]+2[SiF6]2–, respectively. [ABSTRACT FROM AUTHOR]

The fast-growing area of battery technology requires the availability of highly stable, energy-efficient batteries for everyday applications. This, in turn, calls for research into new battery materials, especially with regard to a battery's main component: the electrolytes. Besides the demands associated with solid ionic conduction and appropriate electrochemical behaviour, considerable effort will be necessary to thoroughly reduce safety risks in terms of flammability, leakage, and thermal runaway. Consequently, completely new classes of electrolytes need to be developed that are compatible with energy storage systems. Despite the progress made in solid polymer electrolytes, such materials have suffered from limitations to their real-world application. Now, ionic liquids are considered a class of electrolytes with the most potential for the creation of more advanced and safer lithium–ion batteries. In recent decades, ILs have been widely explored as potential electrolytes in the search for new breakthroughs in the ESS field, such those associated with fuel cells, lithium–ion batteries, and supercapacitors. The present review will discuss ILs that present high ionic conductivity, a lower melting point below 100 °C, and which feature up to 5–6 V wide electrochemical potential windows vs. Li+/Li. Furthermore, ILs exhibit good thermal stability, non-flammability, and low volatility—all of which are attributes realized by appropriate cation–anion combinations. This paper seeks to review the status of research concerning ILs, along with the advantages and challenges yet to be overcome in their development. [ABSTRACT FROM AUTHOR]

Optoelectronic devices performance is governed by the band alignment nature in heterojunctions. Interfacial Layers (ILs) play an immense role in charge carrier‐selectivity and their transport behavior. Considering the investigations on a wide array of solid‐state surfaces and heterojunctions performed both experimentally and theoretically, we found that the electron localizability, which is quantifiable through the bandgap energy and band width, affects the surface properties of crystals and hence the electronic properties of the interfaces. In combination with other observations, a strategy for contact design is developed for enhancing charge carrier transport across the boundaries and the interfaces, one can optimize stack structures with IL by maximizing their respective transport mechanism, similar to what has been done with silicon solar cells by doping. In this case, charge carrier transport across the interface can be maximized by making the depletion region width smaller without altering the heterojunction barrier's height. [ABSTRACT FROM AUTHOR]

We report the synthesis and characterization of a novel asymmetric imidazolium-based ionic liquid crystal (ILC) dimer exhibiting stable smectic phases over a wide temperature range, including room temperature. This unique molecular structure, combining two distinct mesogenic cores, reduces packing density, which enhances ion mobility and achieves high ionic conductivity in the smectic phase (0.1 mS cm−1 at 40 °C). Electrochemical impedance spectroscopy (EIS) confirmed improved ionic conductivity at lower temperatures, along with a stable electrochemical window of ±3 V. Application as a solid-state electrolyte in an electrochromic device demonstrated effective switching behavior and reversible redox cycles. These findings suggest that this asymmetric imidazolium-based ILC is a viable candidate for advanced electrochemical applications due to its structural stability and anisotropic ionic pathways. [ABSTRACT FROM AUTHOR]

Crystal structures, microtopography, morphologies, elemental compositions, and ionic conductivity have been investigated for Li5- x La3(Nb,Ta)O12- y using X-ray diffraction (XRD), field-emission analytical scanning and transmission electron microscopies (S/TEM), and electrochemical impedance spectroscopy. Using Rietveld refinements with powder XRD patterns, we determined that the number of Li atoms in the formula is less than 5 and that Li5- x La3(NbTa)O12- y crystallizes in the cubic garnet structure with a space group Ia- 3 d. Sintering at varying temperatures (750–1000 °C) for 5 h in an ambient atmosphere produced distinct outcomes. Rietveld refinements disclosed that the sample sintered at 1000 °C (Li3.43(2)La3Nb1.07(2)Ta0.93(2)O12- y , a = 12.8361(7) Å, V = 2114.96(3) Å3) exhibited the highest ionic conductivity, while the 850 °C sample had the lowest conductivity, characterized by lower Li concentration and impurity phases (Li(Nb,Ta)3O88, Li2CO3). Analyses, including XRD and electron microscopy, confirmed the 1000 °C sample as a relatively phase pure with enhanced Li content (Li/La = 1.2), larger grains (15 μm), and uniform crystallinity. The 1000 °C sample introduced additional partially filled Li3 (96 h) sites, promoting Li migration, and enhancing ionic conductivity. The resulting XRD pattern at 1000 °C has been submitted to the Powder Diffraction File as a reference. [ABSTRACT FROM AUTHOR]

Multifunctional ionic plastic crystals (IPCs) are a class of unique materials that exhibit a wide range of advanced applications. In this work, we proposed a strategy for the design of multifunctional, superior ion‐conducting IPCs with bistability in both magnetic and electric properties, moreover, we successfully prepared and thoroughly characterized such an IPC, [PMPyr][Ni(mnt)2] (1; PMPyr+=N‐propyl‐N‐methylpyrrolidinium, and mnt2−=maleonitriledithiolate). Plastic crystal 1 exhibits superior ion conduction near room temperature, and its ion conductivity reaches the order of 10−2 S cm−1 at 373 K. Remarkably, the crystal‐to‐plastic crystal transformation results in 1 simultaneously exhibiting electrical bistability and magnetic transition. Our study paves the way for the development of new IPCs with desirable functional properties. [ABSTRACT FROM AUTHOR]

A MoO2-doped Li5.5PS4.5Cl1.5 solid electrolyte with ionic conductivity of 12 mS cm−1 and an electrochemical window of 4.3 V vs. Li/Li+ was prepared, which enables a LiNi0.8Co0.1Mn0.1O2-based full cell to deliver a specific capacity of 194 mA h g−1 at 0.1C and retain 80% capacity after 3500 cycles at 1C. [ABSTRACT FROM AUTHOR]

Perovskite solar cells are among the most promising candidates for the next generation of photovoltaic technology. However, the heterogeneous nature of mixed halide perovskites as ionic crystals raises challenges to their photovoltaic performance and long‐term stability. Herein, a functional molecule, named 2‐amino‐4‐trifluoromethylpyridine (2A4TP), is introduced as an inhibitor of impurity phases in perovskite wet films, enabling the formation of optically active pure phase (α‐phase) perovskites at room temperature. Meanwhile, reducing aggregation barrier for perovskite colloidal particles contribute to accelerate perovskite nucleation rate. Ultimately, the resulting uniform perovskite films afford to the optimized perovskite solar cells (0.09 cm2) exhibited a champion efficiency of 24.59% along with superior thermal and operational stability. Finally, 30x30 cm2 modules fabricated in this way delivers an impressive efficiency of 16.12% (with an aperture area of 655.2 cm2), demonstrating the large‐area compatibility of the strategy. [ABSTRACT FROM AUTHOR]

Sodium salt of 1,3‐bis(5‐tetrazolyl)triazene (NaH2BTT ⋅ 4H2O) was obtained through diazo‐couple reaction with 5‐aminotetrazole as starting reactants, and a family of energetic ionic crystals of the 1,3‐bis(5‐tetrazolyl)triazene anions HnBTT(3−n)− with different cations were investigated, including protonated amines (ethanediamine, hydrazinium, aminoguanidine, methylhydrazinium) and Y(H2O)83+. The structures and physicochemical properties of these compounds were characterized by IR, Raman, X‐ray diffraction (XRPD) and TG‐DSC. Ethanediamine salt is the best thermal stable, while hydrazinium salt possesses a highest nitrogen rich value of 79.76 %. Both of them show a rapid collapse of the BTT main frame, and almost all of the dissociation products are released in the form of gas. [ABSTRACT FROM AUTHOR]

The crystal structure uniformity is numerically estimated as the standard deviation of the crystal space quantizer ⟨G3⟩. This criterion has been applied to explore the uniformity of ionic sublattices in 21465 crystal structures of inorganic ionic compounds. In most cases, at least one kind of sublattice (whole ionic lattice, cationic or anionic sublattice) was found to be highly uniform with a small ⟨G3⟩ value. Non‐uniform structures appeared to be either erroneous or essentially non‐ionic. As a result, a set of uniformity criteria is proposed for the estimation of the stability of ionic crystal structures. [ABSTRACT FROM AUTHOR]

In response to the problem that the conventional concentrated sulfuric acid catalyst for esterification reactions are prone to corrosion and generate large amounts of acid-containing wastewater, highly efficient gel resin-loaded ionic liquid solid acid (SA-ILs) catalysts were prepared by a one-pot method of loading ionic liquids onto gel resins. It is shown that the gel resin carrier has a strong water-absorbing structure, and the ionic liquids are covalently loaded on the gel resin carrier through chemical bonding, leading to SA-ILs catalysts with excellent acidity and good structural stability. With an optimal ionic liquid loading of 11% and acid density of 3.25 mmol·g−1,the synthesized SA-ILs catalysts showed good catalytic performance in the transesterification reaction between acetic acid and ethanol at 80 °C for 1.5 h. The catalyst dosage was 10 wt% of the total mass of acetic acid and ethanol, and the ethanol to acetic acid addition was at a molar ratio of 1.5:1. Ethyl acetate yields of up to 81% were achieved after the reaction. The catalyst also showed slightly decrease of the catalytic performance after reused for five cycles. The lower activation energy of the catalyst is proved to be the key to facilitate the catalytic transesterification reaction. [ABSTRACT FROM AUTHOR]

The ionicity of ionic solids is typically characterized by the electronegativity of the constituent ions. Electronegativity measures the ability of electron transfer between atoms and is commonly considered under ambient conditions. However, external stresses profoundly change the ionicity, and compressed ionic compounds may behave differently. Here, we focus on silver halides, with constituent ions from one of the most electropositive metals and some of the most electronegative nonmetals. Using first-principles calculations, we find that the strengths of the ionic bonds in these compounds change greatly under pressure owing to downshifting of the Ag 4d-orbital. The center of this orbital is lowered to fill the antibonding state below the Fermi level, leading to chemical decomposition. Our results suggest that under pressure, the orbital energies and correspondingly the electronegativities still tune the ionicity and control the electron transfer, ionicity, and reactivity of both the metal and the nonmetal elements. However, the effects of orbital energies start to become dominant under pressure, causing substantial changes to the chemistry of ionic compounds and leading to an unusual phenomenon in which elements with substantial electronegativity differences, such as Ag and Br, do not necessarily form ionic compounds, but remain in their elemental forms. [ABSTRACT FROM AUTHOR]

In this paper, we focus on surface electrostatic potentials and a variety of statistically derived quantities defined in terms of the surface potentials. These have been shown earlier to be meaningful in describing features of these potentials and have been utilized to understand the interactive tendencies of molecules in condensed phases. Our current emphasis is on ionic salts and liquids instead of neutral molecules. Earlier work on ionic salts has been reviewed. Presently, our results are for a variety of singly charged cations and anions that can combine to form ionic solids or liquids. Our approach is computational, using the density functional B3PW91/6-31G(d,p) procedure for all calculations. We find consistently that the average positive and negative surface electrostatic potentials of the cations and anions decrease with the size of the ion, as has been noted earlier. A model using computed statistical quantities has allowed us to put the melting points of both ionic solids and liquids together, covering a range from 993 °C to 11 °C. [ABSTRACT FROM AUTHOR]

Regulating the nucleation temperature and growth rates during inverse temperature crystallization (ITC) is vital for obtaining high-quality perovskite single crystals via this technique. Precise control over these parameters enables growing crystals optimized for various optoelectronic devices. In this study, it is demonstrated that incorporating a 1-butyl-3-methylimidazolium bromide (BMIB) ionic liquid into the precursor solution of cesium lead bromide (CsPbBr3) brings about a dual enhancement effect. This includes a reduction in nucleation temperature from 85 °C to 65 °C and a significant improvement in both optoelectronic characteristics and crystal properties. The CsPbBr3 single crystals grown using ITC with BMIB added (method (2)) demonstrate improved chemical and physical properties (crystallinity, lattice strain, nonradioactive recombination, and trap density) compared to CsPbBr3 single crystals produced through conventional 85 °C ITC alone (method (1)). The exceptional quality of CsPbBr3 single crystals produced with the inclusion of BMIB allowed for the development of a highly responsive optoelectronic device, demonstrating heightened sensitivity to green light. The findings of this investigation reveal that the growth of perovskite single crystals assisted by ionic liquid exerts a substantial impact on the characteristics of the crystals. This influence proves advantageous for the development of optoelectronic devices based on single crystals. [ABSTRACT FROM AUTHOR]

The ionic conductivity of Na3PS4 can be improved via the aliovalent substitution of P and S as well as multivalence cation substitution of Na. Although the enhanced ionic conductivities of tetragonal and cubic Na3PS4 have been theoretically and experimentally studied, the dynamics of sodium ions in these systems have been rarely reported. In this study, (100−x)Na3PS4−xCa3N2 (0 ≤ x ≤ 10) glass samples were synthesizing using high‐energy planetary ball‐milling method. These samples were subjected to heat treatment at 280°C for 1 h in an argon atmosphere to obtain glass–ceramic samples. The structures of these samples were characterized via Raman spectroscopy and X‐ray diffraction analysis. The lattice parameter and cell volume of the glass–ceramic samples strongly depended on the x value in (100−x)Na3PS4−xCa3N2 (0 ≤ x ≤ 10). Their ionic conductivities were determined via alternating current electrochemical impedance spectroscopy (EIS). 92Na3PS4−8Ca3N2 glass–ceramics exhibited an ionic conductivity of 8.14 × 10−4 Scm−1 at 25°C. Charge carrier concentration and hopping rate were extracted from the EIS data to determine the ionic conductivities of the samples. The activation energies of DC conductivity and mobile ion formation and migration were also derived from the EIS data to analyze the effect of Ca3N2 doping on the ionic conductivity of the synthesized samples. [ABSTRACT FROM AUTHOR]

Fluoride ion batteries (FIBs) are emerging as a promising alternative to conventional lithium-ion batteries, primarily because of their high theoretical energy density and environmentally sustainable characteristics. For the development of a high-performance solid-state fluoride ion battery, an engineered electrolyte is crucial. As the synthesis technique impacts the phase, microstructure, and morphology of the materials, a unique and facile sonochemical route is employed for the first time herein for synthesizing Tin (II) fluoride as a solid electrolyte. The XRD investigations have indicated the formation of the α-SnF 2 phase with a monoclinic structure, and space group C 2/c. The particle size of SnF 2 synthesized using 225 W and 325 W power of probe sonicator is found to be 2 μm and 0.8 μm respectively, as revealed by Scanning Electron Micrographs. SnF 2 prepared with 325 W ultrasonic power has exhibited the maximum ionic conductivity of value 3.4 × 10−4 S/cm at room temperature, with a significant enhancement regarding the values reported so far. The anionic transport number of the electrolyte estimated at room temperature using the combined AC-DC technique is found to be 0.96, indicating fluoride ion conduction. [ABSTRACT FROM AUTHOR]

Space charge layers (SCLs) formed at grain boundaries (GBs) are considered to critically influence the properties of polycrystalline materials such as ion conductivities. Despite the extensive researches on this issue, the presence of GB SCLs and their relationship with GB orientations, atomic-scale structures and impurity/solute segregation behaviors remain controversial, primarily due to the difficulties in directly observing charge distribution at GBs. In this study, we directly observe electric field distribution across the well-defined yttria-stabilized zirconia (YSZ) GBs by tilt-scan averaged differential phase contrast scanning transmission electron microscopy. Our observation clearly reveals the existence of SCLs across the YSZ GBs with nanometer precision, which are significantly varied depending on the GB orientations and the resultant core atomic structures. Moreover, the magnitude of SCLs show a strong correlation with yttrium segregation amounts. This study provides critical insights into the complex interplay between SCLs, orientations, atomic structures and segregation of GBs in ionic crystals. Here the authors directly observe space-charge-induced electric fields at yttria-stabilized zirconia grain boundaries, revealing how space charge layers corelate with grain boundary orientations, core atomic structures, and yttrium segregation amounts. [ABSTRACT FROM AUTHOR]

We designed V-shaped ionic liquid crystals with two sterically congested ionic parts at the vertex. Depending on the degree of steric hindrance, atropisomerisation occurred in solution. All compounds formed bicontinuous cubic phases with double-gyroid structures in the bulk state, partially owing to the co-existence of atropisomers with opposite chirality. [ABSTRACT FROM AUTHOR]

Solid‐state lithium metal batteries based on fluorinated solid electrolytes have attracted attention due to their safety and stability advantages. However, the fluoride solid electrolytes face the problem of relatively low Li‐ion conductivity due to the lacking of suitable structural prototypes and their corresponding modulation modes. In this work, a chlorine‐doped fluoride solid electrolyte Li3AlF5.87Cl0.13 is developed with high ionic conductivity by thermal fluorination and weak chlorination of mixed ionic liquids. The Cl anion is doped into the cryolite‐like open framework structure, and the electrolyte particle boundaries are decorated by solidified thin‐layer (≈2 nm) ionic liquid. Both the bulk and interface modifications enable the improvement of Li‐ion conductivity to 2 × 10−4 S cm−1 at 30 °C, which is the highest level among fluoride solid electrolytes. The Li3AlF5.87Cl0.13 with residual solidified ionic liquid shows the excellent stability of interface contact with Li metal, and the corresponding Li symmetric cell exhibits a small overvoltage (≈100 mV) with outstanding cycle life (at least 500 h). For the first time, a conversion‐type solid‐state Li/FeF3 battery is developed based on this fluoride electrolyte, delivering a reversible capacity as high as 430 mAh g−1. The existence of natural F‐rich interface promotes the conversion reaction reversibility of FeF3 cathode. [ABSTRACT FROM AUTHOR]

In the current research, various weight percentages of flyash were incorporated into a mixed system of 85.32% NaNO3 and 14.68% Sr(NO3)2. The system was analyzed using the studies of conductivity, dielectric and electric modulus. An increase in DC conductivity was observed with the addition of flyash, peaking at 10% by weight. Beyond this concentration, the conductivity began to decrease. This increase in conductivity is attributed to the formation of an amorphous phase within the mixed sytem. XRD, FTIR, SEM, and DSC analyses of the flyash dispersed systems indicated the formation of an amorphous phase. The amorphous phase may be due to the surface interaction between fly-ash(silica)and phase of mixed system. The AC conductivity, which depends on frequency, adheres to universal power law. Power law parameter were determined. [ABSTRACT FROM AUTHOR]

The current investigation conducts a thorough analysis of the nonlinear optical properties, binding characteristics, and electronic features of 1‐proplene‐3‐methylimidazolium (PMIM)‐X ionic liquid (IL) crystal. These findings reveal that the dissociation energy of PMIM‐X indicates a preference for ionic dissociation over neutral dissociation. Notably, the ionic dissociation energy shows an increasing trend with both the electron affinity (EA) and the size of X. In the process of forming the IL crystal PMIM‐X, this study observes a charge transfer from PMIM to X species. It is noteworthy that the extent of charge transfer intensifies with the increasing size of X. Additionally, the calculated energy gap exhibits a positive correlation with both EA and the size of X. Although these results suggest promising nonlinear optical behavior for PMIM‐X, it is crucial to acknowledge the limitations of the study. All calculations are conducted on single atoms in the gas phase, overlooking potential effects that may arise in the liquid phase or bulk conditions. Therefore, future investigations should consider these factors for a more comprehensive understanding of the behavior of PMIM‐X in practical applications. [ABSTRACT FROM AUTHOR]

Despite their potential as next-generation energy storage devices, all-solid-state batteries (ASSBs) have not been widely developed because of the low ionic conductivity of solid electrolytes and the high interfacial impedance with electrodes. This study addressed these issues by enhancing the electrochemical properties through composition control. A composite solid electrolyte (CSE) was fabricated using Li6.5Ga0.2La2.95Rb0.05Zr2O12 (Ga–Rb-doped LLZO) and poly(ethylene oxide) (PEO) with various compositions. The results demonstrated high ionic conductivity and electrochemical stability when the weight ratio of Ga–Rb-doped LLZO to PEO was 6:4. These characteristics effectively mitigated Li dendrite formation and ensured excellent interfacial stability. Notably, LiFePO4/CSEs/Li full cells retained 92.3% of their initial capacity after 100 cycles at a 0.3 C rate. This study will promote the research and development of practical ASSBs incorporating LLZO solid electrolytes. [ABSTRACT FROM AUTHOR]

The development of highly conductive and thermally stable solid electrolytes is crucial for the next generation of intermediate temperature solid oxide fuel cells (IT-SOFCs). This study investigates the influence of copper (Cu) doping on the microstructure and ionic conductivity of 8 mol. % yttria-stabilized zirconia (8YSZ) when sintered at lower temperatures. The mechanochemical synthesized 1, 3, and 5 wt. % Cu-doped 8YSZ compacts were extensively characterized their properties through a suite of analytical techniques like X-ray diffraction, Raman, X-ray photoelectron, UV–Vis diffused reflectance, particle size analyzer, BET surface area, Emission Scanning Electron Microscopy-Energy Dispersive X-Ray, and AC impedance. The results revealed enhanced ionic conductivity and sinterability, at reduced temperature of 1373 K, with the 5 wt. % Cu-doped 8YSZ demonstrating the highest ionic conductivity of 4.18 × 10−3 S cm−1 at 1023 K, alongside reduced activation energy of 1.14 eV. The lower sintering temperatures and consequential benefits in performance metrics suggest Cu-doping as an effective strategy for optimizing 8YSZ-based electrolytes lowering SOFC manufacturing costs without compromising performance for IT-SOFCs. [Display omitted] • 1. Copper -doped 8YSZ synthesized via mechanochemical process results in varied cubic, tetragonal, and monoclinic crystal phases. 2. Copper doping improves 8YSZ's ionic conductivity and sinterability for intermediate -temperature solid oxide fuel cells. 3. 5 wt. % Cu -doped 8YSZ achieves the highest conductivity (4.18 × 10−3 S cm−1 at 1023 K) and lowest activation energy (1.11 eV). 4. Copper doping is suggested to make 8YSZ-based solid oxide fuel cell electrolytes more cost-effective. [ABSTRACT FROM AUTHOR]

The realm of self-healing materials integrates chemical and physical mechanisms that prevent wear and fracturing and extend the operational lifetime. Unlike the favorable rheology of amorphous soft materials that facilitates efficient contact between fragments, the efficiency of recovery of atomistically ordered materials is restricted by slower interfacial mass transport and the need for ideal physical alignment, which limits their real-world application. We report drastic enhancements in efficiency and recovery time in the self-healing of anilinium bromide, challenging these limitations. Crystals of this material recovered up to 49% within seconds and up to 95% after 100 min via ferroelastic detwinning. The spatial evolution of strain during cracking and healing was measured in real time using digital image correlation. Favorable alignment and strong ionic bonding across the interface of partially fractured crystals facilitate self-healing. This study elevates organic crystals close to the best-in-class self-healing polymers and sets an approach for durable crystal-based optoelectronics. Self-healing in structurally ordered materials is restricted by slow interfacial mass transport and the need for ideal physical alignment. Here the authors show self-healing in an anilinium bromide crystals achieving up to 95% recovery through ferroelastic detwinning. [ABSTRACT FROM AUTHOR]

In this work, we describe the phase behaviour and the dielectric and conductivity response of new light-responsive ionic liquid crystals, ILCs, which can be applied as controllable electrolytes. The materials include two different dicationic viologens, the asymmetric 6BP18 and the symmetric EV2ON(Tf)2, containing bistriflimide as the counterions, mixed with 5% and 50% molar, respectively, of one new photoresponsive mesogen called CNAzO14. These mixtures exhibit liquid crystal behaviour, light responsiveness through the E-Z photoisomerisation of the azobenzene groups in CNAzO14, and strong dielectric responses. The 5%-CNAzO14/Ev2ON(Tf)2 mixture displays direct current conductivities in the 10−7 S·cm−1 range, which can be increased by a two-fold factor upon the irradiation of UV light at 365 nm. Our findings set the grounds for designing new smart ionic soft materials with nanostructures that can be tuned and used for energy conversion and storage applications. [ABSTRACT FROM AUTHOR]

Ionic liquid crystals (ILCs), a class of soft matter materials whose properties can be tuned by the wise pairing of the cation and anion, have recently emerged as promising candidates for different applications, combining the characteristics of ionic liquids and liquid crystals. Among those potential uses, this review aims to cover chromogenic ILCs. In this context, examples of photo-, electro- and thermochromism based on ILCs are provided. Furthermore, thermotropic and lyotropic ionic liquid crystals are also summarised, including the most common chemical and phase structures, as well as the advantages of confining these materials. This manuscript also comprises the following main experimental techniques used to characterise ILCs: Differential Scanning Calorimetry (DSC), Polarised Optical Microscopy (POM) and X-Ray Powder Diffraction (XRD). Chromogenic ILCs can be interesting smart materials for energy and health purposes. [ABSTRACT FROM AUTHOR]

All‐solid‐state sodium metal batteries face the challenges of low ionic conductivity of solid electrolytes and poor wettability towards metallic Na anode. Herein, Na3Zr2Si2PO12 solid electrolyte is doped with Ca2+, obtaining a high ionic conductivity of 2.09×10−3 S cm−1 with low electronic conductivity of 1.43×10−8 S cm−1 at room temperature, which could accelerate Na+ transportation and suppress sodium dendrite growth. Meanwhile, a graphite‐based interface layer is coated on Na3.4Zr1.8Ca0.2Si2PO12 (Na3.4Zr1.8Ca0.2Si2PO12‐G) in order to improve the solid‐solid contact between solid electrolyte and Na anode, realizing a uniform current distribution and smooth Na metal plating/stripping, and thus achieving a triple higher critical current density of 3.5 mA cm−2 compared with that of Na3.4Zr1.8Ca0.2Si2PO12. In addition, the assembled Na3V2(PO4)3/Na3.4Zr1.8Ca0.2Si2PO12‐G/Na all‐solid‐state battery exhibits excellent electrochemical performances with a reversible capacity of 81.47 mAh g−1 at 1 C and capacity retention of 97.75 % after 500 cycles. [ABSTRACT FROM AUTHOR]

This study examines the potential of fungal chitosan derived from Aspergillus niger as a sustainable alternative to traditional petrochemical-based ingredients in cosmetic products. Specifically, the research examines the solubility of fungal chitosan in aqueous solutions of varying ionic strength and its adsorption onto negatively charged surfaces that mimic human hair keratin. The adsorption behavior, water content, and frictional properties of chitosan films were evaluated using a quartz crystal microbalance with dissipation monitoring and a surface force apparatus (SFA). The findings indicated that fungal chitosan exhibits good solubility at a pH of 4.5. Conversely, the adsorption of chitosan is subject to the influence of both polymer concentration and ionic strength. At the lowest ionic strengths, a screening-enhanced adsorption process occurs as a consequence of the reduction in chitosan solubility in the presence of salt. This results in the depletion of polymer chains from the solution and their subsequent deposition. An increase in ionic strength above 15–20 mM results in a worsening of the chitosan–surface interaction, due to the simultaneous screening of both the chitosan and the surface charges. This results in a hindrance to the adsorption process. The deposited films are highly hydrated, and this hydration increases with both polymer concentration and ionic strength. Furthermore, the films exhibit a predominantly elastic behavior, and the response of the films under shear deformations shows a strong dependence on the polymer concentration. These findings contribute to the development of environmentally friendly cosmetic formulations that meet consumer demands for sustainability. [ABSTRACT FROM AUTHOR]

The removal of phosphorous from wastewater in metal-orthophosphate systems typically occurs by simultaneous adsorption on poorly soluble metal hydroxides and by precipitation reactions between metal ions and orthophosphates in solution. To understand the individual contribution of these mechanisms to the removal of phosphorus, the main aim of this study was to determine the kinetics of consumption of contaminant orthophosphates by the precipitation reaction with aluminium ions in a solution free of insoluble aluminium hydroxide. To define the amount of aluminium and phosphorous compounds to be dissolved in water to have this desired reacting condition at a given pH, the solubilities of KH2PO4(s), Al(OH)3(s) and AlPO4(s) were examined at 25 °C in the pH range ∼2.6 to 7.9. pH-solubility diagrams for these ionic solids were made by solving a system of nonlinear algebraic equations involving dissolution, dissociation and hydrolysis reactions at equilibrium. The kinetics of the reaction between aluminium and orthophosphate ions at a reacting condition free of solids except for the product AlPO4(s) was investigated in a well-stirred batch reactor at pH ∼3.1 and 3.5 at 25 °C. A detailed kinetic model involving ten species, seven reversible reactions of hydrolysis of soluble aluminium and orthophosphate species and one reversible precipitation reaction between aluminium and phosphate ions revealed a rate constant for the latter reaction of 5.968 × 1010 L mol−1 s−1 (p = 0.191). XRD, TGA/DTGA and EDX analyses of the filtered and dried reacting mixture confirmed that the only solid product of the precipitation reaction was hydrated AlPO4(s). [ABSTRACT FROM AUTHOR]

Modifying the chemical environment of active surfaces with ionic liquids (IL) is an emerging strategy for tailoring novel electrocatalytic systems, including carbon dioxide reduction (CO2RR). Although copper (Cu) catalysts have recently gained more attention in this field, their modification with ILs is yet to be investigated. This work tested a range of common hydrophobic ILs impregnated into carbon‐supported Cu catalysts, following the "solid catalyst with ionic liquid layer" (SCILL) approach. The latter was used to showcase the applicability of real‐time product detection for CO2RR employing electrochemical mass spectrometry. The observed patterns of C1 to C3 product selectivity offered valuable insights into the intricate reaction mechanism. In addition, increasing the size of the IL cation showed an opposite and significant effect on the reaction selectivity. The obtained qualitative results were partially compared with conventional long‐term experiments. [ABSTRACT FROM AUTHOR]

Li metal is regarded as the "Holy Grail" in the next generation of anode materials due to its high theoretical capacity and low redox potential. However, sluggish Li ions interfacial transport kinetics and uncontrollable Li dendrites growth limit practical application of the energy storage system in high‐power device. Herein, separators are modified by the addition of a coating, which spontaneously grafts onto the Li anode interface for in situ lithiation. The resultant alloy possessing of strong electron‐donating property promotes the decomposition of lithium bistrifluoromethane sulfonimide in the electrolyte to form a LiF‐rich alloy‐doped solid electrolyte interface (SEI) layer. High ionic alloy solid solution diffusivity and electric field dispersion modulation accelerate Li ions transport and uniform stripping/plating, resulting in a high‐power dendrite‐free Li metal anode interface. Surprisingly, the formulated SEI layer achieves an ultra‐long cycle life of over 8000 h (20,000 cycles) for symmetric cells at a current density of 10 mA cm−2. It also ensures that the NCM(811)//PP@Au//Li full cell at ultra‐high currents (40 C) completes the charging/discharging process in only 68 s to provide high capacity of 151 mAh g−1. The results confirm that this scalable strategy has great development potential in realizing high power dendrite‐free Li metal anode. [ABSTRACT FROM AUTHOR]

A blue fluorescent tetraphenylethylene-based dication and a red-NIR phosphorescent rhenium octahedral cluster tetra-anion are associated electrostatically to generate a supramolecular ionic framework which crystallizes in the P1¯ centric space group. The emission properties of the hybrids are studied in the crystalline state and in solution revealing a resonant energy transfer and a high sensitivity toward oxygen. [ABSTRACT FROM AUTHOR]

Original experimental methods for studying the dislocation structure and mechanical properties of solids developed at the Andronikashvili Institute of Physics are described: (1) a method for exciting mechanical vibrations of an ionic crystal, (2) a high-quality tuning fork of a new type (three-reed), (3) a method of crystal deformation by shear, (4) a method for generating dislocations of the same mechanical sign, (5) a method for determining the parameters of the relaxation process, and (6) a vibrating superconductor method. [ABSTRACT FROM AUTHOR]

The main goal is to study the structural and dielectric characteristics of advanced composite materials based on ionic metal alkanoates with various types of nanoparticles. The matrix Cd+2(C7H15COO)−2 formed as a result of the reaction of cadmium with the carboxylate groups of alkanoate (C7H15COO)−2 is used for the synthesis of nanoparticles. At room temperature, the matrix of the ionic crystalline material represents multilayer structure with each layer thickness of 1.8 nm. However, when heated in the temperature range from 100 °C to 180 °C, the matrix undergoes a phase transition into the liquid crystalline smectic A phase, preserved after cooling to room temperature. This transition opens up possibilities for the synthesis of carbon and gold nanoparticles. The temperature treatments of the matrix allow to control of the size and shape of nanoparticles during synthesis and create highly stable nanocomposites. The structural features and dielectric properties of these nanocomposites are studied using transmission electron microscopy, enabling to determine of the sizes of nanoparticles and their dispersion and impedance spectroscopy, respectively. Dielectric properties of nanocomposite materials were studied at different temperatures corresponding to two material phases. We carried out an analysis of the dielectric characteristics of the pure matrix in comparison with nanocomposite materials, containing carbon and gold nanoparticles to identify the role of the nanoparticles. Based on our experimental data, we proposed a model to explain the charge transfer process, taking into account relaxation processes and polarization of nanocomposite materials. [ABSTRACT FROM AUTHOR]

The increasing demand for safe and high-energy-density battery systems has led to intense research into solid electrolytes for rechargeable batteries. One of these solid electrolytes is the NASICON-type Li1+xAlxTi2−x(PO4)3 (LATP) material. In this study, different boron compounds (10% B2O3 doped, 10% H3BO3 doped, and 5% B2O3 + 5% H3BO3 doped) were doped at total 10 wt.% into the Ti4+ sites of an LATP solid electrolyte to investigate the structural properties and ionic conductivity of solid electrolytes using the solid-state synthesis method. Characterization of the synthesized samples was conducted using X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The XRD patterns of the boron-doped LATP (LABTP) samples show that the samples have a rhombohedral phase with space group R 3 ¯ c together and low amounts of impurity phases. While all the LABTP samples exhibited similar ionic conductivity values of around 10−4 S cm−1, the LABTP2 sample doped with 10 wt.% H3BO3 demonstrated the highest ionic conductivity. These findings suggest that varying B3+ ion doping strategies in LATP can significantly advance the development of solid electrolytes for all-solid-state lithium-ion batteries. [ABSTRACT FROM AUTHOR]