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Asymmetrically coordinated single‐atom catalysts are attractive for the implementation of high‐performance lithium–sulfur (Li─S) batteries. However, the design principle of the asymmetric coordination that can efficiently promote bidirectional conversion of polysulfides has not been fully realized. Herein, a series of Co─N3X1 (X refers to F, O, Cl, S, or P) configurations are established, and theoretically unravel that the relative electronegativity value (REV) can be used as an index parameter for characterizing the catalytic activity. By virtue of enhanced chemical affinity with sulfur species and lowered Li2S decomposition, chlorine‐atom‐constructed asymmetric configurations with an optimal REV exhibit stronger catalytic effect to inhibit shuttling. Such a REV‐related catalytic effect is termed as REV effect. Following this principle, a novel single‐atom catalyst with dominated Co─N3Cl1 configuration is successfully synthesized through an inside‐out thermal reaction strategy and used as a modified layer on the cathode‐side separator. Interestingly, the assembled Li─S batteries exhibit quite high rate capacity (804.3 mAh g−1 at 5.0 C), durable cyclability (0.023% capacity decay per cycle), and competitive areal capacity (7.0 mAh cm−2 under 7.5 mg cm−2 sulfur loading and lean electrolyte). The guideline provided in this work gives impetus to the pursuit of highly efficient single‐atom catalysts for practical Li─S batteries. [ABSTRACT FROM AUTHOR]

Schematic diagram of the whole process for detecting sulfur-containing components in lithium-sulfur batteries, including graded leaching, efficient oxidation and precise quantitative detection. [Display omitted] • A highly effective approach for the graded leaching and precise quantitative detection techniques of sulfur-containing components within Li-S batteries has been successfully developed. The total detection rate of this method for sulfur-containing components in Li-S batteries exceeds 99 %. • Clarify that the presence of lithium polysulfide in the electrolyte after discharge is the main factor for restricting the full utilization of Li-S batteries' capacity, and propose targeted improvement measures. • This study offers a considerably refined and comprehensive methodology for the capacity fading and failure mechanisms assessment of high-energy-density Li-S batteries. Lithium-sulfur (Li-S) batteries are a strong contender for the new-generation battery system to meet the growing energy demand due to their significantly high energy density (2600 Wh/kg) and cost-effectiveness. However, the practical operating conditions yield an initial capacity of less than 80 % of the theoretical capacity, resulting in a limited lifespan and hindering broader application. What's worse, current mechanism, especially the evolution process of sulfides for the initial capacity degradation is not clear due to the practical difficulties of effective separation and detection of sulfur-containing components. Herein, we have developed an instrumental analysis method enabling graded leaching and quantitative determination of sulfur-containing components. This technology achieves a detection precision surpassing 99.11 %, addressing the inherent deficiency in calculating sulfur-containing components using the decrement method. Applying this method reveals that the presence of lithium polysulfides in the electrolyte (26.34 wt%) after discharging is the primary factor causing insufficient capacity utilization in Li-S batteries. This work not only demonstrates the unique behavior of Li-S batteries at high sulfur loading but also provides a systematic evaluation method to guide further research on high-energy-density batteries, and provides theoretical and technical support to promote the development of high-energy, long-life Li-S batteries. [ABSTRACT FROM AUTHOR]

Lithium polysulfides (LiPSs) are pivotal intermediates involved in all the cathodic reactions in lithium–sulfur (Li−S) batteries. Elucidating the solvation structure of LiPSs is the first step for rational design of electrolyte and improving Li−S battery performances. Herein, we investigate the solvation structure of LiPSs and find that Li salt anions tend to enter the first solvation sheath of LiPSs and form contact ion pairs in electrolyte. The anion‐involved solvation structure of LiPSs significantly influences the intrinsic kinetics of the sulfur redox reactions. In particular, the LiPS solvation structure modified by lithium bis(fluorosulfonyl)imide endows Li−S batteries with reduced polarization and enhanced rate performances under high sulfur areal loading and lean electrolyte volume conditions. This work updates the fundamental understanding of the solvation chemistry of LiPSs and highlights electrolyte engineering for promoting the performances of Li−S batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have attracted attention as promising next‐generation batteries due to their remarkably high capacity compared to lithium‐ion batteries and the low cost of sulfur. However, one of the inherent problems of LSBs is the "shuttle effect," which causes lithium metal anode instability and capacity fading. This is still a major barrier that must be overcome before it is used in the industry. Therefore, to commercialize LSBs, it is essential to suppress this shuttle effect. From this point of view, this review focuses on the categorization of the methods and materials for interlayer and separator modification, which is one of the effective ways to address the shuttle effect. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Guangdong University of Technology is the property of Journal of Guangdong University of Technology 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 severe shuttle effect and the sluggish redox reaction kinetics are the two most urgent issues with lithium-sulfur batteries (LSBs). In this work, Se vacancy-rich molybdenum selenide-modified graphene aerogels are designed to serve as both cathode host ( MoSe2-x@GA/S) and freestanding interlayers ( MoSe2-x@GA) for LSBs. The graphene network-supported binder-free sulfur host maximizes electron conductivity/Li+ migration rate and alleviates bulk expansion. The defect-rich MoSe2-x with sulfiphilic-lithiophilic properties accelerates the nucleation and dissociation of Li2S, while the insertion of a bifunctional interlayer not only facilitates the adsorption and conversion of polysulfides but also regulates the uniform lithium deposition and inhibit the growth of lithium dendrites. As a result, the assembled MoSe2-x@GA/S+interlayer electrode obtains good feedback in terms of capacity enhancement and cycling stability, possessing a high initial discharge capacity of 1256.9 mA h g-1 at 0.2 C and a slow decay ratio of 0.024% per cycle at a high current density of 1 C after 1000 long-term cycling, and achieve high specific capacity (720.6 mA h g-1) at high sulfur loading (4.8 mg cm-2) and lean electrolyte (5.5 µL mg-1) conditions. This insightful work contributes new ideas for the design of binder-free sulfur host and the application of defective electrocatalytic engineering. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries have been garnered significant attention in the energy storage field due to their high theoretical specific capacity and low cost. However, Li–S batteries suffer from issues like the shuttle effect, poor conductivity, and sluggish chemical reaction kinetics, which hinder their practical development. Herein, a novel hollow flower-like architecture composed of MoS2/Mo2C heterostructures in N-doped carbon substrate (H-Mo2S/Mo2C/NC NFs), which were well designed and prepared through a calcination-vulcanization method, were used as high-efficiency catalyst to propel polysulfide redox kinetics. Ex situ electrochemical impedance spectroscopy verify that the abundant heterojunctions could facilitate electron and ion transfer, revealed the excellent interface solid–liquid–solid conversion reaction. The adsorption test of Li2S6 showed that Mo2S and Mo2C formed heterostructure generate the binding of polysulfide could be enhanced. And cyclic voltammetry test indicate boost the polysulfide redox reaction kinetics and ion transfer of H-Mo2S/Mo2C/NC/S NFs cathode. Benefiting from the state-of-the-art design, the H-Mo2S/Mo2C/NC/S NFs cathode demonstrates remarkable rate performance with a specific capacity of 1351.9 mAh g−1 at 0.2 C, when the current density was elevated to 2 C and subsequently reverted to 0.2 C, the H-Mo2S/Mo2C/NC/S NFs cathode retained a capacity of 1150.4 mAh g−1, and it maintains exceptional long cycling stability (840 mA h g−1 at 2 C after 500 cycles) a low capacity decay of 0.0073% per cycle. This work presents an effective approach to rapidly fabricating multifunctional heterostructures as an effective sulfur host in improving the polysulfide redox kinetics for lithium sulfur batteries. [ABSTRACT FROM AUTHOR]

The deployment of Li–S batteries in the commercial sector faces obstacles due to their low electrical conductivity, slow redox reactions, quick fading of capacity, and reduced coulombic efficiency. These issues stem from the "shuttle effect" associated with lithium polysulfides (LiPSs). In this work, a haystack-like CeO2 derived from a cerium-based metal-organic framework (Ce-MOF) is obtained for the modification of a polypropylene separator. The carbon framework and CeO2 coexist in this haystack-like structure and contribute to a synergistic effect on the restriction of LiPSs shuttling. The carbon network enhances electron transfer in the conversion of LiPSs, improving the rate performance of the battery. Moreover, CeO2 enhances the redox kinetics of LiPSs, effectively reducing the "shuttle effect" in Li–S batteries. The Li–S battery with the optimized CeO2 modified separator shows an initial discharge capacity of 870.7 mAh/g at 2 C, maintaining excellent capacity over 500 cycles. This research offers insights into designing functional separators to mitigate the "shuttle effect" in Li–S batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) are recognized as among the best potential alternative battery systems to lithium-ion batteries and have been widely investigated. However, the shuttle effect has severely restricted the advancement in their practical applications. Here, we prepare vanadium nitride (VN) nanoparticles grown in situ on a nitrogen-doped carbon skeleton (denoted as VN@NC) derived from the MAX phase and use it as separator modification materials for LSBs to suppress the shuttle effect and optimize electrochemical performance. Thanks to the outstanding catalytic performance of VN and the superior electrical conductivity of carbon skeleton derived from MAX, the synergistic effect between the two accelerates the kinetics of both lithium polysulfides (LiPSs) to Li2S and the reverse reaction, effectively suppresses the shuttle effect, and increases cathode sulfur availability, significantly enhancing the electrochemical performance of LSBs. LSBs constructed with VN@NC-modified separators achieve outstanding rate performance and cycle stability. With a capacity of 560 mAh g−1 at 4 C, it exhibits enhanced structural and chemical stability. At 1 C, the device has an incipient capacity of 1052.4 mAh g−1, and the degradation rate averaged only 0.085% over 400cycles. Meanwhile, the LSBs also show larger capacities and good cycling stability at a low electrolyte/sulfur ratio and high surface-loaded sulfur conditions. Thus, a facile and efficient way of preparing modified materials for separators is provided to realize high-performance LSBs. [ABSTRACT FROM AUTHOR]

The shuttle effect in lithium–sulfur batteries, which leads to rapid capacity decay, can be effectively suppressed by solid polymer electrolytes. However, the lithium-ion conductivity of polyethylene oxide-based solid electrolytes is relatively low, resulting in low reversible capacity and poor cycling stability of the batteries. In this study, we employed the activator generated through electron transfer atom transfer radical polymerization to graft modify the surface of silica nanoparticles with a bifunctional monomer, 2-acrylamide-2-methylpropanesulfonate, which possesses sulfonic acid groups with low dissociation energy for facilitating Li+ migration and transfer, as well as amide groups capable of forming hydrogen bonds with polyethylene oxide chains. Subsequently, the modified nanoparticles were blended with polyethylene oxide to prepare a solid polymer electrolyte with low crystallinity and high ion conductivity. The resulting electrolyte demonstrated excellent and stable electrochemical performance, with a discharge-specific capacity maintained at 875.2 mAh g−1 after 200 cycles. [ABSTRACT FROM AUTHOR]

Nitrogen-doped hierarchical porous carbon microspheres derived from low-cost biomass with surface-coated AlF 3 nanolayers as multifunctional sulfur hosts. Based on the synergistic effect of enhancing conductivity, buffering volume deformation, and limiting the shuttle effect, the cathode developed here exhibits superior electrochemical performance. This work presents a facile, sustainable, and efficient strategy for developing advanced lithium-sulfur batteries. [Display omitted] The electrically insulating and volumetric deformation of sulfur and the shuttle effect of the intermediate lithium polysulfide (LiPSs) have severely hindered the development of lithium-sulfur batteries (LSBs). Herein, a synergistic strategy of hierarchical porous nitrogen-doped carbon microspheres (PNCM) derived from low-cost biomass with surface-coated AlF 3 nanolayer as a multifunctional sulfur host (denoted as PNCM@S@AlF 3) was developed. The PNCM not only possesses an abundant pore structure, large surface area, and high electrical conductivity but also features an intrinsic N -doped and fluorinated framework, which effectively enhances the physical adsorption and chemical anchoring to LiPSs. In addition, the AlF 3 nanolayer protects the open surface of the porous carbon to isolate sulfur species from the electrolyte to reduce irreversible losses while accelerating the redox kinetics of LiPSs through strong polar adsorption and bonding. Hence, the PNCM@S@AlF 3 cathode exhibits an initial capacity as high as 1176.2 mAh/g at 0.2C, and the cycling stability and rate capability are superior to that of PNCM@S without AlF 3 coating. Impressively, the PNCM@S@AlF 3 cathode delivers stable long-term cycling performance at a high rate of 2C, with 95.6% capacity retention after 500 cycles. This work presents a facile, sustainable, and efficient synergistic strategy for developing advanced LSBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Although lithium-sulfur (Li-S) batteries have attracted a great deal of attention due to their ultrahigh energy density, the significant dissolution and shuttle of polysulfides, coupled with the unstable electrode structure, result in a substantial decline in capacity, thereby hindering their practical application in rapidly advancing energy storage systems. In this work, we prepare an environmentally friendly binder (LA-GA) that possesses self-healing abilities and high adhesion by combining dynamic disulfide (S S) bonds with abundant polar functional groups. Significantly, the self-healing capability provided by S S bonds facilitates the repair of cracks resulting from cathode volume expansion. Simultaneously, the polar functional groups (carboxyl and pyrogallol) not only enhance adhesion, preserving cathode integrity, but also effectively participate in lithium polysulfide adsorption, thereby inhibiting the shuttle effect. As a result, sulfur cathodes incorporating the LA-GA binder demonstrate favorable cycling stability, with a high capacity retention of 81.9 % when tested at 0.2C for 100 cycles. Additionally, the long-term cycling performance is satisfactory, showing a small capacity decline rate of 0.0469 % per cycle over 700 cycles at 1.0C. [ABSTRACT FROM AUTHOR]

[Display omitted] • CoSe 2 @C as adsorption-catalytic mediator for high performance Li-S batteries. • The CoSe 2 @C cube structure effectively alleviate the migration of polysulfides. • The interaction between CoSe 2 and S drives the enhancement of redox kinetics. • Li-S batteries achieved fine rate properties and enduring lifespan. Although lithium-sulfur batteries (LSBs) are an attractive next-generation rechargeable battery with high theoretical energy density (2600 Wh kg−1) and specific capacity (1675 mA h g−1), the shuttle of soluble lithium polysulfides (LiPSs) is still the protruding obstacle to accelerate the redox reaction of LSBs. Here, cubic cobalt diselenide@carbon (CoSe 2 @C) derived from zeolite imidazole framework-67 (ZIF-67) was employed as the functional coating of polypropylene (PP) separator to efficiently adsorb and catalyze polysulfides, inhibit "shuttle effect" and improve the electrochemical reaction kinetics of LSBs. The CoSe 2 @C offers larger mesopore proportion of 77.19 % and abundant active sites to ensure space as a secondary reaction region, and infiltration of electrolyte and rapid transport of Li+. The involved adsorption and catalysis effect are discussed by static adsorption experiment, XPS, and Li 2 S nucleation kinetics analysis. The results show that CoSe 2 @C exhibits strong adsorption effect and catalytic activity on LiPSs, and CoSe 2 @C/PP cells display fast Li+ diffusion and improved redox kinetics (high Li 2 S nucleation peak current of 0.27 mA and deposition capacity of 148.46 mA h g−1). Ascribe to these advantages, the CoSe 2 @C/PP cell provides an initial discharge specific capacity of 1335.01 mA h g−1 at 0.1 C and a fine reversible capacity at 5.0 C, and achieves stable and durable lifespan with an average capacity decay rate of 0.12 % over 400 cycles at 0.5 C. This work could promote the practical application of metal selenides in the key components and devices for LSBs. [ABSTRACT FROM AUTHOR]

Achieving healthy active‐material microenvironment (ME@AM) for stable and efficient electron/ion transport around each active‐material particle is crucial for high‐performance battery electrodes. However, this goal has been proved extremely challenging for most high‐capacity AMs such as sulfur, owing to its notable volume change and severe shuttle effect. Here, a multifunctional hybrid material with zein protein reinforced catalytic single Cu atom/carbon composite (Cu─C) (zein/Cu─C) is coated onto sulfur/carbon (SC) particle, to prepare the advanced zein/Cu─C@SC core–shell particle. Similar to the multifunctional cell membrane well‐known in biology, this multifunctional zein/Cu─C coating helps build a healthy and stable ME@AM within sulfur cathode. Specifically, it can simultaneously provide robust protective shell for the AM particle, adsorption and catalyst function to the dissolved polysulfides, and AM surface treatment to improve AM/conductive agent interface. All these functions are the keys to build and maintain a healthy ME@AM in sulfur cathode. This study not only brings effective solutions to the challenges in volume‐change high‐capacity sulfur active materials and beyond, but also helps achieve comprehensive understanding of the key factors controlling the structuring and final quality of ME@AM. [ABSTRACT FROM AUTHOR]

The implementation of a functional separator represents a highly encouraging approach to mitigating polysulfide shuttling in lithium–sulfur (Li–S). In this study, a two-dimensional (2D) 1,3,5-triformylphloroglucinol (Tp)-p-phenylenediamine (Pa) covalent organic framework/reduced graphene oxide (rGO) functional layer was introduced to enhance the performance of the commercial separator in Li–S batteries. The resulting 2D TpPa@rGO modified separators exhibit significantly improved electronic and ionic conductivity when compared to the unmodified separator, effectively mitigating lithium polysulfide shuttling and enhancing sulfur cathode utilization. It is indicated that a heterostructured composite of a nitrogen-group-containing COF and an electronic conductive addictive is an effective modification to the separator. Consequently, the modified cell demonstrated a minimal degradation rate of only 0.12% per cycle over 350 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li‐S) batteries have received tremendous academic and industrial attentions owing to their ultrahigh energy density. However, technical challenges including lithium dendrite formation, polysulfide shuttling and sluggish sulfur reaction kinetics limit their cycle life, rate capability and areal capacity, especially at practically high sulfur loadings. Here, coordination‐engineered graphite carbon nitrides is proposed to effectively address these challenges. On the anode a layer of novel N‐rich graphitic carbon nitride (g‐C3N5) is applied, in which tricoordinated N atoms display strong affinity to Li+, to guide lithium deposition and efficiently inhibit dendrite formation. Besides, a layer of defective g‐C3N5 carrying highly active bicoordinated N vacancies and cyano N atoms is applied on the cathode, which significantly adsorb polysulfides and catalyze the reversible conversion, as well as the nucleation and dissolution of Li2S thereby outcompeting polysulfide shuttling and raising kinetics at high sulfur loading. This coordination‐engineering strategy based on g‐C3N5 enables Li‐S batteries exhibiting high stability and low capacity‐fading‐rate (0.03% per cycle) in 400 cycles at the high current rate of 4 C, as well as Li‐S pouch cells showing a high areal capacity of 11.69 mAh cm−2 at a high sulfur loading of 9.02 mg cm−2, demonstrating the feasibility of Li‐S batteries in practical applications. [ABSTRACT FROM AUTHOR]

Lithium-sulfur (Li-S) batteries, known for their high energy density, are attracting extensive research interest as a promising next-generation energy storage technology. However, their widespread use has been hampered by certain issues, including the dissolution and migration of polysulfides, along with sluggish redox kinetics. Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity, strong chemical adsorption with polysulfides, and remarkable electrocatalytic capabilities for polysulfide conversion. In this review, the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized, with a special focus on sulfur hosts and functional separators. The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials' structure and electrochemical performances. Moreover, the remaining issues/challenges and future perspectives are highlighted. By offering a detailed understanding of the crucial roles of metal sulfides, this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur (Li−S) batteries emerge as compelling contenders for next‐generation energy‐storage devices, boasting a noteworthy mass‐specific energy of 2600 Wh kg−1. However, the cycle stability and commercialization of Li−S batteries encounter challenges because of polysulfide shuttle and uncontrolled lithium dendrite growth. In this study, we present a polyoxometalates‐based dual‐function [PMo12O40]3− cluster@carbon nanotube modified polypropylene (PP) separator (PMo12@CNT/PP) to regulate polysulfide transformation and safeguard the lithium anode in Li−S batteries. Leveraging its multi‐electron redox properties and stable cluster structure, the PMo12 cluster acts as a polysulfide mediator, effectively capturing and promoting electrochemical polysulfide transformation. The incorporation of CNT fosters consistent Li‐ion nucleation, stabilizes the lithium anode, and impedes dendrite formation throughout cycling. Hence, Li−S cells equipped with the PMo12@CNT/PP separator display higher capacity and better stability (675 mAh g−1 at 3.0 C and 0.02 % capacity decay per cycle over 700 cycles). The pouch cells with a sulfur loading 4.5 mg cm−2 exhibit an initial discharge specific capacity of 925 mAh g−1 at 0.1 C, and remain 849 mAh g−1 after 40 cycles, underscoring the significant potential for practical applications of Li−S batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries promise high‐energy‐density potential to exceed the commercialized lithium‐ion batteries but suffer from limited cycling lifespan due to the side reactions between lithium polysulfides (LiPSs) and Li metal anodes. Herein, a three‐way electrolyte with ternary solvents is proposed to enable high‐energy‐density and long‐cycling Li–S pouch cells. Concretely, ternary solvents composed of 1,2‐dimethoxyethane, di‐isopropyl sulfide, and 1,3,5‐trioxane are employed to guarantee smooth cathode kinetics, inhibit the parasitic reactions, and construct a robust solid electrolyte interphase, respectively. The cycling lifespan of Li–S coin cells with 50 µm Li anodes and 4.0 mg cm−2 sulfur cathodes is prolonged from 88 to 222 cycles using the three‐way electrolyte. Nano‐heterogeneous solvation structure of LiPSs and organic‐rich solid electrolyte interphase are identified to improve the cycling stability of Li metal anodes. Consequently, a 3.0 Ah‐level Li–S pouch cell with the three‐way electrolyte realizes a high energy density of 405 Wh kg−1 and undergoes 27 cycles. This work affords a three‐way electrolyte recipe for suppressing the side reactions of LiPSs and inspires rational electrolyte design for practical high‐energy‐density and long‐cycling Li–S batteries. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g‐C3N4) is a highly recognized two‐dimensional semiconductor material known for its exceptional chemical and physical stability, environmental friendliness, and pollution‐free advantages. These remarkable properties have sparked extensive research in the field of energy storage. This review paper presents the latest advances in the utilization of g‐C3N4 in various energy storage technologies, including lithium‐ion batteries, lithium‐sulfur batteries, sodium‐ion batteries, potassium‐ion batteries, and supercapacitors. One of the key strengths of g‐C3N4 lies in its simple preparation process along with the ease of optimizing its material structure. It possesses abundant amino and Lewis basic groups, as well as a high density of nitrogen, enabling efficient charge transfer and electrolyte solution penetration. Moreover, the graphite‐like layered structure and the presence of large π bonds in g‐C3N4 contribute to its versatility in preparing multifunctional materials with different dimensions, element and group doping, and conjugated systems. These characteristics open up possibilities for expanding its application in energy storage devices. This article comprehensively reviews the research progress on g‐C3N4 in energy storage and highlights its potential for future applications in this field. By exploring the advantages and unique features of g‐C3N4, this paper provides valuable insights into harnessing the full potential of this material for energy storage applications. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) have received substantial interest because their theoretical energy density is considerably higher than that of conventional lithium-ion batteries. However, the difficulty in confining the soluble intermediate polysulfide (PS) species of LSBs hinders the prolonged cycling of the cell. In this study, a Spartina anglica-derived carbon-coated polyethylene (PE) separator (SC-coated PE separator), which can confine the PS species on the cathode side, is developed to improve the cycling retention of LSBs. Spartina anglica, which is considered a predominant marine waste, is converted to task-specific carbon materials via size-controlled milling and carbonization, and is embedded on a PE separator through a simple casting process. The SC-coated PE separator improves the electrolyte affinity, which is characterized by measuring the contact angle, electrolyte uptake, and transference number of Li+; consequently, the migration of Li+ is undisturbed in the cell, even if an additional layer is formed on the PE separator. Based on the electrochemical performance, the SC-coated PE separator exhibits a higher initial specific capacity than the PE separator, in addition to a remarkably increased cycling retention (65.3% vs. 27.7%) after 100 cycles. The SC-coated PE separator effectively inhibits the PS species through physical absorption, thereby increasing the utilization of the active sulfur species. Moreover, the SC-coated PE separator presents a relatively stable interfacial morphology of the cycled Li anode, revealing that the comprehensive interfacial stability of the Li–S cell is enhanced by effectively confining the PS species in the cell. [ABSTRACT FROM AUTHOR]

In this study, the cathode was coated with Super P, a low-cost conductive carbon, to simplify the process and reduce cost. Electrodes with different sulfur ratios were assembled into cells to characterize their CV curves and impedances. The S0.6-sp cell shows a high discharge capacity of 600 mAh g−1 at 2 C and 967 mAh g−1 at 0.5 C. These values are 10% and 25% higher, respectively, compared to S0.53 cells with the same carbon-to-sulfur ratio. Afterward, the S0.6-sp cell was disassembled to observe the suppression of the shuttle effect by confirming the appearance of the separator. In addition, through SEM images, electrode structure collapse caused by the Li2S/Li2S2 layer was insignificant. [ABSTRACT FROM AUTHOR]

Lithium sulfide (Li2S) as a cathode material for lithium-sulfur (Li-S) batteries, one of the most promising advanced batteries in the future, has received tremendous attention in the past decades. However, developing the practical Li2S cathode confronts challenges of low conductivity for Li-ions and electrons, high sensitivity to environmental moisture, big overpotential barrier to electrochemical activation, and poor cyclability due to the shuttle effect of intermediate species. This article herein reports a simple and effective strategy for making Li2S@Li2S2@Li2S6 double-shelled microparticles, which can significantly mitigate these problems. They are synthesized by dissolving Li2S together with S in dimethoxyethane, then drying off the solvent, and finally calcining the collected solid. Compared with pure Li2S, such a double-shell material presents a 26.7% improvement in cycling capacity, 0.5 V lower in activation overpotential, and prolonged tolerance in the ambient environment. The density functional theory calculation shows that the performance enhancement lies in the higher stability of Li2S6 in contact with moisture and some autocatalytic effect of Li2S2@Li2S6. Such a double-shell structure becomes a universal performance-enhancing approach when being combined with other means, such as cathodes composited with catalytic MoS2, separators modified with selenium-doped sulfurized-polyacrylonitrile/montmorillonite, electrolytes containing fluorenone additive, and Li anodes coated with a layer of Li3N. The corresponding capacity retention shows up to 80% improvement compared with pure Li2S. [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 construction of lithium–sulfur battery cathode materials while simultaneously achieving high areal sulfur‐loading, adequate sulfur utilization, efficient polysulfides inhibition, rapid ion diffusion, etc. remains a major challenge. Herein, an internal regulatory strategy to fabricate the unique walnut‐like yolk–shell carbon flower@carbon nanospheres is presented (WSYCS) as sulfur hosts. The internal carbon flower, suitable cavity, and external carbon layer effectively disperse the insulate sulfur, accommodate volumetric expansion, and confine polysulfides, thus improving the performance of lithium–sulfur batteries. The finite element simulation method also deduces the enhanced Li+ diffusion and lithium–sulfur reaction kinetics. More importantly, WSYCS2 is grafted onto carbon fiber (CF) by electro‐spinning method to form a tandem WSYCS2@CF 3D film as a sulfur host for the free‐standing electrode. The corresponding battery exhibits an extremely high areal capacity of 15.5 mAh cm−2 with a sulfur loading of 13.4 mg cm−2. Particularly, the flexible lithium–sulfur pouch cell delivers a high capacity of 8.1 mAh cm−2 and excellent capacity retention of 65% over 800 cycles at a relatively high rate of 1C, corresponding to a calculated energy density of 539 Wh kg−1 and 591 Wh L−1. This work not only provides guidance for tailoring thick carbon/sulfur electrodes but also boosts the development of practical lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are expected to be one of the next generations of high-energy-density battery systems due to their high theoretical energy density of 2600 Wh kg−1. Embracing the trends toward flexibility, lightweight design, and cost-effectiveness, paper-based electrodes offer a promising alternative to traditional coated cathodes in Li–S batteries. Within paper-based electrodes, conductive fibers such as carbon nanotubes (CNTs) play a crucial role. They help to form a three-dimensional network within the paper matrix to ensure structural integrity over extended cycling while mitigating the shuttle effect by confining sulfur within the cathode. Herein, we explore how variously functionalized CNTs, serving as conductive fibers, impact the physical and electrochemical characteristics of paper-based sulfur cathodes in Li–S batteries. Specifically, graphitized hydroxylated carbon nanotubes (G-CNTs) exhibit remarkable capacity at low currents owing to their excellent conductivity and interaction with lithium polysulfide (LiPS), achieving the highest initial specific capacity of 1033 mAh g−1 at 0.25 C (1.1 mA cm−2). Aminated multi-walled carbon nanotubes (NH2-CNTs) demonstrate an enhanced affinity for LiPS due to the -NH2 groups. However, the uneven distribution of these fibers may induce electrode surface passivation during charge–discharge cycles. Notably, hydroxylated multi-walled carbon nanotubes (OH-CNTs) can establish a uniform and stable 3D network with plant fibers, showcasing superior mechanical properties and helping to mitigate Li2S agglomeration while preserving the electrode porosity. The paper-based electrode integrated with OH-CNTs even retains a specific capacity of approximately 800 mAh g−1 at about 1.25 C (5 mA cm−2), demonstrating good sulfur utilization and rate capacity compared to other CNT variants. [ABSTRACT FROM AUTHOR]

1. Theoretical calculation confirmed the heterostructure of Mo 2 C-MoP exhibits moderate adsorption energies with LiPSs, which benefits for the conversion of LiPSs. 2. The Mo 2 C trigger the ring-opening polymerization of the DOL solvent to generate a surface gel layer. The gel layer covers the surface of the Mo 2 C electrocatalyst and renders reduced electrocatalytic activity. 3. The introducing of MoP can avoid the surface gelation of the catalyst, and thus improved the performance of the catalyst in the actual battery. [Display omitted] The cathodic polysulfides electrocatalyst, such as Mo 2 C, offers a promising approach to mitigate the shuttling effect by providing strong polysulfide adsorption and catalyst abilities to improve the electrochemical performance of Lithium-sulfur (Li-S) batteries. However, according to the Sabatier principle, excessive adsorption of Mo 2 C undermines the conversion of polysulfides. This undesirable effect can be mitigated by forming the heterostructure of Mo 2 C-MoP. Even more importantly, the introduction of MoP can prevent the surface gelation of Mo 2 C and expose more active sites. Consequently, the Li-S batteries with the Mo 2 C-MoP sulfur host exhibit outstanding long-term cycling stability, showcasing a mere 0.035% capacity decay per cycle over 800 cycles at 1 C. This work on the balance between adsorption capacity and catalytic active of cathodic polysulfides electrocatalyst provides a new vision for realizing a high-performance Li-S batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] Owing to the extremely high theoretical specific capacity and energy density, the catalytic materials of lithium-sulfur (Li-S) batteries are widely explored. The "shuttle effect", poor electrode conductivity, and slow charge–discharge reaction dynamics are some of the key issues that have seriously hampered their commercialization process. Herein, based on the density-functional-theory (DFT), the catalytic performances of a series of single-atom catalysts (SACs) designed by regulating the N-content around coordination center in C 3 N (TM@N 2 C 2 /N 3 C/N 4 -C 3 N (TM = Ti, V, Fe, Co, Ni)), are systematically analyzed and evaluated. Among all the constructed SACs, Ti-centered configurations with fewer d electrons, especially for the Ti@N 2 C 2 -C 3 N, have the remarkable catalytic effect in improving the electron conductivity, trapping soluble polysulfides and accelerating the redox reaction. The in-depth mechanism indicates that the interaction between d orbital of Ti, mainly the splitting d z 2 , and p orbital of S is the key factor for achieving high-effective adsorption. More importantly, the integral value of crystal orbital Hamiltonian population (ICOHP) of the Li-S bond in the adsorbed Li 2 S can serve as an excellent descriptor for evaluating the overall catalytic ability of substrates. Our work has vital guiding significance for designing high-performance SACs of Li-S batteries. [ABSTRACT FROM AUTHOR]

While lithium-sulfur batteries (LSBs) have tremendous potential in capacity and energy, their application in practice is limited by short cycle life, slow reaction kinetics, and underutilization of sulfur. To tackle these challenges, we have developed a multifunctional host consisting of sandwich-type CoSe 2 -CNWs@NG that were hydrothermally synthesized through self-assembly of CoSe 2 -embedded carbon nanowires (CoSe 2 -CNWs) with N-doped graphene (NG). Through the implementation of CoSe 2- CNWs@NG as a host material, active sulfur can be effectively intercalated within the interlayer spaces of neighboring NG layers. The extensive contact area between sulfur and NG sheets facilitates rapid electron transfer, thereby maximizing sulfur utilization. N-doped graphene and polar CoSe 2 provide sufficient chemisorption sites for polysulfides, while the catalytic activity of CoSe 2 promotes polysulfide conversion. In addition to building a good conductivity structure for fast carrier transport and electrolyte diffusion, the sandwich structure of CoSe 2 -CNWs@NG physically restricts polysulfides and buffers substantial sulfur volume changes during cycling. As a result, the CoSe 2 -CNWs@NG/S cathode possessing high-load sulfur capacity (4.06 mg cm−2) exhibits superior cell performance at an ultrahigh rate as well as low E/S ratio. After 1000 cycles at 10 C, it achieves a remarkable reversible capacity of 314.4 mAh g−1 with an impressively low average fading rate of 0.023 % per cycle. Even at a low E/S ratio of 5 μL mg−1, the cathode exhibits remarkable performance, retaining a reversible capacity of 628.2 mAh g−1 after 150 cycles at the rate of 1 C. [ABSTRACT FROM AUTHOR]

Although in‐plane heterostructure with high ion transport pathway and unique interfacial atomic structure offers endless possibilities in the catalysis field, it is still challenging to directly synthesize MXene‐based in‐plane heterostructure due to the differences in crystal structures and growth conditions. Here, Mo2C–MoS2 in‐plane multi‐heterostructures are synthesized by topological conversion of sandwich‐like mesoporous Mo2C–SiO2 layers in sulfur vapor and subsequent removal of SiO2. During the conversion process, the exposed Mo2C will efficiently converted to 2H phase MoS2, meanwhile, the covered Mo2C remained stable, affording metallic Mo2C MXene and semiconducting MoS2 in‐plane multi‐heterostructures compatible in one layer. The resultant Mo2C–MoS2 layer has multiple heterointerfaces, build‐in electric fields as well as abundant defects. Such structural features enable to improve of the electrochemical active surface area (16.4 mF cm−2), which not only facilitates the bidirectional sulfur electrochemistry between solid Li2S and soluble lithium polysulfides, but also enhances the transfer kinetics of electrons and ions, giving rise to a high‐rate performance (642 mAh g−1 at 5 C) and a long‐term cycle life (1000 cycles at 5 C) in lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (Li–S) are recognized as the next generation of secondary batteries due to their satisfactory theoretical specific capacity and energy density. However, a series of problems such as disordered migration behavior, sluggish redox kinetics, and serious shuttle effect of lithium polysulfides (LiPSs) greatly limit the commercial application. Herein, nanoreactors encapsulate heterostructure to guarantee sulfur conversion in the hosts where the heterostructure consists of FeP with moderate adsorption ability, excellent catalytic active and low work function, and Fe3O4 with strong adsorption ability and high work function. This rational configuration of heterostructure controls the direction of the interface built‐in electric field (BIEF) between catalyst and adsorbent, realizing the successive "trapping‐directional migration‐conversion" reaction mechanism to sulfur species. Thanks to BIEF as a bridge to connect the trapping site and catalytic site, Fe3O4/FeP@C─S cathode delivers an ultrahigh initial specific capacity of 1402 mAh g−1 at 0.1 C and remains more than 450 mAh g−1 at 5 C after 350 cycles. Even with a sulfur loading of 5.20 mg cm−2, it displayed the initial specific capacity of 970 mAh g−1. This work provided an effective strategy to design high‐performance electrocatalysts for commercial Li–S batteries. [ABSTRACT FROM AUTHOR]

High sulfur loading and long cycle life are the design targets of commercializable lithium–sulfur (Li–S) batteries. The sulfur electrochemical reactions from Li2S4 to Li2S, which account for 75% of the battery's theoretical capacity, involve liquid‐to‐solid and solid‐to‐solid phase changes in all Li–S battery electrolytes in use today. These are kinetically hindered processes that are exacerbated by a high sulfur loading. In this study, it is observed that an in situ grown bimetallic phosphide/black phosphorus (NiCoP/BP) heterostructure can effectively catalyze the Li2S4 to Li2S reactions to increase the sulfur utilization at high sulfur loadings. The NiCoP/BP heterostructure is a good polysulfide adsorber, and the electric field prevailing at the Mott−Schottky junction of the heterostructure can facilitate charge transfer in the Li2S4 to Li2S2 liquid‐to‐solid reaction and Li+ diffusion in the Li2S2 to Li2S solid‐state reaction. Consequently, a sulfur cathode with the NiCoP/BP catalyst can deliver a specific capacity of 830 mAh g−1 at the sulfur loading of 6 mg cm−2 for 500 cycles at the 0.5 C rate. High sulfur utilization is also possible at a higher sulfur loading of 8 mg cm−2 for 440 cycles at the 1 C rate. [ABSTRACT FROM AUTHOR]

The lithium‐sulfur (Li−S) batteries have a high theoretical specific capacity of 1675 mAh ⋅ g−1 and have become the most promising high‐energy storage system for the next generation batteries technology. However, their applications are hindered by insulated feature and volume expansion of sulfur, as well as the "shuttle effect" of polysulfides. MXenes own metallic conductivity and strong ability of polysulfides adsorption. Besides, their unique two‐dimensional (2D) structure, large specific surface area, abundant functional groups, and adjustability are beneficial to overcome the drawbacks of the sulfur cathode. In this review, different mainstream preparation methods and excellent properties of MXenes are summarized. Significant achievements and recent progress of MXene‐based cathodes and interlayers applied to Li−S cathodes are concluded later. Finally, the challenges, possible solutions and potential applications of MXenes for Li−S batteries are also presented. [ABSTRACT FROM AUTHOR]

Lithium–sulfur batteries (LSBs) are considered a promising candidate for next-generation energy storage devices due to the advantages of high theoretical specific capacity, abundant resources and being environmentally friendly. However, the severe shuttle effect of polysulfides causes the low utilization of active substances and rapid capacity fading, thus seriously limiting their practical application. The introduction of conductive polymer-based interlayers between cathodes and separators is considered to be an effective method to solve this problem because they can largely confine, anchor and convert the soluble polysulfides. In this review, the recent progress of conductive polymer-based interlayers used in LSBs is summarized, including free-standing conductive polymer-based interlayers, conductive polymer-based interlayer modified separators and conductive polymer-based interlayer modified sulfur electrodes. Furthermore, some suggestions on rational design and preparation of conductive polymer-based interlayers are put forward to highlight the future development of LSBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Lithium-sulfur batteries (LSBs) show considerable potential in next-generation high performance batteries, but the heavy shuttle effect and sluggish redox kinetics of polysulfide hinder their further applications. In this paper, to address these shortcomings of LSBs, Co 3 Fe 7 /Co 5.47 N heterostructure were prepared and constructed from their Fe-Co Prussian blue analogue precursors under the condition of high temperature pyrolysis. The obtained Co 3 Fe 7 /Co 5.47 N display excellent immobilization-diffusion-conversion performance for polysulfides by synergistic effect in successfully hindering the shuttle effect of polysulfides. When the Co 3 Fe 7 /Co 5.47 N heterostructure were applied to modify the commercial polypropylene (PP) separator, the batteries displayed fantastic rate capacity and cycling stability. Specifically, the Co 3 Fe 7 /Co 5.47 N-PP batteries exhibit an extremely satisfactory initial specific capacity of 1430 m Ah/g at 0.5C, wonderful rate capacity of around 780 m Ah/g at 3C and superior per cycle decaying rate of 0.08 % for 500 cycles at 0.5C. When the current density reaches to 2C, the batteries still exhibit 501 m Ah/g after 900 cycles with 0.015 % per cycle decay rate. Besides, even in the high loading of sulfur (3.0 mg cm−2) at 0.5C, the superior cycling stability (0.075 % per cycle decay rate after 200 cycles) and high specific capacity (741 mAh/g after 200 cycles) can still be performed. Thus, this work provides a facile method for high-powered and long-life Li-S batteries with eminent entrapping-conversion processes of polysulfides. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries (Li-S) are highly promising due to their high energy density and specific capacity; however, the poor conductivity of the active material leads to slow reaction kinetics, and the shuttle effect of the intermediate product lithium polysulfides leads to rapid capacity decay. Here, the effective encapsulation of Al-BDC by TiO2 particles is achieved by encapsulating an aluminum-based metal organic framework (Al-BDC) with terephthalic acid as the organic ligand and heat-treating at different temperatures. This method shows that the TiO2 particles can effectively encapsulate Al-BDC while maintaining the structural stability of Al-BDC after heat treatment at 400°C. The TiO2 crystallization is disordered after heat treatment at 300°C, and the TiO2 is exfoliated and the Al-BDC is collapsed after heat treatment at 500°C. In addition, TiO2 particles can be partially filled into the pores of Al-BDC. Therefore, Al-BDC@TiO2-400 can effectively inhibit the shuttle of polysulfides, and the corresponding Li-S batteries can achieve relatively high discharge specific capacity, rate performance and cycling stability. In particular, the Al-BDC@TiO2-400@S can achieve an initial discharge specific capacity of 907.6 mAh g−1 at 0.1C, and 686.5 mAh g−1 at 2C with remained capacity of 379.8 mAh g−1 after 400 cycles. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li–S) batteries are favored as ideal batteries for next‐generation electrical stored energy systems owing to their high theoretical energy diversity and low operating costs. Therefore, the development of Li–S batteries with excellent rate capability and stable cycling is still a challenge. In this article, the electrochemical performance of lithium–sulfur batteries with high capacity and long cycle stability is achieved through dual physical and chemical adsorption effects using polypyrrole (PPy) attached to Co3O4/TiO2 heterojunction structures based on metal–organic frameworks (MOFs) backbone materials. Co3O4/TiO2 polyhedra form a built‐in electric field, which is also a good adsorbent for polysulfides PPy nanotubes have a vacant structure, thus minimizing the volume expansion during deformation and maintaining the stability of the structure. The reversible specific capacities of lithium–sulfur batteries prepared based on Co3O4/TiO2/PPy electrodes are 1095 and 739.4 mAh g−1 at 0.1 C and 1 C multiplicity, respectively, and the capacity retention rate is 77.84% after 500 cycles at 1 C multiplicity. The structural design of the S@Co3O4/TiO2/PPy anode demonstrates an excellent ability to limit LiPS and has great potential to provide a promising avenue for the practical application of lithium–sulfur batteries. [ABSTRACT FROM AUTHOR]

Traditional carbon materials suffer from weak adsorption of lithium polysulfides and excessive consumption of electrolyte. A simple and feasible molten salt method is applied for constructing an active nanocrystalline TiC shell on the surface of porous carbon. The highly active TiC nanoshells endow the core–shell composite with efficient chemical–physical synergistic adsorption, which can effectively confine and convert polysulfides, thereby improving the electrochemical performance of lithium–sulfur batteries. The lithium–sulfur batteries assembled with modified separator deliver a high initial discharge specific capacity of 1396 mAh g−1 at a discharge rate of 0.5 C and a high capacity retention of 747.1 mAh g−1 after 500 cycles, with a high coulombic efficiency of 98% during cycling. Besides, this molten salt method can be applied to modify the porous carbon materials of various composite sulfur cathodes such as graphene, carbon nanotubes, and 3D nonwoven carbon fabrics. [ABSTRACT FROM AUTHOR]

Abstract 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 Catalysis is crucial to improve redox kinetics in lithium–sulfur (Li–S) batteries. However, conventional catalysts that consist of a single metal element are incapable of accelerating stepwise sulfur redox reactions which involve 16‐electron transfer and multiple Li2Sn (n = 2–8) intermediate species. To enable fast kinetics of Li–S batteries, it is proposed to use high‐entropy alloy (HEA) nanocatalysts, which are demonstrated effective to adsorb lithium polysulfides and accelerate their redox kinetics. The incorporation of multiple elements (Co, Ni, Fe, Pd, and V) within HEAs greatly enhances the catalytically active sites, which not only improves the rate capability, but also elevates the cycling stability of the assembled batteries. Consequently, HEA‐catalyzed Li–S batteries achieve a high capacity up to 1364 mAh g−1 at 0.1 C and experience only a slight capacity fading rate of 0.054% per cycle over 1000 cycles at 2 C, while the assembled pouch cell achieves a high specific capacity of 1192 mAh g−1. The superior performance of Li–S batteries demonstrates the effectiveness of the HEA catalysts with maximized synergistic effect for accelerating S conversion reactions, which opens a way to catalytically improving stepwise electrochemical conversion reactions.

Ion-selective separators, are crucial and in high demand for maximizing the performance of lithium-sulfur (Li–S) batteries, which can conduct lithium ions while efficiently blocking polysulfides. However, commercial separators cannot effectively block the shuttle of polysulfides after multiple cycles due to their large porosity and easy dissolution, resulting in a reduced battery life. Herein, a covalent organic framework nanosheets (CON) ion-coated separator is prepared on the commercial separator. Due to the smaller pore size of CON-TFSI compared to polysulfides, the CON-TFSI modified separator can effectively block the polysulfide from migrating across the separator. By incorporating this innovative functional layer, Li–S batteries demonstrate outstanding performance. In a Li–S battery featuring a sulfur loading of 0.6 mg/cm2, it attains an initial discharge specific capacity of up to 891.9 mA h g−1, and exhibits the capacity retention of 54.6 % after 500 cycles at a current density of 0.2 C. This work offers a fresh perspective on the advancement of high-performance membranes for Li–S batteries.

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 high-performance 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−1 after 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.

Free radicals can improve the reaction rate, but most of them are unstable due to unpaired electrons. Simultaneously maintaining their stability and activity is challenging. Herein, taking sulfur (S) radicals as an example, we propose a strategy in which solvated metal complexes constructed by Al(acetylacetonate)3 and different solvents can stabilize high concentrations of S radicals with good activity through ion–dipole interactions. Based on this strategy, it is first demonstrated that S4·− is selectively stabilized by controlling the configurations of the solvated complexes. As a result, the reaction rate of S↔Li2S is increased by 8 times, and the energy efficiency and rate capability of the Li–S batteries are significantly improved, especially the 5-fold increase in cell capacities at a low electrolyte/sulfur ratio. This work provides an important strategy in which solvated metal complexes balance the activity and stability of free radicals to accelerate reactions and their application in various fields.

All‐solid‐state lithium‐sulfur (ASS‐Li/S) batteries have recently attracted considerable attention owing to their high energy density and safety. To produce the cathode of an ASS‐Li/S battery, sulfur (the cathode active material) must be combined with a conductive additive (electron conductor) because of the electronic insulating property of sulfur. Therefore, a compositing process of sulfur and conductive additives is necessary to produce ASS‐Li/S batteries. However, existing compositing methods are neither scalable nor productive. Herein, for the first time, a hot‐melt kneading process, as a scalable and productive compositing process, to produce composite particles of sulfur and a conductive additive for ASS‐Li/S batteries is employed. The composite particles prepared from the hot‐melt kneading process show larger particle sizes, less fine conductive additive particles, and better flowability than the simple mixture. The obtained composite particles have a matrix‐type structure, in which conductive additive particles exist even inside the sulfur particles. Concerning the electrochemical performance, compositing sulfur and a conductive additive using the hot‐melt kneading process improves the electrochemical performance because of the matrix‐type structure of the composite particles. Moreover, by estimating the productivity of the process, the study demonstrates that the hot‐melt kneading process has a significantly better productivity compared with conventional compositing processes.

Abstract The development of lithium–sulfur (Li–S) batteries is hindered by the disadvantages of shuttling of polysulfides and the sluggish redox kinetics of the conversion of sulfur species during discharge and charge. Herein, the crystallinities of a titanium nitride (TiN) film on copper‐embedded carbon nanofibers (Cu‐CNFs) are regulated and the nanofibers are used as interlayers to resolve the aforementioned crucial issues. A low‐crystalline TiN‐coated Cu‐CNF (L‐TiN‐Cu‐CNF) interlayer is compared with its highly crystalline counterpart (H‐TiN‐Cu‐CNFs). It is demonstrated that the L‐TiN coating not only strengthens the chemical adsorption toward polysulfides but also greatly accelerates the electrochemical conversion of polysulfides. Due to robust carbon frameworks and enhanced kinetics, impressive high‐rate performance at 2 C (913 mAh g−1 based on sulfur) as well as remarkable cyclic stability up to 300 cycles (626 mAh g−1) with capacity retention of 46.5% is realized for L‐TiN‐Cu‐CNF interlayer‐configured Li–S batteries. Even under high loading (3.8 mg cm−2) of sulfur and relatively lean electrolyte (10 μL electrolyte per milligram sulfur) conditions, the Li–S battery equipped with L‐TiN‐Cu‐CNF interlayers delivers a high capacity of 1144 mAh g−1 with cathodic capacity of 4.25 mAh cm−2 at 0.1 C, providing a potential pathway toward the design of multifunctional interlayers for highly efficient Li–S batteries.

Abstract Ingenious design and fabrication of advanced carbon‐based sulfur cathodes are extremely important to the development of high‐energy lithium‐sulfur batteries, which hold promise as the next‐generation power source. Herein, for the first time, we report a novel versatile hyphae‐mediated biological assembly technology to achieve scale production of hyphae carbon fibers (HCFs) derivatives, in which different components including carbon, metal compounds, and semiconductors can be homogeneously assembled with HCFs to form composite networks. The mechanism of biological adsorption assembly is also proposed. As a representative, reduced graphene oxides (rGOs) decorated with hollow carbon spheres (HCSs) successfully co‐assemble with HCFs to form HCSs@rGOs/HCFs hosts for sulfur cathodes. In this unique architecture, not only large accommodation space for sulfur but also restrained volume expansion and fast charge transport paths are realized. Meanwhile, multiscale physical barriers plus chemisorption sites are simultaneously established to anchor soluble lithium polysulfides. Accordingly, the designed HCSs@rGOs/HCFs‐S cathodes deliver a high capacity (1189 mA h g−1 at 0.1 C) and good high‐rate capability (686 mA h g−1 at 5 C). Our work provides a new approach for the preparation of high‐performance carbon‐based electrodes for energy storage devices.

Abstract Lithium‐sulfur batteries (LSBs) are greatly promising next‐generation energy storage systems due to their high theoretical specific capacities and energy density. However, the dissolution of lithium polysulfides (LIPs) causees low capacity and short lifespan, impeding the practical application of LSBs. To address this challenge, the composites of oxygen‐doped porous carbon nanotubes (CNTs) wrapped in Bi2O3 were synthesized by the calcinating method (CNTs@Bi2O3). The CNTs@Bi2O3 composites as absorbent immobilize LIPs via the physical limitations of porous CNTs and the chemical adsorption of Bi2O3 and carbon‐oxygen polar bond. After loading sulfur, the CNTs@Bi2O3/S composites with the encapsulated structure can provide a large space to withstand the significant volume expansion during the electrochemical reaction process, ensuring the stability of the electrode structure. Thus, the batteries with CNTs@Bi2O3/S exhibit a high capacity (1232 mA h g−1 at 0.1 C) and good cycle stability (639.1 mA h g−1 after 150 cycles at 0.5 C). This work presents an innovative design suitable for the encapsulated structure of Bi2O3, serving as a valuable reference for the development of Bi2O3 in LSBs.

Lithium–sulfur batteries are considered as promising candidates for next‐generation energy storage devices for grid applications due to their high theoretical energy density. However, the inevitable shuttle effect of lithium polysulfides and/or dendrite growth of Li metal anodes hinder their commercial viability. Herein, the microporous Zr fumarate metal–organic framework (MOF)‐801(Zr) is considered to produce thin (≈15.6 μm, ≈1 mg cm2) mixed‐matrix membranes (MMM) as a novel interlayer for Li–S batteries. It is found that the MOF‐801(Zr)/C/PVDF‐HFP composite interlayer facilitates Li+ ions diffusion, and anchors polysulfides while promoting their redox conversion effectively. It is demonstrated that MOF‐801 effectively trapped polysulfides at the cathode side, and confirmed for the first time the nature of the interaction between the adsorbed polysulfides and the host framework, through a combination of solid‐state nuclear magnetic resonance and molecular dynamics simulations. The incorporation of MOF‐801(Zr)/C/PVDF‐HFP MMM interlayer results in a notable enhancement in the initial capacity of Li–S batteries up to 1110 mA h g−1. Moreover, even after 50 cycles, a specific capacity of 880 mA h g−1 is delivered.

Lithium–sulfur batteries are considered potential high-energy-density candidates to replace current lithium-ion batteries. However, several problems remain to be solved, including low conductivity, huge volume change, and a severe shuttle effect on the cathode side, as well as inevitable lithium dendrites on the anode side. Rare earth compounds, which play vital roles in various industries, show latent capacity as cathode hosts or interlayers to tackle the inherent problems of lithium–sulfur batteries. However, the application of rare earth compounds in lithium–sulfur batteries has not been reviewed so far, despite they showing obvious advantages for tuning polysulfide retention and conversion. In this mini-review, we start by introducing the concept of lithium–sulfur batteries and providing background information on rare earth-based materials. In the main body, we explore rare earth compounds as cathode hosts or interlayers, then discuss various types of each. Finally, we offer an outlook on the existing challenges and possible opportunities for using rare earth compounds as cathode hosts or interlayers for lithium–sulfur batteries.

Lithium–sulfur batteries (Li-S batteries) have attracted wide attention due to their high theoretical energy density and the low cost of sulfur cathode material. However, the poor conductivity of the sulfur cathode, the polysulfide shuttle effect, and the slow redox kinetics severely affect their cycling performance and Coulombic efficiencies, especially under low-temperature conditions, where these effects are more exacerbated. To address these issues, this study designs and synthesizes a microspherical cobalt molybdate@reduced graphene oxide (CoMoO4@rGO) composite material as the cathode material for Li-S batteries. By growing CoMoO4 nanoparticles on the rGO surface, the composite material not only provides a good conductive network but also significantly enhances the adsorption capacity to polysulfides, effectively suppressing the shuttle effect. After 100 cycles at room temperature with a current density of 1 C, the reversible specific capacity of the battery stabilizes at 805 mAh g−1. Notably, at −20 °C, the S/CoMoO4@rGO composite achieves a reversible specific capacity of 840 mAh g−1. This study demonstrates that the CoMoO4@rGO composite has significant advantages in suppressing polysulfide diffusion and expanding the working temperature range of Li-S batteries, showing great potential for applications in next-generation high-performance Li-S batteries.