Ion-conducting Glasses Research Articles

Mechanism and experimental study of in situ metallization on the surface of silver ion conductive glass

AbstractIn situ metallization of Ag+ conductive glass was successfully achieved by applying electric and temperature fields to the glass to ensure the controlled migration of ions inside the glass. The transport and kinetic characteristics of Ag+ under the combined effect of electric field and temperature field were investigated by calculating and analyzing Ag+ diffusion coefficient. The correlations between ion transport and current were characterized with potential energy equations. The simulations and experiments of ion transport in the conducting glass were implemented, which revealed the mechanisms of ion transport and interfacial precipitation within the conducting glass. Further more, the existence of Ag+ deprivation layer was confirmed and it was clarified that the depth of the deprivation layer reached 30 µm under thermal polarization conditions of 60 V and 300°C. The microscopic morphology of in situ silver deposition layer was observed using SEM and TOF–SIMS. In addition, It was determined that the in situ metallization of conductive glass under the polarization condition of 60 V at 250°C was the best, and the thickness of deposited silver dendrites reached 1000 nm in the side of cathodically. This paper provides theoretical and experimental references for the optimization of the in situ metallization process for the ion conductive glass.

Electrochemical Behavior of Tris(2,2'-bipyridine)Iron Complex in 1-Butyl-1-Methylpyrrolidinium Bis(fluorosulfonyl)Amide Ionic Liquid in the Presence and Absence of Lithium Ion

Ionic liquids composed of bis(fluorosulfonyl)amide (FSA–) have been investigated as the promising electrolytes for rechargeable batteries because of the formation of favorable solid electrolyte interphase (SEI) for some alkali metal ions in addition to relatively low viscosity. The FSA–-based ionic liquids are also considered to be applied to redox flow batteries, which utilize the electrode reactions of soluble species on inert electrodes. However, few electrode reactions of dissolved species have been explored in the FSA–-based ionic liquids. On the other hand, ion-conductive membranes are necessary for development of redox flow batteries. An inorganic solid-state conductor, lithium ion conductive glass ceramics (LICGC, Li1+x+y Al x (Ti,Ge)2-x Si y P3-y O12), is one of the possible membranes usable in ionic liquids containing Li+. In the present study, the electrochemical behavior of tris(2,2'-bipyridine)iron complexes, [Fe(bpy)3]2+, was investigated in BMPFSA (BMP = 1-butyl-1-methylpyrrolidinium) in the presence and absence of Li+.The redox reactions of [Fe(bpy)3]3+/2+, [Fe(bpy)3]2+/+, [Fe(bpy)3]+/0, and [Fe(bpy)3]0/– were observed by cyclic voltammetry in the absence of Li+. However, these reactions were affected by the SEI formation at a negative potential region in the presence of Li+. The donor number of BMPFSA was estimated from the formal potential of [Fe(bpy)3]3+/2+. The diffusion coefficients of [Fe(bpy)3]3+ and [Fe(bpy)3]2+ were determined by chronoamperometry. The standard rate constant for [Fe(bpy)3]3+/2+ was evaluated by electrochemical impedance spectroscopy. The relationship between these kinetic parameters and physical properties was discussed.

Ionic Conductivity of K-ion Glassy Solid Electrolytes of K2S-P2S5-KOTf System

Ternary glassy electrolytes containing K2S as a glass modifier and P2S5 as a network former are synthesized by introducing a new type of complex and asymmetric salt, potassium triflate (KOTf), to obtain unprecedented K+ ion conductivity at ambient temperature. The glasses are synthesized using a conventional quenching technique at a low temperature. In general, alkali ionic glassy electrolytes of ternary systems, specifically for Li+ and Na+ ion conductivity, have been studied with the addition of halide salts or oxysalts such as M2SO4, M2SiO4, M3PO4 (M = Li or Na), etc. We introduce a distinct and complex salt, potassium triflate (KOTf) with asymmetric anion, to the conventional glass modifier and former to synthesize K+-ion-conducting glassy electrolytes. Two series of glassy electrolytes with a ternary system of (0.9–x)K2S-xP2S5-0.1KOTf (x = 0.15, 0.30, 0.45, 0.60, and 0.75) and z(K2S-2P2S5)-yKOTf (y = 0.05, 0.10, 0.15, 0.20, and 0.25) on a straight line of z(K2S-2P2S5) are studied for their K+ ionic conductivities by using electrochemical impedance spectroscopy (EIS). The composition 0.3K2S-0.6P2S5-0.1KOTf is found to have the highest conductivity among the studied glassy electrolytes at ambient temperature with the value of 1.06 × 10−7 S cm−1, which is the highest of all pure K+-ion-conducting glasses reported to date. Since the glass transition temperatures of the glasses are near 100 °C, as demonstrated by DSC, temperature-dependent conductivities are studied within the range of 25 to 100 °C to determine the activation energies. A Raman spectroscopic study shows the variation in the structural units PS43−, P2S74−, and P2S64− of the network former for different glassy electrolytes. It seems that there is a role of P2S74− and P2S64− in K+-ion conductivity in the glassy electrolytes because the spectroscopic results are compatible with the composition-dependent, room-temperature conductivity trend.

Fragmentary Model of the Atomic Structure of the Ion-Conducting Semiconductor Glass AgGeAsSe3

Fragmentary Model of the Atomic Structure of the Ion-Conducting Semiconductor Glass AgGeAsSe3

Fragmentary Model of the Atomic Structure of the Ion-Conducting Semiconductor Glass AgGeAsSe3

The atomic radial distribution function of vitreous AgGeAsSe3, obtained based on the experimental intensity curves taken with monochromatic copper and molybdenum radiation, is interpreted using a fragmentary model in the entire ordering region (~9 Å). It is shown that the glass consists of selenium and selenium-arsenic tetrahedra with germanium and silver atoms inside. The spatial arrangement of such tetrahedra in glass within the ordering region is similar to their arrangement in the GeAsSe and GeSe2 structures. It is proposed that the “openwork” structure of the fragments of these structures allows the movement of Ag+ ions (ionic conductivity) in vitreous AgGeAsSe3. Fragments of the structure of the ion-conducting compound Ag2Se are not found in the studied glass.

Physical properties and dielectric response of (Gd, Pr)-dual doped samarium iron garnet

Samarium iron garnet, Sm3Fe5O12, co-doped with Gd3+ and Pr3+ ions, having the chemical formula Sm3-2xGdxPrxFe5O12 (0.0 ≤ x ≤ 0.8), were synthesized by the co-precipitation method. The structural study confirmed the cubic crystallization of the Sm3Fe5O12 phase in the addition of two secondary phases, α-Fe2O3 and SmFeO3. The variation of the lattice parameters and crystalline size indicated that both Gd3+ and Pr3+ ions were incorporated into the lattice. The elemental analysis confirmed the stoichiometry proposed for Sm3-2xGdxPrxFe5O12. The co-doping process of SmIG affected the absorbance of photo-radiations, making them possible candidates for transparent electrodes and optoelectronic devices. Energy band gap values were in the range of 2.921–3.004eV. DC electrical conductivity measurements studied the transport properties through which two activation energies were determined. The co-doping process affected the dielectric constants (ε′, ε″, tan δ), which reached a maximum value for x = 0.2. Dielectric relaxation was observed in the measurements, which could be due to the presence of oxygen vacancies as detected in XPS results. The Nyquist plots revealed that all the samples exhibited a negative temperature coefficient of impedance, where the arc of the semicircles decreased as the temperature increased from 413 to 743K. Also, the contribution of the resistance at high-frequency was related to the grains and grain boundaries. The ac conductivity mechanism followed the small polaron and the correlated barrier hopping models. In the temperature range between 333 and 583K, the prepared samples are promising for ion-conducting glasses and ionic crystals.

Using LAMMPS to shed light on Haven’s ratio: Calculation of Haven’s ratio in alkali silicate glasses using molecular dynamics

Haven and Verkerk studied the diffusion of ions in ionic conductive glasses with and without an external electric field to better understand the mechanisms behind ionic conductivity. In their work, they introduced the concept now known as Haven’s ratio (HR), which is defined as the ratio of the tracer diffusion coefficient (Dself) of ions to the diffusion coefficient from steady-state ionic conductivity (Dσ), calculated by the Nernst–Einstein equation. Dσ can be challenging to obtain experimentally because the number of charge carriers has to be implied, a subject still under discussion in the literature. Molecular dynamics (MD) allows for direct measurement of the mean squared displacement (r2) of diffusing cations, which can be used to calculate D, avoiding the definition of a charge carrier. Using MD, the authors have calculated the r2 of three alkali ions (Li, Na, and K) at different temperatures and concentrations in silicate glass, with and without the influence of an electric field. Results found for HR generally fell close to 0.6 at lower concentrations (x = 0.1) and close to 0.3 at higher concentrations (x = 0.2 and 0.3), comparable to the literature, implying that the electric field introduces new mechanisms for the diffusion of ions and that MD can be a powerful tool to study ionic diffusion in glasses under external electric fields.

In-situ study of phase changes in glass by impedance spectroscopy and scaling

Transformation in “evolving glass” in ion-conducting silicate glasses, glass ceramics or ceramics containing an intergranular glass is studied by in-situ impedance spectroscopy and scaling laws. Approaches are developed to scale frequency-dependent electrical conductivity and dielectric properties of multiphase ion-conducting materials to derive temperature-independent information on bulk phases and interfaces in presence. A material's scaled electric conductivity provides a unique response over a range of temperature, if the material remains unaltered, but changes, once modifications in the material occur. Therefore, impedance spectroscopy in combination with scaling can be used for tracking modifications in structure, organization, chemistry and microstructure in “evolving (ion-conducting) glass”.In a first part of this work, our approach is validated through application to stable silicate glasses and glass ceramics. Then “evolving glass” is studied in bulk glasses and ceramics with intergranular glass. Examples include ceramming of glass under formation of a glass ceramic, glass-glass phase separation, modification of intergranular glass in ceramics as result of chemical reactions or melt corrosion.Our approach allows to determine onset of phase separation, nucleation or reaction with high precision. It further reveals that nucleation in our exemplary lithium aluminum silicate glass starts with formation of interfaces (phase separation) prior to forming a well-organized crystal lattice. During phase separation in glass, early capacitive contributions in the impedance spectra indicate that the formation of glass-glass interface precedes the compositional changes in the bulk glass.Impedance of refractories is monitored during thermal treatments or corrosion in glass melt at temperatures up to 1600 °C, and glass characteristics of refractories with glass content as low as 3% are extracted. Conductivity and/or level and/or interconnectivity of the refractory's glass are shown to change during thermal treatments due to reactions between glass and crystalline refractory phases, due to phase transformation or, in case of melt corrosion, due to melt infiltration and ion exchange with the melt.In-situ tracking of impedance and application of scaling laws is shown to be able to reveal changes in bulk glass and intergranular glass.

Effect of doping with different sulphur group elements on the performance of silver ion-conducting glass

Ion-conducting glasses of AgI-based Ge-Ga-S, Ge-Ga-Se and Ge-Ga-Te with different sulphur group elements were prepared by melt quenching technique. The electrical properties and thermodynamic stability were investigated and compared. Glass transition temperatures and crystallisation temperatures of the samples were measured using differential scanning calorimetry. Results showed that Ge-Ga-S-AgI had the best thermodynamic stability and glass-forming ability, highest ionic conductivity (1.33 × 10−7 S/cm) at room temperature and lowest conductivity activation energy of 0.41 eV. Raman spectroscopy analysis showed that the [GeInS4-n] (n = 1,2,3) structural units in the S series glasses provided a good environment for the effective transport of Ag+ and formed an active ion transport channel. By contrast, the structural units in the Se and Te series contributed less to the transport of Ag+. This work systematically explored the effects of three elements in the sulphur main group on the performance of Ag+ conductive glasses. This study provides a reference for the rational formulation of sulphur-based Ag+ conductive glass components with enhanced comprehensive properties.

Ionic conduction of glasses and their potential applications

Ionic conduction of glasses and their potential applications

Decoupling polymer, water and ion transport dynamics in ion-selective membranes for fuel cell applications

Ion conducting polymer membranes are designed for applications ranging from separation and dialysis, to energy conversion and storage technologies. A key application is in fuel cells, where the semi-permeable polymer membrane plays several roles. In a fuel cell, electrical power is generated from the electrochemical reaction between oxygen and hydrogen, catalysed by metal nanoparticles at the cathode and anode sites. The polymer membrane permits the selective transport of H + or OH − to enable completion of the electrode half-reactions, plays a major role in the management of water that is necessary for the conduction process and is a product in the reactions, and provides a physical barrier against leakage across the cell. All of these functions must be optimised to enable high conduction efficiency under operational conditions, including high temperatures and aggressive chemical environments, while ensuring a long lifetime of the fuel cell. Polymer electrolyte membranes used in current devices only partially meet these stringent requirements, with ongoing research to assess and develop improved membranes for a more efficient operation and to help realise the transition to a hydrogen-fuelled energy economy. A key fundamental issue to achieving these goals is the need to understand and control the nature of the strongly coupled dynamical processes involving the polymer, water and ions, and their relationship to the conductivity, as a function of temperature and other environmental conditions. This can be achieved by using techniques that give access to information across a wide range of timescales. Given the complexity of the dynamical map in these systems, unravelling and disentangling the various processes involved can be accessed by applying the “serial decoupling” approach introduced by Angell and co -workers for ion-conducting glasses and polymers. Here we introduce this concept and propose how it can be applied to proton- and anion-conducting fuel cell membranes using two main classes of these materials as examples. • The serial decoupling approach is a powerful way of disentangling coupled dynamics in polymers. • It is now been extended to disentangle relaxation and diffusional processes. • We demonstrate how it provides a useful approach for decoding the membrane function and performance.

Influence of Inorganic Glass Ceramic Particles on Ion States and Ion Transport in Composite Single-Ion Conducting Gel Polymer Electrolytes with Varying Chain Chemistry

A major goal of next-generation battery development is the engineering of nonflammable solid-state electrolytes with high enough ionic conductivity to compete with traditional liquid electrolytes. Composite polymer electrolytes (CPEs), which combine inorganic fillers or electrolytes with a polymer matrix, are seen as a strategy to boost the ionic conductivity of flexible polymer electrolytes while overcoming the brittle aspect of inorganic electrolytes. In this work, we examine the impact of polymer backbone chemistry on Li+ ion conduction within crosslinked single-ion conducting gel polymer electrolytes (SIPEs) that contain a lithium ion-conducting glass ceramic electrolyte (LICGC). Certain SIPE compositions based on poly(tetrahydrofuran) diacrylate (PTHFDA) crosslinking macromonomers exhibit a significant increase in conductivity with the inclusion of LICGC, a result unexpected from prior literature. With the use of Raman spectroscopy, small angle X-ray scattering, and particle-induced gamma-emission spectroscopy (PIGE), it is proposed that the enhanced conductivity comes from the formation of percolated LICGC particles sheathed in an ion-rich domain. This region develops in the pre-polymer solution due to interactions between the LICGC particle surface and the ionic comonomer, much like the formation of space-charge regions in soggy-sand liquid electrolytes, and persists post-polymerization to yield a CPE of enhanced conductivity. The particle–ionic monomer interactions are modulated by the crosslinking macromonomer polarity, polymer casting solvent, and particle surface area. While there is ample room for continued optimization, the best SIPEs in this study are capable of Li metal dissolution/deposition, and they reach Li+ conductivities greater than 2 × 10–4 S/cm at 25 °C, surpassing the practical use threshold.

Correlation between Structural Disorder and Transport Properties in Fast Ion-Conducting Glass Materials

Correlation between Structural Disorder and Transport Properties in Fast Ion-Conducting Glass Materials

Ion trapping model of the ac conductivity in disordered solids

In this paper, we develop an approach based on ions trapping to describe the conductivity spectra in disordered solids. Applying the multiple trapping model and the diffusion equation for ions, we obtained a new expression for the ac conductivity, which allows us to describe the conductivity spectra in wide ranges of frequencies and temperatures. In the high-temperature region, the new expression for the ac conductivity reproduces the Jonscher behavior, and with decreasing temperatures transforms into an expression of the NCL-type. A new expression for the ac conductivity was successfully tested on the conductivity spectra of ion-conducting glasses.

Network former mixing effects in alkali germanotellurite glasses: A vibrational spectroscopic study

Alkali germanotellurite glasses of composition 0.3M2O–0.7[(1-x)GeO2–xTeO2], M=Li, Na and 0 ≤ x ≤ 1, were investigated by Raman and infrared vibrational spectroscopic techniques to search for the origins of the alkali ion-dependent network former mixing (NFM) effect in these ion-conducting glasses. The vibrational spectra measured on mixed network-former glasses, and the spectral comparison between equimolar-mixed glasses (x = 0.5) and pellet-mixtures of the endmember glasses, 0.3M2O–0.7GeO2 and 0.3M2O–0.7TeO2, provided evidence for the formation of hetero-atomic Ge–O–Te linkages and structural rearrangements in the germanate and tellurite components of the glass. The mixing-induced structural rearrangements were expressed in terms of chemical equilibria between the network-building units and were used to make qualitative predictions for changes in the network cross-linking density and the related network-strain energy, as well as in the binding energy part of the activation energy for ion conduction. Thus, it is proposed that the mixing-induced structural modifications in the germanate and tellurite parts of glass cause the cancelation of changes in the binding energy and the network-strain energy contributions to the activation energy for ion transport. These qualitative predictions were discussed in the context of the previously found absence of an NFM effect in ionic conductivity for M=Na and the presence of a weak positive NFM effect for M=Li.

Towards Higher Electric Conductivity and Wider Phase Stability Range via Nanostructured Glass-Ceramics Processing.

This review article presents recent studies on nanostructured glass-ceramic materials with substantially improved electrical (ionic or electronic) conductivity or with an extended temperature stability range of highly conducting high-temperature crystalline phases. Such materials were synthesized by the thermal nanocrystallization of selected electrically conducting oxide glasses. Various nanostructured systems have been described, including glass-ceramics based on ion conductive glasses (silver iodate and bismuth oxide ones) and electronic conductive glasses (vanadate-phosphate and olivine-like ones). Most systems under consideration have been studied with the practical aim of using them as electrode or solid electrolyte materials for rechargeable Li-ion, Na-ion, all-solid batteries, or solid oxide fuel cells. It has been shown that the conductivity enhancement of glass-ceramics is closely correlated with their dual microstructure, consisting of nanocrystallites (5–100 nm) confined in the glassy matrix. The disordered interfacial regions in those materials form “easy conduction” paths. It has also been shown that the glassy matrices may be a suitable environment for phases, which in bulk form are stable at high temperatures, and may exist when confined in nanograins embedded in the glassy matrix even at room temperature. Many complementary experimental techniques probing the electrical conductivity, long- and short-range structure, microstructure at the nanometer scale, or thermal transitions have been used to characterize the glass-ceramic systems under consideration. Their results have helped to explain the correlations between the microstructure and the properties of these systems.

Low-Temperature Densification of Nasicon-Type Electrolyte for Bulk-Type All-Solid-State Battery

Submicron particles of Na SuperIonic CONductor (NASICON)-type Li2O-Al2O3-TiO2-P2O5 (LATP) are possible to be densified at low temperature of 300 ºC by applying high pressure of 600 MPa during spark-plasma sintering (SPS) process. This process provides a novel route for assembling bulk-type all-solid-state lithium-ion battery (ASS-LIB), which promises high safety and high durability of energy storages since the origins of flammability and undesirable electrochemical events are prevented by using oxide as an electrolyte instead of the non-aqueous liquid.The main challenge for assembling bulk-type ASS-LIB are how to reduce the sintering temperature of the oxide electrolyte since most of the electrode materials decompose readily at high temperatures. Previously, we have attempted to design LiCoO2-electrode/NASICON-type LiTi2(PO4)3-electrolyte interface by conventional SPS process since quick/low-temperature treatment by the SPS has a possibility for reducing the decomposition kinetically.1 However, the several-μm ion-blocking interphase was easily-produced at the interface. Therefore, further low-temperature technique is required for the design of impurity-free electrode/electrolyte heterointerfaces. Commonly, the low-temperature sinterability of ceramic (or metal) particles could be accomplished with the increase of the contact for active surfaces by reducing particle size and/or applying higher pressure under sintering. Kinemuchi et al. has suggested that the low-temperature densification (LTD) of the oxide was performed by combining the use of nano particles and external pressure of over several-hundred MPa during the SPS.2 The LTDs for lithium-ion conductive oxides have possibilities for producing impurity-free electrode/electrolyte interface, and therefore would be one of the promising techniques for assembling oxide-based bulk-type ASS-LIB.In the present study, we used submicron size of NASICON-type Li2O-Al2O3-TiO2-P2O5 (LATP) powder as high bulk lithium-ion conductive oxides, which have been developed as Lithium Ion Conductive Glass Ceramics; LICGCTM, by OHARA INC..3,4 The densification of the LATP powder compact could be certified at low temperature of 200 - 250 °C under applying a pressure of 600 MPa during the SPS. Generally, the LTDs for oxides were achieved using not submicron particles but nano particles. However, the LTDs of the submicron-size particles could be confirmed in a phosphate group, which includes Li3PO4, AlPO4, and also LATP. Therefore, the bulk-type ASS-LIBs with phosphate-based electrodes such as LiFePO4 and Li2CoPO4F were successfully assembled by the LTD processes because the undesirable-thermal impurities at electrode/electrolyte interface were prevented during the low-temperature treatment. The characterization of LiFePO4/LATP interface and the electrochemical performance of ASS-LIB cell (Li/dry polymer/LATP/LiFePO4) will be presented in the conference.

Effect of Electrode Overpotential in Secondary Solution on Lithium Recovery Rate for Electrodialysis with Two Power Supplies and Three Electrodes

Demand for lithium-ion batteries (LIB) is rapidly increasing with the electrification of automobiles and the spread of new energy management systems. It is desired to recover lithium resources, whose supply and demand are tight, from spent LIB and seawater. Lithium for LIB must have a high purity of 99.9% or higher. The electrodialysis method using a lithium ion electrolyte has a high potential for recovering such high-purity lithium. Kunugi et al. [1] reported that only lithium ions could be recovered from LiCl-NaCl-KCl mixed aqueous solution by electrodialysis using La0.55Li0.35TiO3 as an electrolyte. Hoshino [2] demonstrated the possibility of using lithium ion conductive glass ceramics (LICGCTM). However, in either method, the lithium recovery rate is too low for practical use. We have devised an electrodialysis system with two power sources and three electrodes, which is different from a general electrodialysis cell consisting of two electrodes and one power source, and experimentally confirmed a large lithium recovery rate. In this study, we investigate the effect of electrode overvoltage in the secondary solution on the lithium recovery rate by this new electrodialysis method. An anode (primary solution side) and a cathode (secondary solution side) were formed on both sides of the La0.57Li0.29TiO3 (LLTO) by firing a Pt paste. As a third electrode, a Ni mesh electrode was placed in the secondary solution at a position apart from the cathode. A constant DC voltage was applied between the anode and the cathode. A constant DC voltage of another magnitude was also applied between the cathode and the Ni mesh electrode. The electric resistance of the solution between the cathode and the third electrode was changed by changing the lithium concentration in the secondary side solution or the distance between the cathode and the third electrode. The change in the lithium recovery rate due to this change in electrical resistance was investigated. The recovery rate was calculated using the lithium concentration in the secondary side solution measured by inductively coupled plasma optical emission spectroscopy. The electrical resistance of the solution between the cathode and the third electrode decreased due to the increase of the lithium-ion concentration in the secondary side solution, and the overpotential for the electrochemical reaction on the cathode and the third electrode increased. As a result, the lithium recovery rate was increased.[1] S. Kunugi, Y. Inaguma and M. Itoh, Solid State Ionics, 122, 35-39 (1999).[2] T. Hoshino, Desalination, 359, 59-63 (2015).

Conductivity and structural properties of fast Ag-ion-conducting GaGeSbS–AgI glassy electrolytes

The use of ion-conducting chalcogenide glass, a promising solid electrolyte, is encouraged at higher conductivity for all-solid-state rechargeable battery. Herein, a new quaternary glass of GaGeSbS–AgI system was successfully prepared, and its structural and electrochemical properties were investigated by XRD, Raman, and AC impendence measurement. The relatively high conductivity of 2.955 × 10−3 S/cm and low activation energy of 0.07 eV were obtained after optimized structure regulation. The short-range schematic of the glass structure was explored to determine the fast-migrating mechanism involved in conducting Ag+ ions. By controlling the proper ratio of Ga(Ge) and Sb cations, the loose and porous layer structure of [SbSxI3-x] linking by the [Ga(Ge)S4] tetrahedron was formed, resulting in the rapid transport of Ag+ ions with a reduced migration energy barrier. The current work is the first time that a sulfide solid electrolyte in quaternary glass system with desirable electrochemical characteristics was used to address energy and safety issues.

Nanoscale Mapping of Extrinsic Interfaces in Hybrid Solid Electrolytes

Summary Inorganic-organic hybrid solid electrolytes are promising material systems for all solid-state batteries (ASSBs). These electrolytes contain numerous solid | solid interfaces that govern transport pathways, electrode | electrolyte compatibility, and durability. This paper evaluates the role that electrode | electrolyte interfaces and electrolyte structure have on electrochemical performance. Atomic force microscopy techniques reveal how mechanical, adhesion, and morphological properties transform in a series of model hybrid solid electrolytes. These measurements are mapped to sub-surface microstructural features using synchrotron nano-tomography. Hybrid solid electrolytes with shorter polymer chains demonstrate a higher adhesion ( > 100 nN), Young's Modulus (6.4 GPa), capacity (114.6 mAh/g), and capacity retention (92.9%) than hybrid electrolytes with longer polymer chains (i.e., higher molecular weight). Extrinsic interfacial properties largely dictate electrochemical performance in ASSBs. Microstructural control over inorganic constituents may provide a means for tailoring interfacial properties in hybrid solid electrolytes.