Cation Transport Number Research Articles

Structure and transport properties of LiTFSI-based deep eutectic electrolytes from machine-learned interatomic potential simulations.

Deep eutectic solvents have recently gained significant attention as versatile and inexpensive materials with many desirable properties and a wide range of applications. In particular, their characteristics, similar to those of ionic liquids, make them a promising class of liquid electrolytes for electrochemical applications. In this study, we utilized a local equivariant neural network interatomic potential model to study a series of deep eutectic electrolytes based on lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) using molecular dynamics (MD) simulations. The use of equivariant features combined with strict locality results in highly accurate, data-efficient, and scalable interatomic potentials, enabling large-scale MD simulations of these liquids with first-principles accuracy. Comparing the structure of the liquids to the reported results from classical force field (FF) simulations indicates that ion-ion interactions are not accurately characterized by FFs. Furthermore, close contacts between lithium ions, bridged by oxygen atoms of two amide molecules, are observed. The computed cationic transport numbers (t+) and the estimated ratios of Li+-amide lifetime (τLi-amide) to the amide's rotational relaxation time (τR), combined with the ionic conductivity trend, suggest a more structural Li+ transport mechanism in the LiTFSI:urea mixture through the exchange of amide molecules. However, a vehicular mechanism could have a larger contribution to Li+ ion transport in the LiTFSI:N-methylacetamide electrolyte. Moreover, comparable diffusivities of Li+ cation and TFSI- anion and a τLi-amide/τR close to unity indicate that vehicular and solvent-exchange mechanisms have rather equal contributions to Li+ ion transport in the LiTFSI:acetamide system.

Твёрдые полимерные электролиты на основе нафиона для литий-ионных и натрий-ионных аккумуляторов

The use of solid polymer electrolytes is a novel and promising approach for enhancing the safety of lithium-ion and sodium-ion batteries. A number of publications on manufacturing electrolytes with lithium-ion and sodium-ion conductivity based on Nafion-like polymers have appeared in recent decade. The present mini-review analyses various methods of the synthesis of such electrolytes and their properties, as well as the information on laboratory lithium-ion and sodium-ion batteries using such electrolytes. The conclusion is made that the use of Nafion-based solid polymer electrolytes with Li+ and Na+ cation conductivity opens the way to creation of a new generation of lithium-ion and sodium-ion batteries. The principal advantage of Nafion-based solid polymer electrolytes over traditional PEO-based electrolytes is a fairly high cation transport number, which provides a sharp decrease in concentration polarization and, consequently, the increase in the energy efficiency of batteries.

Sodium Ion-Conducting Electrolytes Based on Chloroaluminate Ionic Liquids and δ-NaCl.

Sodium-containing ionic liquids are very promising candidates as ion-conducting materials in alternative to electrolytes based on lithium chemistry. Here we investigate a series of seven ionic liquids with formula (EMImCl/(AlCl3)1.5)/(δ-NaCl)x (0≤x≤0.74). The salt is comprised of a disordered form of NaCl prepared by metalorganic synthesis, which assures faster dissolution in high concentration. The vibrational investigation carried out by FT-IR spectroscopy in the medium IR region shed light on salt-IL interactions. The ionic conductivity was investigated by Broadband Electric Spectroscopy. The direct current conductivity (σdc) profiles versus the reciprocal temperature exhibited a Vogel-Tamman-Fulcher behavior indicating the assistance of micro-Brownian motions to ionic migration. The value of σdc at 25 °C for x=0.74 was found to be 1.2×10-2 S cm-1. Reversible deposition of Na and Al-containing species take place with high Coulombic efficiency (up to 97 %) and a high Na+ cation transport number (up to 0.95). The understanding of ionic speciation was investigated in comparison with aqueous acid-base systems exploring the benefits and limitations of such analogy. The role of a Grotthuss-type mechanism facilitating the exchange of chlorides between acidic catenated chloroaluminate species in anionic domains of the ILs is considered.

Comparative study on graphene oxide and sulfonated graphene oxide reinforced polyethersulfone-based cation-exchange membrane

In this research, polyethersulfone/sulfonated graphene oxide (PES/SGO) heterogeneous cation exchange membranes were fabricated by the mold casting method. The sulfonation of GO was carried out using the diazonium salt of sulfanilic acid. The properties of the synthesized GO and SGO were compared in terms of chemical structure, morphology, surface charge, crystallinity, and thermal stability. The variations in surface morphology and roughness, hydrophilicity, dimensional stability, and ionic conductivity of the PES-based membranes as a function of GO and SGO content were investigated. Results revealed that SGO enjoyed a higher level of oxygenated groups contributing to its higher surface charge. SGO also tolerated a higher temperature before being fully decomposed due to the presence of the sulfur-containing groups. A finer nanostructured morphology was observed in the SGO-containing membranes, resulting in a considerably lower surface roughness of these membranes than the corresponding GO-based membranes. The membrane comprising 10 wt% SGO showed the lowest surface roughness of 88 nm, and the highest water uptake of 16.66 %, ion-exchange capacity of 1.12 meq g-1, and the lowest charge transfer resistance of 3.6 Ω and area resistance of 0.9 Ωcm2. This was accompanied with a considerable increment in the permselectivity and cation (Na+) transport number of this membrane to 95.9 % and 97.5 %, respectively, due to the higher surface adhesion energy of 94.57 J m-2 and higher Na+ flux of 4.43×10-7 mol m-2 s-1, which were significantly higher than that obtained for the corresponding PES-based membrane containing 10 wt% GO. Furthermore, a lower weight loss and resistance change were observed for PES/SGO after being exposed to the Fenton reagent for 9 h, indicating the impact of the sulfonated groups on the oxidative stability enhancement of the membrane.

Polymer electrolytes with high cation transport number for rechargeable Li–metal batteries: current status and future direction

The high-cation transport number polymer electrolytes (HTPEs) with simultaneously high cation transport number and high ionic conductivity could provide a solution to enable high-performance solid-state batteries.

Understanding the Connection between Li-Ion Transport Number and Electrochemical Performance in Fluorinated Ether-Based Electrolytes

As high-performance batteries increase in demand, lithium metal batteries (LMBs) have attracted increasing attention in recent years. Nonetheless, LMBs are limited in their performance due to a low cation transport number (tLi+) of non-aqueous liquid electrolytes, which is the ratio of charge transport of Li-ions to its counterion. This study investigated fluorinated ether-based electrolytes (1,2-(1,1,2,2-tetra fluoroethoxy) ethane, TFEE) with 1,2-dioxolane (DOL) as a co-solvent that were found to have tLi+ of 0.70, which was determined through electrochemical impedance spectroscopy, EIS. This electrolyte mixture gives a low electrolyte coulombic efficiency and poor stability tested in both Li-Cu half and Li – Li4Ti5O12 full cells. The same fluorinated electrolyte with dimethoxy ethane (DME) as a co-solvent showed better coulombic efficiency and stability despite its low tLi+ of 0.18. A significant migration resistance through the porous solid electrolyte interface (SEI) in the case of TFEE-DOL electrolytes is suspected to explain the observed discrepancy, as demonstrated by EIS and X-ray photoelectron spectroscopy. We propose that the properties/process of the Li anode are more crucial for LMBs’ performance than the ionic transport through the bulk electrolyte. Furthermore, the transport number should be determined carefully to avoid any spurious effects associated with SEI properties. Acknowledgments This work has received funding from the European Union Horizon 2020 research and innovation DESTINY program under grant agreement No. 945357. Co-financing from Slovenian Research Agency (ARRS) is fully acknowledged.

Pentablock Copolymer Membranes for Non-Aqueous Redox Flow Batteries

Long duration energy storage devices, such as redox flow batteries, are needed to enable smart grids and widespread adoption of renewable energy sources. Sodium based electrochemical energy storage is of interest for large-scale applications due to sodium’s low cost and high abundance compared to lithium and vanadium. The membrane plays a critical role in flow batteries by providing counterion transport while separating the catholyte and anolyte. Considering that the membrane is a significant source of internal resistance and capacity fade (e.g., due to crossover) in an operating battery, developing membranes with controlled swelling, high ionic conductivity, and low active species crossover is imperative. In this work, we studied electrolyte uptake and ion transport in cation exchange pentablock copolymer membranes with sodium sulfonate and sodium trifluoromethanesulfonimide (TFSI) functionality for nonaqueous flow battery applications. The TFSI Na membranes exhibit an ionic conductivity of 7.2 x 10-5 S/cm at room temperature and a cation transport number of 0.75 in 0.5 M sodium triflate/tetraethylene glycol dimethyl ether (TEGDME) electrolyte. Methods improve the ionic conductivity and limit electrolyte uptake of the membranes, such as crosslinking will be discussed. Acknowledgements This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) and is sponsored by the U.S. Department of Energy through the Energy Storage Program in the Office of Electricity.

Structure and ion transport in super-concentrated water-in-salt electrolytes: Insights from molecular dynamics simulations

Water-in-salt electrolyte (WISE) systems hold promise as materials for high performance, more reliable and affordable, energy storage devices including batteries and supercapacitors. However, the structure and ion dynamics in these systems is significantly different from those of aqueous electrolytes and are poorly understood. Here, we present molecular dynamics investigation of water-in-salt electrolyte materials having pure as well as eutectic mixtures of Li-NTF2, and Li-MM3411 salts at several concentrations. We find the existence of small water clusters such as dimers and trimers even at extremely high salt concentrations, but not pockets of bulk water molecules. We find that the water molecules are bound to the cation as well as anion at extremely high salt concentrations. It is found that Li ions display a variety of solvation environments in super concentrated electrolyte solutions depending on the salt and its concentration in water. Our simulation results suggests that ion transport follows a solvent-assisted Li-ion diffusion mechanism whereby Li ion diffuses along with the water molecules, with the Li-ions hopping from one anion site to the other. The cation transport number in WISE systems can be regulated by adding small amount of another salt; for example, the transference of WISE materials Li-NTF2 salt can be improved by adding small amount Li-MM3411 salt. Further, we show that there exists an optimal salt concentration in water, at which high apparent transference number for Li+ as well as high ionic conductivity can be achieved. These observations will provide a guidance for the design of new electrolyte systems and interphases with consequences for accelerating the development of batteries and supercapacitors with enhanced energy density and cycling stability.

Effect of polymer blending on the electrochemical properties of porous PVDF/PMMA membrane immobilized with organic solvent based liquid electrolyte

Abstract In this paper, experimental studies on blend gel polymer electrolyte membranes comprising of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) saturated with 0.1 M liquid electrolyte of sodium tetrafluoroborate (NaBF4) in the mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) are presented. Membranes are prepared by phase inversion technique. The effect of blending on the ionic conductivity, electrochemical stability window, ionic transference number, and cation transport number has been investigated using complex impedance spectroscopy, linear sweep voltammetry and DC polarization technique. Ion dynamics in the electrolyte membranes has also been investigated using dielectric studies. The optimized electrolyte membrane with composition PVDF:PMMA (95:5) + 0.1 M NaBF4 + EC + DEC shows highest ionic conductivity of 0.6 mS cm−1 which follows Vogel–Tamman–Fulcher (VTF) behavior with temperature. The membrane shows an electrochemical stability window of 3.5 V and sodium ion transport number as ∼0.33.

Improvement of Selectivity of RALEX-CM Membranes via Modification by Ceria with a Functionalized Surface.

Ion exchange membranes are widely used for water treatment and ion separation by electrodialysis. One of the ways to increase the efficiency of industrial membranes is their modification with various dopants. To improve the membrane permselectivity, a simple strategy of the membrane surface modification was proposed. Heterogeneous RALEX-CM membranes were surface-modified by ceria with a phosphate-functionalized surface. Despite a decrease in ionic conductivity of the prepared composite membranes, their cation transport numbers slightly increase. Moreover, the modified membranes show a threefold increase in Ca2+/Na+ permselectivity (from 2.1 to 6.1) at low current densities.

Synergistic theoretical and experimental study on the ion dynamics of bis(trifluoromethanesulfonyl)imide-based alkali metal salts for solid polymer electrolytes.

Model validation of a well-known class of solid polymer electrolyte (SPE) is utilized to predict the ionic structure and ion dynamics of alternative alkali metal ions, leading to advancements in Na-, K-, and Cs-based SPEs for solid-state alkali metal batteries. A comprehensive study based on molecular dynamics (MD) is conducted to simulate ion coordination and the ion transport properties of poly(ethylene oxide) (PEO) with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt across various LiTFSI concentrations. Through validation of the MD simulation results with experimental techniques, we gain a deeper understanding of the ionic structure and dynamics in the PEO/LiTFSI system. This computational approach is then extended to predict ion coordination and transport properties of alternative alkali metal ions. The ionic structure in PEO/LiTFSI is significantly influenced by the LiTFSI concentration, resulting in different lithium-ion transport mechanisms for highly concentrated or diluted systems. Substituting lithium with sodium, potassium, and cesium reveals a weaker cation-PEO coordination for the larger cesium-ion. However, sodium-ion based SPEs exhibit the highest cation transport number, indicating the crucial interplay between salt dissociation and cation-PEO coordination for achieving optimal performance in alkali metal SPEs.

Single-Ion Conducting Polymeric Protective Interlayer for Stable Solid Lithium-Metal Batteries

With many reported attempts on fabricating single-ion conducting polymer electrolytes, they still suffer from low ionic conductivity, narrow voltage window, and high cost. Herein, we report an unprecedented approach on improving the cationic transport number (tLi+) of the polymer electrolyte, i.e., single-ion conducting polymeric protective interlayer (SIPPI), which is designed between the conventional polymer electrolyte (PVEC) and Li-metal electrode. Satisfied ionic conductivity (1 mS cm-1, 30 °C), high tLi+ (0.79), and wide-area voltage stability are realized by coupling the SIPPI with the PVEC electrolyte. Benefiting from this unique design, the Li symmetrical cell with the SIPPI shows stable cycling over 6000 h at 3 mA cm-2, and the full cell with the SIPPI exhibits stable cycling performance with a capacity retention of 86% over 1000 cycles at 1 C and 25 °C. This incorporated SIPPI on the Li anode presents an alternative strategy for enabling high-energy density, long cycling lifetime, and safe and cost-effective solid-state batteries.

A Polymer Electrolyte with High Cationic Transport Number for Safe and Stable Solid Li-Metal Batteries

A Polymer Electrolyte with High Cationic Transport Number for Safe and Stable Solid Li-Metal Batteries

Efficient charge storage by ZnCo2S4 nanoflakes@MgCo2O4 nanorods composite in Mg2+/Zn2+/K+ conducting electrolytes

Heretofore unreported, a unique binder free composite cathode of zinc cobalt sulfide nanoflakes (NFs) and magnesium cobaltite nanorods (NRs) (ZnCo2S4@MgCo2O4) is presented and its potential for efficient energy storage is realized in terms of (1) a high electrical conductivity of ~0.7 mS cm−1 imparted by the mixed-valence states of Co2+/Co3+, (2) the mesoporous structure of the MgCo2O4 NRs enabling fast ion-diffusion and (3) the 3D ZnCo2S4 flakes with large exposed facets that allow abundant electrolyte-electroactive site-interactions. These factors cumulatively result in a high specific capacitance (SC) of 609 F g−1 (at 1.25 A g−1), Emax of 217 Wh kg−1 and a Pmax of 8 kW kg−1 over a voltage window of 1.6 V along with a cycle life of 10,000 cycles with 98 % SC retention for the ZnCo2S4@MgCo2O4//AC asymmetric supercapacitor (ASC) with KOH as the electrolyte. These performance metrics are superior to those reported in literature for similar oxides/chalcogenides. The electrolyte's role in controlling the redox-behaviour of the ASC is also assessed by using four different uni-molar electrolytes that obey the following order: KOH > Mg(OH)2 > MgCl2 > ZnCl2, in terms of their ionic conductivities (σ: 189, 84, 83 and 58 mS cm−1), cation transport number (t+: 0.85, 0.83, 0.75 and 0.57) and SCs (609, 315, 208, 100 F g−1 at 1.25 A g−1) for the corresponding ASCs. With the KOH electrolyte, a dominant contribution from diffusional transport (68 %) relative to the capacitive double layer storage (32 %) (at 10 mV s−1) is ascertained which confirms the ZnCo2S4@MgCo2O4 composite's ability to exhibit facile Faradaic reactions for charge storage, thereby aligning with the morphological and spinel structure benefits. A green-LED-illumination with a 3S(series)-configuration encompassing three-fully-charged ASCs, further validates this configuration's applicability for niche applications in consumer-electronic-devices.

Plastic crystal in rubbery matrix for light and safe batteries

Solid-state batteries (SSBs) will provide a transformative leap forward in mobile energy storage while achieving the solid electrolytes with desired properties, and stability is the major bottleneck in SSBs. This preview highlights a novel plastic-crystal-embedded elastomer electrolyte (PCEE) exhibiting a combination of mechanical flexibility, high ionic conductivity, and high cationic transport number. Insights on such PCEEs enabling light and safe lithium-metal batteries as well as traditional misunderstandings related to battery evaluation are also discussed.

Controlling the Ion Transport Number in Solvent-in-Salt Solutions.

Solvent-in-salt (SIS) systems present promising materials for the next generation of energy storage applications. The ion dynamics is significantly different in these systems from that of ionic liquids and diluted salt solutions. In this study, we analyze the ion dynamics of two salts, Li-TFSI and Li-FSI, in highly concentrated aqueous and acetonitrile solutions. We performed high-frequency dielectric measurements covering the range of up to 50 GHz and molecular dynamics simulations. The analysis of the conductivity spectra provides the characteristic crossover time between individual charge rearrangements and the normal charge diffusion regime resulting in DC conductivity. Analysis revealed that the onset of normal charge diffusion occurs at the scale of ∼1.5-3.5 Å, comparable to the average distance between the ions. Based on the idea of momentum conservation, distinct ion correlations were estimated experimentally and computationally. The analysis revealed that cation-anion correlations can be suppressed by changing the solvent concentration in SIS systems, leading to an increase of the light ion (Li+ in our case) transport number. This discovery suggests a way for improving the light cation transport number in SIS systems by tuning the solvent concentration.

Cover Feature: New Highly Stable Ionic Compounds Composed of Multivalent Graphene Quantum Dot Anions and Alkali Metal Cations (Batteries & Supercaps 3/2022)

The Cover Feature shows a new class of ionic compounds, composed of the nano-sized graphene quantum dot (GQD) polyanions and alkali-metal cations. They exhibit excellent thermal/electrochemical inertness, decent ionic conductivity, and a high transport number of cations as salts for electrolytes. More information can be found in the Research Article by K.-W. Park, I.-S. Shin, H. Kim and co-workers.

Unraveling Ion Transport in Pentablock Copolymer Membranes for Non-Aqueous Redox Flow Batteries

Medium to long duration energy storage devices, such as redox flow batteries, will be imperative for implementing smart grids and accommodating the increasing use of renewable energy sources. Sodium (Na) based electrochemical energy storage is of interest for large-scale applications due to sodium’s low cost and high abundance compared to lithium and vanadium. The membrane plays a critical role in a flow battery, separating the catholyte and anolyte by preventing transport of the redox active species through the membrane. Thus, it is critical to develop mechanically robust, chemically resistant membranes. Considering that the membrane is a significant source of internal resistance and capacity fade in an operating battery, understanding the effect of electrolyte type and concentration on membrane transport properties is imperative for optimizing the performance of non-aqueous flow batteries. This study aims to unravel relationships between membrane transport properties and electrolyte concentration in a polar and non-polar organic solvent for a Na-based non-aqueous flow battery. A pentablock copolymer with a Na-transporting trifluoromethanesulfonimide (TFSI) center block was successfully synthesized. The fabricated membranes were equilibrated in tetraethylene glycol dimethyl ether (TEGDME) and propylene carbonate (PC) solutions with varying concentrations of sodium triflate (NaTf). Membrane properties such as uptake, conductivity, transport number, and salt absorption were measured as a function of electrolyte concentration. The membranes achieve an ionic conductivity of 7.2 x 10-5 S/cm in TEGDME and 1.4 x 10-4 S/cm in PC at moderate electrolyte concentrations. A high cation transport number (>0.75) was maintained across the concertation range for PC and up to 0.5M NaTf in TEGDME. This study suggests new design parameters for Na-conducting membranes for non-aqueous flow battery, where optimum membrane performance; a balance between uptake, conductivity, and charge carrier selectivity; can be achieved at moderate electrolyte concentrations of 0.5 M to 0.75 M NaTf.

Investigation of Ionic Conductive Behavior of SL-Based Gel Polymer Electrolyte and Interfacial Property of Li / Gel Polymer Electrolyte

IntroductionLithium-Sulfur (Li-S) batteries are attracting attention as high energy density rechargeable battery. Elemental sulfur (S8) has high theoretical capacity (1,672 mAhg-1) as positive electrode active material. However, S8 electrode is degraded by redox shuttle effect of lithium-polysulfide (Li2S n ), which are generated during charge-discharge reactions. To solve this problem, many electrolyte designs were proposed. Sulfolane (SL) based high Li salt concentration electrolyte solution was reported as low solubility electrolyte of Li2S n [1]. The aim of this concept is chemically protection of Li2S n dissolution into electrolyte solution. Therefore, we proposed new polymer electrolyte, which protects chemically and physically dissolution and diffusion of Li2S n . In this study, we prepared SL-based solid gel polymer electrolytes (GPEs), ionic conductive property and time dependence of Li/GPEs interfacial resistance were evaluated.ExperimentalSulfolane (SL), LiN(SO2CF3)2 (LiTFSA), and polyether-based P(EO/PO) macromonomer (EO/PO=8/2) were used as electrolyte materials for GPEs. First, electrolyte solution samples were prepared by mixing LiTFSA and SL at each molar ratio of SL : LiTFSA = x : 1 (x=1, 1.5 and 2, respectively). Next, prepared electrolyte solution and P(EO/PO) macromonomer were mixed at weight ratio of electrolyte solution is 70, 80, 90 wt%, respectively, and added DMPA as photo initiator. After that, these materials were radical polymerized by UV irradiation. Temperature dependence of ionic conductivity of prepared GPEs were investigated by AC impedance measurements (353～217 K). Impressed voltages were changed from 100mV to 500 mV under 258 K. Also, [Li | GPE | Li] symmetrical cells were assembled, and impedance measurements of these cells were carried out to investigation of Li/GPE interfacial resistance at 333 K.Results & DiscussionFig.1 shows temperature dependence of ionic conductivity (s) of GPEs. Conventional polyether-based solid electrolyte ([Li]/[O]=0.1: black circle) was showed for comparison. s of all GPEs indicated higher value compared with [Li]/[O]=0.1. s increased with electrolyte solution composition or decrease of Li salt composition. These should be related with mobility of polymer chain or microscopic viscosity of GPEs, like a T gs. Also, s observed at around or less than T gs by changing impressed voltage. At this area, temperature dependence was changed inconsecutively. Therefore, ionic transport mechanism changes with segmental motion of polymer chain might be occurred below T g.Fig.2 shows time dependence of Li/GPE interfacial resistance (R Li) at 333 K. R Li moderately increased over time, which wasn’t stabilized over 1000 h. (Measurement was interrupted temporary at broken line.) R Li of general polyether based solid electrolyte reported as ca. 100 W cm2 [2],[3]. However, R Li indicated quite low values of 30～40 W cm2 at 1000 h. Therefore, favorable SEI formation might be occurred between Li metal and GPE. In presentation, temperature dependence of R Li and lithium cation transport number (t Li+) will be discussed.

Reducing of Grain Boundary Influences By Hybridization of Inorganic / Polymer Materials for Li-Conductive Solid Electrolyte

Introduction Recently, rechargeable batteries are strongly desired as energy storage systems. In particular, Li-ion batteries have been realized for practical use from consumer use (e.g., smartphone, laptop computer) to large-scaled energy storage devices such as for in/output control of renewable energy and electric vehicle owing to their high-energy-density and cycle performances. However, safety will be the most important demands with the scale of batteries, and many ignition accidents have been reported. ‘Solvent-free’ all-solid-state batteries exhibit quite high safety and have high-energy-density due to realization of thin-film electrolyte layer without separators. Generally, solid electrolytes are mainly categorized to polymer and inorganic electrolytes. Polymer electrolyte have a sufficient self-standing property, formability of stable interface with electrode and mechanical properties. However, it exhibits relatively low ionic conductivity and Li cation transport number. On the other hand, inorganic electrolyte shows relatively high ionic conductivity, even though it have grain boundary (GB) and be easily broken by external force (e.g. dropping and expansion / contraction with charge-discharge processes). Therefore, in this study, we propose polymer / inorganic hybrid electrolyte for usage of both advantages. Hybrid electrolytes of P(EO/PO) network polymer and two-types of Li1.5Al0.5Ge1.5(PO4)3 (LAGP) presence/absence GB resistance were investigated for developing high-performance all-solid-state Li batteries. Experimental Sample preparation All samples were prepared in a glove box under Ar atmosphere. LiN(SO2CF3)2, rhombohedral (r, having GB resistances) and amorphous (a, not having GB resistances) LAGP (Toshima mfg.), DMPA (photo initiator) and acetonitrile (solvent) were dissolved into polyether-based macromonomer (P(EO/PO) (TA-210, Dai-ichi Kogyo Seiyaku)). Amount of LiTFSA was [Li]/[O]=0.1 per mole of oxygen units of P(EO/PO). Amount of hybridized LAGP((a) or (r)) were 0, 1, 3, 5, 10, 20, 30, 40, 50, 75, 100, 150, 200 wt% with polymer electrolytes, respectively. Mixed samples were dried in vacuum for 12h to evaporate acetonitrile. Then the slurry was casted between two glass plates separated by spacers (Teflon sheet with a thickness of 0.5 mm) and radical polymerized by UV irradiation at 5 min. Measurements Ionic conductivities of hybrid solid electrolyte were measured by AC impedance method. In this study, we used two types of electrode, one is blocking electrode and the other is non-blocking electrode. First, blocking electrode cells (SUS / electrolyte (0.5 mm thickness) / SUS) were prepared Measurement samples were 12mm diameter disk. Frequency range is from 200kHz to 10mHz with 100 mV amplitude. Temperature range is 80oC to -30oC and all samples were thermally equilibrated at each temperature at least 1.5 h prior to the measurement. Secondly, non-blocking electrode cells (Li metal / electrolyte (0.5 mm thickness) / Li metal) were prepared. Measurement samples were 18mm diameter disk (diameter of Li metal were 16mm). Samples were measured under similar measurement conditions as above described.Additionally, molecular-level structures of prepared samples were analyzed by high-energy X-ray diffraction at SPring-8 (BL04B2). LAGP-free polyether electrolyte, Polyether/ LAGP(a)150wt% hybrid electrolyte and LAGP(a) powder were enclosed in a sample tube and measured. Results and discussion From the result of impedance measurement by blocking electrode systems, possibility of influence of GB may not appear when using an amorphous material was suggested. To compare the effects of GB, non-blocking electrode systems, led clear difference between amorphous and rhombohedral by the difference of frequency properties [1]. Fig.1 shows impedance spectrum of several electrolytes by non-blocking electrode systems. LAGP-free (0%) electrolyte showed two semicircular arcs and all amorphous LAGP systems also showed the two semicircular arcs. In both systems, high and low frequency components were assigned as bulk resistance and interfacial resistance with Li metal. However, rhombohedral LAGP systems showed clearly different spectrum. GB resistance appears between the two resistance components. This result shows that amorphous LAGP obtain no GB resistance component into hybrid electrolyte. By using amorphous inorganic electrolyte into polyether electrolyte, the influence of GB could be eliminated. Therefore, one of reducing technique of GB influences was established. Fig.2 shows radial distribution function of three samples. A periodic structure appeared in all electrolytes. The radial distribution function of hybrid electrolyte was confirmed between polyether electrolyte and LAGP powder. This result exhibits the spectral proximity, suggestion of good interfacial matching (effective interactions) between the polymer and the inorganic electrolyte. Moreover, this measurement method was also effective for the local structure analysis because of their ability to analyze hybrid material of amorphous polymer and inorganic systems. Conclusion From the standpoint of electrochemical and spectroscopic measurements, we clarified the influence of grain boundary by using amorphous inorganic electrolyte into polyether electrolyte.[1] M. Kato, K. Hiraoka, S. Seki, J. Electrochem. Soc., 167, 070559 (2020). Figure 1