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[Naoto Tanibata](https://orcid.org/0000-0001-8521-9690), Naoki Nonaka, Daisuke Urushihara, Hayami Takeda, Ryo Kobayashi, [Naoaki Kuwata](https://orcid.org/0000-0002-0736-6967), Masanobu Nakayama

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[High‐Throughput Screening and Characterization of Non‐Flammable Na‐Cl Solid Electrolytes](https://mdr.nims.go.jp/datasets/adc04082-164c-4657-bc41-47f0350b4e40)

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High‐Throughput Screening and Characterization of Non‐Flammable Na‐Cl Solid ElectrolytesAdvanced Electronic Materials www.advelectronicmat.deRESEARCH ARTICLEHigh-Throughput Screening and Characterization of Non-Flammable Na-Cl Solid Electrolytes Naoto Tanibata1 Naoki Nonaka1 Daisuke Urushihara1 Hayami Takeda1 Ryo Kobayashi2 Naoaki Kuwata3 Masanobu Nakayama1 1 Department of Advanced Ceramics, Nagoya Institute of Technology, Nagoya, Aichi, Japan 2 Department of Applied Physics, Nagoya Institute of Technology, Nagoya, Aichi, Japan 3 Research Center for Energy and Environmental Materials (GREEN), National Institute for Materials Science (NIMS), Tsukuba, Ibaraki, Japan Correspondence: Naoto Tanibata ( tanibata.naoto@nitech.ac.jp) Received: 1 October 2025 Revised: 15 December 2025 Accepted: 7 January 2026 Keywords: all-solid-state batteries | chloride solid electrolytes | ignition temperature | sodium-ion conductivity ABSTRACT Non-flammable solid electrolytes are key materials in all-solid-state batteries. Chloride solid electrolytes exhibit high ionic conductivities derived from weak Coulomb interactions with carrier ions. However, not all chlorides are stable, and a limited number of Na-Cl-based materials exhibit ionic conductivities above 10− 4 S cm− 1 . Herein, the ionic conductivities of Na-Cl compounds in a structural database (Materials Project) are comprehensively calculated through force field molecular dynamics and density functional theory calculations. The results predict that Na3 La5 Cl18 (mp-1173723) is thermodynamically stable with a high ionic conductivity (1.5 × 10− 2 S cm− 1 ) at 298 K. Moreover, the 1D conduction pathway along the c -axis of Na3 La5 Cl18 is confirmed. Nuclear magnetic resonance measurements confirm the high ionic conductivity ( > 10− 4 S cm− 1 at 298 K) of synthesized Na3 La5 Cl18 . Analysis of characterization results reveals that the ionic conductivity of Na3 La5 Cl18 can be further improved by suppressing La mixing in the 1D conduction pathway, while impedance measurements and relaxation time analysis show that conductivity is enhanced by reducing the large crystallite grain boundary resistance. Na3 La5 Cl18 has a higher ignition temperature ( > 800◦C) compared to the sulfide electrolyte Na3 PS4 ( ∼ 300◦C). The results of this study enable the realization of ASSBs with improved safety.                    1 Introduction The development of high-performance storage batteries witha low environmental impact is required to solve energy andenvironmental problems [ 1 ]. All-solid-state Li batteries usingnonflammable solid electrolytes have gained attention in recentyears because of their potential for high safety operation andhigh energy density [ 2 ]. All-solid-state Na batteries, in which Liis replaced by the chemically similar and more abundant Na,can reduce the risk associated with resources such as Li [ 3 ]. Torealize Na-based all-solid-state batteries, a solid electrolyte withhigh Na-ion conductivity is essential [ 4 ]. In addition to high ionicThis is an open access article under the terms of the Creative Commons Attribution License, which permcited. © 2026 The Author(s). Advanced Electronic Materials published by Wiley-VCH GmbH Advanced Electronic Materials , 2026; 12:e00688 https://doi.org/10.1002/aelm.202500688conductivity, solid electrolytes must exhibit high deformability and a wide potential window. Conventional oxide materialshave low deformability, and the fabrication of all-solid-statebatteries, where charge–discharge reactions occur at the solid-solid interface, generally involves sintering at high temperatures[ 5 ]. The sintering process can cause the volatilization of theconstituent elements and induce side reactions between the electrode and electrolyte. These limitations significantly restrict the number of suitable materials [ 6 ]. In Li systems, chlorideelectrolytes that satisfy all these properties have been recentlyreported and explored [ 7 ]. Chloride systems are expected toexhibit high ionic conductivity and deformability due to the highits use, distribution and reproduction in any medium, provided the original work is properly 1 of 9http://www.advelectronicmat.dehttps://doi.org/10.1002/aelm.202500688https://orcid.org/0000-0001-8521-9690mailto:tanibata.naoto@nitech.ac.jphttp://creativecommons.org/licenses/by/4.0/https://doi.org/10.1002/aelm.202500688http://crossmark.crossref.org/dialog/?doi=10.1002%2Faelm.202500688&domain=pdf&date_stamp=2026-01-21FIGURE 1 (a) Comprehensive calculation results of three parameters (Na ion conductivity σ at 298 K, energy above hull, and shear modulus) for Na-Cl materials in the structure database (Materials Project). Materials in which Na did not diffuse during molecular dynamic calculations are plotted as having a low ionic conductivity with σ= 10− 10 S cm− 1 as the lower limit. (b) Trajectory of Na ions during molecular dynamic calculations for Na3 La5 Cl18 , which is suggested to be a high ionic conductor.                                                            2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativepolarization and low charge density of chloride ions, which resultin low interactions with counter cations. However, not all chlo-ride materials exhibit high ionic conductivity and deformability,and the Na-Cl systems that have been investigated so far haveconductivities that are lower than those of Li-Cl systems. Roomtemperature ionic conductivities above 10− 4 S cm− 1 have beenreported for Li-Cl-based crystals [ 8 ], while Na-Cl-based crystalshave room temperature ionic conductivities below 1 × 10− 4 S cm− 1 .Specifically, the ionic conductivities are 3.9 × 10− 6 S cm− 1 forNaAlCl4 [ 9 ]; 1.8 × 10− 5 S cm− 1 for Na2 ZrCl6 [ 10 ]; 6.6 × 10− 5 S cm− 1 for Na2.25 Y0.25 Zr0.75 Cl6 [ 11 ]; 6.2 × 10− 5 S cm− 1 for NaTaCl6 [ 12 ]; and1 × 10− 4 S cm− 1 for Na1.1 Ta0.9 Zr0.1 Cl6 [ 13 ]. In this study, promising Na-Cl-based ionic conductors wereexhaustively explored through the computational screening ofcompounds in a structural database (Materials Project) [ 14 ]. Theionic conductivity of the electrolyte was determined throughmolecular dynamics using a high-throughput force field (FF) [ 15 ],in which the FF parameter sets were derived from short densityfunctional theory-molecular dynamics (DFT-MD) simulations(2 ps simulation time). It has been established that the shearmodulus is a good indicator of deformability in Li systems,which was also observed in the present study using densityfunctional perturbation theory [ 16 ]. Furthermore, to increasesynthesizability, we also considered the energy above the hull(the energetic distance above the convex hull, which is formed bythe energetically lowest states) in the Materials Project databaseand selected materials for experimental investigation. Then, theflammability of the selected Na-Cl electrolyte, which is onefactor that significantly influences the safety of the all-solid-statebatteries, is evaluated by ignition and flash tests. 2 Results and Discussion The computational screening results for the NaCl compounds areshown in Figure 1a . While Na does not diffuse in many materials2 of 9(plotted at σ = 10− 10 S cm− 1 as the lower limit), Na3 La5 Cl18 (mp-1173723) showed a high ionic conductivity (1.5 × 10− 2 S cm− 1 ) at298 K, which is comparable to that of organic liquid electrolytes.The shear modulus is relatively large (16 GPa) in the NaCl system,suggesting that low deformability with a large grain boundaryresistance may be an issue. Na3 La5 Cl18 is of interest in this studybecause it also has a relatively small energy above the hull(0.0091 eV atom− 1 ), which indicates that it is thermodynamicallystable. Information on the other materials is summarized in TableS1 . Na3 La5 Cl18 has a LaCl8 polyhedron that forms a 1D tunnellingpillar structure with Na ions in the tunnel and pillar. High-precision first-principles DFT-MD calculations were performed on this material at 900 K. The mean square distance (MSD)values of the DFT-MD calculations are shown in Figure S1a ,where only Na was diffused. In addition, the MSD profiles of Naions decomposed into the a -, b -, and c -axis components (FigureS1b ) and Na trajectory during molecular dynamics calculations(Figure S1c–e ) indicates a clear 1D conduction path along the c -axis, similar to the trajectory of Na during molecular dynamicscalculations using the high-throughput screening force field, as shown in Figure 1b . Na3 La5 Cl18 was calculated to have a low decomposition energy and was synthesized through a solid-state reaction following previous reports [ 17 ]. Powder X-ray diffraction (XRD) patterns(Figure 2 ) show that the raw material peaks disappeared anda single phase of monoclinic Na3 La5 Cl18 was obtained. The Rietveld analysis results based on Inorganic Crystal StructureDatabase (ICSD) structures (ICSD No. 74923, S.G .: P 63 / m ) [ 20 ]are presented in Figure 2 and Table 1 . In the optimized andvalidated structure ( Rwp = 5.34%, RB = 7.73%, RF = 3.92%, S= 1.34), the La atom, which was supposed to be at the 2 dsite, was found at the 2 b site of the Na+ conduction pathwayby approximately 4%. The structure was also found to containapproximately 10% less Na at the 2 b sites and 10% more Naat the 2 d La sites. These results suggest that some cationmixing occurred between Na+ and La3 + with close ionic radii Advanced Electronic Materials, 2026 Commons LicenseFIGURE 2 (a) Rietveld refinement XRD pattern for the synthesized Na3 La5 Cl18 particles. (b) Adapted crystal structure model. TABLE 1 Structural parameters after Rietveld refinement. Atom Site g x y z B ( Å2 ) Na1 2 b 0.300(-) 0 0 0 1.0 Na2 2 d 0.200(-) 2/3 1/3 1/4 1.0 La1 2 d 0.800(3) 2/3 1/3 1/4 1.0 La2 2 b 0.033(-) 0 0 0 1.0 Cl1 6 h 1 0.0832(4) 0.3850(5) 1/4 1.0 S.G .: P 63 / m (176). Lattice parameter ( Å ): a = 7.571(2), c = 4.3540(7). Reliability factors: Rwp = 5.34, RB = 7.73, RF = 3.92, S = 1.34.                                                        2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativ(Na+ : 1.02 nm; 6-coordination, La3 + : 1.03 nm; 6-coordination)[ 18 ]. The analysis results for the compacted Na3 La5 Cl18 samples areshown in Figure 3 . The AC impedance plot (Figure 3a ) showsa large semicircle and a spike. As the spike was assumed tooriginate from the ion-blocking electrode, the ionic conductivitywas calculated from the size of the semicircle ( Rtotal ) in thediagram. The calculated ionic conductivity (5.5 × 10− 8 S cm− 1 )is much lower than the value suggested by the MD calculation(1 × 10− 2 S cm− 1 ). To investigate the resistive component inmore detail, a relaxation time distribution (DRT) analysis [ 19,20 ] was performed on the impedance spectrum. In the DRTspectrum (Figure 3b ), two resistive components (DE1 and DE2),consisting of resistance R and time constant T , were detectedin addition to resistance R0 at the intersection with the realaxis. Therefore, the fitting was performed using the equivalentcircuit shown in the inset. R0 is a reference value that wasfixed at an intermediate stage of the fitting procedure, becausethe solution did not converge when R0 was fitted simultane-ously with the other resistance components. To determine theresistive components, the capacitance C was calculated usingEquation ( 1 ). 𝐶 = 𝐷𝐸 − 𝑇 𝐷𝐸 − 𝑅 (1)Advanced Electronic Materials, 2026where DE- T and DE- R are the relaxation time and resistanceof the DE component, respectively. Information on the resistivecomponents is presented in Table 2 . The capacitance of DE1,which has a higher resistance, is 2.3 × 10− 10 F, whereas thecapacitance of DE2 is 7.6 × 10− 9 F. The capacitance within thebulk crystallite is approximately 10− 12 F, based on the dielectricconstants of common materials [ 21 ]. Furthermore, it is knownfrom the brickwork model that the capacitance at the grainboundaries is proportional to the size of the crystallites, andincreases from the capacitance in the crystallite bulk in the ratioof the crystallite size to the thickness of the grain boundary(approximately 10− 10 m) [ 21 ]. The crystallite size was calculatedusing the Halder–Wagner method (91 nm), and the capacitanceof the crystallite grain boundary ( Ccb ), approximated usingthe Brickwork model, was 10− 10 F, which corresponds to thecapacitance of the first resistive component, DE1. This indicatesthat DE1 is mainly derived from the crystallite grain boundary.The same concept can also be applied to the capacitance ofthe particle grain boundary resistance, which is assumed to belarger than the crystallite bulk capacitance based on the ratio ofthe particle size to the grain boundary thickness. The particlegrain boundary capacitance (10− 8 F) estimated from the particle size (several micrometers) observed in the scanning electron microscopy (SEM) image of the Na3 La5 Cl18 powder (Figure S2 )is close to the capacitance of the second resistive componentDE2 (7.6 × 10− 9 F). Therefore, the second resistive component isderived mainly from the particle–grain boundary resistance. The crystallite grain boundary resistance accounted for a significant proportion (84%) of this resistance. One of the factors responsiblefor this large grain-boundary resistance may be the influence of1D conduction, as suggested by computational chemistry. The percentage of particle grain boundary resistance to the total grainboundary resistance (where the latter is defined as the sum ofthe crystallite grain boundary resistance and the particle grainboundary resistance), which is also an indicator of the deforma-bility of the particles, is 16%. To investigate the deformabilityof the particles, SEM observations of the fractured surfaces ofthe compacted Na3 La5 Cl18 were performed (Figure 3c ), revealing many voids between the particles. In addition, the relative density,calculated from the apparent density of the compacted Na3 La5 Cl18 powder, and the crystal lattice density of hexagonal Na3 La5 Cl18 3 of 9e Commons LicenseFIGURE 3 Analytical results for the pressed Na3 La5 Cl18 powder. (a) AC impedance plot. (b) DRT spectrum. The inset shows the proposed equivalent circuit model and a pie chart of the resistive component fraction after fitting. Rbulk , Rcgb , and Rpgb correspond to the resistance of the crystalline bulk, crystallite grain boundary, and particle grain boundary, respectively. (c) Fracture surface SEM image of the compacted Na3 La5 Cl18 pellet. To reduce charge-up, 10 wt.% Ketjen black was hand mixed. TABLE 2 Resistivity analysis results for the Na3 La5 Cl18 pellet. The resistance and capacitance obtained from equivalent circuit fitting and the resistance components are listed. R0 is a reference value that was fixed during the fitting process because it diverged when fitted simultaneously with the parameters of the other resistance components. Symbol Resistance / Ω Capacitance / F Resistance component R0 (585.4) ― Crystalline bulk resistance Rbulk R1 9.6 × 105 2.3 × 10− 10 Crystallite grain boundary resistance Rcgb R2 1.8 × 105 7.6 × 10− 9 Particle grain boundary resistance Rpgb                                             2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativ(3.54 g cm− 3 ) is low (77%). However, necks formed between thegrains, which may explain the relatively low grain boundary resis-tance. These deformability values (relative density and particleresistance ratio) are consistent with the relationship between theshear modulus and deformability suggested for the Li system, asshown in Figure S2 . Therefore, the relationship between the shearmodulus and deformability of the Li system may be applicable tothe Na system. Because this material is prone to developing strongtexturing due to its tunnel-type structure, press treatments underhigh-temperature or high-pressure conditions are not necessarilyappropriate. Nevertheless, we believe that systematically exam-ining these processing conditions in future studies will furtherdeepen the above discussion on the separation of grain-boundaryresistances. The ionic conductivity of the crystallite bulk is calculated to be1.5 × 10− 4 S cm− 1 from the resistance of R0 . To confirm this ionicconductivity, 23Na-NMR measurements were also performed. Inthe 23Na-NMR spectrum shown in Figure 4a , a peak with ashoulder was observed with a chemical shift around -15 ppm. Peakseparation of this peak using the forked function revealed a largepeak on the high field side (signal 1) and a small peak on the lowfield side (signal 2). There are two Na sites in Na3 La5 Cl18 , 2 b and2 d , and that their site ratio is 2 b : 2 d = 2 : 1. From this, signal 1with a high integrated intensity was attributed to Na at the 2 b siteand signal 2 with a low integrated intensity was attributed to Naat the 2 d site. The integrated intensities for these two peaks wascalculated to be 53 : 47 for signal 1 and signal 2, indicating that theproportion of La mixing with Na sites in the Na+ conduction path-way is similar (~7.8%) to that of the Rietveld analysis (~6.0%). The4 of 9etemperature dependences of the half-widths of the 23 Na-NMR spectra are shown in Figure S4 , indicating a conductor-specificmotional narrowing. Motional narrowing is known to occur innon-diffusing atoms because of the diffusing atoms [ 22 ], and thehalf-width of the nonconducting site at site 2 d is assumed to bereduced by the diffusion of Na at site 2 b , which is diffused in theMD calculations shown in Figure 2 . If the half-width is ΔW , theactivation energy of ionic conduction, Ea , can be determined byEquation ( 2 ) [ 23 ]: Δ𝑊0 = 𝐴𝑒𝑥 𝑝( 𝐸𝑎 𝑘 𝑇 ) + Δ𝑊 (2) where k is the Boltzmann’s constant, A is a constant in the pre-exponential factor, and ∆W0 is the width at half-maximum at303 K. Consequently, the diffusion activation energy of the 2 bsite on the conduction path was as low as 0.30 eV. The ionicconductivity was then determined by measuring the spin-lattice relaxation time T1 for the conduction-site-derived signal 1. T1 was measured at each temperature using the saturation recoverymethod described in Equation ( 3 ) [ 24 ]. 𝑀𝑧 ( 𝜏) = 𝑀0 { 1 − exp ( − 𝜏𝑇1 ) } (3) where Mz ( τ) is the nuclear magnetization in the same directionas the external magnetic field and τ is the saturation recoverytime. The inverse of the spin-lattice relaxation time T1 − 1 shown inAdvanced Electronic Materials, 2026 Commons LicenseFIGURE 4 23 Na-MAS NMR measurements. (a) NMR spectra. (b) Temperature dependence of the spin-lattice relaxation time T1 − 1 . (c) Arrhenius plot of ionic conductivity obtained from the spin-lattice relaxation time.                                                           3 4  2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable CreativeFigure 4b reaches a maximum in its temperature dependence atT = 383 K. The molecular correlation time, τc , can be calculatedusing Equation ( 4 ) from the Bloembergen-Purcell-Pound (BPP)theory [ 25, 26 ], which explains the contribution of T1 − 1 to iondynamics. 1 𝑇1 = 𝐶( 𝜏𝑐 1 + 𝜔2 0 𝜏2 𝑐 +4𝜏𝑐 1 + 4 𝜔2 0 𝜏2 𝑐 ) (4)where ω0 is the frequency of the external magnetic field, and C is aconstant that depends on the relaxation mechanism; τc = 0.616/ ω0 holds at the maximum value of T1 − 1 , so that T1 and τc have a one-to-one relationship. The τc obtained here can be converted intothe self-diffusion coefficient D using the Einstein–Smolkowskiequation [ 27 ] expressed in Equation ( 5 ). 𝐷 = 𝑙2 2 𝑑𝜏𝑐 (5)where l is the jump distance, and d is the diffusion dimension.In this case, l is the distance between the conduction sites (2 bsites) of the crystal structure, and d is calculated to be 1 becausethe material is a 1D conductor. The Nernst–Einstein equation,expressed in Equation ( 6 ), calculates the ionic conductivity σ fromthe diffusion coefficient D . 𝜎𝑇 = 𝑧2 𝐹2 𝑐 𝑅 𝐷 (6)where z is the ionic valence, F is the Faraday constant, c is thedensity of the carrier Na at the 1D conduction site, R is the gasconstant, and T is the absolute temperature. An Arrhenius plot ofthe ionic conductivity obtained from the spin-lattice relaxationtime shown in Figure 4c gives an ionic conductivity of 2.9 ×10− 4 S cm− 1 at 298 K and an activation energy of 0.27 eV. Thisactivation energy is in close agreement with the value obtainedfrom the motional narrowing (0.30 eV). This ionic conductivity iscomparable to the bulk conductivity (1.5 × 10− 4 S cm− 1 ) calculatedfrom the bulk resistance obtained by impedance measurements,supporting that the bulk resistance value fixed during the fittingprocedure does not significantly affect the above discussionon grain-boundary resistance. Therefore, we conclude that theprimary reason why the ionic conductivity of the pellet estimatedAdvanced Electronic Materials, 2026from impedance measurements is several orders of magnitude lower than that obtained from MD calculations and NMR mea-surements is the extremely large grain-boundary resistance. Note that the influence of differences arising from the measurementtechniques, such as the Haven ratio [ 28 ], is considered to benegligible compared with the more than four orders of magnitudedifference observed in this study. On the other hand, the ionicconductivity value is relatively high in the Na-Cl system; however,it was still lower than the ionic conductivity (10− 2 S cm− 1 )obtained from the MD simulations. This can be attributed to thefact that the conduction of Na ions occurs in one dimension. Inthe case of 1D conduction, in addition to a larger grain boundaryresistance owing to the anisotropy of conduction, defects such asthose suggested by NMR spectroscopy and Rietveld analysis blockthe conduction pathways and significantly reduce conductivity. A semi-quantitative discussion of the effects of blocking defectson 1D conduction [ 29 ] is provided below. In the present material,Rietveld refinement reveals that approximately 3.3% of the Na+ conduction sites (2 b ) are occupied by immobile multivalent La3 + ions. The average crystallite size is 91 nm, and considering ac -axis lattice parameter of 4.3540 Å and two 2 b sites per unitcell, approximately 418 Na+ conduction sites are estimated to be continuously aligned along a single 1D conduction channel.With 3.3% of these sites blocked by La3 + , each 1D conductionchannel is estimated to contain, on average, approximately 13.8La3 + -induced blocking defects randomly distributed along the channel. As a result of this random distribution of more thanten blocking defects, the probability of forming a continuous1D superionic conduction pathway over long distances becomes extremely low, and the conduction pathway is effectively frag-mented into short segments. Consequently, in contrast to the localsuperionic diffusion behavior predicted by MD simulations for anideal, defect-free structure, the ionic conductivity experimentally observed in real materials is thought to be strongly limited by suchpathway fragmentation. Therefore, in future studies, synthesis with the suppression of defect formation and an increase in con-duction pathways by elemental substitution will be performed, and the superionic conductivity suggested by MD simulationswill be measured. Finally, the flammability of the chloride electrolyte, which deter-mines the safety of all-solid-state batteries, was evaluated andcompared to that of a typical sulfide solid electrolyte (Na PS5 of 9 Commons LicenseFIGURE 5 Ignition test results. Photograph of (a) Na3 PS4 powder in contact with a heat source at 300◦C and (b) Na3 La5 Cl18 powder in contact with a heat source at 800◦C. XRD patterns before and after the ignition test for (c) Na3 PS4 powder and (d) Na3 La5 Cl18 powder. (e) Elemental ratios determined by EDS of Na3 PS4 and Na3 La5 Cl18 powders before and after the ignition test.                            2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativglass-ceramic). As shown in Figure 5a,b , Na3 La5 Cl18 does notignite even when in contact with a heat source at 800◦C, whereasNa3 PS4 ignites when the heat source temperature is 300◦C.Elemental analysis using energy dispersive X-ray spectroscopy(EDS) before and after the ignition test (Figure 5e ) reveals thatthe ignition test reduced the flammable S component in Na3 PS4 but not the Cl component in Na3 La5 Cl18 . Moreover, in the XRDpatterns shown in Figure 5c,d , for MnO2 (the electrode activematerial in the charged state), it can be observed that in Na3 PS4 the MnO2 peak disappears because of the ignition test and theformation of a reduced Mn compound (MnS), while in Na3 La5 Cl18 the MnO2 peak was maintained at 400◦C and 800◦C. The flashtest also confirmed that Na3 PS4 exhibits the flash phenomenonat 200◦C, whereas Na3 La5 Cl18 did not ignite, at least up to 300◦C.These results show that chloride-based solid electrolytes are notflammable, ensuring the safety of all-solid-state batteries. Infuture studies, evaluations at higher temperatures, as well assafety comparisons with oxide-based and other chloride-basedelectrolytes, will be investigated. 6 of 93 Conclusions Among solid electrolytes, Na-Cl compounds are expected to havehigh-performance properties (such as high ionic conductivity, high deformability, and high oxidation potential), making them excellent materials for the next generation of Na-based all-solid-state sodium batteries; however, material exploration is stilllimited. In this study, computational screening was performed forNa-Cl compounds, which suggested the existence of Na3 La5 Cl18 with a 1D path of super-ionic conduction ( σ25 > 10− 2 S cm− 1 )at 298 K. 23 Na-NMR spectroscopy of the as-synthesized sample showed a bulk Na ionic conductivity above 10− 4 S cm− 1 atroom temperature. This ionic conductivity is high, reported forthe Na-Cl system; however, it is lower than the theoreticalconductivity determined by molecular dynamics calculations. A possible reason for this is the presence of dilute amountsof La cations in the 1D conduction pathway, as confirmedby NMR spectroscopy and Rietveld analysis. Therefore, higher ionic conductivities can be expected in the future by optimizingAdvanced Electronic Materials, 2026e Commons License                                                                             2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativsynthesis methods and elemental substitutions. The crystallinegrain boundary resistance suggested by impedance measure-ments and DRT analysis is also expected to improve by enhancingthe fabrication conditions and multi-dimensionalization of theconduction pathways. Finally, the chloride electrolyte has ahigher ignition temperature than the sulfide electrolyte, indi-cating that it is an excellent solid electrolyte for realizingnonflammable all-solid-state batteries. In future work, compre-hensive battery-level performance evaluations will be consideredonce improvements in the ionic conductivity of the pelletizedsamples are confirmed. 4 Experimental Section 4.1 Computational Screening for Na-Cl Solid Electrolytes A total of 86 compounds containing Na–Cl listed in the crystalstructure database (Materials Project) [ 14 ] were examined. The Nadiffusion coefficients were calculated through molecular dynam-ics simulations using a high-throughput force field (FF-MD) asdescribed in a previous study [ 15 ]. Force-field parameters weredetermined using a metaheuristic algorithm (Cuckoo search)[ 30 ] with a density functional theory-molecular dynamics (DFT-MD) dataset. DFT MD simulations were performed at 900 Kfor 1 ps (1 fs per step). The kinetic energy cut-off was set at350 eV. Owing to the limited computational resources, 1 × 1× 1 k -point sampling was performed. The energy convergencecriterion was set to 10− 3 eV. Specifically, classical force fieldparameters were optimized using the Cuckoo search algorithmso as to reproduce structural descriptors obtained from DFT-MD and FF-MD simulations, including the radial distributionfunction (RDF), angular distribution function (ADF), and latticeparameters. The force field (FF) model employed in this studyconsists of two-body and three-body potential terms. The two-body potential U ( rij ), defined by the interatomic distance rij between particles i and j , is similar to a Bond Valence Sum–basedforce field (BVS-FF) and is composed of two terms, as shown inEquation ( 7 ). 𝑈(𝑟𝑖𝑗 )= 1 4 𝜋𝜖0 𝑞𝑖 𝑞𝑗 𝑟𝑖𝑗 erf c ( 𝑟𝑖𝑗 𝜌𝑖𝑗 ) + 𝐷𝑒 { 𝑒 𝑥𝑝 [ − 2 𝛼 ( 𝑟 − 𝑅𝑒 ) ] − 2 𝑒 𝑥𝑝 [ − 𝛼 ( 𝑟 − 𝑅𝑒 ) ] } (7)The first term represents interactions between like-chargedspecies (anion–anion and cation–cation) and was described bya screened Coulomb potential. The second term accounts forinteractions between oppositely charged species (cation–anion)and was represented by a Morse potential. In the screenedCoulomb potential, the screening effect was described usingthe charges qi and qj together with the error function, and thescreening length ρij is treated as an optimization parameter. Incontrast, for the Morse potential, the equilibrium bond distanceRe , well depth De , and the parameter α, which determines thepotential width, are used as optimization parameters. For thethree-body interactions among particles i , j , and k , the angular-dependent term of the Stillinger–Weber potential (Equation 8 )Advanced Electronic Materials, 2026was employed to account for the effects of bond lengths and bondangles. 𝑈(𝑟𝑖 𝑗 𝑘 )= 𝜆𝑒𝑥𝑝[ ( 1 𝑟𝑖𝑗 − 𝑟𝑐𝑢𝑡( 3 𝑏 ) ) +( 1 𝑟𝑖𝑘 − 𝑟𝑐𝑢𝑡( 3 𝑏 ) ) ] (cos 𝜃𝑖 𝑗 𝑘 − 𝛾)2 (8) here, λ and γwere treated as optimization parameters. To improvecomputational efficiency, the cutoff distance for the three-body interactions, rcut(3 b ) , was fixed at 3.5 Å, while the cutoff distance forthe two-body interactions, rcut(2 b ) , was set to 5.0 Å. The mismatchbetween the RDFs, ADFs, and lattice parameters obtained fromDFT-MD and FF-MD simulations was defined as a loss function,which was minimized during the parameter optimization. The final values of the loss function were summarized in TableS1 . Although no absolute criterion exists for the loss functionvalue, several samples exhibit loss function values exceeding 0.1,suggesting that the reliability of the corresponding FF parameterswas not necessarily high. This may be attributed to limitationsor deviations inherent in the classical force field forms definedin Equations ( 7 ) and ( 8 ). For reference, Figure S5 comparesthe RDFs of all constituent elements obtained from DFT-MDand FF-MD simulations using the optimized parameters. The Na+ conductivities were calculated using the Nernst–Einstein equation from the diffusion coefficient obtained from the slope ofthe MSD in the MD calculation of 298 K using the obtained forcefield. Furthermore, the shear moduli were calculated using theelastic tensors obtained from the DFT calculations [ 31 ]. All forcefield parameter fitting and molecular dynamics (MD) calculations described above were performed using the Nagoya Atomistic- simulation Package (NAP) [ 32, 33 ]. The DFT-based moleculardynamics (DFT-MD) calculations were carried out using the Vienna Ab initio Simulation Package (VASP) [ 34 ]. 4.2 Theoretical Evaluation of Na3 La5 Cl18 Na diffusivity was evaluated using first-principles MD calcula- tions for Na3 La5 Cl18 , which was suggested to be a high-Na-ionconductor using classical force-field calculation screening. In addition, the loss function value for the optimized FF parametersof the Na3 La5 Cl18 material was 0.06, indicating that the structuralfeatures observed in the RDF (Figure S5 ) were reproducedrelatively well. DFT MD simulations were performed at 900 K for1 ns (1 fs per step). The kinetic energy cut-off was set at 350 eV.Owing to the limited computational resources, 1 × 1 × 1 k -pointsampling was performed. The energy convergence criterion was set to 10− 3 eV. 4.3 Synthesis Na3 La5 Cl18 was synthesized from NaCl (Wako Pure Chemical Industries, Ltd., 99.5%) and LaCl3 powders (Thermo Scientific Chemicals, 99.9%) through a solid-state reaction. A mixture ofstoichiometric ratios was placed in a 45 mL stainless steel pot with10 ZrO2 balls (10 mm in diameter) and milled with a planetaryball mill apparatus (Fritsch Japan Co., Ltd., P-7 classic line) at arotation speed of 500 rpm for 4 h. The samples were then pressedinto pellets at 30 kN in a glove box in an Ar atmosphere following7 of 9e Commons License                                                                       2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable Creativethe published ICSD protocol, vacuum sealed in Pyrex tubes, andheated in a tube furnace at 500◦C for two weeks. 4.4 Characterization The Na3 La5 Cl18 powder was identified using XRD (Philips X’pertPro α1). The characteristic X-rays generated by a Cu tube weremonochromatized to K α1 lines using a pre-mounted monochro-mator and measured in a fast scan with a 1D semiconductordetector. The measured voltage and current were 45 kV and40 mA, respectively. The scan step and speed were 0.013◦ and0.57◦ min− 1 , respectively. Samples were placed in airtight holdersand measured in an Ar atmosphere. To perform AC impedancemeasurements, pellets of the prepared powder samples wereprepared. Na3 La5 Cl18 powder was placed in a cylindrical poly-carbonate with a 10 mm inner diameter, sandwiched betweenstainless steel as ion-blocking electrodes, and pressurized to30 kN using a hydraulic press. The AC impedance measure-ments were performed at an applied voltage of 300 mV in afrequency range of 102 –106 Hz; Z-Assist software (TOYO Co.)was used for the DRT analysis. The fractured surfaces of thecompacts were examined using an electron microscope (JSM-6360LV, JEOL, Ltd.) at an acceleration voltage of 10 kV. Toinvestigate the local structure and ion dynamics of the synthe-sized samples on short-range scales, the chemical shifts andspin-lattice relaxation times of 23 Na nuclei were measured inthe temperature range of 298–423 K using an NMR spectrometer(JEOL RESONANCE: ECA600II). The external magnetic fieldwas 14.1 T, and the relaxation time was measured at eightpoints divided by a logarithmic ratio between 0.001 and 2 s.All of the above measurements were performed under an Aratmosphere. 4.5 Ignition Tests An oxidizing agent (MnO2 ) simulating the charged state ofthe cathode was mixed in a mortar with various electrolytes(Na3 La5 Cl18 and Na3 PS4 ) in a weight ratio of 1:1 and broughtinto contact with the heat source, a nichrome wire, for up to60 s. Measurements were performed in air, at a temperature of11◦C and a humidity of 37% (dew point approximately 3◦C). Thenichrome wire was 10 mm thick, and the sample was set atapproximately 0.5 mL. A flash test was also performed accordingto the JIS standards. Acknowledgements This work was partially supported by Grants-in-Aid for ScientificResearch (Grant Numbers 24K01157, 24K17755, 24H02203, and 25H01973)from the Ministry of Education, Culture, Sports, Science, and Technology(MEXT), Japan; a CREST grant from the Japan Science and TechnologyAgency, Japan (Grant Number JPMJCR21O6); and the Data Creationand Utilization-Type Material Research and Development Project (GrantNumber JPMXP1122712807) from MEXT. The authors thank Editage forediting and reviewing the manuscript for the English language. Figuresillustrating the crystal structures were drawn using the Visualization forElectronic Structural Analysis (VESTA) software (National Institute forMaterials Science, Tsukuba, Japan) [ 35 ]. 8 of 9Funding This work was partially supported by Grants-in-Aid for ScientificResearch (Grant Numbers 24K01157, 24K17755, 24H02203, and 25H01973) from the Ministry of Education, Culture, Sports, Science, and Technology(MEXT), Japan; a CREST grant from the Japan Science and TechnologyAgency, Japan (Grant Number JPMJCR21O6); and the Data Creationand Utilization-Type Material Research and Development Project (Grantnumber: JPMXP1122712807) from MEXT. Conflicts of Interest The authors declare no conflicts of interest. Data Availability Statement The data that support the findings of this study are available from thecorresponding author upon reasonable request. References 1 . B. Dunn, H. Kamath, and J.-M. Tarascon, “Electrical Energy Storagefor the Grid: A Battery of Choices,” Science 334 (2011): 928–935, https://doi.org/10.1126/science.1212741 . 2 . J. Janek and W. G. Zeier, A Solid Future For Battery Development (NaturePublishing Group, 2016): 16141. 3 . N. Yabuuchi, K. Kubota, M. Dahbi, and S. Komaba, “Research Develop-ment on Sodium-Ion Batteries,” Chemical Reviews 114 (2014): 11636–11682, https://doi.org/10.1021/cr500192f. 4 . S. Lou, F. Zhang, C. Fu, et al., “Interface Issues and Challenges in All-Solid- State Batteries: Lithium, Sodium, and Beyond,”Advanced Materials33 (2021): 2000721, https://doi.org/10.1002/adma.202000721 . 5 . V. Thangadurai, S. Narayanan, and D. Pinzaru, “Garnet-Type Solid-State Fast Li Ion Conductors For Li Batteries: Critical Review,” ChemicalSociety Reviews 43 (2014): 4714–4727. 6 . S. Wang, Y. Zhang, X. Zhang, et al., “High-Conductivity ArgyroditeLi6 PS5 Cl Solid Electrolytes Prepared via Optimized Sintering Processesfor All-Solid-State Lithium–Sulfur Batteries,” ACS Applied Materials & Interfaces 10 (2018): 42279–42285, https://doi.org/10.1021/acsami.8b15121 . 7 . Y. Nikodimos, W. Su, and B. J. Hwang, “Halide Solid-State Electrolytes:Stability and Application for High Voltage All-Solid-State Li Batteries,”Advanced Energy Materials 13 (2023): 2202854–2202890, https://doi.org/ 10.1002/aenm.202202854 . 8 . B. He, F. Zhang, Y. Xin, et al., “Halogen Chemistry Of Solid ElectrolytesIn All-Solid-State Batteries,” Nature Reviews Chemistry 7 (2023): 826–842, https://doi.org/10.1038/s41570- 023- 00541- 7 . 9 . J. Park, J. P. Son, W. Ko, et al., “NaAlCl4 : New Halide Solid Electrolytefor 3 V Stable Cost-Effective All-Solid-State Na-Ion Batteries,”ACS EnergyLetters 7 (2022): 3293–3301, https://doi.org/10.1021/acsenergylett.2c01514 . 10 . H. Kwak, J. Lyoo, J. Park, et al., “Na2 ZrCl6 Enabling Highly Stable 3 VAll-Solid-State Na-Ion Batteries,” Energy Storage Materials 37 (2021): 47–54, https://doi.org/10.1016/j.ensm.2021.01.026 . 11 . E. A. Wu, S. Banerjee, H. Tang, et al., “A Stable Cathode-SolidElectrolyte Composite For High-Voltage, Long-Cycle-Life Solid-State Sodium-Ion Batteries,” Nature Communications 12 (2021): 1256, https:// doi.org/10.1038/s41467- 021- 21488- 7 . 12 . K. Motohashi, H. Tsukasaki, A. Sakuda, S. Mori, and A. Hayashi,“NaTaCl6 : Chloride as the End-Member of Sodium-Ion Conduc- tors,” ACS Materials Letters 6 (2024): 1178–1183, https://doi.org/10.1021/ acsmaterialslett.3c01445 . 13 . Z. Huang, S. Yoshida, H. Akamatsu, K. Hayashi, and S. Ohno,“NaMCl6 (M = Nb and Ta): A New Class of Sodium-Conducting Halide-Based Solid Electrolytes,” ACS Materials Letters 6 (2024): 1732–1738, https://doi.org/10.1021/acsmaterialslett.4c00315 . Advanced Electronic Materials, 2026 Commons Licensehttps://doi.org/10.1126/science.1212741https://doi.org/10.1021/cr500192fhttps://doi.org/10.1002/adma.202000721https://doi.org/10.1021/acsami.8b15121https://doi.org/10.1002/aenm.202202854https://doi.org/10.1038/s41570-023-00541-7https://doi.org/10.1021/acsenergylett.2c01514https://doi.org/10.1016/j.ensm.2021.01.026https://doi.org/10.1038/s41467-021-21488-7https://doi.org/10.1021/acsmaterialslett.3c01445https://doi.org/10.1021/acsmaterialslett.4c00315                                            T        2199160x, 2026, 4, Downloaded from https://advanced.onlinelibrary.wiley.com/doi/10.1002/aelm.202500688 by Naoaki Kuwata - National Institute For , Wiley Online Library on [05/03/2026]. See the Terms and Conditions (https://onlinelibrary.wiley.com/terms-and-conditions) on Wiley Online Library for rules of use; OA articles are governed by the applicable C14 . A. Jain, S. P. Ong, G. Hautier, et al., “Commentary: The Materi-als Project: A Materials Genome Approach To Accelerating MaterialsInnovation,” APL Mater 1 (2013): 011002. 15 . R. Kobayashi, “nap: A Molecular Dynamics Package With Parameter-Optimization Programs For Classical And Machine-Learning Potentials,”Journal of Open Source Software 6 (2021): 2768, https://doi.org/10.21105/joss.02768 . 16 . N. Tanibata, S. Aizu, M. Koga, et al., “Guidelines For DesigningHigh-Deformability Materials For All-Solid-State Lithium-Ion Batteries,”Journal of Materials Chemistry A 12 (2024): 15601, https://doi.org/10.1039/D4TA02328E . 17 . H. J. Seifert, “Ternary Chlorides of the Trivalent Late Lanthanides:Phase Diagrams, Crystal Structures and Thermodynamic Properties,” JTherm Anal Calorim 83 (2006): 479–505, https://doi.org/10.1007/s10973- 005-7132-7 . 18 . R. D. Shannon, “Revised Effective Ionic Radii and Systematic Stud-ies of Interatomic Distances in Halides and Chalcogenides,” ActaCrystallographica Section A 32 (1976): 751–767, https://doi.org/10.1107/S0567739476001551 . 19 . N. Tanibata, S. Takimoto, and K. Nakano, et al., “Metastable ChlorideSolid Electrolyte with High Formability for Rechargeable All-Solid-StateLithium Metal Batteries,” ACS Mater Lett 2 880–886, https://doi.org/10.1021/acsmaterialslett.0c00127 . 20 . H. Sumi, H. Shimada, Y. Yamaguchi, et al., “Degradation Evaluationby Distribution of Relaxation Times Analysis for Microtubular SolidOxide Fuel Cells,” Electrochim Acta 339 (2020): 135913, https://doi.org/10.1016/j.electacta.2020.135913 . 21 . J. T. S. Irvine, D. C. Sinclair, and A. R. West, “Electroceramics:Characterization by Impedance Spectroscopy,” Advanced Materials 2(1990): 132–138, https://doi.org/10.1002/adma.19900020304 . 22 . A. Dorai, S. Kim, N. Kuwata, et al., “Understanding Ion Dynamicsin Closoborate-Type Lithium-Ion Conductors on Different Time-Scales,”The Journal of Physical Chemistry Letters 15 (2024): 4 864–4 871, https://doi.org/10.1021/acs.jpclett.4c00754 . 23 . J. R. Hendrickson and P. J. Bray, “A Phenomenological EquationFor NMR Motional Narrowing In Solids,” Journal of Magnetic Resonance(1969) 9 (1973): 341–357, https://doi.org/10.1016/0022- 2364(73)90176- 5 . 24 . P. Heitjans, A. Schirmer, and S. Indris, “NMR and β-NMR Studiesof Diffusion in Interface-Dominated and Disordered Solids,” Diffusion InCondensed Matter: Methods, Materials, Models (Springer, 2005): 367–415,https://doi.org/10.1007/3- 540- 30970-5_9 . 25 . N. Bloembergen, E. M. Purcell, and R. V. Pound, “Relaxation Effects inNuclear Magnetic Resonance Absorption,” Physical Review 73 (1948): 679,https://doi.org/10.1103/PhysRev.73.679 . 26 . G. Hasegawa, N. Kuwata, K. Hashi, et al., “Lithium-Ion Diffusion inPerovskite-Type Solid Electrolyte Lithium Lanthanum Titanate Revealedby Pulsed-Field Gradient Nuclear Magnetic Resonance,” Chemistry ofMaterials 35 (2023): 3815–3824, https://doi.org/10.1021/acs.chemmater.2c03340 . 27 . A. Einstein, “Über die von der molekularkinetischen Theorie derWärme geforderte Bewegung von in ruhenden Flüssigkeiten sus-pendierten Teilchen [AdP 17, 549 (1905)],” Annalen der Physik 517 (2005):182–193, https://doi.org/10.1002/andp.200590005 . 28 . G. MURCH, “The Haven Ratio in Fast Ionic Conductors,” Solid StateIon 7 (1982): 177–198, https://doi.org/10.1016/0167- 2738(82)90050- 9 . 29 . R. Malik, D. Burch, M. Bazant, and G. Ceder, “Particle Size Depen-dence of the Ionic Diffusivity”, Nano Lett 10 (2010): 41234127, https://doi.org/10.1021/nl1023595 . 30 . X. S. Yang and S. Deb, “Cuckoo Search: Recent Advances andApplications”, Neural Comput Appl 24 (2014): 169–174. 31 . S. Aizu, S. Takimoto, N. Tanibata, et al., “Screening Chloride Li-ionConductors Using High-Throughput Force-Field Molecular Dynamics,”Advanced Electronic Materials, 2026Journal of the American Ceramic Society 106 (2023): 30353044, https://doi.org/10.1111/jace.18991 . 32 . R. Kobayashi, et al., “nap: A Molecular Dynamics Package WithParameter-Optimization Programs for Classical and Machine-Learning Potentials,” J Open Source Softw 6 (2021): 2768, https://doi.org/10.21105/joss.02768 . 33 . R. Kobayashi, Y. Miyaji, K. Nakano, and M. Nakayama, “High-hroughput Production of Force-Fields for Solid-State Electrolyte Mate-rials,” APL Mater 8 (2020):, https://doi.org/10.1063/5.0015373 . 34 . G. Kresse and J. Furthmüller, “Efficient Iterative Schemes for ab InitioTotal-Energy Calculations Using a Plane-Wave Basis set”, Phys Rev BCondens Matter Mater Phys 54 (1996): 11169–11186, https://doi.org/10.1103/PhysRevB.54.11169 . 35 . K. Momma and F. Izumi, “VESTA: A Three-Dimensional Visu-alization System For Electronic And Structural Analysis,” Journal of Applied Crystallography 41 (2008): 653–658, https://doi.org/10.1107/ S0021889808012016 . Supporting Information Additional supporting information can be found online in the SupportingInformation section. Supporting File : aelm70277-sup-0001-SuppMat 1.docx. 9 of 9reative Commons Licensehttps://doi.org/10.21105/joss.02768https://doi.org/10.1039/D4TA02328Ehttps://doi.org/10.1007/s10973-005-7132-7https://doi.org/10.1107/S0567739476001551https://doi.org/10.1021/acsmaterialslett.0c00127https://doi.org/10.1016/j.electacta.2020.135913https://doi.org/10.1002/adma.19900020304https://doi.org/10.1021/acs.jpclett.4c00754https://doi.org/10.1016/0022-2364(73)90176-5https://doi.org/10.1007/3-540-30970-5_9https://doi.org/10.1103/PhysRev.73.679https://doi.org/10.1021/acs.chemmater.2c03340https://doi.org/10.1002/andp.200590005https://doi.org/10.1016/0167-2738(82)90050-9https://doi.org/10.1021/nl1023595https://doi.org/10.1111/jace.18991https://doi.org/10.21105/joss.02768https://doi.org/10.1063/5.0015373https://doi.org/10.1103/PhysRevB.54.11169https://doi.org/10.1107/S0021889808012016 High-Throughput Screening and Characterization of Non-Flammable Na-Cl Solid Electrolytes 1 | Introduction 2 | Results and Discussion 3 | Conclusions 4 | Experimental Section 4.1 | Computational Screening for Na-Cl Solid Electrolytes 4.2 | Theoretical Evaluation of Na3La5Cl18 4.3 | Synthesis 4.4 | Characterization 4.5 | Ignition Tests Acknowledgements Funding Conflicts of Interest Data Availability Statement References Supporting Information