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All‐solid‐state sodium‐ion batteries (NIBs) are emerging as a strong contender to the widely used lithium‐ion batteries due to their abundant resources and high safety performance. Solid‐state electrolytes, as the key component of SSBs, have gained widespread attention for their high safety and chemical stability. This study presented a novel solid glass‐ceramic electrolyte, Na3Sb0.75As0.25S4, which was synthesized by high ball milling and heat treatment. The findings demonstrate that elemental As can have a dual effect of improving ionic conductivity and successfully lowering H2S gas emission. Na3Sb0.75As0.25S4 exhibits superior performance in the cubic phase due to the partial replacement of Sb by As, with ionic conductivity up to 2.42 mS/cm and a low activation energy of 0.119 eV at room temperature. Furthermore, it releases only 0.017 cm3/g H2S in a conventional humidity environment for 30 min, much lower than the amount of 0.05 cm3/g H2S released by undoped Na3SbS4, making it an excellent candidate for all‐solid‐state NIB electrolyte. [ABSTRACT FROM AUTHOR]

All‐solid‐state sodium ion batteries (ASSIBs) attract growing attention as the next generation of batteries due to their high energy density, excellent safety, and the abundance of sodium resources. As a vital component of ASSIBs, chalcogenide Na‐ion solid‐state electrolytes (SSEs) have been widely studied due to their high ionic conductivity and outstanding ductility. However, due to the susceptibility to organic solvents and moisture, no chalcogenide Na‐ion SSEs membrane has been reported while only thick SSEs pellets have been investigated, which introduces abundant "dead" weight and lowers the energy density of ASSIBs. Herein, utilizing the excellent air stability of Na3SbS4, a thin (∼220 μm) Na3SbS4 membrane is prepared in air via a facile dry‐film method with polytetrafluoroethylene fibrillation, which exhibits a high ionic conductivity of 0.19 mS cm and an excellent critical current density of 0.6 mA/cm2. In summary, the chalcogenide Na‐ion SSEs membranes with high ionic conductivity and the simple preparation process could be readily adopted by pragmatic high‐performance ASSIBs. [ABSTRACT FROM AUTHOR]

Chalcogenides with high ionic conductivity and appropriate mechanical properties are promising solid‐state electrolytes (SSEs) to substitute current liquid electrolytes in lithium‐ion batteries. Yet, their practical applications in all‐solid‐state batteries are still retarded by both the low critical current density and the inferior interfacial stability toward electrodes. In this work, a series of superior SSEs, that is, Li2S‐P2S5‐B2S3 electrolytes, are developed via a ball‐milling and then melt‐quenching strategy. These SSEs exhibit a high critical current density of 1.65 mA cm−2 and a long cycling life of over 300 h. In addition, the evolution mechanism of the interphase between SSEs and metallic lithium is revealed via operando electrochemical impedance spectroscopy, depth‐profiling XPS, and in situ Raman spectroscopy. The structural and chemical heterogeneities are found to be the main origins of the continual interphase evolution. The resulting "multi‐layer mosaic like" interphase facilitates the suppression of Li dendrite growth, and hence, prolongs the lifetime of lithium‐ion all‐solid‐state batteries. In addition, the preparation technique of SSEs developed in the present work is feasible for scale‐up production. [ABSTRACT FROM AUTHOR]

Chalcogenide solid‐state electrolytes (SSEs) have been receiving growing attentions due to their high ionic conductivity and suitable mechanic properties, especially the Li2S–P2S5 systems incorporated with a second glass network formers (Si, Ge, Sn, and so on) besides P. Although the ionic conductivities are generally enhanced with the second glass network formers, the comprehensive effects of different glass formers on other properties, including electrochemical, cycling, and air stability, remain elusive. To acquire deeper understanding, herein, three common but representative glass network formers (SiS2, GeS2, and SnS2) were introduced into Li2S–P2S5, and their individual effects were investigated systematically. The results of multiscale characterizations before and after lithium stripping/plating cycling confirmed that the introduction of metal cations (Ge, Sn) generally leads to worse electrochemical stability and shorter cycle life of these SSEs toward lithium metal compared with SSEs with nonmetal cation (Si) modification. However, the air stability is related to the binding energy of M–S (M = Si, Ge, Sn), which is consistent with the hard base soft acid theory. This work provides valuable understanding for designing pragmatic Li2S–P2S5–MS2‐based SSEs with high electrochemistry, cycling, and air stability. [ABSTRACT FROM AUTHOR]

An amorphous superionic conductor is a promising solid electrolyte (SE) with excellent ionic conductivity and high energy density, which would be promising candidates for all‐solid‐state lithium‐ion batteries. However, these advantageous features alone are difficult to achieve large‐scale practical applications. Having a simple, effective synthetic route and good air stability is also critically important for SEs. Here, Li3PS4–xLiBr glass SE with high conductivity was obtained by simple mechanical milling and subsequent short‐term low‐temperature treatment. The site disorder between S2− and Br− anions facilitates ionic transport. Our comparison of air stability before and after doping with halogen revealed that Br− doping well reduced the production of H2S gas and improved the air stability of the SE. [ABSTRACT FROM AUTHOR]

High ionic conductivity, low grain boundary impedance, and stable electrochemical property have become the focus for all‐solid‐state lithium–sulfur batteries (ASSLSB). One of the approaches is to promote the rapid diffusion of lithium ions by regulating the chemical bond interactions within the framework. The structure control of P5+ substitution for Sn4+ on lithium‐ion transport was explored for a series of Li3PS4–Li4SnS4 glass–ceramic electrolytes. Results showed that the grain boundary impedance of the glass electrolyte was reduced after heat treatments. The formation of LiSnPS microcrystals, a good superionic conductor, was detected by X‐ray diffraction tests. Electrochemical experiments obtained the highest conductivity of 29.5 S cm−1 at 100°C and stable electrochemical window from –0.1 to 5 V at 25°C. In addition, the cell battery was assembled with prepared electrolyte, which is promoted as a candidate solid electrolyte material with improved performance for ASSLSB. [ABSTRACT FROM AUTHOR]

Novel chalcogenide glasses of pseudo-binary (100 – x)Sb2S3–xCuI systems were synthesized by traditional melt-quenching method. The glass-forming region of Sb2S3-CuI system was determined ranging from x = 30 mol% to 40 mol%. CuI acts as a non-bridging modifier to form appropriate amount of [SbSI] structural units for improving the glass-forming ability of Sb2S3. Particularly, as-prepared glassy sample is able to transmit light beyond 14 μm, which is the wider transparency region than most sulfide glasses. Their physical properties, including Vickers hardness (Hv), density (ρ), and ionic conductivity (σ) were characterized and analyzed with the compositional-dependent Raman spectra. These experimental results would provide useful knowledge for the development of novel multi-spectral optical materials and glassy electrolytes. [ABSTRACT FROM AUTHOR]

Ion‐conducting chalcogenide glass is a promising solid electrolyte with excellent conductivity and energy density for all‐solid‐state batteries. A suitable ionic channel for carriers in the amorphous network is urgently needed. In this work, the structural evolution of co‐doped metal cations (Ge and Ga) in the glass matrix and its influence on electrochemical behavior were studied using a series of GexGa16‐xSb64S128‐40AgI glass samples. The macroscopic properties of samples were examined by X‐ray diffraction (XRD), differential scanning calorimetry (DSC), and Raman tests. The electrochemical behavior of samples was investigated by AC impendence spectroscopy and cyclic voltammetry (CV) measurement. Furthermore, a deliquescence experiment was applied for the chemical stability test of glass samples. The ionic conductivity of samples was developed by adding Ga components. Notably, the electrochemical window of electrolytes was remarkably wide at approximately 5 V. The resistance of samples to humidity was characterized by the decreased Raman peaks. Analysis results show that the Ga‐related bonding structure evidently increased the chemical stability compared with the non‐Ga sample. This work provides an insight into the effective and stable ions transport, especially in the Ge(Ga)SbS glass system. These results promote the further investigation of sulfide solid electrolytes and practical application of all‐solid‐state batteries. [ABSTRACT FROM AUTHOR]

The glass‐ceramics of AgI‐based electroconductive chalcogenide system was realized using an appropriate heat treatment at a fairly high temperature (Tg + 40°C) and different times ranging from 4 to 20 hours. The crystallization behavior and electroconductive properties of the heat‐treated samples were studied in detail. Transmission study was performed, and the results show that the cut‐off edge of the short wavelength is red‐shifted at prolonged annealing time but remains an excellent transmittance in the mid‐infrared (IR) region. XRD and scanning electron microscopy results indicated that the precipitated crystalline phases are mainly β‐/γ‐AgI. Moreover, a small amount of α‐AgI, which rarely existed at room temperature, is precipitated in the AgI‐rich chalcogenide glass‐ceramics. The ionic conductivity of all glass‐ceramics was enhanced by heat treatment in contrast to that of base glass. Raman analysis exhibited the structure variation in the glass sample after heat treatments. This study provided an observation of crystallization in chalcogenide glass containing large amounts of AgI and be of good guidance to fabricate novel AgI‐based chalcogenide glass‐ceramics that can be candidates in infrared optics and solid electrolyte applications. [ABSTRACT FROM AUTHOR]

Series of glassy and glass-ceramic samples in the GeSe2-Ga2Se3-NaI system is prepared by melt-quenching technique and the glass-forming region is well-defined by XRD investigations. Na-ion conduction behavior is systemically studied by impedance measurements. For the glasses in the series (100 - 2x)GeSe2-xGa2Se3-xNaI, ionic conductivities increased with increasing x, whereas the attributed activation energy of ion conduction decreases. The enhanced mechanism is discussed by employing Raman spectra. In addition, the effect of the crystal phases NaI and Ga2Se3 on the ionic conduction behavior in the (70 - x)GeSe2-xGa2Se3-30NaI samples is discussed. Although it shows that the poorly conducting crystallites of NaI and Ga2Se3 have a negative effect on the ionic conductivities in this series, the highest ionic conductivity of 1.65 × 10-6 S/cm is obtained in the 45GeSe2-25Ga2Se3-30NaI glass. Finally, this study also demonstrates a possible way to search appropriate Na-ion solid electrolytes for allsolid-state batteries. [ABSTRACT FROM AUTHOR]

Chalcogenide solid states electrolytes (SSEs) are considered as one of the most promising alternative to replace liquid electrolytes for their high ionic conductivity and appropriate mechanical properties. However, the commercial applications of chalcogenide SSEs in all-solid lithium-ion batteries (ASSIBS) are still limited by the inferior interfacial stability, which leads to lithium dendrite growth and continual interphase formation. Here, the interfacial stability of Li 2 S–P 2 S 5 –B 2 S 3 SSEs have been enhanced effectively via LiI incorporation. In detail, a series of (100- x) (75Li 2 S–15P 2 S 5 –10B 2 S 3)- x LiI (x = 0, 5, 15, 30, 40) SSEs are prepared via ball-milling and then melt-quenching, which exhibit a high ionic conductivity of 1.53 mS cm−1 and a steady long cycling life up to 1637 h without obvious resistance growth at 0.1 mA cm−2. This excellent cycle life is originated from the electronic insulation interphase containing LiI without unaltered the "multi-layer mosaic like" structure of Li 2 S–P 2 S 5 –B 2 S 3 ternary glass system. In addition, this work also confirmed that LiI can act as a catalyst to enhance the charge transfer kinetics within S composite electrode thereby reducing the interface impedance. The stable interface performance obtained by this work could facilitate the development of ASSIBS with prolonged cycle life. [ABSTRACT FROM AUTHOR]

Among the chalcogenide solid-state electrolytes (SSEs), Na 3 SbS 4 is of particular importance because of its high ionic conductivity and compatibility with moist air, which reduces processing costs and favors large-scale industrial deployment. However, the cation doping effects on the electrochemical properties of the Na 3 SbS 4 remain elusive. Here, a series of Na (3-2x) Sb (1-x) Mo x S (4-x) I x (x = 0.05, 0.1 0.15, 0.2) SSEs were fabricated via the ball milling and melt quenching strategy. The valence state of Mo is revealed to be 4+ not 6+. A high ionic conductivity of 0.54 mS cm−1 and an excellent critical current density of 1.5 mA cm−2 was obtained at room temperature. The cycling life of the symmetric cell is up to 112 h. The as-prepared SSEs also exhibit outstanding chemical stability. This work provides insightful understanding of the valence state of cations and impacts on the electrochemical performance of chalcogenide SSEs, which are vital for designing optimal SSEs. [ABSTRACT FROM AUTHOR]

The co doping of P and O in the Na 3 SbS 4 electrolyte system resulted in a uniform bridging oxygen structure, stabilizing the interface between the sodium metal and the electrolyte, and maintaining a constant current cycling at room temperature for 260h. [Display omitted] The all-solid-state sodium battery has emerged as a promising candidate for energy storage. However, the limited electrochemical stability of the solid electrolyte, particularly in the presence of Na metal at the anode, along with low ionic conductivity, hinders its widespread application. In this work, the design of P and O elements in Na 3 SbS 4 solid electrolyte was investigated through a series of structural tests and characterizations. The electrochemical stability was remarkably improved in the Na/Na 3 SbP 0.16 S 3.6 O 0.4 /Na battery, exhibiting a stability of 260 h under a current of 0.1 mA cm−2. Additionally, the room temperature conductivity of Na 3 SbP 0.16 S 3.6 O 0.4 was enhanced to 3.82 mS cm−1, maintaining a value comparable to commercial standards. The proposed design strategy provides an approach for developing sodium ion solid-state batteries with high energy density and long lifespan. The stability of the solid electrolyte interface at the Na | solid electrolyte interface proves critical for the successful assembly of all-solid-state sodium ion batteries. [ABSTRACT FROM AUTHOR]

Here, we report the SiS 2 –NaBr double-doped sulfide superionic conductor Na 3.02 Si 0.1 Sb 0.9 S 3.92 Br 0.08. The dual-doping effect of SiS 2 and NaBr in the Na 3 SbS 4 electrolyte was investigated by mechanical ball milling and high-temperature heat treatment. The improved glass–ceramic Na 3.02 Si 0.1 Sb 0.9 S 3.92 Br 0.08 solid electrolyte obtained a high ionic conductivity of 2.26 × 10−3 S/cm and a low activation energy of 0.077 eV (0.25 eV for Na 3 SbS 4) at room temperature. Moreover, the electrochemical property test was characterized by a higher critical current density of 1.228 mA/cm2 (0.585 mA/cm2 for Na 3 SbS 4) and stable cycling at 0.1 mA cm−2 current densities exceeding 120 h (50.33 h for Na 3 SbS 4). Some Si atoms occupying the Sb position greatly contributed to the formation of the Na 3 SbS 4 high-ionic conductive phase. The introduction of an appropriate amount of halogen improved the compactness of the sample and nearly suppressed the majority of H 2 S release from the original electrolyte. The substitution effect and the ion conduction structure were analyzed in detail. [ABSTRACT FROM AUTHOR]

High-capacity and affordable all-solid-state Na-ion batteries have gathered increasing interest in recent years owing to low-cost sodium, which contributes to reducing the price of these Na-ion batteries to approximately 70% of that in lithium batteries. However, in terms of electrolyte performance and battery cost, the complete replacement of lithium batteries has a long way to go. In this work, low-cost and high-safety Na 2 S·9H 2 O materials are used in synthesizing Na 3 SbS 4 solid electrolyte, the price of which is only one-fifth that of high-purity Na 2 S. The structure and electrochemical properties are studied through X-ray diffraction analysis, Raman spectroscopy, scanning electron microscopy, and electrochemical tests. Results indicate that a multiphase Na 3 SbS 4 structure containing cubic and tetragonal phases formed after heat treatment at 300 °C. In addition, a third phase transition of Na 3 SbS 4 is inferred after further heating at 600 °C. This phase structure contributes to the improvement of electrochemical performance by promoting increasing ionic conductivity to 0.54 mS cm−1 at room temperature (25 °C) and reducing activation energy to 0.076 eV. This work provides an affordable material with good electrochemical properties and not only simplifies the preparation but also greatly reduces the risk of the process. [ABSTRACT FROM AUTHOR]

A new glass system of (100- x) (0.2Ga 2 S 3 -0.8Sb 2 S 3)- x NaI (x = 5–30 mol%) was investigated through a melt-quenching method for solid-state electrolyte application. Na+ was added into the glass matrix as a conductive ion to study its effect on the properties of glass samples. XRD result indicated that the glasses retained their amorphous state until the NaI content exceeded 30 mol%. With increased NaI component, the density and hardness of glasses slightly decreased. DSC measurement showed that the glass-transition temperature of samples decreased, whereas the glass thermal stability improved. We speculated that the incorporation of NaI may have caused the destruction of [S 3 Ga–GaS 3 ] ethane-like units and formation of [GaS 4−x I x ] structure, thereby decreasing the connectivity of the glass network. The conductivity of glass samples was further determined using the AC impedance method. • Infrared chalcogenide glass system of Ga2S3-Sb2S3–xNaI are fabricated successfully. • Modification of NaI in glass samples is beneficial to the thermal properties. • The structure of glass network are compared about adding NaI and AgI. [ABSTRACT FROM AUTHOR]

In addition to the widely used lithium-ion secondary batteries, more and more concerns have been paid to solid-state batteries (SSBs) in the research on future-generation energy storage systems. The availability of sodium solid electrolytes, especially those with excellent ambient temperature conductivity and prominent chemical stability, is crucial for sodium-based SSBs. In this study, Na 3.1 Ge 0.1 Sb 0.9 S 4 , a novel sodium-ion solid-state electrolyte, was obtained via a solid-state chemical reaction utilizing the economical Na 2 S·9H 2 O as one of the raw ingredients. The properties of this new electrolyte were examined by using X-ray diffractometry, Raman spectroscopy, differential scanning calorimetry, scanning electron microscopy, and electrochemical techniques. The Na 3.1 Ge 0.1 Sb 0.9 S 4 electrolyte, which released low amounts of H 2 S under ambient conditions, demonstrated the ionic conductivity of 5.1 × 10−3 S/cm at normal atmospheric temperature and the conducting activation energy of 0.156 eV. The enhanced ionic conductivity was attributed to the improvement of crystallinity and the unit cell enlargement caused by interstitial sodium defects. • High room-temperature ionic conductivity (5.1 × 10−3 S/cm). • Low conduction activation energy (0.156 eV). • Enhanced air stability (Ge-doped Na 3 SbS 4). • cost-effective (Na 2 S·9H 2 O as one of the raw materials). [ABSTRACT FROM AUTHOR]