Ultrathin Conductive Interlayer with High-Density Antisite Defects for Advanced Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries are promising next-generation rechargeable batteries due to thier high energy density, low cost, and environmental friendliness. However, the extremely low electrical conductivity of sulfur and the dissolution of polysulfides limit their actual electrochemical performances, especially in the case of high sulfur mass loading. Here, a new strategy based on intrinsic point defects of materials is proposed to simultaneously enhance the electrical conductivity of active material and regulate the migration of polysulfides. Taking advantage of ultrathin and lightweight Bi₂Te_2.7Se_0.3 (BTS) interlayers with high-density antisite defects on the separator surface, the Li–S battery with BTS interlayer shows a capacity of 756 mAh g⁻¹ at 2C and a low capacity decay rate of 0.1% over 300 cycles. The BTS interlayer can not only enhance the active material utilization but also improve capacity retention. The defect engineering strategy accompanied with facile method is promising for the development of advanced Li–S batteries for practical application.     

Challenges and Solutions for Lithium–Sulfur Batteries with Lean Electrolyte

Lithium–sulfur (Li–S) batteries have high theoretical energy density and are regarded as next-generation batteries. However, their practical energy density is much lower than the theoretical value. In previous studies, the increase of the areal capacity of the cathode and the decrease of the negative/positive ratio can be well achieved, yet the energy density shows no corresponding increase. The main reason is the difficulty in decreasing electrolyte dosage because lean electrolyte inevitably causes the deterioration of reaction kinetics and sulfur utilization. Thus, the electrolyte/active material ratio in the reported works is usually higher than 10 µL mg⁻¹, much higher than that in Li-ion batteries (usually lower than ≈0.3 µL mg⁻¹ for cathode). Although many works have focused on this topic, a systematic discussion is still rare. This review systematically discusses the key challenges and solutions for assembling high-performance lean-electrolyte Li–S batteries. First, the key challenges arising from lean-electrolyte conditions are discussed in detail. Then, the approaches and the recent progress to reduce electrolyte usage, including optimization of electrode porosity and ion conduction, the introduction of electrocatalysis, exploration of new active materials, electrolyte regulation, and Li metal protection are reviewed. Finally, future research directions in lean-electrolyte Li–S batteries are proposed.     

Scavenging of “Dead Sulfur” and “Dead Lithium” Revealed by Integrated–Heterogeneous Catalysis for Advanced Lithium–Sulfur Batteries

The simultaneous engineering of sulfur cathode and Li anode is critical for electrolyte-starved high energy density Li–S batteries, in which slow electrochemical conversions and side chemical reactions of dead sulfur are found to be the determining factors in limiting the sulfur utilization, corresponding to the poor reversible capacity of Li–S batteries. Herein, this work challenges the conventional wisdom of heterogeneous and homogeneous catalyses in Li–S batteries and proposes the concept of integrated–heterogeneous catalysis to simultaneously scavenge the dead sulfur and dead lithium to compensate the active materials sulfur and lithium loss simply through adding a small amount of ZnI₂ into conventional electrolyte of Li–S cells. Regulated by integrated–heterogeneous catalysis, over 1300 h of cycling is realized in Li||Li symmetric cells, revealing superb compatibility of the ZnI₂-incorporated electrolyte with lithium metal. Meanwhile, the ZnI₂ shows good prospects in promoting the reutilization of dead sulfur in both theoretical calculation and experimental tests. Practically, a high initial capacity of 1170 mAh g⁻¹ with decent cycling stability is achieved in electrolyte-starved and high-loading pouch cells (5.0 µL mg⁻¹ and 5.2 mg cm⁻²).     

A Universal Graphene-Selenide Heterostructured Reservoir with Elevated Polysulfide Evolution Efficiency for Pragmatic Lithium–Sulfur Battery

The practical application of lithium–sulfur (Li–S) batteries has been handicapped by the notorious polysulfide shuttling and sluggish sulfur conversion kinetics. Although the functional modification of separator is readily proposed as an effective strategy to optimize the Li–S redox reactions, the excessive material dosage and invalid structural design still result in inferior electrocatalyst utilization. Herein, generic graphene-metal selenide heterostructures (Gr-M_xSe_y, M = Mo, W, Mn, Cu and Zn) are controllably grown on commercial glass fiber (GF) separator employing a sequential low-temperature chemical vapor deposition procedure. Such a tailored reservoir can not only render ample active sites but also realize the synergy of polar and catalytic framework, which maximizes the electrochemical functions in alleviating shuttle effect and guiding Li₂S nucleation/decomposition. The thus-derived Gr-M_xSe_y/GF separator affording favorable heatproof feature endows the Li–S battery with an outstanding cycling stability (100% capacity retention over 100 cycles at 0.2 C). Furthermore, the flexible Li–S pouch cell based on this new separator delivers good device performance (with a capacity decay of 0.25% per cycle over 100 cycles). This study offers comprehensive insight into the reliable separator design toward working Li–S batteries.     

Non-Carbon-Dominated Catalyst Architecture Enables Double-High-Energy-Density Lithium–Sulfur Batteries

The commonly used “catalyst on carbon” architecture as a sulfur host is difficult to jointly achieve high gravimetric and volumetric energy densities for lithium–sulfur (Li–S) batteries due to the contradiction between low tap density/poor catalytic activity of carbon and the easy agglomeration of metal-based compounds without carbon. Here, a non-carbon-dominated catalytic architecture using macroporous nickel/cobalt phosphide (NiCoP) is reported as the sulfur host for Li–S batteries. The macroporous framework, which accommodates a large amount of sulfur, can accelerate the electrochemical reaction kinetics by accelerated e⁻ transport, Li⁺ diffusion, and superior adsorption and catalytic activity of inherent Ni₂P/CoP heterostructures. The high tap density (0.45 g cm⁻³) and mechanically hard features contribute to the excellent structural and physicochemical stability of the NiCoP@S electrode after the pressing and rolling process. These features enable the Li–S coin cell to exhibit excellent electrochemical performance under conditions of high sulfur loading (10.2 mg cm⁻²) and lean electrolyte (electrolyte/sulfur of 2 µL mg⁻¹). Inspiringly, the assembled pouch cell can simultaneously deliver a gravimetric energy density of 345.2 Wh kg⁻¹ and an impressive volumetric energy density of 952.7 Wh L⁻¹ based on the entire device configuration.     

Lithium Tritelluride as an Electrolyte Additive for Stabilizing Lithium Deposition and Enhancing Sulfur Utilization in Anode-Free Lithium–Sulfur Batteries

Despite the potential to become the next-generation energy storage technology, practical lithium–sulfur (Li–S) batteries are still plagued by the poor cyclability of the lithium-metal anode and sluggish conversion kinetics of S species. In this study, lithium tritelluride (LiTe₃), synthesized with a simple one-step process, is introduced as a novel electrolyte additive for Li–S batteries. LiTe₃ quickly reacts with lithium polysulfides and functions as a redox mediator to greatly improve the cathode kinetics and the utilization of active materials in the cathode. Moreover, the formation of a Li₂TeS₃/Li₂Te-enriched interphase layer on the anode surface enhances ionic transport and stabilizes Li deposition. By regulating the chemistry on both the anode and cathode sides, this additive enables a stable operation of anode-free Li–S batteries with only 0.1 m concentration in conventional ether-based electrolytes. The cell with the LiTe₃ additive retains 71% of the initial capacity after 100 cycles, while the control cell retains only 23%. More importantly, with high utilization of Te, the additive enables significantly better cyclability of anode-free pouch full-cells under lean electrolyte conditions.     

Covalently Interlinked Graphene Sheets with Sulfur-Chains Enable Superior Lithium–Sulfur Battery Cathodes at Full-Mass Level

Sulfur represents a low‑cost, sustainable, and high theoretical capacity cathode material for lithium–sulfur batteries, which can meet the growing demand in portable power sources, such as in electric vehicles and mobile information technologies. However, the shuttling effect of the formed lithium polysulfides, as well as their low conductivity, compromise the electrochemical performance of lithium–sulfur cells. To tackle this challenge, a so far unexplored cathode, composed of sulfur covalently bonded directly on graphene is developed. This is achieved by leveraging the nucleophilicity of polysulfide chains, which react readily with the electrophilic centers in fluorographene, as experimental and theoretical data unveil. The reaction leads to the formation of carbon–sulfur covalent bonds and a particularly high sulfur content of 80 mass%. Owing to these features, the developed cathode exhibits excellent performance with only 5 mass% of conductive carbon additive, delivering very high full‑cathode‑mass capacities and rate capability, combined with superior cycling stability. In combination with a fluorinated ether as electrolyte additive, the capacity persists at ≈700 mAh g⁻¹ after 100 cycles at 0.1 C, and at ≈644 mAh g⁻¹ after 250 cycles at 0.2 C, keeping ≈470 mAh g⁻¹ even after 500 cycles.     

Electrolyte Tuned Robust Interface toward Fast-Charging Zn–Air Battery with Atomic Mo Site Catalyst

Stable operation of sustainable Zn–air batteries (ZABs) has attracted considerable attention, but it remains a huge challenge to achieve temperature-adaptive and fast-charging ZABs. The poor Zn | electrolyte interface and the sluggish charging kinetic are the major obstacles. Here, high-performance ZABs are constructed by designing polarized zincophilic solid-state electrolyte (SSE) with the unique solvation interaction of Zn²⁺ with ethylene glycol (EG), and atomic Mo site cathode catalyst. On the one hand, the modulation of the solvation structure of Zn²⁺ ions by partial substitution of H₂O with EG inhibits Zn dendrite growth and parasitic reactions, leading to the improvement of the Zn | electrolyte interface. Moreover, the polarized terminal groups in SSE are strongly coordinated with Zn/H₂O, which exerts a profound influence on Zn | electrolyte interface stability and low-temperature properties. On the other hand, atomic Mo incorporated α-Co(OH)₂ mesoporous nanosheets decrease the overpotential of oxygen evolution reaction via strong electronic interaction. Consequently, the assembled aqueous ZABs exhibit ten-time fast-charging ability and remarkable cycling stability. Moreover, the assembled solid-state ZABs show unprecedented stability (1400 cycles at 5 mA cm⁻²) and high energy efficiency at −40 °C.     

Cobalt(II)-Centered Fluorinated Phthalocyanine-Sulfur SNAr Chemistry for Robust Lithium–Sulfur Batteries with Superior Conversion Kinetics

Due to the exceptional theoretical energy density and low cost of elemental sulfur, lithium–sulfur (Li–S) batteries are spotlighted as promising post-lithium-ion batteries. Despite these advantages, the performance of Li–S batteries would need to be improved further for their wide dissemination in practical applications. Here, cobalt(II)-centered fluorinated phthalocyanine, namely, F-Co(II)Pc, is reported as a multi-functional component for sulfur cathodes with the following benefits: 1) enhanced conversion kinetics as a result of the catalytic effect of the cobalt(II) center, 2) efficient sulfur linkage via the fluorine functionality, which undergoes a nucleophilic aromatic substitution (S_NAr) reaction, 3) suppression of the shuttling issue by the nitrogen atoms because of their strong affinity with polysulfides, and 4) the necessary aromaticity to engage in π–π interaction with reduced graphene oxide for electrical conductivity. The resulting electrode has promising electrochemical properties, such as sustainable cycling for 700 cycles and robust operation with a sulfur loading of 12 mg_sulfur cm⁻², unveiling the promising nature of phthalocyanine and its related molecular families for advanced Li–S batteries.     

Combined Defect and Heterojunction Engineering in ZnTe/CoTe2@NC Sulfur Hosts Toward Robust Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are feasible candidates for the next generation of energy storage devices, but the shuttle effect of lithium polysulfides (LiPSs) and the poor electrical conductivity of sulfur and lithium sulfides limit their application. Herein, a sulfur host based on nitrogen-doped carbon (NC) coated with small amount of a transition metal telluride (TMT) catalyst is proposed to overcome these limitations. The properties of the sulfur redox catalyst are tuned by adjusting the anion vacancy concentration and engineering a ZnTe/CoTe₂ heterostructures. Theoretical calculations and experimental data demonstrate that tellurium vacancies enhance the adsorption of LiPSs, while the formed TMT/TMT and TMT/C heterostructures as well as the overall architecture of the composite simultaneously provide high Li⁺ diffusion and fast electron transport. As a result, v-ZnTe/CoTe₂@NC/S sulfur cathodes show excellent initial capacities up to 1608 mA h g⁻¹ at 0.1C and stable cycling with an average capacity decay rate of 0.022% per cycle at 1C during 500 cycles. Even at a high sulfur loading of 5.4 mg cm^–2, a high capacity of 1273 mA h g⁻¹ at 0.1C is retained, and when reducing the electrolyte to 7.5 µL mg⁻¹, v-ZnTe/CoTe₂@NC/S still maintains a capacity of 890.8 mA h g⁻¹ after 100 cycles at 0.1C.     

Water-Soluble Cross-Linking Functional Binder for Low-Cost and High-Performance Lithium–Sulfur Batteries

Binders play an important role in battery systems. The lithium–sulfur (Li–S) batteries have poor cycling performance owing to large volume alteration of sulfur and shuttle effect. Herein, a novel water-soluble functional binder (named GN-BA) is prepared by the cross-linking effect between gelatin and boric acid. The excellent binder can effectively maintain the integrated electrode stable, buffer the volume changes, prevent active materials exfoliation from current collectors, and anchor polysulfides by chemical bonding. Sulfur electrodes in this binder also exhibit a loosely stacked porous structure, which is advantageous to the electrolyte permeation and fast ion diffusion. X-ray photoelectron spectroscopy, ultraviolet-visible spectroscopy, and density functional theory calculations further verified that the binder can anchor polysulfides by forming B O Li, C O Li, and C N Li chemical bonds. At 0.5 C, a high initial capacity of 980 mA h g⁻¹ can be obtained, which is higher than those sulfur cathodes with traditional poly(vinylidene fluoride) binder. When the sulfur loading is up to 5.0 mg cm⁻², a high areal specific capacity of 5.7 mA h cm⁻² and excellent cycling stability are achieved. This study proposes an economical and environmentally friendly strategy for the construction of advanced binders and promotes the practical application of high-energy Li–S batteries.     

Regulating Electronic Structure of Fe–N4 Single Atomic Catalyst via Neighboring Sulfur Doping for High Performance Lithium–Sulfur Batteries

Constructing high performance electrocatalysts for lithium polysulfides (LiPSs) adsorption and fast conversion is the effective way to boost practical energy density and cycle life of rechargeable lithium–sulfur (Li–S) batteries, which have been regarded as the most promising next generation high energy density battery but still suffering from LiPSs shuttle effect and slow sulfur redox kinetics. Herein, a single atomic catalyst of Fe–N₄ moiety doping periphery with S (Fe–NSC) is theoretically and experimentally demonstrated to enhance LiPSs adsorption and facilitated sulfur conversion, due to more charge density accumulated around Fe–NSC configuration relative to bare Fe–N₄ moiety. Thereafter, the graphene oxide supported Fe–NSC catalyst (Fe–NSC@GO) is modified to the commercial separator through a simple slurry casting method. Thus, Li–S cells with Fe–NSC@GO modified separators display high discharge capacity and excellent cyclability, showing 1156 mAh g⁻¹ at 1 C rate and a low capacity decay of only 0.022% per cycle over 1000 cycles. Even with a high sulfur loading of 5.1 mg cm⁻², the cell still delivers excellent cycling stability. This work provides a fresh insight into electrocatalyst structural tuning to improve the electrochemical performance of Li–S batteries.     

Tandem Carbon Hollow Spheres with Tailored Inner Structure as Sulfur Immobilization for Superior Lithium–Sulfur Batteries

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.     

Status and Prospects of MXene-Based Lithium–Sulfur Batteries

Lithium–sulfur (Li–S) batteries with a theoretical energy density of 2567 Wh kg⁻¹ are very promising next-generation energy storage systems, but suffer from the insulativity of sulfur and Li₂S, the shuttle effect due to the dissolution and migration of polysulfides, and the lithium dendrite issue. MXenes, a family of 2D transition metal carbides/nitrides, which have metallic conductivity, structural variety, strong chemical adsorption ability to polysulfides, effective catalytic effect for fast kinetics, and inducing effect for uniform growth of Li, exhibit promising potential for high-performance Li–S batteries. In this review, the recent progress and achievements of MXene-based Li–S batteries are summarized, including the use of MXenes in sulfur cathode, interlayer between cathode and separator, and Li anode. The architecture construction and chemical modification of MXenes, as well as hybridization with other materials are demonstrated. The enhancement on electrochemical performance and the related mechanisms of MXenes and MXene-based composites are discussed. Finally, challenges and perspectives of MXenes for Li–S battery application are also given.     

In Situ Reconstruction of Electrocatalysts for Lithium–Sulfur Batteries: Progress and Prospects

The current research of Li–S batteries primarily focuses on increasing the catalytic activity of electrocatalysts to inhibit the polysulfide shuttling and enhance the redox kinetics. However, the stability of electrocatalysts is largely neglected, given the premise that they are stable over extended cycles. Notably, the reconstruction of electrocatalysts during the electrochemical reaction process has recently been proposed. Such in situ reconstruction process inevitably leads to varied electrocatalytic behaviors, such as catalytic sites, selectivity, activity, and amounts of catalytic sites. Therefore, a crucial prerequisite for the design of highly effective electrocatalysts for Li–S batteries is an in-depth understanding of the variation of active sites and the influence factors for the in situ reconstruction behaviors, which has not achieved a fundamental understanding and summary. This review comprehensively summarizes the recent advances in understanding the reconstruction behaviors of different electrocatalysts for Li–S batteries during the electrochemical reaction process, mainly including metal nitrides, metal oxides, metal selenides, metal fluorides, metals/alloys, and metal sulfides. Moreover, the unexplored issues and major challenges of understanding the reconstruction chemistry are summarized and prospected. Based on this review, new perspectives are offered into the reconstruction and true active sites of electrocatalysts for Li–S batteries.     

Lamellar MXene Composite Aerogels with Sandwiched Carbon Nanotubes Enable Stable Lithium–Sulfur Batteries with a High Sulfur Loading

Realizing long cycling stability under a high sulfur loading is an essential requirement for the practical use of lithium–sulfur (Li–S) batteries. Here, a lamellar aerogel composed of Ti₃C₂T_x MXene/carbon nanotube (CNT) sandwiches is prepared by unidirectional freeze-drying to boost the cycling stability of high sulfur loading batteries. The produced materials are denoted parallel-aligned MXene/CNT (PA-MXene/CNT) due to the unique parallel-aligned structure. The lamellae of MXene/CNT/MXene sandwich form multiple physical barriers, coupled with chemical trapping and catalytic activity of MXenes, effectively suppressing lithium polysulfide (LiPS) shuttling under high sulfur loading, and more importantly, substantially improving the LiPS confinement ability of 3D hosts free of micro- and mesopores. The assembled Li–S battery delivers a high capacity of 712 mAh g⁻¹ with a sulfur loading of 7 mg cm⁻², and a superior cycling stability with 0.025% capacity decay per cycle over 800 cycles at 0.5 C. Even with sulfur loading of 10 mg cm⁻², a high areal capacity of above 6 mAh cm⁻² is obtained after 300 cycles. This work presents a typical example for the rational design of a high sulfur loading host, which is critical for the practical use of Li–S batteries     

Rational Engineering CoxOy Nanosheets via Phosphorous and Sulfur Dual-Coupling for Enhancing Water Splitting and Zn–Air Battery

Herein, an efficient multifunctional catalyst based on phosphorus and sulfur dual-doped cobalt oxide nanosheets supported by Cu@CuS nanowires is developed for water splitting and Zn–air batteries. The formation of such a unique heterostructure not only enhances the number and type of electroactive sites, but also leads to modulated electronic structure, which produces reasonable adsorption energy toward the reactant, thereby improving electrocatalytic efficiency. The catalyst demonstrates small overpotentials of 116 and 280 mA cm⁻² to achieve 10 mA cm⁻² for hydrogen and oxygen evolution, respectively. As a result, a developed electrolyzer displays a cell voltage of 1.52 V at 10 mA cm⁻² and long-term stability with a current response of 92.3% after operating for 30 h. Moreover, using such a catalyst in the fabrication of a Zn–air battery also leads to a cell voltage of 1.383 V, along with a power density of 130 mW cm⁻² at 220 mA cm⁻².     

A Robust Ternary Heterostructured Electrocatalyst with Conformal Graphene Chainmail for Expediting Bi-Directional Sulfur Redox in Li–S Batteries

Designing high-performance electrocatalysts for boosting aprotic electrochemistry is of vital importance to drive longevous Li–S batteries. Nevertheless, investigations on probing the electrocatalytic endurance and protecting the catalyst activity yet remain elusive. Here, a ternary graphene-TiO₂/TiN (G-TiO₂/TiN) heterostructure affording conformal graphene chainmail is presented as an efficient and robust electrocatalyst for expediting sulfur redox kinetics. The G-TiO₂/TiN heterostructure synergizes adsorptive TiO₂, catalytic TiN, and conductive graphene armor, thus enabling abundant anchoring points for polysulfides and sustained active sites to allow smooth bi-directional electrocatalysis. Encouragingly, in situ crafted graphene chainmail ensures favorable protection of inner TiO₂/TiN to retain their catalytic robustness towards durable sulfur chemistry. As expected, sulfur cathodes mediated by ternary G-TiO₂/TiN harvest an impressive rate capability (698.8 mAh g⁻¹ at 5.0 C), favorable cycling stability (a low decay of 0.054% per cycle within 1000 cycles), and satisfactory areal capacity under elevated loading (delivering 8.63 mAh cm⁻² at a sulfur loading of 10.4 mg cm⁻²). The ternary heterostructure design offers an in-depth insight into the electrocatalyst manipulation and protection toward long lifespan Li–S batteries.     

Asymmetric Polymer Electrolyte Constructed by Metal–Organic Framework for Solid-State,Dendrite-Free Lithium Metal Battery

Solid-state polymer electrolytes (SPEs) with flexibility, easy processability, and low cost have been regarded as promising alternatives for conventional liquid electrolytes in next-generation high-safety lithium metal batteries. However, SPEs generally suffer poor strength to block Li dendrite growth during the charge/discharge process, which severely limits their wide practical applications. Here, a rational design of 3D cross-linked network asymmetric SPE modified with a metal–organic framework (MOF) layer on one side is proposed and prepared through an in-situ polymerization process. In such unique asymmetric SPEs, the nanoscale MOF layer acts as a shield that effectively suppresses the growth of Li dendrites and regulates the uniform Li⁺ transport, and the polymer electrolyte can be scattered in the whole cell to endow the smooth transmission of Li⁺. As a result, the asymmetric SPE exhibits high ionic conductivity, wide electrochemical window, high thermal stability and safety, which endows the Li/Li symmetrical cell with outstanding cyclic stability (operate well over 800 h at a current density of 0.1 mA cm⁻² for the capacity of 0.1 mAh cm⁻²).     

Anchoring Polysulfides and Accelerating Redox Reaction Enabled by Fe-Based Compounds in Lithium–Sulfur Batteries

The synergetic mechanism of chemisorption and catalysis play an important role in developing high-performance lithium–sulfur (Li–S) batteries. Herein, a 3D lather-like porous carbon framework containing Fe-based compounds (including Fe₃C, Fe₃O₄, and Fe₂O₃), named FeCFeOC, is designed as the sulfur host and the interlayer on separator. Due to the strong chemisorption and catalytic ability of FeCFeOC composite, the soluble lithium polysulfides (LiPSs) are first adsorbed and anchored on the surface of the FeCFeOC composite and then are catalyzed to accelerate their conversion reaction. In addition, the Fe_xO_y in Fe-based compounds can spontaneously react with LiPSs to form magnetic FeS_x species with a larger size, further blocking the penetration of LiPSs cross the separator. As a result, the assembled Li–S cells show excellent long-term stability (748 mAh g⁻¹ over 500 cycles at 1.0 C, and ≈0.036% decay per cycle for 1000 cycles at 3.0 C), a superb rate capability with 659 mAh g⁻¹ at 5.0 C, and lower electrochemical polarization. This work introduces a feasible strategy to anchor and accelerate the conversion of LiPSs by designing the multifunctional Fe-based compounds with high chemisorption and catalytic activity, which advances the large-scale application of high-performance Li–S batteries.