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Polyethylene oxide (PEO) holds significant importance in the field of batteries due to its high processability, intrinsic properties, and potential for high ionic conductivity. Achieving simulation at different scales is crucial for gaining a comprehensive understanding of its properties and thus improving them. In this context, we conducted a comparative study on the molecular physical structure, thermodynamic, and dynamic properties of PEO using three distinct coarse-grained (CG) procedures and all-atom (AA) simulations. The three CG simulation procedures involved modeling with MARTINI forcefield, SPICA forcefield, and an IBI derived potential from AA simulations. The AA simulation has been performed using the class 2 pcff+ forcefield. The ensuing simulated densities align significantly with the literature data, indicating the reliability of our approach. The solubility parameter from the AA simulation closely corresponds to literature reported values. MARTINI and SPICA yield almost similar solubility parameters, consistent with the similar density predicted by both the forcefields. Notably, SPICA forcefield closely reproduces the intermolecular structure of atomistic systems, as evidenced by radial distribution function (RDF). It also comprehensively replicates the distribution of radius of gyration (Rg) and the end-to-end distance (Re) of the atomistic samples. IBI ranks second to SPICA in emulating the structural properties of the atomistic systems, such as Rg, Re, and RDF. However, IBI falls short in accurately representing the solubility parameter of the amorphous PEO samples, while MARTINI does not provide an accurate representation of the structural properties of the systems. The use of SPICA forcefield results in enhanced dynamics of the systems in comparison with IBI and MARTINI. [ABSTRACT FROM AUTHOR]

The fundamental understanding of the relationship between ion transport and segmental dynamics of polymer chains in polymer electrolytes is crucial for achieving high ionic conductivity at room temperature for technological applications in supercapacitors, batteries, etc. In this work, the ion dynamics and relaxation have been studied for gel polymer electrolytes (GPEs) containing P(VdF-HFP) as host polymer, adiponitrile as a plasticizer, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide as ionic liquid, and diphenylamine and copper iodide redox additives as fillers. The crystallization temperature of the ionic liquid and the melting temperature of the plasticizer play important roles in ion dynamics. The highest room-temperature ionic conductivity (3.3 × 10−3 S/cm) was obtained for the GPE filled with dual redox additives. The broadband ac conductivity spectra have been analyzed by using the Universal Power law model coupled with the Poisson–Nernst–Planck (PNP) model. The solid–solid phase transition of the ionic liquid affects the grain and grain boundary regions of the GPEs due to the presence of redox fillers. The temperature dependence of the dielectric spectra of the GPEs containing redox fillers confirms the phase transition at the crystallization temperature. The electric modulus and dielectric spectra have been analyzed by using the Havrilliak–Nigami, Kohlrausch–Williams–Watts, and derivative dielectric constant functions. The scaling of ac conductivity and modulus spectra confirms a common ion conduction and relaxation mechanism for the GPEs. The influence of dual redox additives is clearly observed in the values of ionic conductivity, ion diffusivity, and relaxation time. [ABSTRACT FROM AUTHOR]

Dielectric interfaces are crucial to the behavior of charged membranes, from graphene to synthetic and biological lipid bilayers. Understanding electrolyte behavior near these interfaces remains a challenge, especially in the case of rough dielectric surfaces. A lack of analytical solutions consigns this problem to numerical treatments. We report an analytic method for determining electrostatic potentials near curved dielectric membranes in a two-dimensional periodic "slab" geometry using a periodic summation of Green's functions. This method is amenable to simulating arbitrary groups of charges near surfaces with two-dimensional deformations. We concentrate on one-dimensional undulations. We show that increasing membrane undulation increases the asymmetry of interfacial charge distributions due to preferential ionic repulsion from troughs. In the limit of thick membranes, we recover results mimicking those for electrolytes near a single interface. Our work demonstrates that rough surfaces generate charge patterns in electrolytes of charged molecules or mixed-valence ions. [ABSTRACT FROM AUTHOR]

In this report, the high-temperature transport properties of (Dy1−xCax)(Zr0.2Hf0.2Sn0.2Ti0.2Ge0.2)O7 pyrochlore oxides with x = 0, 0.05, and 0.1 are studied in dry and humid air. The phase composition and crystal structure were determined by using x-ray and neutron diffraction. The addition of calcium to the structure caused an increase in the concentration of oxygen vacancies, indicating an ionic charge compensation mechanism. Electrical studies allowed us to determine the total electrical conductivity as a function of the synthesis atmosphere and pH2O. The electrical conductivity turned out to be at the level of ∼10−3 S/cm at 800 °C, and only a slight effect of the presence of protonic defects in the structure on the total electrical conductivity was observed. In general, the samples had a low electrical conductivity with a relatively high activation energy of conduction. [ABSTRACT FROM AUTHOR]

Numerical simulations of the evolution of mobile and immobile dislocations in ceramics under applied pressure in dry pressing at a relatively low temperature are performed in order to study the possibility of production of all-dislocation-ceramics of solid electrolytes, which are expected to have extremely high ionic conductivity without dendrite formation because the diameter of a dislocation pipe is considerably larger than the distance between neighboring dislocations. The present numerical simulations are only for the densification process by plastic deformation of grains under high pressure under the assumption that the compaction of particles by their rearrangement is completed beforehand. By the plastic deformation, new dislocations are generated inside the grains. The required total dislocation density of about 1017 m−2 seems to be achievable under some conditions of dry pressing according to the present numerical simulations. Very short ultrasound irradiation at the beginning of the dry pressing sometimes considerably increases the dislocation density, while for other cases, it even considerably decreases the dislocation density due to enhanced annihilation of mobile dislocations by ultrasound. [ABSTRACT FROM AUTHOR]

The glass formation and the dipolar reorientational motions in deep eutectic solvents (DESs) are frequently overlooked, despite their crucial role in defining the room-temperature physiochemical properties. To understand the effects of these dynamics on the ionic conductivity and their relation to the mechanical properties of the DES, we conducted broadband dielectric and rheological spectroscopy over a wide temperature range on three well-established carboxylic acid-based natural DESs. These are the eutectic mixtures of choline chloride with oxalic acid (oxaline), malonic acid (maline), and phenylacetic acid (phenylaceline). In all three DESs, we observe signs of a glass transition in the temperature dependence of their dipolar reorientational and structural dynamics, as well as varying degrees of motional decoupling between the different observed dynamics. Maline and oxaline display a breaking of the Walden rule near the glass-transition temperature, while the relation between the dc conductivity and dipolar relaxation time in both maline and phenylaceline is best described by a power law. The glass-forming properties of the investigated systems not only govern the orientational dipolar motions and rheological properties, which are of interest from a fundamental point of view, but they also affect the dc conductivity, even at room temperature, which is of high technical relevance. [ABSTRACT FROM AUTHOR]

Glass formation and reorientational motions are widespread but often-neglected features of deep eutectic solvents although both can be relevant for the technically important ionic conductivity at room temperature. Here, we investigate these properties for two mixtures of ethylene glycol and ZnCl2, which were recently considered superior electrolyte materials for application in zinc-ion batteries. For this purpose, we employed dielectric spectroscopy performed in a broad temperature range, extending from the supercooled state at low temperatures up to the liquid phase around room temperature and beyond. We find evidence for a relaxation process arising from dipolar reorientation dynamics, which reveals the clear signatures of glassy freezing. This freezing also governs the temperature dependence of the ionic dc conductivity. We compare the obtained results with those for deep eutectic solvents that are formed by the same hydrogen-bond donor, ethylene glycol, but by two different salts, choline chloride and lithium triflate. The four materials reveal significantly different ionic and reorientational dynamics. Moreover, we find varying degrees of decoupling of rotational dipolar and translational ionic motions, which can partly be described by a fractional Debye–Stokes–Einstein relation. The typical glass-forming properties of these solvents strongly affect their room-temperature conductivity. [ABSTRACT FROM AUTHOR]

Recent experimental results have demonstrated that zwitterionic ionogel comprised of polyzwitterion (polyZI)-supported lithium salt-doped ionic liquid exhibits improved conductivities and lithium transference numbers than the salt-doped base ionic liquid electrolyte (ILE). However, the underlying mechanisms of such observations remain unresolved. In this work, we pursued a systematic investigation to understand the impact of the polyZI content and salt concentration on the structural and dynamic properties of the poly(MPC) ionogel of our model polyZI ionogel, poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] supported LiTFSI/N-butyl-N-methylpyrrolidinium TFSI base ionic liquid electrolyte. Our structural analyses show strong lithium–ZI interaction consistent with the physical network characteristic observed in the experiments. An increase in polyZI content leads to an increased fraction of Li+ ions coordinated with the polyZI. In contrast, an increase in salt concentration leads to a decreased fraction of Li+ ions coordinated with the polyZI. The diffusivities of the mobile ions in the poly(MPC) ionogel were found to be lower than the base ILE in agreement with experiments at T > 300 K. Analysis of ion transport mechanisms shows that lithium ions within the poly(MPC) ionogel travel via a combination of structural, vehicular diffusion, as well as hopping mechanism. Finally, the conductivity trend crossover between the poly(MPC) ionogel and the base ILE was rationalized via a temperature study that showed that the base ILE ions are influenced more by the variation of temperature when compared to the poly(MPC) ions. [ABSTRACT FROM AUTHOR]

We present a strategic approach for enhancing the ionic conductivity of block copolymer electrolytes. This was achieved by introducing mixed ionic liquids (ILs) with varying molar ratios, wherein the imidazolium cation was paired with either tetrafluoroborate (BF4) anion or bis(trifluoromethylsulfonyl)imide (TFSI) anion. Two polymer matrices, poly(4-styrenesulfonate)-b-polymethylbutylene (SSMB) and poly(4-styrenesulfonyl (trifluoromethanesulfonyl)imide)-b-polymethylbutylene (STMB), were synthesized for this purpose. All the SSMB and STMB containing mixed ILs showed hexagonal cylindrical structures, but the type of tethered acid group significantly influenced the interfacial properties. STMB electrolytes demonstrated enhanced segregation strength, which was attributed to strengthened Coulomb and hydrogen bonding interactions in the ionic domains, where the ILs were uniformly distributed. In contrast, the SSMB electrolytes exhibited increased concentration fluctuations because the BF4 anions were selectively sequestered at the block interfaces. This resulted in the effective confinement of imidazolium TFSI along the ionic domains, thereby preventing ion trapping in dead zones and facilitating rapid ion diffusion. Consequently, the SSMB electrolytes with mixed ILs demonstrated significantly improved ionic conductivities, surpassing the expected values based on the arithmetic average of the conductivities of each IL, whereas the ionic conductivity of the STMB was aligned with the expected average. The methodology explored in this study holds great promise for the development of solid-state polymer electrolytes. [ABSTRACT FROM AUTHOR]

Describing analytically the transport properties of electrolytes, such as their conductivity or the self-diffusion of the ions, has been a central challenge of chemical physics for almost a century. In recent years, this question has regained some interest in light of Stochastic Density Field Theory (SDFT) – an analytical framework that allows the approximate determination of density correlations in fluctuating systems. In spite of the success of this theory to describe dilute electrolytes, its extension to concentrated solutions raises a number of technical difficulties, and requires simplified descriptions of the short-range repulsion between the ions. In this article, we discuss recent approximations that were proposed to compute the conductivity of electrolytes, in particular truncations of Coulomb interactions at short distances. We extend them to another observable (the self-diffusion coefficient of the ions) and compare them to earlier analytical approaches, such as the mean spherical approximation and mode-coupling theory. We show how the treatment of hydrodynamic effects in SDFT can be improved, that the choice of the modified Coulomb interactions significantly affects the determination of the properties of the electrolytes, and that comparison with other theories provides a guide to extend SDFT approaches in this context. [ABSTRACT FROM AUTHOR]

We investigate the effect of pectin on the structure and ion transport properties of the room-temperature ionic liquid electrolyte 1-n-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) using molecular dynamics simulations. We find that pectin induces intriguing structural changes in the electrolyte that disrupt large ionic aggregates and promote the formation of smaller ionic clusters, which is a promising finding for ionic conductivity. Due to pectin in [BMIM][PF6] electrolytes, the diffusion coefficient of cations and anions is observed to decrease by a factor of four for a loading of 25 wt. % of pectin in [BMIM][PF6] electrolyte. A strong correlation between the ionic diffusivities (D) and ion-pair relaxation timescales (τc) is observed such that D ∼ τc−0.75 for cations and D ∼ τc−0.82 for anions. The relaxation timescale exponents indicate that the ion transport mechanisms in pectin-[BMIM][PF6] electrolytes are slightly distinct from those found in neat [BMIM][PF6] electrolytes (D ∼ τ c − 1 ). Since pectin marginally affects ionic diffusivities at the gain of smaller ionic aggregates and viscosity, our results suggest that pectin-ionic liquid electrolytes offer improved properties for battery applications, including ionic conductivity, mechanical stability, and biodegradability. [ABSTRACT FROM AUTHOR]

We used equilibrium and non-equilibrium atomistic simulations to probe the influence of anion chemistry on the true conductivity, dynamical correlations, and ion transport mechanisms in polymeric ionic liquids. An inverse correlation was found between anion self-diffusivities, ionic mobilities, and the anion size for spherical anions. While some larger asymmetric anions had higher diffusivities than smaller spherical anions, their diffusivities and mobilities did not exhibit a direct correlation to the anion volumes. The conductivity and anion dynamical correlations also followed the same trends as displayed by the diffusivity and mobility of anions. All the systems we examined displayed positively correlated motion among anions, suggesting a contribution that enhances the conductivity beyond the ideal Nernst–Einstein value. Analysis of ion transport mechanisms demonstrated very similar hopping characteristics among the spherical anions despite differences in their sizes. [ABSTRACT FROM AUTHOR]

This paper presents the molecular dynamics simulation of 1 mol kg−1 LiPF6 in a binary solvent of ethylene carbonate (EC) and dimethylcarbonate, which is a representative electrolyte solution for lithium-ion batteries. The simulation successfully reproduced the diffusion coefficient, ionic conductivity, and shear viscosity as functions of EC content at 300 K, which had been experimentally determined in our previous study. The Yukawa potential was adopted to model intercharge interactions to reduce computational costs, which consequently allowed us to precisely calculate the conductivity and viscosity by directly integrating time-correlation functions without explicitly modeling the molecular polarization. Breaking down microscopic current correlation functions into components revealed that, whereas the cation–anion attractive interaction dominantly impedes the conduction when the EC content is low, it is the cation–cation and anion–anion repulsive interactions that reduce the conductivity at a high EC content. An analysis of the pressure correlations revealed that all components positively contribute to the viscosity in the binary solvent without the electrolyte. On the other hand, negative terms are observed in five out of six cross correlations in the presence of the electrolyte, implying that these correlations negatively contribute to the shear stress and entropy production, both of which are net positive. [ABSTRACT FROM AUTHOR]

Lithium ions shuttle between electrodes through the ceramic solid electrolyte across the boundary regions in a solid-state Li-ion battery. This work demonstrates how phonon vibrations get altered by sintering conditions, and grain boundaries (GBs) could be useful in enhancing the ionic conductivity of solid electrolytes. GB engineered Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramics are prepared using a sol-gel process and performed sintering under different conditions, viz., spark plasma sintering (SPS) and conventional isothermal sintering (CIS). The former exhibits GB regions with amorphous characteristics, whereas the latter shows a sharp boundary between crystalline grains. LATP-SPS ceramic shows two orders of higher ionic conductivity (σ = 1.02 × 10−5 S/cm at 300 K and 100 Hz) than LATP-CIS. We investigate the interrelation between lattice vibration and lithium-ion migration by monitoring the changes in vibrational mode characteristics of LATP ceramics through temperature-dependent Raman spectroscopy. Raman modes of LATP-SPS exhibit a higher Raman shift (∼2 cm−1 at 123 K) due to increased defects, preferentially from grain boundary regions, compared to the LATP-CIS pellet. Most of the vibrational modes undergo a red shift (∼10 cm−1) with increasing temperature, except for the O–P–O bending mode [A1g(3)], which exhibits a blue shift (∼3 cm−1). These observations correlate with interstitial ionic migration in the LATP framework. Force constant of the observed Raman modes suggests that lithium-ion migration is assisted significantly by dynamic structural changes of the (PO4)3− sublattice. Anharmonicities observed from temperature-dependent changes in Raman profiles are explained using three-phonon and four-phonon scattering processes, which lower the migration barrier and, hence, contribute to higher ionic conductivity. [ABSTRACT FROM AUTHOR]

The development of solid-state electrolytes (SSEs) with high lithium ionic conductivities is critical for the realization of all-solid-state Li-ion batteries. Crystal structure distortions, Li polyhedron volumes, and anion charges in SSEs are reported to affect the energy landscapes, and it is paramount to investigate their correlations. Our works uncover the cooperative effect of lithium site distortions, anion charges, and lattice volumes on Li-ion migration energy barrier in superionic conductors of LiMS2 (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni) and Li2MO3 (M = Sc, Ti, V, Cr, Mn, Fe, Co, and Ni). Combined with the Least Absolute Shrinkage and Selection Operator analyses, the volume and Continuous symmetrical methods (CSMs) of Li tetrahedral (Tet) sites appear to have a larger effect on the manipulation of Ea for Li migration, compared to that of Li octahedral (Oct) sites, which is further confirmed by the results from the face-centered cubic (fcc) anion lattice model. For the Tet–Oct–Tet Li migration path, the CSM (the volume of Li site) has a negative (positive) correlation with Ea, while for the Oct–Tet–Oct Li migration paths, opposite correlations have been observed. The understanding of the correlation between site preference, anion charge, lattice volume, and structural distortion as well as the prediction model of Ea in terms of these three factors, namely, C–V–D model, could be useful for the design of solid-state electrolytes with lower activation energy. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) has extensively utilized in electric vehicles and portable electronics due to their high energy density and prolonged lifespan. However, the current commercial LIBs are plagued by relatively low energy density. High-entropy materials with multiple components have emerged as an efficient strategic approach for developing novel materials that effectively improve the overall performance of LIBs. This article provides a comprehensive review the recent advancements in rational design of innovative high-entropy materials for LIBs, as well as the exceptional lithium ion storage mechanism for high-entropy electrodes and considerable ionic conductivity for high-entropy electrolytes. This review also analyses the prominent effects of individual components on the high-entropy materials' exceptional capacity, considerable structural stability, rapid lithium ion diffusion, and excellent ionic conductivity. Furthermore, this review presents the synthesis methods and their influence on the morphology and properties of high-entropy materials. Ultimately, the remaining challenges and future research directions are outlined, aimed at developing more effective high-entropy materials and improving the overall electrochemical performance of LIBs. [ABSTRACT FROM AUTHOR]

Enhancing the electronic and ionic conductivity of Li 4 Ti 5 O 12 electrode materials, as well as suppressing the interface reaction between Ti4+ on the surface of Li 4 Ti 5 O 12 and the electrolyte, is one of the key factors in preparing high-power and long-life Li 4 Ti 5 O 12 lithium-ion batteries. To tackle these challenges, fluorine ions with strong electronegativity was chosen as dopants to engineer fluorine-doped Li 4 Ti 5 O 12 electrode materials. Fluorine ion doping changes the surface state of Li 4 Ti 5 O 12 , increases the interface compatibility, suppresses the reactivity between Li 4 Ti 5 O 12 and the electrolyte, and forms a uniform SEI film during cycling. Moreover, fluorine ion doping induces the generation of oxygen vacancies and improves the crystallinity of Li 4 Ti 5 O 12 , thereby fostering improved electronic and ionic transport kinetics. The above appealing features enables the prepared fluorine-doped Li 4 Ti 5 O 12 material demonstrates exceptional high-rate performance, delivering specific capacities of 175 mAh·g−1/0.5C, 159 mAh·g−1/10C, and 138 mAh·g−1/50C. In essence, the fluoride ion doping strategy holds profound implications for enhancing electrode interface characteristics, transport kinetics, and the fabrication of high-power lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The non-stoichiometric Bi 4 (V 0.9 Cu 0.1) x O 6+2.35 x (nx-BICUVOX) samples were designed and synthesized by solid-state reactions. The tetragonal γ -Bi 4 (V 0.9 Cu 0.1) x O 6+2.35 x solid solution is identified as 1.80 ≤ x ≤ 2.05 by X-ray diffraction (XRD) analysis. The unit cell of nx-BICUVOX shows an anisotropic in-plane layer shrinkage and the cell volume V decreases from 240.18(2) Å3 to 237.99(1) Å3 as x increases from 1.80 to 2.05. The nx-BICUVOX shows a large positive thermal expansion with the volume thermal expansion coefficient (TEC) estimated to be 5.20 × 10−5 K−1, 5.48 × 10−5 K−1, 5.90 × 10−5 K−1 from RT to 700 °C, for Bi 4 (V 0.9 Cu 0.1) 1.80 O 10.23 , Bi 4 (V 0.9 Cu 0.1) 1.90 O 10.465 , Bi 4 (V 0.9 Cu 0.1) 2.00 O 10.7 , respectively. The nx-BICUVOX shows an obvious electronic insulating manner. Three peaks of V-2 p , three peaks of O-1 s and two peaks of Bi-4 f are observed in X-ray photo-electron spectroscopy (XPS) of nx-BICUVOX, which agrees with the crystal structure of the nx-BICUVOX. The grain conductivity of nx-BICUVOX (x ≠ 2.00) is significantly higher than that of stoichiometric Bi 4 (V 0.9 Cu 0.1) 2.00 O 10.7. The Bi 4 (V 0.9 Cu 0.1) 1.95 O 10.5825 and Bi 4 (V 0.9 Cu 0.1) 2.05 O 10.8175 show the highest grain conductivity, in which accompanying with the smallest activation energy. Therefore, the composition control of nx-BIMEVOX is an effective way in the research and development of new BIMEVOX electrolytes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Well-complexed PEGDA generates extra Na+ transport pathways. • The optimized quasi-solid PPE-50 exhibits a high ionic conductivity of 3.42 × 10–4 S cm−1. • PPE-50 displays high electrochemical oxidation stability and mechanical strength. • PPE-50 guides the formation of flexible and rigid SEI and dense and homogeneous CEI. • Na|PPE-50|Na and Na 3 V 2 (PO 4) 3 |PPE-50|Na cells demonstrate excellent long-term cyclability and capacity. Sodium-metal batteries (SMBs) are ideal for large-scale energy storage due to their stable operation and high capacity. However, they have safety issues caused by severe dendrite growth and side reactions, particularly when using liquid electrolytes. Therefore, it is critically important to develop electrolytes with high ionic conductivity and improved safety that are non-flammable and resistant to dendrites. Here, we developed polymerized polyethylene glycol diacrylate (PEGDA)-modified poly(vinylidene fluoride- co -hexafluoropropylene) (PVDF-HFP) electrolytes (PPEs) with highly conductive sodium bis(trifluoromethanesulfonyl)imide and corrosion-inhibitive sodium bis(oxalato)borate salts for SMBs. Well-complexed PEGDA not only increases the amorphicity of the PVDF matrix, but also offers numerous Lewis basic sites through the polar groups of carbonyl and ether groups (i.e., electron donors). The presence of the Lewis basic sites facilitates the dissociation of sodium salt and transportation of Na+ within the PVDF matrix. This results in the generation of additional Na+ transport pathways, which can enhance the performance of the battery. Among PPEs, the optimized PPE-50 exhibits a high ionic conductivity of 3.42 × 10–4 S cm−1 and a mechanical strength of 14.0 MPa. A Na||Na symmetric cell with PPE-50 displays high stability at 0.2 mA cm−2 for 800 h. PPE-50 further displays high capacity, e.g., a Na 3 V 2 (PO 4) 3 |PPE-50|Na battery delivers a decent discharge capacity of 101.5 mAh g−1 at 1.0C after 650 cycles. Our work demonstrates the development of high-performance quasi-solid polymer electrolytes with multiple transport pathways suitable for room-temperature SMBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Solid polymer electrolytes (SPEs) have shown great promise in the development of lithium-metal batteries (LMBs), but SPEs' interfacial instability and limited ionic conductivity still prevent their widespread applications. Herein, high-concentration hybrid dual-salt "polymer-in-salt" electrolytes (HDPEs) through formulation optimization were facilely prepared to simultaneously boost ionic conductivity, improve interfacial compatibility, and ensure a wide-temperature-range operation with high safety. An optimized electrolyte (HDPE-0.6) shows negligible corrosion to the aluminum current collector after manipulating the salt ratio of lithium bis(trifluoromethane)sulfonimide and lithium bis(oxalato)borate. In addition, HDPE-0.6 has excellent ionic conductivity (i.e., ∼0.536, ∼0.898, and ∼1.28 mS cm−1 at 0, 30, and 60 °C), approaching 1 mS cm−1 at room temperature. Furthermore, HDPE-0.6 exhibits a high lithium transference number of 0.6 and a high electrochemical oxidation stability potential of > 4.8 V vs. Li/Li+. Additionally, due to the formulation of high-concentration thermally stable lithium salts and the employment of flame-retardant trimethyl phosphate as the solvent, HDPE-0.6 has no safety issues. The resultant LiFePO 4 |HDPE-0.6|Li cell exhibits high discharge capacity, good rate capability, and excellent cycle stability at extended temperatures of 0, 30, and 60 °C. By coupling theoretical calculations and in-depth X-ray photoelectron spectroscopy, we attribute the excellent cycle stability to the formation of a stable interphase. Moreover, our formulation strategy is suitable for the Na 3 V 2 (PO 4) 3 //Na battery when replacing the lithium salts with sodium salts (i.e., sodium bis(trifluoromethane)sulfonimide and sodium bis(oxalato)borate) to yield HDPE-0.6-Na, as demonstrated by excellent cycle stability (e.g., 98.6 % of capacity retention after 300 cycles). Our work demonstrates that the as-developed quasi-solid HDPEs are suitable for LMBs and sodium-metal batteries, and HDPEs can function normally in a wide temperature range. [ABSTRACT FROM AUTHOR]

Solid-state electrolyte structures using sodium polyaluminate ceramics, have been fabricated for the first time using direct ink writing; a material extrusion-based additive manufacturing process. A series of test samples were prepared using a high solids loading (80 wt%; 51.2 vol%) ceramic paste formulations with suitable rheological characteristics for 3D printing. Following optimum densification via conventional sintering at 1600 °C for 30 min, the additively manufactured electrolyte test samples exhibited an ionic conductivity of σ = 0.14 ± 0.019 S·cm−1 at 300 °C and density of ρ = 3.1 ± 0.02 g·cm−3 (relative density of 95%). These results suggest that direct ink writing of sodium polyaluminates is a promising approach for electrolyte manufacture. Additionally, this approach shows great potential for manufacturing complete solid-state battery structures, through multi-material direct ink writing. [ABSTRACT FROM AUTHOR]

An innovative sintering technique, the Cold Sintering Process (CSP), has been employed to obtain dense Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) Solid-State Electrolytes (SSE) by optimising the particle size (d 50) of the starting powder. The CSP is carried out at 700 MPa, 150 ºC, and 90 min of sintering time, using acetic acid solution as Transient Liquid Phase (TLP). The CSP lowers the LATP sintering temperatures almost 1000 ºC. To study the electrical properties, an in operando Electrochemical Impedance Spectroscopy (EIS) technique has been used. The optimum d 50 is 0.415 µm, yielding to competitive microstructure and electrical properties (ionic conductivity of 6.93·10−5 S cm−1 at 30 ºC, activation energy of 0.363 eV, and a relative density of 81.2 ± 0.8%). Relative density, ionic conductivity and TLP content must be balanced, because at small d 50 , although relative density is enhanced the ionic conductivity is reduced. A packing model has been used to understand this behaviour and the mass transfer mechanisms. [Display omitted] • Cold Sintering Process method to sinter LATP Solid Electrolyte. • Combination of 3 cornerstones: particle size, CSP and in operando impedance. • Effect of particle size on microstructure and electrical properties. • Dissolution-precipitation mechanisms involving the Cold Sintering Process. [ABSTRACT FROM AUTHOR]

Solid-state electrolytes (SSEs) play a crucial role in solid-state lithium metal batteries, with covalent organic frameworks (COFs) emerging as a promising materials class for SSE applications. In this study, a series of Tp-COFs materials were successfully synthesized through a solvothermal approach. Subsequently, these COFs underwent a coating process involving lithium salt and polyvinylidene fluoride film to yield TpMa, TpDa, and TpDa-Li SSEs. The materials subjected to characterization for their ionic conductivity, Li+ transfer number, electrochemical window, and charge-discharge cycle performance. Particularly noteworthy was the exceptional performance of TpDa-Li, exhibiting an ionic conductivity of 9.25 × 10−4 S cm−1, a Li+ transfer number of 0.89, an electrochemical window spanning 1.0–4.4 V, and a capacity retention rate of 77% after 300 cycles at 1 C rate and 83% after 300 cycles at 0.2 C rate. • TpMa, TpDa, and TpDa-Li COFs compounds were successfully synthesized through a solvothermal method. • TpPa-Li was applied to all-solid-state lithium metal batteries. • TpDa-Li solid electrolyte shows a high ionic conductivity of 9.25 × 10−4 S cm−1, a Li+ transfer number of 0.89. [ABSTRACT FROM AUTHOR]

Amorphous Li 3 PS 4 , Li 2.94 Mn 0.06/n PS 4 (M = Mg, Ca, Al) and Li 2.94 Ca 0.03 PS 3.94 Xy 0.06/y (X = N, I) solid electrolytes were successfully prepared by planetary ball-milling method. Their structure was investigated using XRD and Raman spectroscopy. The data obtained from complex impedance spectroscopy was analyzed to study the ionic conductivity and relaxation dynamics in the prepared samples. The data was interpreted using conductivity isotherms, electrical modulus and dielectric loss tangent. Among the samples, Li 2.94 Al 0.02 PS 4 exhibited highest ionic conductivity at 25 °C, which was about 6.6 x 10−4 Scm−1. Electrical modulus and dielectric loss tangent analysis suggested that grain boundary polarization and ionic conductivity increased with multivalence cation doping. [ABSTRACT FROM AUTHOR]

The commercial potential of composite polymer electrolytes (CPEs) is significant due to their ability to combine the advantages of both inorganic and polymer solid electrolytes. However, the unstable interface and insufficient ionic conductivity remain important challenges in practical applications of CPEs for achieving high-performance solid-state lithium batteries (SLBs). Herein, we construct a double-layer composite polymer electrolyte (D-CPE) by incorporating nanosized TiO 2 fillers with adjustable concentrations of oxygen vacancies into poly (ethylene oxide) (PEO)-based electrolyte composites. In the D-CPE structure, one CPE layer containing TiO 2 fillers with oxygen vacancies exclusively interfaces with the LiFePO 4 cathode, while the other CPE layer consisting of pristine TiO 2 fillers (with negatively charged surfaces) solely contacts the lithium anode. This design of D-CPE achieves high ionic conductivity, a broad electrochemical window, and interfacial stability without additional resistance at the electrolyte-electrolyte interface simultaneously. The LiFePO 4 /D-CPEs/Li battery exhibits excellent cycling stability at 0.1 C, maintaining a capacity of 157.2 mAh g−1 with a capacity retention rate of 99.1% after 100 cycles. Furthermore, even at 0 °C, it delivers an impressive discharge capacity of 133.1 mAh g−1 at 0.1 C. This work presents a simple and effective approach to achieving superior polymer-based electrolytes for high-performance solid-state lithium batteries. [ABSTRACT FROM AUTHOR]

In this work, perovskite oxide SrCeO3 was synthesized using the solution combustion method (SCM). Synthesized samples have been characterized using X‐ray diffraction (XRD), Raman, ultra violet (UV)–visible spectroscopy, and scanning electron microscopy (SEM) techniques. The XRD and Rietveld refinement has confirmed the orthorhombic structure with space group Pnma. The average grain size of this ceramic sample is 1.2 µm. The dielectric constant, dissipation factor, modulus, impedance, and alternating current (AC) and direct current (DC) conductivities were analyzed in the temperature range RT to 600°C and frequency range 20 Hz–2 MHz. Further, it was observed that the role of grain boundaries in dielectric and electrical properties is significant, at low temperatures. The origin of the dielectric relaxation and conduction process is the same. The activation energy for DC conduction (Edc) was found to be.79 eV. Electrical conduction/relaxation is assigned to the diffusion of doubly ionized oxygen (Vo··). The value of DC conductivity (1.2 × 10−3 Ω−1 cm−1 at 600°C) and activation energy of.79 eV is very close to the values reported for doped CeO2‐based oxide ion conductors for SOFCs. This study has demonstrated that SrCeO3 can be an alternative candidate for the oxide ion conductor electrolyte application and the potential to be used as a thermally stable capacitor application for microwave dielectric applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Compared with bulk NbSe 2 , few-layered wgef-NbSe 2 nanosheets presented shortened activation cycles, lower reaction polarization, better cyclic stability, and accelerated ion diffusion kinetics. • The continuous and intensive charge accumulation region between the NbSe 2 interlayers ensures a strong adsorption tendency of Na+ in virtue of forming a certain Coulombic force. • The interlayers possess a lower Na+ diffusion barrier, which is as low as 0.18 eV, guaranteeing NbSe 2 to achieve rapid reaction kinetics. • During the sodiation, Coulomb force causes the shrinkage of the d -spacing of some specific lattice planes of the NaNbSe 2 intermediate. However, the other planes are immune to the Coulomb force, showing the expansion of d -spacing. • Wgef-NbSe 2 exhibits an intercalation and conversion parallel running mechanism that promises the high structural robustness and high theoretical capacity. The unique superconductivity and charge density wave transition characteristics of NbSe 2 make it worthy of exploring its electrochemical performance and potential applications in the field of batteries. Herein, the bulk NbSe 2 was successfully exfoliated into few-layered NbSe 2 nanostructures by wet grinding exfoliation approach, which solved the issues of its long activation period and poor cycle stability. The strong Nb-Se bond in the plane and weak van der Waals force between the adjacent layers could render the fast Na+ diffusion, provide abundant reaction sites and multi-directional migration paths, thus accelerate the ionic conductivity. The theoretical calculations verified the high Na+ adsorption tendency between the NbSe 2 interlayers stemming from the continuous region of charge accumulation. Thanks to the unique electronic and two-dimensional few-layered structures, the exfoliated NbSe 2 exhibited a high cyclic stability with a capacity of 502 mA h g−1 over 2800 cycles at 10 A/g. In addition, the reaction mechanism was studied by in - situ X-ray diffraction and other tests, indicating a reaction mechanism containing of simultaneous intercalation (N b S e 2 ↔ N a x N b S e 2 ↔ N a N b S e 2 ↔ N a 1 + x N b S e 2) and conversion processes in NbSe 2. This parallelly running mechanism not only alleviates the volume change but also ensures a high specific capacity. Additionally, different lattice planes of the NaNbSe 2 intermediate in the intercalation process experience varying degrees of contraction and expanding in d -spacing due to the influence of Coulombic force. [ABSTRACT FROM AUTHOR]

In this paper, the effects of frequency on the flash sintering behavior and microstructure of Li 6.4 Ga 0.2 La 3 Zr 2 O 12 (0.2Ga-LLZO) were investigated. The results showed that an increase in frequency had little effect on the onset temperature, but this increase reduced the duration of the weak current stage the incubation stage. Moreover, this phenomenon led to a decrease in the power loss during the constant current stage. Scanning Electron Microscope images showed that the microstructure was symmetrically distributed, and the uniformity increased with increasing frequency. Finite element simulations and an IR thermocamera were used to analyze the temperatures of the specimens. The symmetric distribution of temperature during the flash sintering process was the root cause. The results of AC impedance spectroscopy showed that when the frequency of flash sintering was ≥ 400 Hz, the ionic conductivity of Ga-LLZO was greater than that of conventional sintering. The results of this work demonstrated the important role of frequency in controlling the microstructures of ceramic materials in flash sintering. [ABSTRACT FROM AUTHOR]

Li+ ion conduction in two aligned liquid crystalline electrolytes consisting of 10 mol% Li+ salt of a pro-mesogenic anion derived from [closo-1-CB11H12]− in non-ionic hosts was investigated. Using electrochemical impedance spectroscopy (EIS), the ionic conductivity in the parallel (σ‖) and perpendicular (σ⊥) directions of the electrolyte samples was determined using two types of cells: an interdigitated gold electrode and a nylon 6-coated ITO cell. The ratio of ionic conductivities σ⊥/σ‖ in the electrolyte with a nona(ethylene oxide) spacer was about 3 in the entire SmA phase, while in the shorter homologue, the ratio monotonically increases from about 0.4 to 2.9. The liquid crystalline behavior of the hosts and the electrolytes was investigated by optical, thermal, and powder XRD methods. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) exhibit comparable thermal and chemical stability to ionic liquids, coupled with excellent ionic conductivity. Moreover, they boast a higher degree of safety owing to lower toxicity and increased accessibility. Hence, the utilization of DES in gel preparation emerges as an effective solution to address the challenges associated with the inadequate stability of traditional hydrogels and the heightened toxicity of gels composed of ionic liquids. In this paper, eutectogels with excellent low-temperature sensing properties were prepared by using methacrylic acid (MAA) and pyrrole (Py) as monomers and DES as solvent. The eutectogel exhibits excellent sensing capability, with a gauge factor reaching 5.21. Additionally, DES prepared using choline chloride and urea endows the eutectogel with good freeze resistance, enabling sensing at −20 °C while maintaining stability. Moreover, the eutectogel accurately monitors changes in environmental temperature, providing a promising material for temperature-measuring flexible wearable sensor applications. [ABSTRACT FROM AUTHOR]

Proton exchange membranes (PEMs) are the core components of fuel cells, and research has long focused on how to balance their proton conductivity and durability. In this work, a series of homogeneous blend of sulfonated polyimide (SPI) and sulfonated polyether ether ketone (SPEEK) hybrid membranes with were constructed refined with sulfonated MoS 2 (H–MoS 2) and sodium lignosulfonate (SLS). The results showed that the tensile strength of the films was enhanced by 39.4% (67.84 MPa) compared to the base film. The composite films incorporating 1 wt% H-MoS 2 and 2 wt% SLS has excellent proton conductivity, which can reach 50.24 mS/cm at 80°C and 100% humidity. The embed hybrid structure constructed by H–MoS 2 and SLS, which not only effectively solves the limitations of the proton transport channel of traditional polymer materials, but also provides abundant proton transport sites, which provides a new strategy for preparing high-performance PEM. [Display omitted] • The stability of composite films was improved by organic/inorganic co-modification • H–MoS 2 and SLS together construct a continuous proton transport channel • The tensile strength of the best composite film is up to 67.84 MPa [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) have great potential in the field of stationary energy storage due to their low manufacturing cost and high safety. However, the zinc dendrite growth arising from the uneven deposition of zinc ions has been inhibiting the application of AZIBs. In this work, hydrophilic and nanocrystalline carbon quantum dots (CQDs) are synthesized and used as electrolyte additives to improve the dendrite issue. The abundant hydrophilic groups on CQDs are favorable for homogeneous Zn deposition, whereas the improved conductivity due to the high graphitization of CQDs reduces the solid-electrolyte interface impedance and lowers the polarization voltage, resulting in better rate capability of Zn-ion batteries. Owing to the reduced energy barrier of Zn2+ nucleation and the enhanced kinetics of Zn2+ plating/stripping derived from the hydrophilic and nanocrystalline CQDs, the Zn//Zn symmetrical batteries with CQDs can operate stably for more than 1000 h at 1 mA cm−2 and 1 mA h cm−2, and show superior rate performance with low voltage hysteresis of 98.3, 120.5, 156.4, and 210.2 mV at current densities of 1, 2, 3 and 4 mA cm−2. Moreover, Zn//Cu half-cells with CQDs achieve a high average coulombic efficiency of 99.7% at 1 mA cm−2 and 0.5 mA h cm−2, and Zn//MnO2 full batteries can be cycled more than 500 times with a capacity retention of 74%. [ABSTRACT FROM AUTHOR]

Isotropic and anisotropic magnetorheological elastomers (MRE) were prepared using spherical carbonyl iron (CI) particles and electrolyte non-spherical iron (EI) particles having a 60% weight fraction in silicon rubber. The pre-structured MREs were prepared under a constant magnetic field of 0.3 Tesla. A parallel-plate MR rheometer with a magneto-rheological cell was used to conduct dynamic measurements under different normal forces. All the data were recorded under 1 Hz frequency and strain amplitude of 0.1% (in the linear viscoelastic region), and normal force was varied from 1N to 10 N. Results show that the magnetic-induced shear modulus increases in both MREs with normal force for isotropic as well as anisotropic samples. However, in CIP-based MRE, the MR effect increases with a pre-structured sample, whereas for EIP-based pre-structured MRE, the MR effect decreases compared to isotropic samples. Nevertheless, the relative MR (RMR) effect decreases with normal force in both cases. The rate of decrease is different in CIP- and EIP-based MREs. A possible mechanism for the same is discussed in the paper. [ABSTRACT FROM AUTHOR]

Yttria-stabilized zirconia (YSZ) with a yttria content beyond 8%mol is especially interesting for its high ionic conductivity in the high-temperature range (700–1000 °C). Thereby, cubic YSZ properties make it a useful ceramic material for electrodes or electrolytes in various applications, such as solid oxide cell (SOC) technologies for energy conversion or oxygen sensors. This work aims to propose an alternative microstructure, hopefully, to improve material features. Adapting a sol–gel-type process that involves the use of supercritical CO2 (scCO2) to stabilize doped-zirconia nanoparticles in their cubic structure allows the crystallization of powders at temperatures as low as 250 °C. The resulting powders are very fine, with large specific surface areas around 50–150 m2 g−1, low agglomeration, and small-sized crystallites around 8–10 nm. After studying the effect of the operating conditions on the stabilization of the cubic crystalline phase, a well-adapted powder was selected and characterized in detail with respect to its microstructure, and its thermal behavior was investigated to eventually prepare an electrode/electrolyte. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium batteries (ASSLIBs) show significant promise as the next‐generation energy technology due to their high energy density and inherent safety. However, the severe interface reactions between solid electrolyte and the high‐voltage cathodes pose a major challenge, particularly at higher charge voltages. Herein, a H3PO4‐triggered H+/Li+ exchange strategy is proposed to covert LiCoO2 (LCO) surface to spinel Co3O4/Li3PO4 ionic‐conductive interphase. This spinel interphase presents a thickness of 15 nm and good affinity with LCO, which provides long‐lasting protection to suppress interfacial parasitic reactions. Besides, both spinel Co3O4 and amorphous Li3PO4 feature high ionic conductivity compared to bulk LCO, thereby facilitating the interfacial ionic transportation. With such modification, ASSLIBs delivers high specific capacity (146.2 mAh g−1 at 0.1 C), outstanding rate performance (116.4 mAh g−1 at 2 C), and long‐term cyclability (350 cycles at 0.5 C) under a cut‐off voltage of 4.3 V versus Li/Li+. Moreover, this robust spinel interphase further improves the stable cycling (168.9 mAh g−1 at 0.1 C for 100 cycles) under elevated cut‐off voltage (4.5 V vs Li/Li+). This finding highlights the H+/Li+ exchange to convert LCO surface to a spinel ionic‐conductive interphase, which poses new insights for interface design in ASSLIBs. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) ferroionics is appealing in performing complex artificial intelligence tasks due to the interesting property of coexistence of ferroelectricity and ionic activities. CuInP2S6 (CIPS), as a typical 2D ferroionic material, is highly conducive to rich functions of information devices due to the displacement of Cu+ inducing both ferroelectricity and ionic conductivity. However, the coupling and modulation of polarization and ion migration in CIPS for multifunctional information devices has not been fully explored. Here, this study demonstrates that digital memory and synaptic simulations are realized in Au/CIPS/Au device via engineering ferroelectric polarization reversal and the long‐distance migration of the Cu+ to change conductive modes. Steep resistive switching behavior based on ion‐migration is observed with a high on/off ratio of over 108, long retention time (>2 × 104 s), and current compliance engineered multilevel resistance states, demonstrating reliable nonvolatile high‐density memory characteristics. Based on the continuous modulation of polar order, the key synaptic behaviors are successfully simulated. Moreover, by the co‐modulation of polarization state and ions migration, the paired‐pulse facilitation, paired‐pulse depression, and potentiation following depression are achieved. These results suggest that CIPS is a promising candidate for constructing high‐performance, function‐enriched devices for data storage, information processing, and neuromorphic computing. [ABSTRACT FROM AUTHOR]

The rechargeable zinc‐ion battery is regarded as a promising candidate for the next‐generation energy storage system, however, zinc dendrite growth and hydrogen evolution reaction (HER) have greatly hindered the practical application of the battery. Herein, a functionalized, nano‐engineering Zn2+ coordinated carboxylate cellulose solid‐state electrolyte (denoted as Zn‐CCNF@XG) for zinc‐ion battery is constructed through a straightforward approach. According to the experimental and density functional theory (DFT) results of dissociation energy, the notably decreased dissociation energy by −COOH is favorable to Zn2+ de‐coordinating and rapid ion‐hopping in Zn‐CCNF@XG to achieve high ionic conductivity and transference number. More importantly, the engineered molecular channels are beneficial to enlarging the distance between the nanofibril chains, providing a larger space for the movement of Zn2+. Benefiting from the coordination of Zn2+ with −OH in carboxylate cellulose nanofibrils, Zn‐CCNF@XG as a good ionic conductor displays a high ionic conductivity of 1.17 × 10−4 S cm−1 and transference number of 0.78. The Zn||NaV3O8·1.5H2O full cell with Zn‐CCNF@XG maintains a capacity retention of 83.46% with a coulombic efficiency of 99.99% after 3000 cycles (1 A g−1). The proposed strategy by introducing a functional group to cellulose nanofibrils effectively avoids the dendrite and HER, providing valuable guidelines for the practical application of zinc‐ion batteries. [ABSTRACT FROM AUTHOR]

Woodwork is involved in a variety of interactions with humans through physical contact, which may reveal valuable information if the tactile data can be unnoticeably extracted. In this work, an intelligent iontronic wood (iWood) device, along with its seamlessly integrated architecture into the woodwork, enabled by the iontronic sensing principle, is implemented. Notably, the tactile sensing structure is generated at the iontronic interface between ionic and conductive woods. In particular, the ionic wood is established by infusing an ionic liquid into the wood, followed by immobilizing it via chemical bonding, presenting both prominent ionic conductivity and excellent stability under pressure. By formatting the woods into identical strips, the high‐density tactile sensing array can be simply formed by a braiding process for a scalable interwoven structure. As a result, the iWood device has offered a high sensitivity over a broad detection of 0.5 MPa and an array of 40 × 90 units covering an area up to 3600 cm2. The iWood device is showcased as an interactive human interface, demonstrating its potential as a smart desktop capable of gesture and object recognition, a health‐tracking chair for real‐time ballistocardiograph monitoring, and an embedded intelligent floor for weight management and gait analysis. [ABSTRACT FROM AUTHOR]

Solid electrolytes (SEs) have the potential to enhance the safety and performance of Li‐metal batteries. However, the existence of grain boundaries in polycrystalline SEs presents a significant challenge for both ionic and electronic migration, promoting the propagation of detrimental lithium dendrites. This study compares the roles of grain boundaries in electrical properties of three distinct SEs including garnet‐type Li6.5La3Zr1.5Ta0.5O12 (LLZO), argyrodite‐type Li6PS5Cl (LPSC), and NASICON‐type Li1+x+yAlx(Ti,Ge)2‐xSiyP3‐yO12 (LATP). Results demonstrate that the electronic and ionic conductivities of solid‐state electrolytes are affected differently by grain boundaries, depending on the specific type of electrolyte. For instance, LLZO and LATP experience dielectric breakdown at 3.7 and 5.3 V, respectively, while LPSC does not exhibit such behavior. Here, a new chemical modification is proposed that simultaneously alters the composition of both the surface and grain boundaries of SEs, ultimately reducing electronic conductivity for the LLZO SEs. Consequently, the proposed LLZO exhibits unprecedented dendrite‐free cycling stability, achieving a remarkable 12 000‐h lifetime at room temperature, surpassing conventional strategies such as surface coatings in dendrite mitigation. This study highlights the significance of modifying grain boundaries to design safe and durable Li‐metal batteries. It provides new insights for developing SEs that are highly resistant to dendrite formation. [ABSTRACT FROM AUTHOR]

Physical hydrogels crosslinked by noncovalent interactions are promising in flexible zinc–metal batteries for their component controllability and environmental friendliness. However, the compatibility of PVA‐based electrolyte and kosmotropic salt remains a challenge, which shows an unclear mechanism. Here, a "good‐to‐poor" solvent substitution strategy is adopted to develop a PVA hydrogel electrolyte with good compatibility with kosmotropic salt (ZnSO4). Stretching the polymer conformation by preshielding the strong intrachain hydrogen bonds with good solvents and activating the polymer interchain interaction in situ with poor solvents will induce the formation of a homogeneous polymer network and the release of hydrated hydroxyl groups for fast ion transport. This multiscale microstructure improves the ionic conductivity and liquid retention of PVA hydrogels with kosmotropic salt. Additionally, this strong hydrogen bonds preshielded hydrogel electrolyte offers great battery performance, with 1300 h of stable cycling at 1 mA cm−2 with low voltage hysteresis; and an extended cycle life of 220 h at 68.4% zinc utilization. Importantly, the Zn//MnO2 pouch cell maintains 98.4% capacity after 100 cycles at 0.2 A g−1 and features strong environmental reliability. These concepts address the inherent barriers of kosmotropic salt‐based hydrogel electrolytes and advance their development in soft electronics. [ABSTRACT FROM AUTHOR]

Symmetrical solid oxide fuel cell (S–SOFC) has gained extensive attention for its simplifying fabrication process and reducing cost. Fe-based double perovskite PrBaFe 2 O 5+δ (PBF) is a potential electrode material for S–SOFC due to the excellent mixed electronic and oxygen ionic conductivity. However, the electrochemical performance of PBF is limited by lacking enough oxygen vacancies and the sluggish oxygen-ion transport kinetics. Herein, a BaCoO 3-δ (BCO) impregnated PBF (PBF–BCO) electrode is investigated with enhanced catalytic activity. The BCO decoration can significantly decrease the polarization resistance (Rp) by approximately 36.5% and 26.0% compared to PBF at 800 °C in air and hydrogen atmosphere, respectively. The peak power density (PPD) of an electrolyte-supported S–SOFC with PBF–BCO electrode is nearly 36% higher than that of PBF electrode. The prominent electrochemical performance of the PBF–BCO electrode is attributed to the significantly accelerated oxygen adsorption/dissociation processes, which promote the oxygen reduction reactions (ORR) and enhanced charge transfer processes in H 2 atmosphere for superior hydrogen oxidation reaction (HOR). The results demonstrate that the BCO impregnated PBF is one of the promising electrode materials for S–SOFC. • BCO impregnated PBF are studied as electrodes for S–SOFC. • The introduction of BCO can reduce the Rp of PBF in air and hydrogen atmospheres. • The PBF–25BCO electrode achieves a 36% enhancement in PPD compared with the PBF. • PBF–25BCO cell displays favorable stability under operating conditions. [ABSTRACT FROM AUTHOR]

Recently, halide solid state electrolytes (SSEs) have received great attention owing to their fast ionic conductivity, high oxidation potential, and good chemical and electrochemical compatibility with high voltage cathode materials. However, most of reported halide SSEs contain rather rare and expensive elements, which hinders their sustainable utilizations in practical batteries. Here in this work, under the guidance of systematic modelling based on the density functional theory (DFT), a low‐cost alternative is developed through optimizing the lattice chemistry in a recently identified spinel‐like chloride Li2CrCl4 into Li5/3Cr1/3Zr1/3Cl4 for remarkably enhanced ionic conductivity and stable electrochemical window with respect to the Li‐anode. This new phase has then been synthesized successfully, delivering an ionic conductivity over 1200 times of that of the pristine phase Li2CrCl4, in addition to a high oxidation potential (up to 4.1 V vs Li/Li+) to enable outstanding interfacial compatibility with high voltage cathodes. Such a high‐voltage and fast Li‐ion conducting solid‐state electrolyte is expected to provide a highly desirable basis toward developing high energy‐density all solid‐state batteries (ASSBs) using economical and Earth‐rich elements. [ABSTRACT FROM AUTHOR]

Polyethylene oxide (PEO) solid electrolytes are regarded as a promising candidate for all‐solid‐state lithium batteries owing to their high safety and interfacial compatibility. However, PEO electrolyte is plagued by relatively weak structural strength and unsatisfactory Li+ conductivity. Herein, a mechanically strong and Li+ conductively favorable cellulosic scaffold of PEO is fabricated through amino (‐NH2) modification and g‐C3N4 (CN) incorporation of bacterial cellulose (BC) under a microbial circumstance. The biologically ‐NH2 modified BC (B‐NBC) is entangled with CN nanosheets (CN@B‐NBC) through an in situ secretion of nanocellulose followed by hydrogen bond‐induced self‐assembly. The ‐NH2 groups from B‐NBC weaken the complexation of Li+ with its counterpart, thus facilitating the release of more free Li+. CN with strong C‐N covalence and extra lone electrons of N further strengthens the BC skeleton and meanwhile offers sufficient anchors for Li+ migration. After infiltrating by LiTFSI/PEO (LP), the LP/CN@B‐NBC composite solid electrolyte (CSE) exhibits high lithium transference number and ionic conductivity. Upon coupling with LiFePO4 cathode, the full battery exhibits a remarkably high specific capacity, superior rate capability, and decent cycling stability. This work pioneers the attempts of chemical decoration and ingredient incorporation of BC architecture in CSE with the aid of a bottom‐up biosynthetic avenue. [ABSTRACT FROM AUTHOR]

Phosphides with high theoretical capacity are considered ideal anode materials for lithium‐ion capacitors (LICs), but poor electronic conductivity as well as unsatisfied cyclic stability limits the performance of the phosphides. Here a covalently bonded CoP@C heterostructure is reported, which consists of 5 nm CoP quantum dots (QDs) like pomegranate seeds pinned in carbon polyhedron through interfacial Co─P─C bonding. The ultrafine size of CoP QDs provides more reactive sites and a shorten electrons/ions diffusion path, boosting the specific capacity. The Co─P─C bond induces the energy band variation of CoP and increases the interfacial charge density, bringing about fast kinetics. Besides, the Co─P─C bond introduces a robust pining effect among CoP QDs and carbon polyhedra, greatly improving the structure stability of 5 nm CoP QDs. The CoP@C heterostructure electrode exhibits high capacity (nearly 1000 mAh g−1) and superior cycling stability. It is worth noting that a prototyped LIC full‐cell of YP80//CoP@C presents an impressive high energy density of 172 Wh kg−1 and a power density of 10.8 kW kg−1. Moreover, the LIC possesses an ultra‐long life, retaining 80% after 20,000 cycles. This study offers an effective design for phosphides achieving fast kinetics and superior structure stability through an interfacial bonding approach. [ABSTRACT FROM AUTHOR]

Achieving highly efficient self‐powered fibrous sensing systems is desirable for smart electronic textiles but remains a great challenge. Here, a bifunctional hydrogel is proposed by introducing of polyacrylic acid grafted MXene (MXene‐g‐PAA) into polyacrylamide/chitosan, achieving high‐sensitivity sensor and a stable hydrogel electrolyte of battery. The MXene‐g‐PAA flakes act as ion transport "highway", significantly enhance ionic conductivity, thereby increasing the sensitivity of sensors and facilitating Zn2+ diffusion in Zn‐ion battery (ZIB). The rich hydrogen bonding network in the hydrogel improves its mechanical properties and limits water molecule movement, thus reducing side reactions and prolonging the stability of ZIB. As a result, the fibrous sensor exhibits high strain sensitivity (gauge factor of 2.4) with a wide detection range (0–800%), and the fibrous Zn‐ion battery exhibits high capacity (353 mAh cm−3) with long cycling stability (400 cycles). The hydrogel‐based sensor and ZIB can be easily integrated into a flexible self‐powered sensing system, which effectively detects human movement and 3D ball motion. The bifunctional hydrogel with the integrated fibrous system will shed light on the development of next‐generation smart electronic textiles. [ABSTRACT FROM AUTHOR]

[Display omitted] Traditional dual-ion lithium salts have been widely used in solid polymer lithium-metal batteries (LMBs). Nevertheless, concentration polarization caused by uncontrolled migration of free anions has severely caused the growth of lithium dendrites. Although single-ion conductor polymers (SICP) have been developed to reduce concentration polarization, the poor ionic conductivity caused by low carrier concentration limits their application. Herein, a dual-salt quasi-solid polymer electrolyte (QSPE), containing the SICP network as a salt and traditional dual-ion lithium salt, is designed for retarding the movement of free anions and simultaneously providing sufficient effective carriers to alleviate concentration polarization. The dual salt network of this designed QSPE is prepared through in-situ crosslinking copolymerization of SICP monomer, regular ionic conductor, crosslinker with the presence of the dual-ion lithium salt, delivering a high lithium-ion transference number (0.75) and satisfactory ionic conductivity (1.16 × 10−3 S cm−1 at 30 °C). Comprehensive characterizations combined with theoretical calculation demonstrate that polyanions from SICP exerts a potential repulsive effect on the transport of free anions to reduce concentration polarization inhibiting lithium dendrites. As a consequence, the Li||LiFePO 4 cell achieves a long-cycle stability for 2000 cycles and a 90% capacity retention at 30 °C. This work provides a new perspective for reducing concentration polarization and simultaneously enabling enough lithium-ions migration for high-performance polymer LMBs. [ABSTRACT FROM AUTHOR]

Samarium praseodymium (Sm–Pr) co-doped ceria was synthesized by the co-precipitation technique as an electrolyte for low-temperature solid oxide fuel cell (LT-SOFC) applications. The structural, morphological, compositional, and electrical characterization of the synthesized samples were evaluated via x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and impedance spectroscopy. The generation of a single-phase fluorite structure of co-doped ceria without any secondary phases has been verified by XRD analysis, exhibiting the successful incorporation of Sm and Pr ions into the ceria lattice. Vegard's law is utilized for Pr redox behavior explaining the variation in lattice constant values. SEM pictures show that the co-doped ceria powder has a homogeneous and well-dispersed microstructure, and has enhanced particle size. The impedance spectroscopy results indicate that Sm–Pr co-doped ceria has much higher ionic conductivity than single-doped ceria. The highest amount of ionic conductivity (σ i o n i c ) for the composition Ce 0.80 Sm 0.10 Pr 0.10 O 2 − δ recorded as 2.12 × 10 − 2 S / c m at 500 ° C , and 6.19 × 10 − 2 S / c m at 750 ° C with the lowest activation energy E a = 0.48 e V , which has been not reported earlier. Sm and Pr are chosen as dopants because of their capacity to generate oxygen vacancies and improve ceria's ionic conductivity. This study contributes to the enhancement in the ionic conductivity of co-doped ceria by co-precipitation technique and the temperature-dependent frequency exponent factor "s" is also explored to comprehend the conduction mechanism of the prepared samples. [ABSTRACT FROM AUTHOR]

Quasi‐solid polymer electrolyte (QPE) lithium (Li)‐metal battery holds significant promise in the application of high‐energy‐density batteries, yet it suffers from low ionic conductivity and poor oxidation stability. Herein, a novel self‐built electric field (SBEF) strategy is proposed to enhance Li+ transportation and accelerate the degradation dynamics of carbon‐fluorine bond cleavage in LiTFSI by optimizing the termination of MXene. Among them, the SBEF induced by dielectric Nb4C3F2 MXene effectively constructs highly conductive LiF‐enriched SEI and CEI stable interfaces, moreover, enhances the electrochemical performance of the QPE. The related Li‐ion transfer mechanism and dual‐reinforced stable interface are thoroughly investigated using ab initio molecular dynamics, COMSOL, XPS depth profiling, and ToF‐SIMS. This comprehensive approach results in a high conductivity of 1.34 mS cm−1, leading to a small polarization of approximately 25 mV for Li//Li symmetric cell after 6000 h. Furthermore, it enables a prolonged cycle life at a high voltage of up to 4.6 V. Overall, this work not only broadens the application of MXene for QPE but also inspires the great potential of the self‐built electric field in QPE‐based high‐voltage batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Na metal batteries using inorganic solid-state electrolytes (SSEs) have attracted extensive attention due to their superior safety and high energy density. However, their development is plagued by the unclear structural/volumetric evolution of SSEs and the corresponding Na+ migration mechanisms. In this work, NaSn 2 F 5 (NSF) clusters are composed of nanoparticles (NPs) with matched lattices induced by dislocations, which can mitigate the volume swelling/shrinkage of the NPs. NSF behaves like a single ion conductor with a high Na+ transference number (t Na+) of 0.79. Specially, the ionic conductivity (σ) of NSF is increased from 7.64 × 10-6 to 5.42 × 10-5 S cm−1 after partial irreversible oxidation of Sn2+ (0.118 Å) → Sn4+ (0.069 Å) with the shrunk ionic radius during the charge process, giving more spaces for Na+ migration. Furthermore, a poly(acrylonitrile)-NaSn 2 F 5 -NaPF 6 composite polymer electrolyte (NSF CPE) was fabricated with a σ of 4.13 × 10-4 S cm−1 and a t Na+ of 0.60. The NSF CPE-based symmetric cell can operate over 3000 h due to the couplings between the different components in NSF CPE, which is beneficial for ion transfer and the construction of stable solid electrolyte interface. And the quasi -solid-state Na|NSF CPE|Na 3 V 2 (PO 4) 3 full cell displays excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn2+ substitution generates beneficial holes to accelerate electron transport while supporting the structure to stabilize the framework. • Al 2 O 3 coating has the triple effect of reducing HClO 4 concentration, inhibiting the dissolution of Mn and acting as a conductive agent. • NVMP@CNTs@1wt.%Al 2 O 3 possesses a porous structure, effectively promoting the rapid Na+ transport. • The excellent structural stability is confirmed by in situ XRD. • NVMP@CNTs@1wt.%Al 2 O 3 reveals a remarkable sodium storage property in both half and full cells. Na 3 V 2 (PO 4) 3 (NVP) encounters significant obstacles, including limited intrinsic electronic and ionic conductivities, which hinder its potential for commercial feasibility. Currently, the substitution of V3+ with Mn2+ is proposed to introduce favorable carriers, enhancing the electronic conductivity of the NVP system while providing structural support and stabilizing the NASICON framework. This substitution also widens the Na+ migration pathways, accelerating ion transport. Furthermore, to bolster stability, Al 2 O 3 coating is applied to suppress the dissolution of transition metal Mn in the electrolyte. Notably, the Al 2 O 3 coating serves a triple role in reducing HClO 4 concentration in the electrolyte, inhibiting Mn dissolution, and functioning as the ion-conducting phase. Likewise, carbon nanotubes (CNTs) effectively hinder the agglomeration of active particles during high-temperature sintering, thereby optimizing the conductivity of NVP system. In addition, the excellent structural stability is investigated by in situ XRD measurement, effectively improving the volume collapse during Na+ de-embedding. Moreover, the Na 3 V 5.92/3 Mn 0.04 (PO 4) 3 /C@CNTs@1wt.%Al 2 O 3 (NVMP@CNTs@1wt.%Al 2 O 3) possesses unique porous structure, promoting rapid Na+ transport and increasing the interface area between the electrolyte and the cathode material. Comprehensively, the NVMP@CNTs@1wt.%Al 2 O 3 sample demonstrates a remarkable reversible specific capacity of 122.6 mAh/g at 0.1 C. Moreover, it maintains a capacity of 115.9 mAh/g at 1 C with a capacity retention of 90.2 mAh/g after 1000 cycles. Even at 30 C, it achieves a capacity of 87.9 mAh/g, with a capacity retention rate of 84.87 % after 6000 cycles. Moreover, the NVMP@CNTs@1wt.%Al 2 O 3 //CHC full cell can deliver a high reversible capacity of 205.5 mAh/g at 0.1 C, further indicating the superior application potential in commercial utilization. [ABSTRACT FROM AUTHOR]