The Detail Matters: Unveiling Overlooked Parameters in the Mechanochemical Synthesis of Solid Electrolytes

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Learn More CiteCitationCitation and abstractCitation and referencesMore citation options ShareShare onFacebookX (Twitter)WeChatLinkedInRedditEmailJump toExpandCollapse ViewpointDecember 16, 2024The Detail Matters: Unveiling Overlooked Parameters in the Mechanochemical Synthesis of Solid ElectrolytesClick to copy article linkArticle link copied!Abdulkadir KızılaslanAbdulkadir KızılaslanEsentepe Campus, Metallurgy and Materials Science Department, Sakarya University, Sakarya 54050, TurkeyMore by Abdulkadir KızılaslanMustafa ÇelikMustafa ÇelikEsentepe Campus, Metallurgy and Materials Science Department, Sakarya University, Sakarya 54050, TurkeyMore by Mustafa Çelikhttps://orcid.org/0000-0003-0246-6165Yuta Fujii*Yuta FujiiFaculty of Engineering, Hokkaido University, Sapporo 060-8618, Japan*[email protected]More by Yuta Fujiihttps://orcid.org/0000-0002-8381-4119Zheng HuangZheng HuangInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, JapanDepartment of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, JapanMore by Zheng HuangChikako MoriyoshiChikako MoriyoshiGraduate School of Science, Hiroshima University, Hiroshima 739-8511, JapanMore by Chikako MoriyoshiShogo KawaguchiShogo KawaguchiJapan Synchrotron Radiation Research Institute (JASRI) SPring-8, Hyogo 679-5198, JapanMore by Shogo KawaguchiSatoshi HiroiSatoshi HiroiFaculty of Materials for Energy, Shimane University, Matsue 690-8504, JapanMore by Satoshi Hiroihttps://orcid.org/0000-0001-5058-6757Koji OharaKoji OharaFaculty of Materials for Energy, Shimane University, Matsue 690-8504, JapanMore by Koji OharaMariko AndoMariko AndoGraduate School of Engineering, Tohoku University, Sendai 980-8579, JapanMore by Mariko AndoKiyoharu TadanagaKiyoharu TadanagaFaculty of Engineering, Hokkaido University, Sapporo 060-8618, JapanMore by Kiyoharu Tadanagahttps://orcid.org/0000-0002-3319-4353Saneyuki Ohno*Saneyuki OhnoInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, JapanDepartment of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan*[email protected]More by Saneyuki Ohnohttps://orcid.org/0000-0001-8192-996XAkira Miura*Akira MiuraFaculty of Engineering, Hokkaido University, Sapporo 060-8618, Japan*[email protected]More by Akira Miurahttps://orcid.org/0000-0003-0388-9696Open PDFSupporting Information (1)ACS Energy LettersCite this: ACS Energy Lett. 2025, 10, XXX, 156–160Click to copy citationCitation copied!https://pubs.acs.org/doi/10.1021/acsenergylett.4c02156https://doi.org/10.1021/acsenergylett.4c02156Published December 16, 2024 Publication History Received 7 August 2024Accepted 18 November 2024Published online 16 December 2024article-commentary© 2024 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY 4.0 . License Summary*You are free to share (copy and redistribute) this article in any medium or format and to adapt (remix, transform, and build upon) the material for any purpose, even commercially within the parameters below:Creative Commons (CC): This is a Creative Commons license.Attribution (BY): Credit must be given to the creator.View full license*DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. This publication is licensed underCC-BY 4.0 . License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator.View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. License Summary*You are free to share(copy and redistribute) this article in any medium or format and to adapt(remix, transform, and build upon) the material for any purpose, even commercially within the parameters below: Creative Commons (CC): This is a Creative Commons license. Attribution (BY): Credit must be given to the creator. View full license *DisclaimerThis summary highlights only some of the key features and terms of the actual license. It is not a license and has no legal value. Carefully review the actual license before using these materials. ACS Publications© 2024 The Authors. Published by American Chemical SocietyThe advent of all-solid-state lithium-ion batteries has advanced energy storage technologies with the development of highly conductive solid electrolytes. Numerous researchers have reported the structural and electrochemical performance of solid electrolytes obtained through different production techniques and with different compositions. (1,2) However, even in relatively robust production techniques using ball-milling with the same composition and stoichiometry, only a minute difference in the synthesis process can significantly affect the crystallization mechanisms and resulting ionic conductivity, thereby highlighting the importance of overlooked parameters. This Viewpoint demonstrates the effects of "premixing"─mixing the precursors with a mortar and pestle prior to the mechanochemical synthesis of glassy solid electrolytes, particularly Li2S–P2S5 sulfides and the newly emerging NaTaCl6 halides─on the structure and transport of the resulting products.Crystal structures and amorphous configurations of sulfide and chloride electrolytes with high ionic conductivities and excellent mechanical properties have been identified. (3−11) These electrolytes are commonly produced through mechanochemical synthesis using ball-milling, which has been widely utilized with various chemical compounds. (12−14) Li7P3S11 is recognized as a metastable phase that is nucleated by the subsequent heat treatment of Li2S–P2S5 glasses produced by planetary ball-milling. NaTaCl6 is recognized as a mixture of crystal and amorphous phases that shows an excellent electrochemical window. In both cases, a wide range of ball-milling experimental parameters have been investigated, including the amount of powder, number of balls, rotation speed, and ball-milling time, leading to the successful synthesis of the target phases. (15−24) This experimental fact makes these synthesis methods for producing Li7P3S11 and NaTaCl6 seemingly very robust. Nonetheless, although the apparent crystal structures evaluated by X-ray diffraction (XRD) are almost identical, there are significant differences in their ion conductivities. (18,25−27) Moreover, only three of 15 studies reported on Li7P3S11 syntheses (3,28,29) have described the hand-mixing of starting powders prior to or intermittently during ball-milling, as given in Table S1. Similarly, one out of three studies of NaTaCl6 have described the hand-mixing of starting powders (Table S2). Although the details of the hand-mixing have been deemed to have negligible effects, this study demonstrates the importance of such a process.This Viewpoint demonstrates the impact of the unspecified details of mechanochemical synthesis on the crystallization mechanisms and ionic conductivities of the products, highlighting the importance of parameters that are often overlooked in such syntheses.Two synthesis routes based on the existing literature (3,6,17,30) were employed to synthesize Li7P3S11 using ball-milling, as shown in Scheme 1. The difference between the two routes is the implementation of a hand-mixing step prior to mechanical milling, referred to as premixing. For Sample 1, the hand-ground Li2S precursor was thoroughly mixed together with P2S5 for 20 min using an agate mortar and pestle. In contrast, the precursors of Sample 2 were just stirred with a spatula for 2 min prior to milling. Similarly, the impact of premixing on the synthesis of NaTaCl6, synthesized by mechanical milling of NaCl and TaCl5, was assessed through investigating two NaTaCl6 samples synthesized with or without premixing. The details of the compositions during the synthesis of the powders, including the required reagents and synthesis process, are given in Tables S3 and S4.Scheme 1Scheme 1. Synthesis Routes of Sulfide Solid Electrolytes Analyzed in This StudyHigh Resolution ImageDownload MS PowerPoint SlideFigure 1(a, b) displays the 31P magic-angle spinning nuclear magnetic resonance (31P MAS NMR) spectra of the Li7P3S11 glass produced by milling with or without premixing before heating. Despite the broad halo patterns in XRD (Figure S1), which indicate that both the samples, with and without premixing, were completely amorphous, distinctly different local anion coordination is observed in the NMR spectra. The spectra of both samples were deconvoluted into three peaks, where PS43– and P2S74– are constituent elements of the target Li7P3S11 phase and P2S64– is the local unit of the Li4P2S6 impurity phase. (19) Figure 1(c) shows a comparison of the area-size fractions of the peaks corresponding to the three anion blocks. Although a glassy phase typically contains various local structures as its nature, the amount of P2S64– in Sample 1 is less than that in Sample 2. Furthermore, the area-size ratios of P2S74–, and PS43– are 1.70 and 1.24 for Samples 1 and 2, respectively. The area-size ratio of Sample 1 approaches 2.00, which is the theoretical stoichiometric ratio of the two components in crystalline Li7P3S11, indicating the anion blocks in Sample 1 are similar to those in Li7P3S11 even before heat treatment. Data with a wider range of chemical shifts, confirming no overlap between sidebands and main peaks, are shown in Figure S2.Figure 1Figure 1. 31P MAS NMR spectra and deconvoluted peak profiles of the as-milled powders of (a) Sample 1 and (b) Sample 2. (c) Area-size fractions of Samples 1 and 2.High Resolution ImageDownload MS PowerPoint SlideIn situ synchrotron X-ray diffraction (SXRD) demonstrates evidently different crystallization processes between the two Li2S–P2S5 glasses (Figure 2). Sample 1 exhibits a single-step crystallization at approximately 220 °C. Conversely, Sample 2 undergoes a two-step crystallization process owing to the sequential formation of Li3PS4 at approximately 220 °C, followed by Li7P3S11 at approximately 240 °C. Rietveld refinement was performed on the temperature-dependent diffractograms to quantify the Li7P3S11, Li3PS4, and Li4P2S6 fractions at various temperatures. Sample 1 crystallizes into Li7P3S11 without apparent side phases, whereas Sample 2 comprises 11% Li3PS4 and 2% Li4P2S6 even at 300 °C, which can degrade its ion-transport properties. (30−33) The diffraction profiles did not show a significant difference in the peaks of the Li7P3S11 phase (Figure S3). Differential thermal analysis (DTA) confirmed the difference in the crystallization processes (Figure S4). While a sharp exothermic signal was observed in Sample 1, a broad signal with two distinct peaks was seen in Sample 2. This trend was reproducible even for the same samples in different batches, indicating the local inhomogeneity of the anion blocks in the original glass states, as revealed in the NMR data.Figure 2Figure 2. SXRD data of the powders heated at 60 °C/min under a N2 flow and phase ratios from Rietveld refinement of (a) Sample 1 and (b) Sample 2.High Resolution ImageDownload MS PowerPoint SlideA distinctly different crystallization process induced by local structural differences leads to variations in the properties of the resulting crystalline Li7P3S11 phases. Figure S5 shows the 31P NMR spectra of the two samples after crystallization. While the quantification of local units is challenging with the spectra from the heat-treated samples due to the appearance of the cross peaks in Sample 1, the qualitative difference is clearly observed. It should be noted that such cross peaks associated with P2S74– and PS43– are commonly observed in well-crystalline Li7P3S11 phases. (34) To further investigate the differences in the crystalline phases of Samples 1 and 2, pair-distribution function (PDF) analysis was performed on Samples 1 and 2. As the data from both samples showed the appearance of long-range ordering only after heating, the two samples were largely similar. However, a slight change in G(r) in short-range order of ∼3.4 Å appeared, depending on the hand-milling processes (Figure S6). The morphologies of Samples 1 and 2 after heating showed no significant differences (Figure S7). Overall, it is evident that the premixing procedure prior to milling severely impacts the resulting structure.The above-mentioned differences led to significant differences in the ion-transport properties of the resulting materials. The powders crystallized at 280–300 °C were pressed into pellets, and their ionic conductivities were measured by temperature-dependent impedance spectroscopy to analyze the Li-ion transport in the samples. Furthermore, the migration barrier of the Li-ion conduction was determined according to the Arrhenius relation:σionT=σ0exp(−Ea/kBT)where T is the absolute temperature, Ea is the activation energy for ion transport, σ0 is the temperature-independent Arrhenius factors, and kB is the Boltzmann constant. The Arrhenius plot reveals the notable difference in the ionic conductivities of Samples 1 and 2 at 25 °C (Figure 3), which are 8.6 × 10–4 and 6.7 × 10–5 S cm–1, respectively. Moreover, the activation energies of Samples 1 (0.27 eV) and 2 (0.37 eV) differ, denoting that a subtle change in the experimental procedure can alter the local structures of glassy phases and the resulting transport properties.Figure 3Figure 3. Arrhenius plots of the temperature and ion conductivity of Samples 1 and 2.High Resolution ImageDownload MS PowerPoint SlideAs another model system to assess the impact of premixing, we employed a newly found halide-based solid electrolyte, NaTaCl6, to further investigate the impact of premixing. The ion-transport properties of NaTaCl6 are reported to significantly vary with its crystallinity. (27) Moreover, the impact of elongated milling time of mechanochemical synthesis on the ion-transport properties has been revealed. (26) In this section, four samples were synthesized, either with or without premixing, and subjected to milling for either 16.5 or 100 h. Figure 4 shows the room-temperature ionic conductivity and activation energies of four samples obtained with different milling times, with or without premixing. The samples without premixing were synthesized via ball-milling; that is, the precursors were directly placed into the ball-mill cup with the milling media. Meanwhile, the samples with premixing were mixed well with a mortar and pestle before ball-milling. Prolonging the milling time from 16.5 to 100 h slightly improved the ionic conductivity. However, more significant improvements in the ionic conductivity were achieved by premixing the precursors well, whereas there is no significant difference in their XRD patterns. Notably, milling for 100 h was insufficient to achieve the same level of ion transport as that of the sample subjected to premixing. These results highlight the importance of the premixing step.Figure 4Figure 4. Ionic conductivity and activation energies of mechanochemically synthesized NaTaCl6 samples under different conditions. Each sample was synthesized three times, and the error bars are the standard deviations from the three batches of samples.High Resolution ImageDownload MS PowerPoint SlideLi7P3S11 and NaTaCl6 syntheses highlight the crucial effect of the hand-mixing step before mechanical milling on the local structure, crystallization temperature, and ionic conductivity. Although further accumulation of experimental evidence is necessary to precisely elucidate the underlying mechanisms, the current findings are as follows:(1)Significant variations in the fractions of the local units, indicating the local inhomogeneity, were observed without the implementation of the premixing step. These localized compositional variations can lead to diverse anionic blocks during the subsequent crystallization processes, which, in turn, alters the structure and properties of the products.(2)In the case of NaTaCl6, extended ball-milling durations did not eliminate localized compositional variations, as inferred from the limited conductivity improvement when the ball-milling time was increased from 16.5 to 100 h. Meanwhile, the resulting ion transport was greatly improved by the introduction of a short premixing step before mechanochemical synthesis. While the impact of extended milling may vary with the chemical and mechanical properties of the precursors, the premixing procedure helps to reduce the synthesis time to obtain the target phases.(3)Differential adhesion to the milling media was proposed as a potential cause of compositional inhomogeneity. Ball-milling homogenized mixed precursors when they were trapped between the milling media or between the media and the inner wall of the cup. This process formed powders with layered structures of various compositions. Such a reaction was promoted by mechanical mixing as the interlayer distance decreased, reducing the diffusion length required to form the target phase. However, when a heterogeneous precursor mixture was introduced into the milling cup, softer materials tended to adhere to the milling medium first. Consequently, we hypothesized that this formed thick layers with a constant diffusion length, leading to pronounced local compositional variations. Mechanical properties of starting materials and final products can be critical for proceeding the reactions. (35)As significant variation in the seemingly reproducible properties─ionic conductivity and cycling performance─is one of the big challenges in the field of solid-state batteries and attracts increasing attention, with the recent reports showcasing the critical issue, (36,37) our findings on the drastic impact of the premixing procedure before the seemingly robust mechanochemical synthesis with ball-milling further highlight the importance of the details in the synthesis conditions.Supporting InformationClick to copy section linkSection link copied!The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acsenergylett.4c02156.Table of the synthesis process of Li7P3S11 and NaTaCl6, characterization details, measurement results (XRD patterns, NMR spectra, DTA curves, PDF and SEM images) of Li7P3S11 (PDF)nz4c02156_si_001.pdf (1.13 MB) Terms & Conditions Most electronic Supporting Information files are available without a subscription to ACS Web Editions. 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Author InformationClick to copy section linkSection link copied!Corresponding AuthorsYuta Fujii - Faculty of Engineering, Hokkaido University, Sapporo 060-8618, Japan; https://orcid.org/0000-0002-8381-4119; Email: [email protected]Saneyuki Ohno - Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan; Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, Japan; https://orcid.org/0000-0001-8192-996X; Email: [email protected]Akira Miura - Faculty of Engineering, Hokkaido University, Sapporo 060-8618, Japan; https://orcid.org/0000-0003-0388-9696; Email: [email protected]AuthorsAbdulkadir Kızılaslan - Esentepe Campus, Metallurgy and Materials Science Department, Sakarya University, Sakarya 54050, TurkeyMustafa Çelik - Esentepe Campus, Metallurgy and Materials Science Department, Sakarya University, Sakarya 54050, Turkey; https://orcid.org/0000-0003-0246-6165Zheng Huang - Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan; Department of Applied Chemistry, Graduate School of Engineering, Kyushu University, Fukuoka 819-0395, JapanChikako Moriyoshi - Graduate School of Science, Hiroshima University, Hiroshima 739-8511, JapanShogo Kawaguchi - Japan Synchrotron Radiation Research Institute (JASRI) SPring-8, Hyogo 679-5198, JapanSatoshi Hiroi - Faculty of Materials for Energy, Shimane University, Matsue 690-8504, Japan; https://orcid.org/0000-0001-5058-6757Koji Ohara - Faculty of Materials for Energy, Shimane University, Matsue 690-8504, JapanMariko Ando - Graduate School of Engineering, Tohoku University, Sendai 980-8579, JapanKiyoharu Tadanaga - Faculty of Engineering, Hokkaido University, Sapporo 060-8618, Japan; https://orcid.org/0000-0002-3319-4353NotesViews expressed in this Viewpoint are those of the authors and not necessarily the views of the ACS.The authors declare no competing financial interest.AcknowledgmentsClick to copy section linkSection link copied!A. Miura is grateful to Ms. Masae Sawamoto for preparing the powder capillaries for the SXRD measurements. The authors are grateful to Mr. Yuki Chiba at Tohoku University for his support with the solid-state MAS NMR measurements. S.O. gratefully acknowledges Toyota Riken for its financial support through the Rising Fellows Program. This study was partially supported by JST PRESTO JPMJPR21Q8, JST Gtex JPMJGX23S5, and JPMJGX23S2.ReferencesClick to copy section linkSection link copied! This article references 37 other publications. 1Ohno, S.; Banik, A.; Dewald, G. F.; Kraft, M. A.; Krauskopf, T.; Minafra, N.; Till, P.; Weiss, M.; Zeier, W. G. Materials Design of Ionic Conductors for Solid State Batteries. Prog. Energy 2020, 2 (2), 022001, DOI: 10.1088/2516-1083/ab73dd Google ScholarThere is no corresponding record for this reference.2Kudu, Ö. U.; Famprikis, T.; Fleutot, B.; Braida, M.-D.; Le Mercier, T.; Islam, M. S.; Masquelier, C. A Review of Structural Properties and Synthesis Methods of Solid Electrolyte Materials in the Li2S - P2S5 Binary System. J. Power Sources 2018, 407, 31– 43, DOI: 10.1016/j.jpowsour.2018.10.037 Google Scholar2A review of structural properties and synthesis methods of solid electrolyte materials in the Li2S - P2S5 binary systemKudu, Omer Ulas; Famprikis, Theodosios; Fleutot, Benoit; Braida, Marc-David; Le Mercier, Thierry; Islam, M. Saiful; Masquelier, ChristianJournal of Power Sources (2018), 407 (), 31-43CODEN: JPSODZ; ISSN:0378-7753. (Elsevier B.V.) All-solid-state-batteries (ASSBs) are one of the most promising post-lithium-ion technologies that can increase the specific energy d. and safety of secondary lithium batteries. Solid sulfide electrolytes are considered as promising candidates to be used in ASSBs owing to high ionic conductivities. In particular, solid electrolytes in the Li2S - P2S5 binary system have attracted considerable attention as they are composed of low-cost elements and they provide ionic cond. values comparable to those of liq. electrolytes (>10-4 Scm-1). In this review, the structural properties and synthesis methods of materials in the binary system are summarized. Distinctions in local structures and Li-ion conduction properties between glassy, glass-ceramic, and cryst. materials are highlighted. Possible mechanisms are proposed for the fast ionic conduction obsd. in glass-ceramics. Important parameters of each synthesis method are suggested and the relationships between structure, synthesis and material properties are discussed. The goals of this review are to provide greater understanding of the state-of-the-art in the field, and to point out the overlooked aspects for application. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC1cXhvFOnurrM&md5=117b2ab7d8890ed93e7062b1dab8b80f3Wenzel, S.; Weber, D. A.; Leichtweiss, T.; Busche, M. R.; Sann, J.; Janek, J. Interphase Formation and Degradation of Charge Transfer Kinetics between a Lithium Metal Anode and Highly Crystalline Li7P3S11 Solid Electrolyte. Solid State Ion. 2016, 286, 24– 33, DOI: 10.1016/j.ssi.2015.11.034 Google Scholar3Interphase formation and degradation of charge transfer kinetics between a lithium metal anode and highly crystalline Li7P3S11 solid electrolyteWenzel, Sebastian; Weber, Dominik A.; Leichtweiss, Thomas; Busche, Martin R.; Sann, Joachim; Janek, JuergenSolid State Ionics (2016), 286 (), 24-33CODEN: SSIOD3; ISSN:0167-2738. (Elsevier B.V.) The properties of the interface between solid electrolytes and electrode materials are of vital importance for the performance of all solid-state batteries (ASSB). Unwanted reactions between alkali metal electrodes and the solid electrolyte can lead to the formation of compds. that either facilitate or block the ion transfer kinetics. In particular for lithium solid electrolytes in the Li2S-P2S5 system with very high lithium ion cond. only little is known about interfacial reactions with lithium metal. Here we monitor the formation of an interphase between Li7P3S11 and lithium metal by a combined anal. approach, comprising in situ photoelectron spectroscopy and time-dependent electrochem. impedance spectroscopy. Utilizing a self-developed XPS peak fit model for Li7P3S11, we identify the components of this interphase, discuss its properties and develop a qual. model, which shows that the reaction between electrolyte and lithium metal, and hence, the interphase growth, is limited to a few nm. The solid electrolyte being used is a highly cryst. form of the superionic conductor Li7P3S11 without any residual glassy phase, and the synthesis of this Li7P3S11 phase is also reported. >> More from SciFinder ®https://chemport.cas.org/services/resolver?origin=ACS&resolution=options&coi=1%3ACAS%3A528%3ADC%252BC2MXitVemt7vI&md5=fd9bb0e2020efbbb61525a2be08359c04Yamane, H.; Shibata, M.; Shimane, Y.; Junke, T.; Seino, Y.; Adams, S.; Minami, K.; Hayashi, A.; Tatsumisago, M. Crystal Structure of a Superionic Conductor, Li7P3S11. Solid State Ion. 2007, 178 (15–18), 1163– 1167, DOI: 10.1016/j.ssi.2007.05.020 Google ScholarThere is no corresponding record for this reference.5Phuc, N. H. H.; Totani, M.; Morikawa, K.; Muto, H.; Matsuda, A. Preparation of Li3PS4 Solid Electrolyte Using Ethyl Acetate as Synthetic Medium. Solid State Ion. 2016, 288, 240– 243, DOI: 10.1016/j.ssi.2015.11.032 Google Scholar5Preparation of Li3PS4 solid ele