Thioantimonate Research Articles

Cellulose-Encapsulated Composite Electrolyte Design: Toward Chemically and Mechanically Enhanced Solid-Sodium Batteries.

Sulfide- and halide-based ceramic ionic conductors exhibit comparable ionic conductivity with liquid electrolytes and are candidates for high-energy- and high-power-density all-solid-state batteries. These materials, however, are inherently brittle, making them unfavorable for applications. Here, we report a mechanically enhanced composite Na+ conductor that contains 92.5 wt % of sodium thioantimonate (Na3SbS4, NSS) and 7.5 wt % of sodium carboxymethyl cellulose (CMC); the latter serves as the binder and an electrochemically inert encapsulation layer. The ceramic and binder constituents were integrated at the particle level, providing ceramic NSS-level Na+ conductivity in the NSS-CMC composite. The more than 5-fold decrease of electrolyte thickness obtained in NSS-CMC composite provided a 5-fold increase in Na+ conductance compared to NSS ceramic pellets. As a result of the CMC encapsulation, this NSS-CMC composite shows increased moisture resistivity and electrochemical stability, which significantly promotes the cycling performance of NSS-based solid-state batteries. This work demonstrates a well-controlled, orthogonal process of ceramic-rich, composite electrolyte processing: independent streams for ceramic particle formation along with binder encapsulation in a solvent-assisted environment. This work also provides insights into the interplay among the solvent, the polymeric binder, and the ceramic particles in composite electrolyte synthesis and implies the critical importance of identifying the appropriate solvent/binder system for precise control of this complicated process.

Mechanochemistry in Sodium Thioantimonate Solid Electrolytes: Effects on Structure, Morphology, and Electrochemical Performance.

Sodium thioantimonate (Na3SbS4) and its W-substituted analogue Na2.88Sb0.88W0.12S4 have been identified as potential electrolyte materials for all-solid-state sodium batteries due to their high Na+ conductivity. Ball milling mechanochemistry is a frequently employed synthetic approach to produce such Na+-conductive solid solutions; however, changes in the structure and morphology introduced in these systems via the mechanochemistry process are poorly understood. Herein, we combined X-ray absorption fine structure spectroscopy, Raman spectroscopy, solid-state nuclear magnetic resonance spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy characterization techniques to provide an in-depth analysis of these solid electrolytes. We report unique changes seen in the structure and morphology of Na3SbS4 and Na2.88Sb0.88W0.12S4 resulting from ball milling, inducing changes in the electrochemical performance of the solid-state batteries. Specifically, we observed a tetragonal-to-cubic crystal phase transition within Na3SbS4 following the ball mill, resulting in an increase in Na+ conductivity. In contrast, the Na+ conductivity was reduced in mechanochemically treated Na2.88Sb0.88W0.12S4 due to the formation and accumulation of a WS2 phase. In addition, mechanochemical treatment alters the surface morphology of densified Na2.88Sb0.88W0.12S4 pellets, providing intimate contact at the solid electrolyte/Na interface. This phenomenon was not observed in Na3SbS4. This work reveals the structural and morphological origin of the changes seen in these materials' electrochemical performance and how mechanochemical synthesis can introduce them.

In-Situ Characterization of Molecular Processes at the Anode/Na3SbS4 Electrolyte Interface in All-Solid-State Sodium Batteries

Sulfur based solid-state Na+ conductors exhibit high ionic conductivity and are promising candidates for electrolytes used in the next generation all-solid-state sodium-ion batteries. Sodium thioantimonate (Na3SbS4), for example, shows an ionic conductivity of 1 mS/cm, comparable to its liquid counterparts. In contrast to the well-known thiophosphate solid-state electrolytes, Na3SbS4 is chemically stable in dry air. However, solid-state Na-ion batteries assembled using Na3SbS4 as the electrolyte show a decaying performance over the charge and discharge cycles. This work characterized the molecular processes occurring at the interface between Na3SbS4 solid electrolyte and the anode. This interfacial chemistry was probed in real-time (in-situ) using Raman spectroscopy while the battery was in operation. Combined with the characterization results obtained from X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), we observed a largely irreversible decomposition of SbS4 3- while Na3SbS4 was directly exposed to negative potentials (vs. Na/Na+). Sb2S3 and elemental Sb are the two major decomposition byproducts formed and accumulated at the Na3SbS4/anode interface. This result unravels the decomposition mechanism at the Na3SbS4/anode interface in all-solid sodium batteries. It provides deep molecular insights into designing ideal protective layers at this critical interface.

Rapid synthesis process and characterization for high purity sodium thioantimoniate nonahydrate.

For the first time, Na3SbS4·9H2O, also known as Schlippe's salt, has been synthesized through high-energy ball milling. This innovative synthesis way allows for obtaining high purity thioantimonate nonahydrate with around 90% yield in only approximately four hours. To validate the synthesis route described herein, the crystal structure has been refined, at room temperature, through high-resolution X-ray diffraction, pair distribution function analysis and energy dispersive spectrometry. Dehydration and rehydration of the compound have also been studied by thermogravimetric analysis and differential scanning calorimetry.

Heavily Tungsten-Doped Sodium Thioantimonate Solid-State Electrolytes with Exceptionally Low Activation Energy for Ionic Diffusion.

A strategy for modifying the structure of solid-state electrolytes (SSEs) to reduce the cation diffusion activation energy is presented. Two heavily W-doped sodium thioantimonate SSEs, Na2.895 W0.3 Sb0.7 S4 and Na2.7 W0.3 Sb0.7 S4 are designed, both exhibiting exceptionally low activation energy and enhanced room temperature (RT) ionic conductivity; 0.09 eV, 24.2 mS/cm and 0.12 eV, 14.5 mS/cm. At -15 °C the Na2.895 W0.3 Sb0.7 S4 displays a total ionic conductivity of 5.5 mS/cm. The 30 % W content goes far beyond the 10-12 % reported in the prior studies, and results in novel pseudo-cubic or orthorhombic structures. Calculations reveal that these properties result from a combination of multiple diffusion mechanisms, including vacancy defects, strongly correlated modes and excessive Na-ions. An all-solid-state battery (ASSB) using Na2.895 W0.3 Sb0.7 S4 as the primary SSE and a sodium sulfide (Na2 S) cathode achieves a reversible capacity of 400 mAh g-1 .

Heavily Tungsten‐Doped Sodium Thioantimonate Solid‐State Electrolytes with Exceptionally Low Activation Energy for Ionic Diffusion

AbstractA strategy for modifying the structure of solid‐state electrolytes (SSEs) to reduce the cation diffusion activation energy is presented. Two heavily W‐doped sodium thioantimonate SSEs, Na2.895W0.3Sb0.7S4 and Na2.7W0.3Sb0.7S4 are designed, both exhibiting exceptionally low activation energy and enhanced room temperature (RT) ionic conductivity; 0.09 eV, 24.2 mS/cm and 0.12 eV, 14.5 mS/cm. At −15 °C the Na2.895W0.3Sb0.7S4 displays a total ionic conductivity of 5.5 mS/cm. The 30 % W content goes far beyond the 10–12 % reported in the prior studies, and results in novel pseudo‐cubic or orthorhombic structures. Calculations reveal that these properties result from a combination of multiple diffusion mechanisms, including vacancy defects, strongly correlated modes and excessive Na‐ions. An all‐solid‐state battery (ASSB) using Na2.895W0.3Sb0.7S4 as the primary SSE and a sodium sulfide (Na2S) cathode achieves a reversible capacity of 400 mAh g−1.

Solution Synthesis of Sb2S3 and Na3SbS4 Solid-State Electrolyte

Sodium thioantimonate (Na3SbS4) is an attractive solid-state electrolyte for sodium-ion batteries due to its high ionic conductivity and stability in protic solvents. Herein, we describe solution-based routes for its synthesis. First, we demonstrate the synthesis of the Sb2S3 precursor via thermodynamically favorable metathesis between Na2S and SbCl3. This solution-based approach is further extended to couple the resulting Sb2S3 with Na2S for the synthesis of Na3SbS4. It is shown that ethanol is a superior solvent to water for solution-based synthesis of Na3SbS4 with respect to yield, morphology, and performance. Amorphous Sb2S3 synthesized from low-temperature metathesis produced highly crystalline Na3SbS4 with a room temperature Na+ conductivity of 0.52 mS cm−1 and low activation energy, comparable to leading values reported in the literature.

Sodium–Sulfur Batteries Enabled by a Protected Inorganic/Organic Hybrid Solid Electrolyte

Sodium–sulfur batteries are promising energy-dense, cost-effective energy storage systems. However, a low-resistance solid electrolyte is necessary to stabilize the sodium anode. While sulfide-based solid electrolytes offer high ionic conductivity, they suffer from chemical reactivity when in contact with sodium metal and are mechanically brittle. This paper implements an in situ cross-linking reaction to embed sodium-ion-conducting sodium thioantimonate in a protective polymer host. The enhanced flexibility enables the formation of a thin but transferable hybrid electrolyte film (30 μm in thickness, 65 ohm cm2 room temperature resistance). Owing to the chemical bonding between sodium thioantimonate and the polymer, the hybrid electrolyte maintains a stable interface with sodium when cycling at a current density of 0.5 mA cm–2. The hybrid solid electrolyte protects the sodium metal from corroding with polysulfide-containing liquid electrolyte and enables the stable operation of a sodium–sulfur battery using a nonencapsulated sulfur cathode for 90 cycles.

Mn(terpy)Sb2S4]n, a 1D Network of MnSb4S5 Rings Exhibiting a Pronounced Magnetocaloric Effect and Luminescence

The solvothermal reaction of an aqueous solution of Na3SbS3 or Schlippe's Salt (Na3SbS4·9H2O) in the presence of Mn(ClO4)2·6H2O and terpy (terpy = 2,2':6',2''‐terpyridine) or the [Mn(terpy)]2+ complex led to crystallization of the new compound [Mn(terpy)Sb2S4]n (I). The unique crystal structure of I features chains formed by fused MnSb4S5 rings. The Mn2+ cation is coordinated by one terpy ligand and two S2– anions resulting in a distorted MnN3S2 trigonal bipyramid. The terpy ligands point to the exterior of the chains, distances between neighbored ligands indicate π···π stacking. Magnetic investigations show paramagnetic behavior (µeff = 5.92 µB/Mn2+ at room temperature). Field‐dependent magnetic susceptibility measurements at different temperatures evidence a significant magnetocaloric effect of –ΔS = 20.54 J kg–1 K–1 at T = 2 K for a magnetic field change of ΔB = 9 T. The compound exhibits blue luminescence, and a detailed analysis allowed assignment of the emission and excitation bands to the different constituents of the compound.

A Coordination Polymer based on Interconnection of Thioantimonate(III) and [Mn(terpy)]2+ Complexes: Synthesis, Crystal Structure, and Properties of {[(Mn(terpy))2Sb4S8]·0.5H2O}n

Applying Schlippe's salt, Na3SbS4·9H2O, in the presence of the in‐situ formed [Mn(terpy)]2+ complex (terpy = 2,2':6',2''‐terpyridine) the new compound {[(Mn(terpy))2Sb4S8]·0.5H2O}n (I) could be obtained under solvothermal conditions. Interestingly, in the crystal structure the two unique Mn2+ cations adopt different environments to form a MnN3S3 octahedron and a MnN3S2 trigonal pyramid. The trigonal pyramidal SbS33– anions share common edges yielding a Sb8S8 ring. Covalent bonds between Mn2+ and S2– generate MnSb2S3 and Mn2Sb4S6 heterocycles. The Sb8S8 and Mn2Sb4S6 rings are condensed to form a chain. The MnN3S3 octahedron and the MnN3S2 polyhedron share a common S2– anion and antiferromagnetic properties are observed mediated by superexchange interactions. {[(Mn(terpy))2Sb4S8]·0.5H2O}n shows luminescence in the blue‐green spectral range, assigned to combined contributions from Mn2+ ions and from the organic ligand.

Recovery of antimony and bismuth from tin anode slime after soda roasting–alkaline leaching

In this study, a combined process of Na2S leaching and NaCl-H2SO4 leaching was developed to extract antimony and bismuth from tin anode slime after soda roasting–alkaline leaching. The optimal conditions for the extraction of antimony have been established as: Na2S concentration of 0.7 mol/L, temperature of 85 °C, liquid-to-solid ratio (L/S) of 14:1, and leaching time of 120 min. Under the conditions, more than 98% of antimony was extracted from tin anode slime, wherein the antimony was converted to liquid sodium thioantimonate, which was then converted into Na3SbS4(H2O)9 crystal via evaporation-crystallization; for this process, the recovery of antimony reached 93.83% at 50% evaporation rate, and the crystallization rate of antimony was 95%. The residue obtained was subjected to NaCl-H2SO4 leaching. About 94.94% of bismuth was extracted under the optimum conditions: H2SO4 concentration of 1 mol/L, NaCl/H2SO4 mole ratio of 2.5:1, L/S of 12:1, temperature of 80 °C, and leaching time of 120 min. The leach solution was then hydrolyzed and precipitated to form BiOCl, which showed a precipitation rate of 95.91% and Bi recovery of 91.12% at the hydrolysis pH of 2.4.

Abnormally Low Activation Energy in Cubic Na3SbS4 Superionic Conductors

Inorganic Na-ion superionic conductors play a vital role in all-solid-state Na batteries that operate at room temperature. Sodium thioantimonate (Na3SbS4), a popular sulfide-based solid electrolyte...

Recovery of antimony compounds from alkaline sulphide leachates

In copper metallurgy, antimony impurities usually form alloys and compounds with the transition metals to make up the basic building blocks of a speiss phase. This speiss phase is generally rich in copper and precious metals, which are desirable to recycle and recover at the smelter. The presence of this impurity unfortunately creates a build-up of this metal in the copper circuit, leading to problems during copper refining processes. Therefore, a removal or reduction of the antimony impurity to an acceptable level is a necessary step before the speiss can be recycled at the smelter for the recovery of its valuable metals. A lead silicate slag that was obtained after smelting a copper speiss admixed with silica, soda and lead oxide, was leached in alkaline sulphide solution to selectively dissolve its antimony content. Furthermore, the pregnant sulphide leachate was purified by precipitation and crystallization techniques to recover antimony as sodium thioantimonate and sodium hydroxyl antimonate using synthetic Na2S-NaOH-Sb2S3 solutions. The leaching results indicate that the highest amount of antimony and arsenic extracted from the material after 24h at 100°C and reagent concentration of 30g/L NaOH+30g/LS2− was 83% and 90%, respectively. In the precipitation process, the addition of hydrogen peroxide to the alkaline sulphide leachate prompts the precipitation of antimony as NaSb(OH)6. The result also implies that <100% of stoichiometric hydrogen peroxide is required to completely oxidize the total amounts of both Sb3+ and S2− in the solution and to quantitatively precipitate >90% of the antimony in solution. The influence of catalytic agents and temperature on the process was not clearly reflected in this investigation due to the exothermic reaction with hydrogen peroxide. Moreover, the addition of elemental sulphur to the sulphide leachate also influences the precipitation of antimony as sodium thioantimonate.

Trilithium thioarsenate octahydrate

The title compound, Li3AsS4·8H2O, is built up from infinite cationic [Li3(H2O)8]3+ chains which extend along [001] and are cross-linked by isolated tetra­hedral AsS4 3− anions via O—H⋯S hydrogen bonds. Two Li and two As atoms lie on special positions with site symmetries -1 (1 × Li) and 2 (1 × Li and 2 × As). The [Li3(H2O)8]3+ chain contains four independent Li atoms of which two are in octa­hedral and two in tetra­hedral coordination by water O atoms. An outstanding feature of this chain is a linear group of three edge-sharing LiO6 octa­hedra to both ends of which two LiO4 tetra­hedra are attached by face-sharing. Such groups of composition Li5O16 are linked into branched chains by means of a further LiO4 tetra­hedron sharing vertices with four adjacent LiO6 octa­hedra. The Li—O bonds range from 1.876 (5) to 2.054 (6) Å for the LiO4 tetra­hedra and from 2.026 (5) to 2.319 (5) Å for the LiO6 octa­hedra. The two independent AsS4 3− anions have As—S bond lengths ranging from 2.1482 (6) to 2.1677 (6) Å [<As—S> = 2.161 (10) Å]. The eight independent water mol­ecules of the structure donate 16 relatively straight O—H⋯S hydrogen bonds to all S atoms of the AsS4 tetra­hedra [<O⋯S> = 3.295 (92) Å]. Seven water mol­ecules are in distorted tetra­hedral coordination by two Li and two S; one water mol­ecule has a flat pyramidal coordination by one Li and two S. At variance with related compounds like Schlippe’s salt, Na3SbS4·9H2O, there are neither alkali–sulfur bonds nor O—H⋯O hydrogen bonds in the structure.

From Zero- to Three-Dimensional Thioantimonates: [Ni(aepa)2]3Sb6S12 (aepa = C5H15N3 = N-(aminoethyl)-1,3-propandiamine), Containing the Unique [Sb6S12]6– Cyclic Anion, [Ni(aepa)2]6(Sb3S6)2(SO4)3·2H2O, with Isolated [Sb3S6]3– anions and [Ni(aepa)2]Sb4S7, Characterized by a Three-Dimensional Network Structure

The new thioantimonates [Ni(aepa)2]3Sb6S12 (1), [Ni(aepa)2]6(Sb3S6)2(SO4)3·2H2O (2), and [Ni(aepa)2]Sb4S7 (3) (aepa = C5H15N3 = N-(aminoethyl)-1,3-propandiamine) were obtained under solvothermal co...

(C6N2H18)Sb4S7 a Thioantimonate(III) with a Layered [Sb4S7]2‐ Anion in the Presence of a Diprotonated Amine as Structure Director.

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Optical activity measurements on solids. 6. Solid state optical activity and circular dichroism measurements of sodium thioantimonate nonahydrate

We have demonstrated that optical circular dichroism (CD) measurements can be carried out on powders suspended in a liquid medium. The refractive indices of the powder and the suspending liquid must be matched, the suspending liquid must not interact significantly with the solid to be measured and must not absorb in the region where the measurements are carried out. Sodium thioantimonate nonahydrate (Na3SbS4·9H2O) powders obtained by grinding oflevo- ordextro-rotatory crystals were found to be excellent examples for the demonstration of this technique. Measurements of the optical rotation forlevo- anddextro-rotatory crystals and powders of Na3SbS4·9H2O were also carried out and provided additional characterization of this salt. In the course of developing the CD measurement technique, CD of NaClO3 and NaBrO3 crystals was also measured.

X-ray diffraction powder data for Schlippe's salt Na3SbS4·9H2O

Schlippe's salt (sodium thioantimonate nonahydrate—Na3SbS4·9H2O) has been investigated by means of X-ray powder diffraction at room temperature. The indexed X-ray powder diffraction data are presented.

Debye-Waller factor and Debye temperature of sodium thioantimonate

Debye-Waller factor and Debye temperature of sodium thioantimonate

Vibrational spectra of Na 3SbS 4, Na 3SbS 4·9H 2O (Schlippe's salt) and Na 3SbS 4·9D 2O

Powder Raman and far i.r. spectra of Na 3SbS 4 and single crystal Raman and powder i.r. spectra of Na 3SbS 4·9H 2O(D 2O) (Schlippe's salt) were measured in the temperature range T = 75–295 K. Assignments are given for internal SbS 4 and H 2O(D 2O) vibrations. The OH(D) stretching frequencies, ν̄ = 3309(2449)–3422(2550) cm −1, support the existence of a marked hydrogen bond system not only between different water molecules, but also between the hydrate water molecules and the sulphur atoms of the SbS 4 groups in Schlippe's salt.