Search

To cope with the shuttling of soluble lithium polysulfides in lithium–sulfur batteries, confinement tactics, such as trapping of sulfur within porous carbon structures, have been extensively studied. Although performance has improved a bit, the slow polysulfide conversion inducing fast capacity decay remains a big challenge. Herein, a NiS2/carbon (NiS2/C) composite with NiS2 nanoparticles embedded in a thin layer of carbon over the surface of micro-sized hollow structures has been prepared from Ni-metal–organic frameworks. These unique structures can physically entrap sulfur species and also influence their redox conversion kinetics. By improving the reaction kinetics of polysulfides, the NiS2/carbon@sulfur (NiS2/C@S) composite cathode with a suppressed shuttle effect shows a high columbic efficiency and decent rate performance. An initial capacity of 900 mAh g−1 at the rate of 1 C (1 C = 1675 mA g−1) and a low-capacity decline rate of 0.132% per cycle after 500 cycles are obtained, suggesting that this work provides a rational design of a sulfur cathode. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are gaining tremendous attention as promising energy storage solutions due to their impressive energy density and the affordability of sulfur. However, the practical use of Li–S batteries encounter major obstacles such as the polysulfide shuttle effect, which leads to capacity loss and decreased cycling stability. Herein, a polyethylene imidazole/polyacrylonitrile (PVIMPAN) nanofibers‐modified Celgard separator is constructed via a facile electrospinning strategy and used as a polysulfides barrier for Li–S batteries. The electron‐deficient imidazole groups introduced on the surface of PVIMPAN separators create a barrier that prevents polysulfide shuttling and extends cycle life. Additionally, the developed PVIMPAN separator exhibits a significantly enhanced Li+ transfer number of 0.60, compared to the commercial Celgard separator (0.20). This enhancement can be attributed to the strong binding energy between imidazole groups and bis(trifluoromethanesulphonyl)imide anion, leading to improved Li plating and stripping performance. Consequently, incorporating the PVIMPAN separator into Li–S batteries enable the achievement of a discharge capacity of 786.0 mAh g−1 with close to 100% Coulombic efficiency after 500 cycles at 1C (25 °C). It is believed that this work can provide valuable insights for designing suitable and robust separators for metal–sulfur batteries. [ABSTRACT FROM AUTHOR]

Polysulfides are significant compounds in life science, pharmaceutical science, and materials science. Therefore, polysulfide construction is in great demand. The controllable sequential installation of groups on both ends of a S−S motif faces an enormous challenge owing to the reversible nature of the covalent S−S bond. A library was established with two divergent mask groups for bilateral unsymmetrical disulfurating reagents (R1O−SS−SO2R2). Sequential coupling with preferential activation of the S−SO2 bond (37.6 kcal/mol) and controllable activation of the S−O bond (54.8 kcal/mol) in the presence of the S−S bond (62.0 kcal/mol) enabled successive reactions at each end of the S−S motif to afford unsymmetrical disulfides and trisulfides, even for the cross‐linkage of natural products, pharmaceuticals, peptides, and a protein (bovine serum albumin). [ABSTRACT FROM AUTHOR]

The extraction of vanadium from spent industrial catalysts is a widely practiced process globally due to the large quantities of material available with appreciable vanadium content. However, some of these spent catalysts are unresponsive to established extraction methods because they have different properties. Therefore, separate studies are necessary to deal with specific cases. This work demonstrates how the leaching step can limit the recovery of vanadium to the solution before the coprecipitation step. The NH4Cl‐H2SO4 synergetic system achieved a high vanadium leaching rate of up to 95 %, resulting in the preparation of high‐purity NH4VO3 with 75.45 % V2O5 content. This demonstrates the potential of the prepared V2O5 as a precursor for vanadium materials used in sodium‐ion batteries, allowing for the adjustment of the valence of vanadium. The Na3V2(PO4)3@C particles exhibit a discharge capacity of 110 mAh g−1 at a current density of 0.1 C and 90 mAh g−1 at 1 C. The synergistic leaching system provides a sustainable method for the recovery and reuse of vanadium from spent vanadium catalysts. This contributes to recycling efforts and the development of sodium‐ion batteries. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries (LSBs) are considered next‐generation energy storage and conversion solutions owing to their high theoretical specific capacity and the high abundance/low‐cost of sulfur‐based cathode materials. However, LSBs still encounter significant challenges, including the low conductivities of sulfur‐based materials, severe volumetric expansion of sulfur during the discharge process, and the persistent "shuttle effect" of polysulfides. In recent years, a tremendous amount of research has been conducted to address the above challenges by developing coating and compositing materials and corresponding fabrication strategies for sulfur‐based cathode materials. In this study, the surface coating, compositing materials, and fabrication methodologies of LSB cathodes are comprehensively reviewed in terms of advanced materials, structure/component characterization, functional mechanisms, and performance validation. Some technical challenges are analyzed in detail, and possible future research directions are proposed to overcome the challenges toward practical applications of lithium‐sulfur batteries. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li‐S) battery are considered as the next generation energy storage system owing to their ultra‐high theoretical specific capacity and energy density. However, the commercialization of Li‐S battery is still hindered by the intrinsically low conductivity of sulfur, sluggish catalytic conversion and notorious shuttle effect of polysulfides. The implantation of defects in sulfur electrocatalyst can effectively increase its conductivity and catalytic efficiency of lithium polysulfides, but the current mainstream defective materials are limited and lack of in‐depth research. Herein, a defective niobium selenide (NbSe2‐x) nanosheet sulfur electrocatalyst is constructed with enriched selenium defects, which demonstrates strong interaction with sulfur species, endowing NbSe2‐x with rapid and reliable sulfur reduction reaction. As a result, the Li‐S cell with NbSe2‐x exhibits excellent multiplicative performance in both coin cell and pouch cell, which maintains stable cycling for over 2000 cycles under 5 C, corresponding to a low‐capacity fading rate of 0.024% per cycle. Ah level pouch cell is also fabricated, showing a decent energy density of 378 Wh kg−1. This creative strategy not only emphasizes the importance of selenium defect engineering in Li‐S batterie toward practical application, but also enlightens the material engineering to realize superior performance in related energy storage and conversion area. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries possess high theoretical energy density, whereas the shuttle effect of polysulfides and the uncontrollable lithium (Li) dendrites seriously reduce the reversible capacity and cycling lifespan. Constructing an interphase to address the issues in both the cathode and anode simultaneously is significant but still challenging. In this study, a strategy of functionalizing commercial polypropylene (PP) separators is proposed by in situ poly(thioctic acid) (PTA) polymerization. Compared with the conventional separator modifications, the ring‐opening polymerization methodology initiated by heat is more facile and environment‐friendly without changing the nanostructures among the porous separators. On the cathode side, the PTA‐coated separator (PTA‐PP) blocks the shuttle of polysulfides through the electrostatic interaction. On the anode side, the PTA‐coated generates a lithium fluoride (LiF)‐rich solid electrolyte interface (SEI), identified by cryo‐transmission electron microscopy (cryo‐TEM), to accelerate the Li+ diffusion and inhibit the growth of Li dendrites. Due to the interphases constructed by the PTA‐PP separator, the Li–S cells exhibit excellent long‐term cycling in which the capacity retention rate is more than 76% after 700 cycles at 0.5 C. The in situ elaborate modification strategy may provide insights into the high‐performance separator design to promote the potentially large‐scale applications of Li–S batteries. [ABSTRACT FROM AUTHOR]

Lithium-sulfur battery (LSB) is renowned for its high energy density storage property yet its development has faced significant challenges including the shuttle effect and slow reaction rates. A vanadium nitride quantum dots decorated N-doped hollow carbon nanosphere (VN@CS) is thus synthesized and applied as the sulfur host material in LSBs. Experimental results demonstrate the efficient adsorption and catalytic conversion character of the polar VN for soluble lithium polysulfides (LiPSs), contributing to an effective inhibition of the shuttle effect and acceleration of LiPSs conversion. Consequently, the S/VN@CS cathode exhibits a high specific capacity of 849.1 mA h g−1 at a high current density of 4 C, along with the long cycling performance, achieving 1000 cycles with a low capacity decay rate of 0.038% per cycle at 2 C. The work presents the successful combination of small yet highly efficient quantum dots with a conductive substrate to achieve excellent electrochemical performances of LSBs. [ABSTRACT FROM AUTHOR]

Novel charge distribution regulation strategy for Mo 2 C, the relationships of Interface-Structure-Property in heterostructures were clarified, facilitating efficient adsorption-catalysis of Li 2 S x (1≤x≤4) [Display omitted] • A novel electronic distribution regulation strategy (Mo-Mo 2 C heterostructure) for molybdenum carbide was developed. • The relationship of the heterointerfaces-structure–property in Mo-Mo 2 C has been clarified. • The modulation of the intrinsic electronic distribution of Mo 2 C results higher adsorption energy for lithium polysulfides (LiPSs) and stronger Mo-S bonding strength. • The sulfur cathode with C@Mo-Mo 2 C an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure engineering is considered a crucial strategy to modulate the intrinsic charge transfer behavior of materials, enhance catalytic activity, and optimize sulfur electrochemical processes. However, parsing the role of heterogeneous interface-structure–property relationships in heterostructures is still a key scientific issue to realize the efficient catalytic conversion of polysulfides. Based on this, molybdenum carbide (Mo 2 C) was successfully partial reduced to molybdenum metal (Mo) via a thermal reduction at high-temperature and the typical Mo-Mo 2 C-based Mott-Schottky heterostructures were simultaneously constructed, which realized the modulation of the electronic structure of Mo 2 C and optimized the conversion process of lithium polysulfides (LPS). Compared with single molybdenum carbide, the modulated molybdenum carbide acts as an electron donor with stronger Mo-S bonding strength as well as higher polysulfide adsorption energy, faster Li 2 S conversion kinetics, and greatly facilitates the adsorption → catalysis process of LPS. As a result, yolk-shell Mo-Mo 2 C heterostructure (C@Mo-Mo 2 C) exhibits excellent cycling performance as a sulfur host, with a discharge specific capacity of 488.41 mAh g−1 for C@Mo-Mo 2 C/S at 4 C and present an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure-acting Mo 2 C electron distribution modulation engineering may contributes to the understanding of the structure-interface-property interaction law in heterostructures and further enables the efficient modulation of the chemical behavior of sulfur. [ABSTRACT FROM AUTHOR]

[Display omitted] The shuttle effect and sluggish redox kinetics of polysulfides have hindered the development of lithium – sulfur batteries (LSBs) as premier energy storage devices. To address these issues, a high - entropy metal phosphide (NiCoMnFeCrP) was synthesized using the sol – gel method. NiCoMnFeCrP, with its rich metal species, exhibits strong synergistic effects and provides numerous catalytic active sites for the conversion of polysulfides. These active sites, possessing significant polarity, can bond with polysulfides. In situ ultraviolet–visible were conducted to monitor the dynamic changes in species and concentrations of polysulfides, validating the ability of NiCoMnFeCrP to facilitate the conversion of polysulfides. The batteries with the NiCoMnFeCrP catalyst as functional separators exhibited minimal capacity decay rates of 0.04 % and 0.23 % after 100 cycles at 0 °C and 60 °C, respectively. This indicates that the NiCoMnFeCrP catalyst possesses good thermal stability. Meanwhile, its area capacity can reach 4.78 mAh cm−2 at a high sulfur load of 4.54 mg cm−2. In conclusion, NiCoMnFeCrP achieves the objective of mitigating the shuttle effect and accelerating the kinetics of the redox reaction, thereby facilitating the commercialization of LSBs. [ABSTRACT FROM AUTHOR]

Copyright of Rare Metals is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The development of lithium–sulfur (Li─S) batteries has been hampered by the shuttling effect of lithium polysulfides (LiPSs). An effective method to address this issue is to use an electrocatalyst to accelerate the catalytic conversion of LiPSs. In this study, heterogeneous MnP‐MnO2 nanoparticles are uniformly synthesized and embedded in porous carbon (MnP‐MnO2/C) as core catalysts to improve the reaction kinetics of LiPSs. In situ characterization and density functional theory (DFT) calculations confirm that the MnP‐MnO2 heterostructure undergo surface sulfidation during the charge/discharge process, forming the MnS2 phase. Surface sulfidation of the MnP‐MnO2 heterostructure catalyst significantly accelerated the SRR and Li2S activation, effectively inhibiting the LiPSs shuttling effect. Consequently, the MnP‐MnO2/C@S cathode achieves outstanding rate performance (10 C, 500 mAh g−1) and ultrahigh cycling stability (0.017% decay rate per cycle for 2000 cycles at 5 C). A pouch cell with MnP‐MnO2/C@S cathode delivers a high energy density of 429 Wh kg−1. This study may provide a new approach to investigating the surface sulfidation of electrocatalysts, which is valuable for advancing high‐energy‐density Li−S batteries. [ABSTRACT FROM AUTHOR]

Despite the very high theoretical energy density, Li‐S batteries still need to fundamentally overcome the sluggish redox kinetics of lithium polysulfides (LiPSs) and low sulfur utilization that limit the practical applications. Here, highly active and stable cathode, nitrogen‐doped porous carbon nanotubes (NPCTs) decorated with NixCo1‐xS2 nanocrystals are systematically synthesized as multi‐functional electrocatalytic materials. The nitrogen‐doped carbon matrix can contribute to the adsorption of LiPSs on heteroatom active sites with buffering space. Also, both experimental and computation‐based theoretical analyses validate the electrocatalytic principles of co‐operational facilitated redox reaction dominated by covalent‐site‐dependent mechanism; the favorable adsorption‐interaction and electrocatalytic conversion of LiPSs take place subsequently by weakening sulfur‐bond strength on the catalytic NiOh2+−S−CoOh2+ backbones via octahedral TM‐S (TM = Ni, Co) covalency‐relationship, demonstrating that fine tuning of CoOh2+ sites by NiOh2+ substitution effectively modulates the binding energies of LiPSs on the NixCo1‐xS2@NPCTs surface. Noteworthy, the Ni0.261Co0.739S2@NPCTs catalyst shows great cyclic stability with a capacity of up to 511 mAh g−1 and only 0.055% decay per cycle at 5.0 C during 1000 cycles together with a high areal capacity of 2.20 mAh cm−2 under 4.61 mg cm−2 sulfur loading even after 200 cycles at 0.2 C. This strategy highlights a new perspective for achieving high‐energy‐density Li‐S batteries. [ABSTRACT FROM AUTHOR]

The inevitable shuttling and slow redox kinetics of lithium polysulfides (LiPSs) as well as the uncontrolled growth of Li dendrites have strongly limited the practical applications of lithium‐sulfur batteries (LSBs). To address these issues, we have innovatively constructed the carbon nanotubes (CNTs) encapsulated Co nanoparticles in situ grown on TiN‐MXene nanosheets, denoted as TiN‐MXene‐Co@CNTs, which could serve simultaneously as both sulfur/Li host to kill "three birds with one stone" to (1) efficiently capture soluble LiPSs and expedite their redox conversion, (2) accelerate nucleation/decomposition of solid Li2S, and (3) induce homogeneous Li deposition. Benefiting from the synergistic effects, the TiN‐MXene‐Co@CNTs/S cathode with a sulfur loading of 2.5 mg cm−2 could show a high reversible specific capacity of 1129.1 mAh g−1 after 100 cycles at 0.1 C, and ultralong cycle life over 1000 cycles at 1.0 C. More importantly, it even achieves a high areal capacity of 6.3 mAh cm−2 after 50 cycles under a sulfur loading as high as 8.9 mg cm−2 and a low E/S ratio of 5.0 μL mg−1. Besides, TiN‐MXene‐Co@CNTs as Li host could deliver a stable Li plating/striping behavior over 1000 h. [ABSTRACT FROM AUTHOR]

Realizing efficient immobilization of lithium polysulfides (LiPSs) as well as reversible catalytic conversion between LiPSs and the insoluble Li2S is vital to restrain the shuttle effect, which requires highly reactive catalysts for highperformance Li-S batteries. Here, three-dimensional ordered porous Mo-based metal phosphides (3DOP Mo3P/Mo) with heterogeneous structures were fabricated and utilized as separator-modified coatings for Li-S batteries to catalyze the conversion of LiPSs. The adsorption, catalytic and electrochemical performance of the corresponding cells were compared among 3DOP Mo3P/Mo and 3DOP Mo, by kinetic and electrochemical performance measurements. It was found that the cell with 3DOP Mo3P/Mo modified separator deliver better electrochemical performance, with a high specific capacity of 469.66 mAh g-1after 500 cycles at a high current density of 1°C. This work provides an idea and a guideline for the design of the separator modification for high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]

The confinement and high utilization of sulfur in the cathodes is critical for improved cycling performance of lithium‐sulfur batteries. In this case one‐pot hydrothermal strategy is developed to produce rGO/MXene/sulfur composite aerogels where sulfur is in situ trapped in the 3D rGO/MXene conductive skeleton. The optimized composite aerogels as free‐standing cathodes delivery a specific capacity of 951 mAhg−1 after 100 cycles at 0.2 C with a low fading rate of 0.062 % per cycle. The excellent cycling performance is correlated with highly oxidized MXene and in situ formed sulfate/thiosulfate complex layer in the long‐term cycles. [ABSTRACT FROM AUTHOR]

The practical application of room‐temperature sodium‐sulfur (RT Na–S) batteries is blocked by the notorious shuttle effect of sodium polysulfides (NaPSs) and sluggish refox reaction kinetics. Single‐atom catalysts (SACs) have been widely studied for boosting the energy storage performance of RT Na‐S batteries. Nevertheless, the catalytic centers of SACs reported so far have focused mainly on symmetrical metal–N4 structures, which offer weak bonding affinity toward polar NaPSs, leading to detrimental shuttle effect and sluggish sulfur conversion kinetics. Herein, a novel asymmetrical Mn–N2 structure is implanted into nitrogen‐doped carbon nanofibers (Mn‐N2/CNs) through thermal NH3 etching of a symmetrical Mn–N2O2 structure. The Mn–N2 structure promotes the bonding affinity and catalytic conversion of NaPSs due to the strengthened d‐p orbital‐hybridization between the d orbital of Mn in the Mn–N2 structure and the p orbital of S in NaPSs. Consequently, Mn‐N2/CNs@S achieves a high capacity of 458 mAh g−1 at 3.0 C with a capacity decay of 0.23% over 2300 cycles. This work offers a promising pathway for regulating the coordination number of SACs with strengthened d‐p orbital‐hybridization for high‐performance RT Na–S batteries. [ABSTRACT FROM AUTHOR]

1,2,3,4,5-pentathiepines (PTEs) are naturally occurring polysulfides of increasing scientific interest based on their identified pharmacological activities. Artificial PTEs with N-heterocyclic backbones are efficiently synthesized via mediation by a molybdenum–oxo-bistetrasulfido complex. A common feature of all precursor alkynes successfully used to date in this reaction is the presence of a –CH(OEt)2 group since the previously postulated mechanism requires the presence of one OEt– as the leaving group, and the second must become a transient ethoxonium moiety. This raised the question of whether there really is a need for two, maybe only one, or possibly even zero ethoxy substituents. This research problem was systematically addressed by respective variations in the precursor-alkyne derivatives and by employing one related allene species. It was found that the total absence of ethoxy substituents prevents the formation of PTEs entirely, while the presence of a single ethoxy group results in the possibility to distinctly functionalize the position on the resulting N-heterocyclic pyrrole five ring in the target compound. This position was previously exclusively occupied by an –OEt for all products of the molybdenum-mediated reaction. The allene was applied with similar success as precursor as with the related alkyne. The now-employable significant change in precursor composition gives access to a whole new PTE subfamily, allowing further modulation of (physico)-chemical properties such as solubility, and provides additional insight into the mechanism of PTE formation; it comprises a merely partial validation of the previous hypothesis. The new alkyne precursors and pentathiepines were characterized by a variety of instrumental analyses (NMR, mass spec, UV–vis) and in six cases (one alkyne precursor, one unexpected side product, and four PTEs) by single-crystal X-ray diffraction. Syntheses, isolation procedures, analytical data, and the impact of the findings on the previously proposed mechanism are described in detail herein. [ABSTRACT FROM AUTHOR]

The room‐temperature sodium‐sulfur (RT Na‐S) batteries have been seriously hindered in their practical application due to the sluggish redox kinetics and incomplete conversion of polysulfides. In this study, a structure‐determined Keggin‐type heteropolyvanadotungstate of H5PW10V2O40·30H2O (PW10V2) is engineered and reveal its catalytic mechanism in RT Na‐S system. With the assistance of precise V sites and highly reversible multi‐electron redox properties, PW10V2 as a bidirectional molecular catalyst expedites the complete conversions between polysulfides and the insoluble sodium sulfide, while undergoing the reversible transformation between its reduced and oxidized states. Furthermore, PW10V2 with multicenter active sites can capture polysulfides efficiently. Consequently, the cell with the constructed PW10V2‐based modified separator achieves the perdurable cyclability up to 4000 loops even at 10 C toward an exceptionally low capacity decay rate of 0.012% per cycle, far surpassing those of current state‐of‐the‐art RT Na‐S batteries that employ the functional materials based on separator. This work first demonstrates the underlying electrochemical reaction processes of polyoxometalate‐based functional materials, which guides solving the challenging issues related to sodium polysulfides in RT Na‐S batteries. [ABSTRACT FROM AUTHOR]

Catalyzing polysulfides conversion for lithium‐sulfur batteries is an efficient strategy to overcome the sluggish kinetics of polysulfides conversion as well as its serious shuttling effect. Due to the multistep and complicated phase transformation of sulfur species, the monofunctional catalyst can hardly promote the overall polysulfides redox process. Herein, a molybdenum‐based heterostructure is proposed, that facilitates the entire reduction process by tandemly catalyzing liquid‐liquid conversion and liquid‐solid conversion. It is uncovered that the MoC physiochemically immobilizes the soluble long‐chain polysulfide and accelerates the conversion between S8 to Li2S4 through adsorbing Li2S8 and extending its S─S bond distance. Then, the kinetics of Li2S precipitation is enhanced by facilitating the migration of Li2S4 from MoC to MoSe2. This is driven by the internal electric field at the heterogeneous interface and the low diffusion energy barrier on MoSe2 for Li2S4. Moreover, MoC‐MoSe2 exhibits the smallest degree of Li2S2 disproportionation throughout the reduction process. Consequently, the cell with MoC‐MoSe2/C/S cathode delivers an initial discharge‐specific capacity of 841.1 mAh g−1 and long‐term cycling stability with a capacity attenuation rate of 0.08% per cycle at 1.0 C. This work presents a novelty view to design a rational multifunction catalyst for sequentially accelerating the stepwise conversion of polysulfides. [ABSTRACT FROM AUTHOR]

Lithium sulfur battery is a novel kind of secondary battery which has high energy density, however its application is greatly affected by the shuttle effect of polysulfides generated in the redox reaction of cathode electrode. Metal active sites are supposed as effective catalysts which can absorb and accelerate the conversion efficiency of lithium polysulfides, thus the shuttle effect will be alleviated. In this work, we conducted a simple way to prepare a metal Fe doped ketjen black to serve as the sulfur host of lithium sulfur battery. Ketjen black has a large specific surface area and rich porous structure, while Fe nanodot is an excellent catalyst for lithium polysulfides. Because of these advantages, the Fe/KB host can effectively confine a large amount of active material and accelerate its, therefore the Fe/KB−S cathode electrode show an excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

Metal sulfide-incorporated graphitic carbon nitride-based semiconductor catalysts have attracted considerable attention in the field of clean energy and environmental remediation because of their low cost, eco-friendliness, high efficiency, and ease of use. Herein, we demonstrate a facile one-pot synthesis of CuS nanoparticles in situ grown on the layered porous sulfur-doped graphitic carbon nitride nanosheets (CuS/S-g-C3N4), which act as a catalyst for the reduction of 4-nitrophenol. 4-Nitrophenol was reduced (converted into 4-aminophenol) by about 89.92% and 99.98% with S-g-C3N4 and CuS/S-g-C3N4 composites, respectively, within 3 min. The results demonstrate that the CuS/S-g-C3N4 nanohybrid composite showed superior catalytic performance compared to bare S-g-C3N4 due to the enhancement caused by increasing the affinity of accessible surface-active edge sites and interfacial contact allowing an effective modification of the electronic structure, high structural porosity, and richness in sulfur vacancy. Further, the fast electron transfer 4-NP reduction mechanism on CuS/S-g-C3N4 was explicated and discussed. Additionally, the CuS/S-g-C3N4 nanocomposite revealed good stability towards catalytic reduction even after repeated usage. Thus, the present study affords an in situ synthesis of CuS on the S-g-C3N4 nanocomposite for improving the catalytic conversion of the nitro group to the amine group. [ABSTRACT FROM AUTHOR]

Polysulfides shuttle and lithium dendrites growth greatly restricts the practical application of lithium–sulfur batteries (LSBs). A rational designed separator combined polysulfide catalyst and lithium regulator can achieve the effect of killing two birds with one stone. Herein, organic–inorganic hybrid materials are designed to construct a complementary interface for LSBs. Specially, two kinds of covalent organic frameworks (COF) with different pore size are in situ grown on the MXene surface by forming Ti–N bond. The high electronic conductivity and abundant surface functional groups of MXene allow it to work as a catalyst to effectively accelerate the polysulfides conversion, while COF can be used as an ion calibrator to guide homogeneous lithium deposition. As expected, the MXene@COF (MCOF) integrated separator realizes complementary advantages that enable a Li||Li symmetric cell to achieve a surprisingly stable lithium plating/stripping process up to 4750 h at 10 mA cm−2. Furthermore, the assembled LSBs exhibit high capacities of 584/563 mAh g−1 at 3 C and low‐capacity decay rates of 0.042%/0.048% per cycle after 1000 cycles at 1 C. This work proposes a strategy of complementary advantages based on the MXene and COF composites in the interface layer, which is of great significance for the separator construction of high‐performance LSBs. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) hold promise for use in next-generation high-energy-density energy storage systems. However, the commercial application of LSBs is hindered by the shuttle effect of polysulfides. In this study, we synthesized a covalent organic framework material (PY−DHBD−COF) and employed it to modify the separators of LSBs in order to buffer the shuttle effect of polysulfides. A modified separator, involving PY−DHBD−COF coating of the commercial Celgard 2500 PP separator, is prepared via a vacuum-assisted self-assembly method. The PY−DHBD−COF features hydroxyl and imine bonds, which can adsorb lithium polysulfides (LiPSs) and buffer the shuttle effect. The PY−DHBD−COF coating exhibits a thin thickness and oriented nanochannels, facilitating electrolyte wetting and Li+ transport. As a result, the LSBs with PY−DHBD−COF-modified separators exhibit a high specific capacity of 373 mAh g−1 at 4 C with only 0.005% capacity decay per cycle after 450 cycles at 2 C, demonstrating an excellent cycling performance. [ABSTRACT FROM AUTHOR]

The discovery of new classes of regulatory molecules in human and animal metabolism always leads to a large-scale study of their properties in the context of biochemistry, physiology, and pharmacology. About 20 years ago, hydrogen sulfide (H2S) and its derivatives called reactive sulfur species (RSS), such as persulfides, polysulfides, nitrosothiols, sulfenic acids, and others became one of such classes of molecules. The participation of RSS in a variety of physiological and pathological processes, including the regulation of vascular tone, inflammation, long-term potentiation in the central nervous system, etc., has been shown. Changes in RSS levels or patterns of modification of their targets are associated with a wide range of cardiovascular, oncological, neurodegenerative, and other pathologies. For a part of these processes, mechanisms have been studied that involve direct modification of regulatory (NF-κB, Keap1) or effector (GAFD, eNOS, TRPA1) proteins through reactions of cysteine residues and metal-containing centers with APS. The presence of different regulated enzymatic systems producing RSS and numerous molecular targets allows us to consider H2S and its derivatives as an important class of small regulatory molecules. H2S is belongs to the class of so-called "gasotransmitters," along with nitric oxide (II) and carbon monoxide. Over the last 20 years, a vast amount of data on the biochemistry of these compounds and approaches to their study has been accumulated. [ABSTRACT FROM AUTHOR]

BACKGROUND: Hot compressed water (HCW), also known as subcritical water (SCW), refers to high‐temperature compressed water in a special physical and chemical state. It is an emerging technology for natural product extraction. The volatile organic compounds (VOCs) generated from the Maillard reaction between l‐ascorbic acid (ASA) and l‐cysteine (Cys) have attracted significant interest in the flavor and fragrance industry. This study aimed to explore the formation mechanism of VOCs from ASA and Cys and examine the effects of reaction parameters such as temperature, time, and pH in HCW. RESULTS: The identified VOCs were predominantly thiophene derivatives, polysulfides, and pyrazine derivatives in HCW. The findings indicated that thiophene derivatives were formed under various pH conditions, with polysulfide formation favored under acidic conditions and pyrazine derivative formation preferred under weak alkaline conditions, specifically at pH 8.0. CONCLUSION: The Maillard reaction between ASA and Cys mainly produced thiophene derivatives, polysulfides, and pyrazine derivatives in HCW. The generation mechanism was significantly dependent on the surrounding pH conditions. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this study, a high-efficiency reduced graphene oxide and Cu 2 S composite counter electrode for quantum dot-sensitized solar cells is investigated via various hydrothermal times (12, 24, and 36 h). Besides, for comparison, Cu 2 S CE was fabricated by hydrothermal and chemical bath deposition methods. The morphology of the nanocomposites was studied using a field emission scanning electron microscope and high-resolution transmission electron microscopy. It confirms the formation of nanoflower-like Cu 2 S intermixed with rGO sheets. The presence of Cu 2 S and rGO in rGO/Cu 2 S composites was identified by X-ray diffraction, selected area electron diffraction, Fourier-transform infrared spectroscopy, and Raman spectra. The chemical composition and purity of rGO/Cu 2 S were examined by X-ray photoelectron spectroscopy. The electrochemical property of the as-fabricated counter electrode was studied by cyclic voltammetry analysis using the sulfide/polysulfide-based electrolyte. The optimum hydrothermal time was 24 h. The power conversion efficiency of 5.187 % for rGO/Cu 2 S 24-h counter electrode is higher than that of reduced graphene oxide (4.013 %), synthesized chemical bath deposition (3.466 %), and hydrothermal Cu 2 S (3.112 %) counter electrodes, respectively. The main reason is the Cu 2 S nanoflower morphology and the conductive reduced graphene oxide network, which provide more catalytically active sites and a rapid electron transport pathway. Overall, the ease of synthesis, low cost, time efficiency, and excellent electrocatalytic characteristics of the rGO/Cu 2 S composites demonstrated a promising counter electrode. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li–S) batteries have received widespread attention as the next-generation energy storage device. The reduction of rate performance and cycle life caused by the shuttle effect is the main obstacle to its commercialization. The modified material of nitrogen-doped carbon modified hollow silica nanotubes (N,C-SNTs) is proposed to suppress the shuttle of polysulfides. The modified material was coated on aramid paper interlayer (AP). The aramid fibre interlayer exhibits excellent flexibility and the interleaved carbon nanotubes in the interlayer can effectively compensate for the poor conductivity of the sulfur electrode. Pure silica nanotubes with hollow structures were selected as the anchoring agent. Firstly, the hollow tubular structure can provide more adsorption sites for polysulfides adsorption than silica spheres, which are highly prone to agglomeration. Second, the polar compound silica can effectively promote the redox reaction of polysulfides. In order to improve the adsorption performance of the materials, we further modified the silica surface using a carbon and nitrogen layer. Combining the strong adsorption performance of the N,C layers and the catalytic oxidation effect of polysulfides of silica, the two synergistically obtain flexible multifunctional interlayers. Therefore, Li–S battery with the modified N,C-SNTs@AP interlayer displayed promising cycle and rate performance. The battery with the N,C-SNTs@AP interlayer retain high specific capacity of 1012 mA h/g after 100 cycles at 0.2C with the capacity retention rate of 86 %. The sulfur mass areal loading increased to 4.1 mg cm−2. The battery can still cycle stably for more than 250 cycles at 1C. The above results indicates that the introduction of N,C-SNTs@AP interlayer should be promising strategy for highly stable Li–S battery. [ABSTRACT FROM AUTHOR]

Due to their low cost, environmental friendliness and high energy density, the lithium-sulfur batteries (LSB) have been regarded as a promising alternative for the next generation of rechargeable battery systems. However, the practical application of LSB is seriously hampered by its short cycle life and high self-charge owing to the apparent shuttle effect of soluble lithium polysulfides. Using MgSO4@MgO composite as both template and dopant, template-guided S-doped mesoporous graphene (SMG) is prepared via the fluidized-bed chemical vapor deposition method. As the polypropylene (PP) modifier, SMG with high specific surface area, abundant mesoporous structures and moderate S doping content offers a wealth of physical and chemical adsorptive sites and reduced interfacial contact resistance, thereby restraining the serious shuttle effects of lithium polysulfides. Consequently, the LSB configured with mesoporous graphene (MG) as S host material and SMG as a separator modifier exhibits an enhanced electrochemical performance with a high average capacity of 955.64 mA h g-1 at 1C and a small capacity decay rate of 0.109% per cycle. Additionally, the density functional theory (DFT) calculation models have been rationally constructed and demonstrated that the doped S atoms in SMG possess higher binding energy to lithium polysulfides than that in MG, indicating that the SMG/PP separator can effectively capture soluble lithium polysulfides via chemical binding forces. This work would provide valuable insight into developing a versatile carbon-based separator modifier for LSB. [ABSTRACT FROM AUTHOR]

Plastics and composites for consumer goods often require flame retardants (FRs) to mitigate flammability risks. Finding FRs that are effective in new sustainable materials is important for bringing them to the market. This study evaluated various FRs in SunBG90 (a composite made from triglycerides and sulfur)—a high sulfur-content material (HSM) promising for use in Li–S batteries, where flame resistance is critical. SunBG90 was blended with FRs from several classes (inorganic, phosphorus-based, brominated, and nitrogen-containing) to assess compliance with UL94 Burning Test standards. Inorganic FRs showed poor flame retardancy and lower mechanical strength, while organic additives significantly improved fire resistance. The addition of 20 wt. % tetrabromobisphenol A enabled SunBG90 to achieve the highest flame retardancy rating (94V-0), while also enhancing wear resistance (52 IW, ASTM C1353) and bonding strength (26 psi, ASTM C482). Selected organic FRs also enhance compressive strength compared to the FR-free SunBG90. This research highlights the potential of HSMs with traditional FRs to meet stringent fire safety standards while preserving or enhancing the mechanical integrity of HSM composites. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) are widely studied as an alternative to lithium-ion batteries, this emphasis being due to their high theoretical energy density and low cost, and to the high natural abundance of sulfur. Lithium polysulfide shuttling and lithium dendrite growth have limited their commercialization. Porous polyvinylidene fluoride (PVDF) separators have shown improved performance (relative to hydrocarbon separators) in lithium-ion batteries due to faster lithium-ion migration and higher Li+ transference number. A thin polar PVDF membrane has now been fabricated via phase inversion (an immersion-precipitation method) yielding a β (polar) phase concentration of 72%. Preparation from commercial PVDF used dimethylformamide (DMF) solvent at the optimized crystallizing temperature of 70 °C, and pores in the membrane were generated by exchange of DMF with deionized water as non-solvent. The polar PVDF film produced has the advantages of being ultrathin (15 µm), lightweight (1.15 mg cm−2), of high porosity (75%) and high wettability (84%), and it shows enhanced thermal stability relative to polypropylene (PP). The porous, polar PVDF membrane was combined with a commercially available PP membrane to give a hybrid, two-layer, separator combination for LSBs. A synergy was created in the two-layer separator, providing high sulfur utilization and curbing polysulfide shuttling. The electrochemical performance with the hybrid separator (PP–β-PVDF) was evaluated in LSB cells and showed good cyclability and rate capability: those LSB cells showed a stable capacity of 750 mA h g−1 after 100 cycles at 0.1 C, much higher than that for otherwise-identical cells using a commercial PP-only separator (480 mA h g−1). [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) battery with high theoretical capacity and high energy density is considered to be a best alternative of Li‐ion battery. However, challenges associated with Li–S batteries are yet to be addressed effectively to enable their commercialization. Uncontrolled shuttling of polysulfides causes rapid capacity decay and low discharge capacity of the battery cell. To address such shuttling effect related to the polysulfide movement, nano‐TiO2‐grafted carbon sheet interlayer is introduced. Proposed material is synthesized by the combined sol–gel and hydrothermal processes. Rietveld analysis is done for the determination of phase(s) present in the material. These are anatase and rutile phases. Scanning and transmission microscopic studies reveal the morphological features of prepared material. Quantitative study of prepared material for its constituents is done by thermogravimetry analysis, which confirms the presence of 83% TiO2. An interlayer of 16 mm diameter is punched out and incorporated in a coin cell assembly. Cell assembled with interlayer shows superior electrochemical performance with initial discharge capacity of 839 mAh g−1 at 0.2 C rate and 63% capacity retention till 100th cycle. Diffusion studies reveal that insertion of interlayer controls the reaction kinetics and supports polar–polar interaction between interlayer and polysulfides. [ABSTRACT FROM AUTHOR]

The shuttle effect of soluble lithium polysulfide (LiPS) is a major obstacle to the practical application of lithium–sulfur (Li–S) batteries. In order to reduce the negative impact of the shuttle effect, Nd-MOF was combined with carbon nanofibers (CNFs) so that Nd-MOF was embedded in the CNFs and the Nd2O3-C/CNF composite was realized as a separation modification material. This embedded structure made the combination between Nd2O3-C and CNFs tighter, and it exhibited better synergistic effects to inhibit the shuttle effect of polysulfides while also enhancing the tensile strength of the separator and improving the safety performance of the battery. Based on these advantages, a lithium–sulfur coin cell with the Nd2O3-C/CNF-modified separator exhibited excellent electrochemical performance. [ABSTRACT FROM AUTHOR]

AbstractInverse vulcanization utilizes alkenyl monomers and elemental sulfur, an excessive by-product of oil and gas refineries, to synthesize dynamically crosslinked sulfur-rich polymers, therefore providing a new way to construct sustainable and versatile materials. The inverse vulcanization of the biological extracts and natural polymers gives rise to a variety of bio-based polysulfides aligning with the concept of green chemistry. In this paper, the development of synthesis strategies, corresponding mechanisms, scope of renewable cross-linking agents, and the properties as well as the potential applications of polysulfides are reviewed. In particular, the progress in the preparation of various polysulfides from fossil resources to bio-based counterparts is deliberated with multiple modification methods elucidated. The bio-derived polysulfides are proved to be outstanding materials and prominent alternatives for traditional petroleum-based products especially for the use as effective ion absorbents, Li-S battery cathode materials, adhesives and controlled release fertilizers, etc. Finally, a few prospects and challenges about the future of these intriguing sulfur-based polymers are raised and discussed. [ABSTRACT FROM AUTHOR]

All‐solid‐state lithium–sulfur batteries (ASSLSBs) are expected to be the next generation of high‐energy battery systems due to their long lifespan and high safety. However, unstable interfaces between elemental sulfur, conductive carbon, and solid electrolytes lead to slow charge transport and mechanical failures, thereby limiting battery performance. Herein, atomic layer deposition‐derived lithium phosphorus oxide is applied to the surface of carbon/sulfur particles to enhance the interfacial stability of the sulfur cathode and improve the electrochemical performance of ASSLSBs. The coating layer can inhibit electrolyte decomposition and improve interfacial stability by blocking electron conduction between carbon and electrolyte. Moreover, it not only serves as an ion‐conducting layer to facilitate Li+ transport but also acts as a stress buffer layer to alleviate contact failure. The assembled ASSLSBs with sulfide electrolyte exhibit an initial specific capacity of 1322 mAh g−1 at 0.2 C and capacity retention of 86.4% after 300 cycles. Furthermore, ASSLSBs maintain a reversible capacity of 645 mAh g−1 at 0.5 A g−1 after 1000 cycles, confirming the long cycling stability of the coated sulfur cathode. Even under high sulfur loading, ASSLSBs achieve high areal capacities of 4.6 mAh cm−2 at 30 °C and 11.7 mAh cm−2 at 60 °C. [ABSTRACT FROM AUTHOR]

The pursuit of efficient host materials to address the sluggish redox kinetics of sulfur species has been a longstanding challenge in advancing the practical application of lithium‐sulfur batteries. In this study, amorphous carbon layer loaded with ultrafine CoP nanoparticles prepared by a one‐step in situ carbonization/phosphating method to enhance the inhibition of 2D black phosphorus (BP) on LiPSs shuttle. The carbon coating layer facilitates accelerated electron/ion transport, enabling the active involvement of BP in the conversion of soluble lithium polysulfides (LiPSs). Concurrently, the ultra‐fine CoP nanoparticles enhance the chemical anchoring ability and introduce additional catalytic sites. As a result, S@BP@C‐CoP electrodes demonstrate exemplary cycling stability (with a minimal capacity decay of 0.054 % over 500 cycles at 1 C) and superior rate performance (607.1 mAh g−1 at 5 C). Moreover, at a sulfur loading of 5.5 mg cm−2, the electrode maintains an impressive reversible areal capacity of 5.45 mAh cm−2 after 50 cycles at 0.1 C. This research establishes a promising approach, leveraging black phosphorus‐based materials, for developing high‐efficiency Li‐S batteries. [ABSTRACT FROM AUTHOR]

Despite of multifarious dominance of sulfur‐based batteries, polysulfide‐shuttling and use of high‐cost organic electrolytes with flammability risks hinder their applicability as commercial devices. Herein a polysulfide‐free aqueous zinc‐sulfur (Zn─S) rechargeable battery is explored, which offers a low‐cost and environmentally friendly energy storage system being Zn and Sulfur (S) highly abundant with high theoretical capacity. However, the stability of Zn anode is quite challenging due to dendritic growth and corrosion leading to the capacity decay. This work showcases the utilization of ethylene glycol (EG) and iodine (I2) as an electrolyte additive in aqueous zinc acetate [Zn(OAc)2] electrolyte for stabilizing the Zn─S battery performance. EG as an additive is able to mitigate the corrosion rate of the Zn electrode by 15 times which is supported by molecular dynamics simulation. The assembled Zn─S battery delivered an outstanding capacity of 1210 mA h g−1 at 0.1 C with a 91% capacity retention even after 250 cycles, along with remarkable reversible prolonged cycling stability of 3000 cycles at 1 C, with 64.5% capacity retention. More importantly, in situ electrochemical Raman spectroscopy is utilized to monitor the real‐time formation of zinc sulfide (ZnS) as a single discharge product and simultaneously debunking the polysulfide shuttling in the system which is further supported by XPS, UV‐Vis and IR spectroscopy. [ABSTRACT FROM AUTHOR]

[Display omitted] The commercial application of lithium-sulfur batteries is primarily impeded by the constant shuttling of soluble polysulfides and sluggish redox kinetics. Nowadays, the discovery of the heterojunction, which combines materials with diverse properties, offers a new perspective for overcoming these obstacles. Herein, a functional coating separator for the lithium-sulfur battery is designed using a MnO 2 -ZnS p-n heterojunction with a spontaneous built-in electric field (BIEF). The MnO 2 nanowire provides suitable adsorption capacity for polysulfides, while the abundant reactive sites brought by ZnS ensure efficient conversion. Moreover, the BIEF significantly facilitates the migration of electrons and polysulfides at the MnO 2 -ZnS interface, enabling a smooth "adsorption-diffusion-conversion" reaction mechanism. By serving as both the adsorption module and catalytic sites, this BIEF allows batteries utilizing separators modified with MnO 2 -ZnS heterojunction to achieve an impressive initial capacity of 1511.1 mAh g−1 at 0.1C and maintain a capacity decay rate of merely 0.048% per cycle at 2.0C after 1000 cycles. Even when increasing sulfur loading to 9.4 mg cm−2 in lean electrolyte (5.4 μL mg−1), the battery still exhibits an ultrahigh areal capacity of 6.0 mAh cm−2 after 100 cycles. [ABSTRACT FROM AUTHOR]

Thiophene is the organic sulfur with good thermal stability in carbon-based fuel, clarifying the conversion mechanism between thiophene and COS is beneficial for achieving in-situ sulfur fixation during CO2 gasification of carbon-based fuels, but the mechanism has rarely been reported. Therefore, calculations based on density functional theory were performed and 16 reaction paths were proposed in this research, clarifying the decomposition mechanism of thiophene and re-fixation mechanism of COS. The attachment of CO2 will lead to the destruction of the thiophene ring and the generation of COS, and CO2 adsorption is the rate-determined step, while the carbon atom that adjacent sulfur atom is the reaction active site. However, the energy barriers of CO2 addition reactions are lower than those of CO2 adsorption reactions, and the energy barrier of reactions occurring on the aliphatics are lower than that occurring on the aromatics. The combination of CO2 and thiophene will thermodynamically lead to the generation of COS and CO. Moreover, gaseous sulfur generated from thiophene decomposition will be converted mutually, while H2S will not be converted into COS. Furthermore, COS will be captured by char, forming solid organic sulfur. The re-fixation of COS will occur on aliphatic chains from the decomposition of aromatics. [ABSTRACT FROM AUTHOR]

All-solid-state lithium batteries (ASSLBs) are increasingly regarded as one of the next-generation energy storage technologies, offering good abuse tolerance, a wide operating temperature range, and a simplified battery system suitable for automotive applications. In the pursuit of cost-effectiveness and battery thermal stability, LiFePO4 (LFP) has recently attracted widespread attention in both industry and academia as a cathode active material for ASSLBs. However, the poor interfacial compatibility between the electrode and electrolytes has significantly hindered the development of LFP-based ASSLBs. In this study, an advanced Li2ZrCl6 (LZC) – Li9.54Si1.74P1.4S11.7Cl0.3 (LiSiPSCl) bilayer electrolyte is rationally designed for LFP-based ASSLBs, aiming to simultaneously achieve favorable interfacial compatibilities with both the LFP cathode layer and alloy anode layer. As a result, the developed LFP-LZC/LZC/LiSiPSCl/Li–In ASSLB can not only deliver a high initial discharge capacity of 144.9 mA h g−1, but also manifest a high-capacity retention up to 89% after 400 cycles at the current density of 1C. The strategy used in this work sheds light on a promising method to engineer stabilized interfaces for LFP-based ASSLBs. [ABSTRACT FROM AUTHOR]

The solubility of long-chain lithium polysulfides (nominally Li2S8) in sulfolane and sulfolane solutions of lithium perchlorate has been studied. It was found that the solubility of sulfur in the species of lithium octasulfide is significantly, by one to two orders of magnitude, higher than the solubility of elemental sulfur. The rate of Li2S8 formation and its solubility decreases, as the concentration of LiClO4 increases. The absorption spectra of Li2S8 are similar to the absorption spectra of elemental sulfur except for the position of the long-wavelength absorption bands, which have a significant bathochromic shift. [ABSTRACT FROM AUTHOR]

This document is an editorial for a special issue on "Valuable Metals Recovery by Mineral Processing and Hydrometallurgy." It emphasizes the importance of metals for society and the need for efficient techniques to process ores and extract metals. The recovery of metals from secondary sources, such as mining waste, is also highlighted. The editorial discusses various aspects and challenges of metal recovery, including the use of flotation in mineral beneficiation and the application of hydrometallurgical methods. It presents studies on grinding media, pulp oxidation-reduction potential, and the use of new reagents for metal recovery. The editorial also explores the extraction of metals from refractory ores and mining waste. Overall, the papers in this special issue demonstrate the potential for recovering valuable metals from various sources using modern techniques and theoretical frameworks. [Extracted from the article]

Recovering manganese from waste batteries is an important issue to promote the development of new energy. Herein, nickel sulfate and cobalt sulfate, representative impurities in waste battery leachate, are selected to examine their influence on the crystallization thermodynamics and crystal nucleation of manganese sulfate monohydrate. This work assessed alterations in solubility and metastable zone width (MSZW) due to the presence of impurities. The results showed a decrease in manganese sulfate monohydrate solubility in water with increasing impurity concentrations of either nickel sulfate or cobalt sulfate. The effects of initial concentration, heating rate, and impurity concentration on MSZW demonstrated a consistent increase in MSZW as these factors increased. The MSZW data are fitted using the self‐consistent Nývlt‐like model and the classical 3D nucleation theory model. The results revealed a general increase in the nucleation rate constant, K, with increasing saturation temperature or decreasing nickel sulfate concentration. Conversely, the solid‐liquid interface energy, γ, generally decreases with increasing saturation temperature or decreasing nickel sulfate concentration. Based on the influence observed on the interface energy, a possible mechanism is proposed that suggests that impurities inhibit crystal nucleation through adsorption. [ABSTRACT FROM AUTHOR]

The diffusion and loss of lithium polysulfides (LiPSs) in lithium-sulfur batteries (LSBs) reduce the sulfur utilization rate and the catalytic conversion efficiency of sulfur species, resulting in early battery failure. Li2ZnTi3O8 (LZTO), characterized by its stable spinel structure, exhibits high Li+ conductivity and holds great potential as an effective adsorbent for LiPSs. This study proposes a collaborative design concept of LZTO host-separator modifier, which offers a complementary and matching approach in the cathode side, effectively addressing the challenges associated with dissolution and inadequate conversion of LiPSs. Density functional theory (DFT) calculation substantiates the pronounced chemical affinity of LZTO towards LiPSs. More importantly, the high efficiency ion transport channels are achieved in separator coating due to the presence of the LZTO particles. Furthermore, the catalytic efficacy of LZTO is validated through meticulous analysis of symmetric batteries and Tafel curves. Consequently, the LZTO host-separator modifier-based cell displays satisfactory rate capability (1449 and 1166 mAh·g−1 at 0.1 and 0.5 C) and an impressively capacity (606 mAh·g−1 after 500 cycles at 1 C). The coordinated strategy of host-separator modifier is supposed to have wide applications in LSBs. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have high energy density and are one of the most promising secondary batteries to alleviating energy scarcity, but many aspects limit their practical applications. Among them, the shuttle effect produced when soluble polysulfides pass through the separator is a big reason for the slow progress in commercialization. In this study, N-doped vanadium pentoxide materials (SZV) were designed and synthesized as a functional material for separator. The SZV material provides abundant adsorption sites and catalytic sites and can effectively inhibit the shuttle effect of polysulfides. The first cycle discharge capacity was 982 mAh g−1 at 1 C, and the capacity decay was only 0.056% per cycle after 1400 cycles. The SZV separator battery have an initial capacity of 869 mAh g−1 at 4 C and retain a capacity of 648 mAh g−1 after 200 cycles. Notably, the modified separator batteries can adapt to temperature changes and show excellent cycling performance. The SZV separator battery has a capacity of 700 mAh g−1 at 60 °C and 864 mAh g−1 at 10 °C after 100 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

The electrochemical output of lithium‐sulfur batteries is highly restricted by the dissolution and shuttling of polysulfide intermediates, which leads to the polysulfide shuttle effect. The binary metal sulfides offer a greater number of active sites and better polysulfide interaction compared to the unitary metal sulfides. Herein, a nickel cobalt sulfide‐carbon nanotube nanocomposite is devised as a highly efficient separator coater for high‐energy Li‐S batteries. The nanocomposite is featured with superior polysulfide confinement ability due to its dual metal sites and improved ionic and electronic conductivity. The material also possesses enhanced electrolyte wettability, better interfacial properties, and frequent electrolyte uptake. By virtue of the above‐mentioned superiorities, the cell reveals an initial discharge capacity of 1152 mAh g−1 at 0.5 C rate and maintains a retained capacity of 82% after 500 cycles. The cell also shows significant electrochemical results with a magnificent rate delivery of 714 mAh g−1 at 2 C rate and maintains a constant open‐circuit potential for 100 h. [ABSTRACT FROM AUTHOR]

Abstract Room‐temperature sodium‐sulfur (RT Na‐S) batteries are a promising next‐generation energy storage device due to their low cost, high energy density (1274 Wh kg−1), and environmental friendliness. However, RT Na‐S batteries face a series of vital challenges from sulfur cathode and sodium anode: (i) sluggish reaction kinetics of S and Na2S/Na2S2; (ii) severe shuttle effect from the dissolved intermediate sodium polysulfides (NaPSs); (iii) huge volume expansion induced by the change from S to Na2S; (iv) continuous growth of sodium metal dendrites, leading to short‐circuiting of the battery; (v) huge volume expansion/contraction of sodium anode upon sodium plating/stripping, causing uncontrollable solid‐state electrolyte interphase growth and “dead sodium” formation. Various strategies have been proposed to address these issues, including physical/chemical adsorption of NaPSs, catalysts to facilitate the rapid conversion of NaPSs, high‐conductive materials to promote ion/electron transfer, good sodiophilic Na anode hetero‐interface homogenized Na ions flux and three‐dimensional porous anode host to buffer the volume expansion of sodium. Heterostructure materials can combine these merits into one material to realize multifunctionality. Herein, the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed. First of all, the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na‐S batteries are described. Then, the application of heterostructures in Na‐S batteries is comprehensively examined. Finally, the current primary avenues of employing heterostructures in Na‐S batteries are summarized. Opinions and prospects are put forward regarding the existing problems in current research, aiming to inspire the design of advanced and improved next‐generation Na‐S batteries.