Efficient Lithium-sulfur Batteries Research Articles

The benzothiadiazole-based COF/CNT composite as host for efficient Li-S batteries with excellent cycling stability

The cycle stability and dynamic performance of lithium-sulfur (Li-S) batteries have been major challenges, which primarily arise from the dissolution and migration of the soluble reaction intermediates during cycling, as well as the low conductivity of sulfur. In this study, a covalent organic framework containing heteroatoms (B/N/S) is uniformly wrapped on the outer surface of carbon nanotubes to form a nanocomposite (COF@CNT). The composite combines the excellent electrical conductivity of CNTs and the COF material containing evenly distributed heteroatoms that can adsorb and catalyze polysulfides. B atom on COF can be chemically adsorbed by the negatively charged SX2−, S and N atoms can interact with Li+ to reduce the “shuttle effect”. At the same time, the heteroatoms promote the liquid-to-solid phase conversion of the soluble long-chain Li2Sx (4 ≤ x ≤ 8), and the subsequent conversion of solid Li2S2 to Li2S, thereby enhancing the dynamic kinetics. As a cathode material, COF@CNT/S exhibits an initial specific capacity of 1176 mAh/g at 0.2 C, maintaining a capacity of 688 mAh/g after 1000 cycles at 1 C with a Coulombic efficiency of 99.7 %. Notably, a quite low capacity decay rate of 0.029 % per cycle has been achieved, making the COF@CNT/S cathode one of the most stable electrode material for Li-S batteries. This work provides insights into improving cycle performance of Li-S batteries, and also enriches the current study on host materials.

Hollow CoP-FeP cubes decorating carbon nanotubes heterostructural electrocatalyst for enhancing the bidirectional conversion of polysulfides in advanced lithium-sulfur batteries

The sluggish redox reaction kinetics and “shuttle effect” of lithium polysulfides (LPSs) impede the advancement of high-performance lithium-sulfur batteries (LSBs). Transition metal phosphides exhibit distinctive polarity, metallic properties, and tunable electron configuration, thereby demonstrating enhanced adsorption and electrocatalytic capabilities towards LPSs. Consequently, they are regarded as exceptional sulfur hosts for LSBs. Moreover, the introduction of a heterogeneous structure can enhance reaction kinetics and expedite the transport of electrons/ions. In this study, a composite of hollow CoP-FeP cubes with heterostructure modified carbon nanotube (CoFeP-CNTs) was fabricated and utilized as sulfur host in advanced LSBs. The presence of carbon nanotubes (CNTs) facilitates enhanced electron and Li+ transport. Meanwhile, the active sites within the heterogeneous interface of CoP-FeP suppress the “shuttle effect” and enhance the conversion kinetics of LPSs. Therefore, the CoFeP-CNTs/S electrode exhibited exceptional cycling stability and demonstrated a capacity attenuation of merely 0.051 % per cycle over 600 cycles at 1C. This study presents a highly effective tactic for synthesizing dual-acting transition metal phosphides with heterostructure, which will play a pivotal role in advancing the development of efficient LSBs.

Rationally designed FeCoNiCrMn high–entropy alloys nanoparticles hybridized rGO modified separator for highly efficient lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are featured with high specific energy density. Here the use of FeCoNiCrMn high–entropy alloys nanoparticles hybridized reduced graphene oxide (denoted as HEA/rGO) is proposed. HEA exhibits synergistic interactions between multiple metal cations in the Face Center Cubic (FCC) structure, resulting in strong chemical confinement and fast conversion kinetics of soluble LiPSs. By combining with the rGO matrix, the well-designed separator affords conductive network to expedite the diffusion of Li+ and exhibit excellent reaction kinetics. The HEA/rGO cell exhibits a high discharge capacity 1344.6 mAh/g at 0.1 C, and 758.5 mAh/g even at 2 C.

VSe2/V2C heterocatalyst with built-in electric field for efficient lithium-sulfur batteries: Remedies polysulfide shuttle and conversion kinetics

Lithium sulfur (Li-S) battery is a kind of burgeoning energy storage system with high energy density. However, the electrolyte-soluble intermediate lithium polysulfides (LiPSs) undergo notorious shuttle effect, which seriously hinders the commercialization of Li-S batteries. Herein, a unique VSe2/V2C heterostructure with local built-in electric field was rationally engineered from V2C parent via a facile thermal selenization process. It exquisitely synergizes the strong affinity of V2C with the effective electrocatalytic activity of VSe2. More importantly, the local built-in electric field at the heterointerface can sufficiently promote the electron/ion transport ability and eventually boost the conversion kinetics of sulfur species. The Li-S battery equipped with VSe2/V2C-CNTs-PP separator achieved an outstanding initial specific capacity of 1439.1 mA h g−1 with a high capacity retention of 73% after 100 cycles at 0.1 C. More impressively, a wonderful capacity of 571.6 mA h g−1 was effectively maintained after 600 cycles at 2 C with a capacity decay rate of 0.07%. Even under a sulfur loading of 4.8 mg cm−2, areal capacity still can be up to 5.6 mA h cm−2. In-situ Raman tests explicitly illustrate the effectiveness of VSe2/V2C-CNTs modifier in restricting LiPSs shuttle. Combined with density functional theory calculations, the underlying mechanism of VSe2/V2C heterostructure for remedying LiPSs shuttling and conversion kinetics was deciphered. The strategy of constructing VSe2/V2C heterocatalyst in this work proposes a universal protocol to design metal selenide-based separator modifier for Li-S battery. Besides, it opens an efficient avenue for the separator engineering of Li-S batteries.

Rationalizing the impact of oxygen vacancy on polysulfide conversion kinetics for highly efficient lithium-sulfur batteries

The “shuttle effect” of lithium polysulfides (LiPSs) is a huge challenge for practical use of high-energy-density lithium-sulfur (Li-S) batteries, and one of the main reasons is the sluggish kinetics of sulfur conversion. Metal oxides are able to expedite the sulfur electrochemistry, and the structural defects enhance the adsorption-conversion ability of metal oxides for polysulfides. However, a significant research gap still remains regarding the relationship between the oxygen vacancy concentration and the adsorptive-catalytic performance of metal oxides. Herein, we establish a correlation between oxygen vacancy concentration and adsorptive-catalytic properties by using tungsten oxide (WOx) as model catalysts. It is revealed that high-concentration oxygen vacancy is beneficial for enhancing the binding between tungsten oxide and LiPSs, reducing the energy barrier of Li2S decomposition, and promoting polysulfide conversion kinetics. Consequently, the Li-S batteries using the tungsten oxide with high-concentration oxygen vacancies deliver high initial discharge capacity of 1169 mA h g−1 at 0.2 C and 865 mA h g−1 at 2 C, low attenuation rate of 0.064% per cycle over 1100 cycles at 2 C. With a high sulfur area loading of 5.34 mg cm−2, the Li-S batteries still exhibit high initial gravimetric capacity of 982 mA h g−1 at 0.1 C and areal capacity of 5.92 mA h cm−2. This work promotes the feasibility of defect engineering on metal oxides as an effective mean to enhance the practicality of Li-S batteries.

具有协同吸附-催化效应的莫特-肖特基异质结构修 饰隔膜助力锂硫电池

The low sulfur usage, strong shuttle effect, and dilatory redox processes limit the practical application of lithium-sulfur batteries (LSBs). The method of separator modification with a unique Mott-Schottky heterostructure used in this work significantly alleviates these issues. This unique structure is synthesized by in situ polymerizing the conductive polymer polypyrrole (PPy) on the surface of Bi2MoO6 nanosheets to form Bi2MoO6-PPy nanosheets. This unique heterostructure can minimize the redox energy barrier on polysulfides due to the strong adsorption effect, high catalytic activity, and built-in electric field of Bi2MoO6-PPy nanosheets. The battery demonstrates good cycling stability when assembled with the functional separator modified by Bi2MoO6-PPy nanosheets, with an ultralow capacity decay of 0.045% per cycle over 500 cycles at 2 C. Furthermore, even with a high sulfur loading (7.5 mg cm−2), the battery retains an areal capacity of 6.3 mA h cm−2 at 0.2 C after 80 cycles. As a result, the suggested Mott-Schottky heterostructure-based Bi2MoO6-PPy nanosheets-modified separator (Bi2MoO6-PPy@PP separator) successfully suppresses the shuttle effect, providing an effective strategy for deploying efficient LSB.

Dual confining polysulfides by growing NiCo2S4 nanosheets on porous carbon nanoboxes to accelerate redox kinetics for efficient lithium-sulfur batteries

It is of particular significance to develop functional materials to regulate the polysulfide shuttling and promote the polysulfide conversion for lithium-sulfur (Li-S) batteries. Herein, we demonstrate the dual confinement of polysulfides on a composite host featuring NiCo2S4 nanosheets grown on porous carbon nanoboxes (CNB). The porous CNBs provide huge cavity for efficient accommodation of sulfur and physical confinement of soluble polysulfides. Meanwhile, the surface-grown NiCo2S4 nanosheets show strong chemical entrappment of polysulfides, and good catalytic effect on the polysulfide conversion. By virtue of the above dual effect on confining polysulfides, the sulfur cathode based on NiCo2S4/CNB host shows a high reversible capacity of 635.6 mAh g−1 at 5 C. Excellent cycle stability with a low capacity decay rate of 0.15% per cycle can be realized with a high sulfur loading of 4.8 mg cm−2 and an electrolyte/sulfur (E/S) ratio of 15 μL mgS−1. Moreover, the S/NiCo2S4/CNB cathode delivers a reversible capacity of 637 mAh g−1 at 1 C with a low E/S ratio of 3 μL mgS−1, as well as a good cycle stability. This work provide an effective strategy for fabricating sulfur hosts that enable a physical/chemical dual confinement of polysulfides for high-performance Li-S batteries.

Oxygen vacancies engineering in hollow and porous MnCo2O4 nanoflowers-coated separators for advanced Li-S batteries

A synergistic adsorption-catalysis functional layer consisting of hollow and porous MnCo2O4 nanoflowers with abundant oxygen vacancies is coated on commercial separators for durable high-performance lithium-sulfur batteries (LSBs). Benefiting from well-abundant oxygen vacancies (Vo) formed at low temperatures, the modified separators exhibit excellent catalytic conversion activity towards lithium polysulfides (LiPS) and prevent LiPS from accumulating on the separator surface. And the Vo in MnCo2O4 with spinel-type structure alters the chemical interactions between MnCo2O4 and LiPS, achieving excellent immobilization towards LiPS. Meanwhile, the hierarchical nanostructures offer numerous spaces for insoluble LiPS deposition, thus ensuring sufficient channels for fast lithium-ions (Li+) transfer. As a result, the batteries assembled with the modified separators present a high initial discharge capacity of 1089 mAh g−1 at 0.5 C with the capacity retention of 83.7% after 200 cycles and outstanding long cycle stability with an ultra-low decay rate of 0.067% each cycle at 2 C. Therefore, such an appealing strategy, combining hierarchical nanostructures with oxygen vacancies engineering in the modified separators, provides a new idea to rationally devise durable and efficient LSBs.

Polar Co9S8 anchored on Pyrrole-Modified graphene with in situ growth of CNTs as multifunctional Self-Supporting medium for efficient Lithium-Sulfur batteries

Lithium-sulfur batteries (LSBs) have stimulated burgeoning interest in both the academic and industrial communities due to their ultrahigh energy density and high cost-effectiveness. However, the real-world application of LSBs has long been plagued by the shuttling effect and sluggish conversion kinetics of soluble lithium polysulfides (LiPSn). Herein, we have designed and synthesized creative metallic and polar Co9S8 nanoparticles with in situ growth of CNTs anchored on pyrrole-modified graphene (Co9S8/CNTs-Gr) via a facile pyrolysis method, which further demonstrates superior electrochemical performance for the fixation of sulfur and effective activation of LiPSn redox conversion. The in situ growth of CNTs and introduction of pyrrole-modified graphene are beneficial for electron migration, thus significantly boost the rate performance of LSBs. Concurrently, the Co9S8 electrocatalyst shows high catalytic activity to reinforce the polysulfide conversion. Benefiting from this exquisite nanoarchitecture design, LSBs with a S@Co9S8/CNTs-Gr cathode exhibit outstanding performance, delivering a high reversible specific capacity of 950 mA h g−1 at 1C with a decay rate of only 0.01 % per cycle. Moreover, the S@Co9S8/CNTs-Gr electrode still achieves good cycling stability with a high sulfur loading of 7.2 mg cm−2, and the specific area capacity reaches as high as ∼ 6 mA h cm−2. This work provides a delicate design to construct Co9S8-based media for high-performance LSBs and can also promote one’s understanding of the advantages of the process of adsorption and redox conversion of LiPSn.

Scalable 3D Honeycombed Co3O4 Modified Separators as Polysulfides Barriers for High-Performance Li-S Batteries.

Lithium sulfur batteries (LSBs) are regarded as one of the most promising energy storage devices due to the high theoretical capacity and energy density. However, the shuttling lithium polysulfides (LiPSs) from the cathode and the growing lithium dendrites on the anode limit the practical application of LSBs. To overcome these challenges, a novel three-dimensional (3D) honeycombed architecture consisting of a local interconnected Co3O4 successfully assembled into a scalable modified layer through mutual support, which is coated on commercial separators for high-performance LSBs. On the basis of the 3D honeycombed architecture, the modified separators not only suppress effectively the "shuttle effects" but also allow for fast lithium-ions transportation. Moreover, the theoretical calculations results exhibit that the collaboration of the exposed (111) and (220) crystal planes of Co3O4 is able to effectively anchor LiPSs. As expected, LSBs with 3D honeycombed Co3O4 modified separators present a reversible specific capacity with 1007 mAh g-1 over 100 cycles at 0.1 C. More importantly, a high reversible capacity of 808 mAh g-1 over 300 cycles even at 1 C is also acquired with the modified separators. Therefore, this proposed strategy of 3D honeycombed architecture Co3O4 modified separators will give a new route to rationally devise durable and efficient LSBs.

Polar Co9s8 Anchored on Pyrrole-Modified Graphene with in Situ Growth of Cnts as Multifunctional Flexible Medium for Efficient Lithium-Sulfur Batteries

Polar Co9s8 Anchored on Pyrrole-Modified Graphene with in Situ Growth of Cnts as Multifunctional Flexible Medium for Efficient Lithium-Sulfur Batteries

Isolated Single-Atom Ni-N5 Catalytic Site in Hollow Porous Carbon Capsules for Efficient Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries suffer from multiple complex and often interwoven issues, such as the low electronic conductivity of sulfur and Li2S/Li2S2, shuttle effect, and sluggish electrochemical kinetics of lithium polysulfides (LiPSs). Guided by theoretical calculations, a multifunctional catalyst of isolated single-atom nickel in an optimal Ni-N5 active moiety incorporated in hollow nitrogen-doped porous carbon (Ni-N5/HNPC) is constructed and acts as an ideal host for a sulfur cathode. The host improved electrical conductivity, enhanced physical-chemical dual restricting capability toward LiPSs, and, more importantly, boosted the redox reaction kinetics by the Ni-N5 active moiety. Therefore, the Ni-N5/HNPC/S cathode exhibits superior rate performance, long-term cycling stability, and good areal capacity at high sulfur loading. This work highlights the important role of the coordination number of active centers in single-atom catalysts and provides a strategy to design a hollow nanoarchitecture with single-atom active sites for high-performance Li-S batteries.

Scalable Synthesis of Ultrathin Polyimide Covalent Organic Framework Nanosheets for High-Performance Lithium-Sulfur Batteries.

Development of new porous materials as hosts to suppress the dissolution and shuttle of lithium polysulfides is beneficial for constructing highly efficient lithium-sulfur batteries (LSBs). Although 2D covalent organic frameworks (COFs) as host materials exhibit promising potential for LSBs, their performance is still not satisfactory. Herein, we develop polyimide COFs (PI-COF) with a well-defined lamellar structure, which can be exfoliated into ultrathin (∼1.2 nm) 2D polyimide nanosheets (PI-CONs) with a large size (∼6 μm) and large quantity (40 mg/batch). Explored as new sulfur host materials for LSBs, PI-COF and PI-CONs deliver high capacities (1330 and 1205 mA h g-1 at 0.1 C, respectively), excellent rate capabilities (620 and 503 mA h g-1 at 4 C, respectively), and superior cycling stability (96% capacity retention at 0.2 C for PI-CONs) by virtue of the synergy of robust conjugated porous frameworks and strong oxygen-lithium interactions, surpassing the vast majority of organic/polymeric lithium-sulfur battery cathodes ever reported. Our finding demonstrates that ultrathin 2D COF nanosheets with carbonyl groups could be promising host materials for LSBs with excellent electrochemical performance.

Multifunction Co-Nx species to manipulate polysulfides conversion kinetics toward highly efficient lithium-sulfur batteries

It is highly important to develop high-performance sulfur cathode to solve low areal sulfur loading, shuttling and sluggish conversion of polysulfides for lithium-sulfur batteries. Herein, a three-dimensional (3D) freestanding framework configured with Co nanoparticles and Co-N x codoped carbon nanotubes anchored in a carbon foam is synthesized and investigated as a new type of sulfur host. Such an architecture can serve not only as a conductive carbon networks but also as host scaffold for high sulfur-containing electrodes. The hierarchical porous structures cooperated with high density and dispersion multifunctional Co-N x species can efficiently trap and manipulate catalytic conversion kinetics of polysulfides. Benefiting from above characteristics, the designed cathodes exhibit a high capacity (1259 mA h g −1 ) at 0.1 C and excellent cycling performance with an ultralow decay of 0.038% per cycle over 500 cycles at a high current density of 3 C. Even with a high sulfur loading (7.0 mg cm −2 ) and lean electrolyte (E/S = 5 μL mg −1 ) operation, a high areal capacity of 4.34 mA h cm −2 is still achieved after 100 cycles at 0.1 C. This work provides a low-cost route for preparation of freestanding cathode materials toward highly efficient lithium-sulfur batteries. • The 3D freestanding material is flexible, compressible and can be directly used as a cathode for Li-S batteries. • Co-N x species can chemically anchor and catalytically manipulate conversion kinetics of polysulfides. • The cathode exhibits a high capacity of 1259 mA h g −1 at 0.1 C, excellent long-cycle performance with an ultralow decay of 0.038% at 3 C. • A high areal capacity of 4.34 mA h cm −2 is achieved for a high sulfur loading of 7.0 mg cm −2 , and lean electrolyte (E/S = 5 μL mg −1 ).

Polypyrrole-enveloped Prussian blue nanocubes with multi-metal synergistic adsorption toward lithium polysulfides: high-performance lithium-sulfur batteries

The development of lithium-sulfur (Li-S) batteries is largely hindered by the shuttling and poor electronic conductivity of polysulfide. To solve these two problems simultaneously, we report a new strategy that combines the advantages of Prussian blue analogues (PBAs) with the conductive characteristic of polypyrrole (ppy) to construct FeCoNi PBA-S-ppy composite. The open metal centers in PBAs act as Lewis acid sites with good affinity to the negatively charged polysulfide anions, while the open framework structure allows effective storage of sulfur and confinement of lithium polysulfides (LiPS). Herein, the polysulfide redox reaction mechanism and kinetics are revealed by using in situ X-ray diffraction. The adsorption ability test and electrochemical performance assessment together with density functional theory calculations reveal that the FeCoNi PBA can achieve enhanced LiPS absorption ability and better cycling performance than the FeNi and FeCo PBAs. This can be attributed to the multi-metal synergistic adsorption toward LiPS within FeCoNi PBA, which can act as an effective chemical-anchor to capture LiPS. After combining the FeCoNi PBA with ppy, a physical barrier formed, and the improvement of the conductivity resulted in remarkable electrochemical performance. We believe that PBAs can play a beneficial role in guaranteeing more stable and efficient Li-S batteries.

Large-scale synthesis of Fe9S10/Fe3O4@C heterostructure as integrated trapping-catalyzing interlayer for highly efficient lithium-sulfur batteries

• A large-scale synthetic route to obtain core-shell Fe 9 S 10 /Fe 3 O 4 @C heterostructures. • Fe 9 S 10 /Fe 3 O 4 @C can effectively trap LiPS and promote the conversion kinetics. • The Fe 9 S 10 /Fe 3 O 4 heterointerface offers a moderate chemical bonding with LiPS. • The cell with Fe 9 S 10 /Fe 3 O 4 @C interlayer exhibits enhanced rate and cycling capability. The shuttle effect of soluble lithium polysulfides (LiPSs) and sluggish electrocatalysis of polysulfides conversion lead to severe capacity decay and poor rate capability, which is a determining factor for limiting the practical applications of lithium-sulfur (Li-S) batteries. To address such issues, a novel core-shell Fe 9 S 10 /Fe 3 O 4 @C architecture with well-defined heterointerfaces as a multifunctional polysulfides barrier for Li-S batteries is reported here. The spherical Fe 9 S 10 /Fe 3 O 4 @C heterostructure can be prepared by spray-drying technology on a large-scale and followed by a one-pot in-situ carbothermal reaction. With both physical entrapments by carbon shells and strong chemical interaction with Fe 9 S 10 /Fe 3 O 4 heterostructure cores, this constructed dense-packing architecture alleviates the shuttle effect. The mechanisms involved in the Fe 9 S 10 /Fe 3 O 4 @C trapping interlayer are confirmed by both experimental results and density functional theory (DFT) calculations. Moreover, due to its high conductivity and intrinsic catalytic activity, the Fe 9 S 10 /Fe 3 O 4 @C facilitates fast electron/ion transport and greatly improves the conversion of LiPSs. Benefit from the integrated trapping-catalyzing effect, the Li-S cell constructed with a Fe 9 S 10 /Fe 3 O 4 @C interlayer exhibits enhanced cycling stability (a low capacity fading rate of 0.08% per cycle for 500 cycles at 1 C) and outstanding rate performance (660 mAh g −1 at 5 C). Even under a high areal sulfur loading of 3 mg cm −2 , the high discharge capacity and capacity retention ratio can also be obtained. This work offers an insight into the construction of multi-functional heterostructures for high-performance Li-S batteries.

2D‐Organic Layered Materials: Atomically dispersed Fe in a C2N Based Catalyst as a Sulfur Host for Efficient Lithium–Sulfur Batteries (Adv. Energy Mater. 5/2021)

2D‐Organic Layered Materials: Atomically dispersed Fe in a C₂N Based Catalyst as a Sulfur Host for Efficient Lithium–Sulfur Batteries (Adv. Energy Mater. 5/2021)

Two-dimensional metal–organic framework with perpendicular one-dimensional nano-channel as precise polysulfide sieves for highly efficient lithium–sulfur batteries

When 2D CuBDC MOF sheets with perpendicular 1D nano-channels (5.2 Å) was were used as polysulfides sieves for Li–S batteries, suppressed “shuttle effect” and enhanced electrochemical performance were achieved.

Enhancing Polysulfide Confinement and Electrochemical Kinetics by Amorphous Cobalt Phosphide for Highly Efficient Lithium-Sulfur Batteries.

The application of lithium-sulfur (Li-S) batteries is severely hampered by the shuttle effect and sluggish redox kinetics. Herein, amorphous cobalt phosphide grown on a reduced graphene oxide-multiwalled carbon nanotube (rGO-CNT-CoP(A)) is designed as the sulfur host to conquer the above bottlenecks. The differences between amorphous cobalt phosphide (CoP) and crystalline CoP on the surface adsorption as well as conversion of lithium polysulfides (LiPSs) are investigated by systematical experiments and density-functional theory (DFT) calculations. Specifically, the amorphous CoP not only strengthens the chemical adsorption to LiPSs but also greatly accelerates liquid-phase conversions of LiPSs as well as the nucleation and growth of Li2S. DFT calculation reveals that the amorphous CoP possesses higher binding energies and lower diffusion energy barriers for LiPSs. In addition, the amorphous CoP features reduced energy gap and the increased electronic concentrations of adsorbed LiPSs near Fermi level. These characteristics contribute to the enhanced chemisorption ability and the accelerated redox kinetics. Simultaneously, the prepared S/rGO-CNT-CoP(A) electrode delivers an impressive initial capacity of 872 mAh g-1 at 2 C and 617 mAh g-1 can be obtained after 200 cycles, exhibiting excellent cycling stability. Especially, it achieves outstanding electrochemical performance even under high sulfur loading (5.3 mg cm-2) and lean electrolyte (E/S = 7 μLE mg-1S) conditions. This work exploits the application potential for amorphous materials and contributes to the development of highly efficient Li-S batteries.

Atomically dispersed Fe in a C2N Based Catalyst as a Sulfur Host for Efficient Lithium–Sulfur Batteries

AbstractLithium–sulfur batteries (LSBs) are considered to be one of the most promising next generation energy storage systems due to their high energy density and low material cost. However, there are still some challenges for the commercialization of LSBs, such as the sluggish redox reaction kinetics and the shuttle effect of lithium polysulfides (LiPS). Here a 2D layered organic material, C2N, loaded with atomically dispersed iron as an effective sulfur host in LSBs is reported. X‐ray absorption fine spectroscopy and density functional theory calculations prove the structure of the atomically dispersed Fe/C2N catalyst. As a result, Fe/C2N‐based cathodes demonstrate significantly improved rate performance and long‐term cycling stability. Fe/C2N‐based cathodes display initial capacities up to 1540 mAh g−1 at 0.1 C and 678.7 mAh g−1 at 5 C, while retaining 496.5 mAh g−1 after 2600 cycles at 3 C with a decay rate as low as 0.013% per cycle. Even at a high sulfur loading of 3 mg cm−2, they deliver remarkable specific capacity retention of 587 mAh g−1 after 500 cycles at 1 C. This work provides a rational structural design strategy for the development of high‐performance cathodes based on atomically dispersed catalysts for LSBs.