Sulfur Redox Reactions Research Articles

Construction of an Ohmic Contact Cathode by Two Metal Sulfides for efficient Capture and Catalysis of Polysulfide.

The slow reaction kinetics and severe shuttle effect of lithium polysulfide make Li-S battery electrochemical performance difficult to meet the demands of large electronic devices such as electric vehicles. Based on this, an electrocatalyst constructed by metal phase material (MoS2) and semiconductor phase material (SnS2) with ohmic contact is designed for inhibiting the dissolution of lithium polysulfide with improving the reaction kinetics. According to the density-functional theory calculations, it is found that the heterostructured samples with ohmic contacts can effectively reduce the reaction-free energy of lithium polysulfide to accelerate the sulfur redox reaction, in addition to the excellent electron conduction to reduce the overall activation energy. The metallic sulfide can add more sulfophilic sites to promote the capture of polysulfide. Thanks to the ohmic contact design, the carbon nanotube-MoS2-SnS2 achieved a specific capacity of 1437.2 mAhg-1 at 0.1 C current density and 805.5 mAhg-1 after 500 cycles at 1 C current density and is also tested as a pouch cell, which proves to be valuable for practical applications. This work provides a new idea for designing an advanced and efficient polysulfide catalyst based on ohmic contact.

Leveraging doping strategies and interface engineering to enhance catalytic transformation of lithium polysulfides for high-performance lithium-sulfur batteries

The commercialization of lithium-sulfur (Li–S) batteries has faced challenges due to the shuttle effect of soluble intermediate polysulfides and the sluggish kinetics of sulfur redox reactions. In this study, a synergistic catalyst medium was developed as a high-performance sulfur cathode material for Li–S batteries. Termed A/R-TiO2@ Ni-N-MXene, this sulfur cathode material features an in-situ derived anatase–rutile homojunction of TiO2 nanoparticles on Ni-N dual-atom-doped MXene nanosheets. Using in-situ transmission electron microscopy (TEM) technique, we observed the growth process of the homojunction for the first time confirming that homojunctions facilitated charge transfer, while dual-atom doping offered abundant active sites for anchoring and converting soluble polysulfides. Theoretical calculations and experiments showed that these synergistic effects effectively mitigated the shuttle effect, leading to improved cycling performance of Li–S batteries. After 500 cycles at a 1C rate, Li–S batteries using A/R-TiO2@Ni-N-MXene as cathode materials exhibited stable and highly reversible capacity with a capacity decay of only 0.056 % per cycle. Even after 150 cycles at a 0.1C rate, a high-capacity retention rate of 62.8 % was achieved. Additionally, efficient sulfur utilization was observed, with 1280.76 mA h/g at 0.1C, 694.24 mA h/g at 1C, alongside a sulfur loading of 1.5–2 mg/cm2. The effective strategy based on homojunctions showcases promise for designing high-performance Li–S batteries.

High-Entropy Metal Nitride Embedded in Concave Porous Carbon Enabling Polysulfide Conversion in Lithium-Sulfur Batteries.

The practical implementation of lithium-sulfur batteries is severely hindered by the rapid capacity fading due to the solubility of the intermediate lithium polysulfides (LiPSs) and the sluggish redox kinetics. Herein, high-entropy metal nitride nanocrystals (HEMN) embedded within nitrogen-doped concave porous carbon (N-CPC) polyhedra are rationally designed as a sulfur host via a facile zeolitic imidazolate framework (ZIF)-driven adsorption-nitridation process toward this challenge. The configuration of high-entropy with incorporated metal manganese (Mn) and chromium (Cr)will optimize the d-band center of active sites with more electrons occupied in antibonding orbitals, thus promoting the adsorption and catalytic conversion of LiPSs. While the concave porous carbon not only accommodates the volume change upon the cycling processes but also physically confines and exposes active sites for accelerated sulfur redox reactions. As a result, the resultant HEMN/N-CPC composites-based sulfur cathode can deliver a high specific capacity of 1274 mAh g-1 at 0.2C and a low capacity decay rate of 0.044% after 1000 cycles at 1C. Moreover, upon sulfur loading of 5.0mg cm-2, the areal capacity of 5.0mAhcm-2 can still be achieved. The present work may provide a new avenue for the design of high-performance cathodes in Li-S batteries.

Coordination networks in accordion-like copper based metal–organic frameworks facilitate efficient catalytic strategies in high performance lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) are attractive for electric vehicles due to their high theoretical capacity and low cost. However, they severely suffer from the “shuttle effect”, which causes capacity fading and self-discharge. Metal-organic frameworks (MOFs) have been proposed as an effective sulfur-loaded matrix material to mitigate this problem via providing sufficient catalytic sites for accelerating sulfur redox reactions (SRR). In this study, a novel accordion-like copper-based coordination network matrix material is constructed with pyridine-2,4-dicarboxylic acid as the ligands, which the layered structure can effectively adsorbs LiPSs, thereby avoiding the loss of reactive active material. Besides that, the coordination network can reduce the activation energy barrier of Li2S decomposition and the redox conversion rate between S8 and Li2S. It is revealed that the materials with ideal layered structure can facilitate SRR via providing Lewis acid-base interactions between Cu atoms and LiPSs. Electrochemical results in a high discharge capacity of 751.25 mAh·g−1 at a high current density of 2C has been achieved and when returns to 0.2C after 60 cycles, it can recover a high reversible capacity of 1093.63 mAh·g−1. It demonstrates that coordination network materials with ideal layered structure can be as a promising strategy for overcoming the challenges of LSBs and expanding their potential applications.

Constructing Orbital Coupling-Modulated Homogeneous Dual-Atom Fe-Fe Sites for Boosting Bidirectional Conversion of Polysulfides.

Homogeneous dual-atom catalysts (HDACs) have garnered significant attention for their potential to overcome the shuttling effect and sluggish reaction kinetics in lithium-sulfur (Li-S) batteries. However, modulating the electron structure of metal atomic orbitals for HDACs to dictate the catalytic activity toward polysulfides has remained meaningful but unexplored so far. Herein, an interfacial cladding strategy is developed to obtain a new type of dual-atom iron matrix with a unique FeN2P1-FeN2P1 coordination structure (Fe2@NCP). The 3d orbital electrons of the Fe centers are redistributed by incorporating phosphorus atoms into the first coordination sphere. The theoretical calculations disclose that the strong coupling between the Fe d orbital and the S p orbital exhibits an enhanced Fe-S bond and improved reactivity toward polysulfides. Moreover, the Fe2@NCP catalyst achieves robust adsorption ability toward Li2Sn (1 ≤ n ≤ 8) and significantly boosts bidirectional sulfur redox reaction kinetics by lowering the Li2S deposition/decomposition energy barriers. Consequently, the assembled Li-S batteries present a high retention ratio of 77.3% after 500 cycles at 1C. Furthermore, the Li-S pouch cell also exhibits good performance at 0.1C (80.2% retention over 100 cycles) for practical application with a sulfur loading of 4.0 mg/cm2. The outcome of this study will facilitate the design of homogeneous dual-atom catalysts for Li-S batteries.

High-Entropy Catalysis Accelerating Stepwise Sulfur Redox Reactions for Lithium-Sulfur Batteries.

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.

Chip-Inspired Design of High-Performance Lithium-Sulfur Batteries by Integrating Monodisperse Sulfur Nanoreactors on Graphene.

For practical application of lithium-sulfur batteries (LSBs), designing devices with an overall optimal structure instead of modifying electrode materials is significant. Herein, we report a chip-inspired design of a vertically integrated structure as an LSB cathode by implanting Mo2C nanoparticles and nanosulfur into the reduced graphene oxide (rGO) matrix. This configuration enabled the synthesis of isolated sulfur nanoreactors (S-NRs) integrated in a tandem array on the rGO, generating chip-like integrated LSBs. The spatial confinement/protection and concentration gradient of the S-NRs effectively avoided the dissolution, diffusion, and loss of polysulfides, thereby enhancing the sulfur utilization and redox reaction kinetics. Additionally, the adaptive storage energy can be improved by utilizing the tandem, isolation, and synergistic multiplicative effect among the nanoreactor units. As a result, the integrated LSB cathode obtained excellent electrochemical performances with an initial capacity of 1392 mAh g-1 at 0.1C, a low capacity decay rate of 0.017% per cycle during 1500 cycles of operation at 0.5C, and a superior rate performance. This work provides a rational design idea and method of further advancing the precise preparation of high-performance energy storage devices.

Quasi-Solid-State Electrolyte Induced by Metallic MoS2 for Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries are a promising high-energy-density technology for next-generation energy storage but suffer from an inadequate lifespan. The poor cycle life of Li-S batteries stems from their commonly adopted catholyte-mediated operating mechanism, where the shuttling of dissolved polysulfides results in active material loss on the sulfur cathode and surface corrosion on the lithium anode. Here, we report in situ formation of a quasi-solid-state electrolyte (QSSE) on the metallic 1T phase molybdenum disulfide (MoS2) host that extends the lifetime of Li-S batteries. We find that the metallic 1T phase MoS2 host is able to initiate the ring-opening polymerization of 1,3-dioxolane (DOL), forming an integrated QSSE inside batteries. Nuclear magnetic resonance analysis reveals that the QSSE consists of ∼13% liquid DOL in a solid polymer matrix. The QSSE efficiently mediates sulfur redox reactions through dissolution-conversion chemistry while simultaneously suppressing polysulfide shuttling. Therefore, while ensuring high sulfur utilization, it avoids degradation of both electrodes, as well as the concomitant electrolyte consumption, leading to enhanced cycling stability. Under a practical lean electrolyte condition (electrolyte-to-sulfur ratio = 2 μL mg-1), Li-S pouch cell batteries with the QSSE demonstrate a capacity retention of 80.7% after 200 cycles, much superior to conventional liquid electrolyte cells that fail within 70 cycles. The QSSE also enables Li-S pouch cell batteries to operate across a wider temperature range (5 to 45 °C), together with improved safety under mechanical damage.

Entropy‐Driven Highly Chaotic MXene‐Based Heterostructures as an Efficient Sulfur Redox Electrocatalysts for Li‐S Battery

AbstractBoth the sluggish sulfur redox reaction (SRR) kinetics and lithium polysulfides (LiPSs) shuttle effect limit the practical application of Li‐S batteries. Designing heterostructure sulfur hosts has emerged as an effective way to address these two issues with one material. However, the principles of heterostructures reinforced Li‐S batteries remain inadequately understood. Here, it is demonstrated for the first time that increasing the entropy of heterostructure can promote its SRR catalytic activity and alleviate the LiPSs shuttling. By a simple solution‐based strategy, a highly chaotic MXene‐based heterostructure (HCMH, TiS2/TiN/TiO2/Ti3C2Tx) is fabricated. The smart integration of “high entropy”, heterostructure, and MXene endow the HCMH catalyst with significantly improved performance, demonstrated by a much smaller Tafel slope of 62.9 mV dec−1 and a higher electron transfer number of 7.10, compared with the moderately chaotic MXene‐based heterostructure (MCMH, TiO2/TiN/Ti3C2Tx) and MXene. DFT theoretical calculations reveal that introducing new phases lowers the Gibbs energy barriers of both rate‐limiting Li2S2/Li2S reduction and Li2S decomposition. Upon the addition of only 5 wt.% HCMH to the sulfur cathode, both the reversible capacity and rate capability of Li‐S cells are greatly improved, which further highlights the importance of the high entropy “cocktail effect” in the design of SRR electrocatalysts in the future.

Promoting sulfur redox reactions by CuBr quantum dot-based electrocatalyst for lean-electrolyte lithium-sulfur batteries

The construction of robust electrodes with promoted kinetics of sulfur redox reactions and enduring redox chemistry is crucial for developing advanced Li-S batteries. Herein, a hybrid sulfur cathode based on CuBr quantum dots (QDs)-interspersed reduced graphene oxide (rGO) is first developed for energy-dense Li-S batteries. With the combination of theoretical calculations and experimental results, it is certified that the CuBr QDs anchored on the rGO surface could efficiently improve the chemical adsorption and transformation of sulfur-related species, which significantly facilitates desired redox reaction, thus resulting in a durable and fast long-term cycling performance. Under practically-relevant conditions, the assembled pouch cell could deliver a high initial gravimetric energy density of 375 Wh kg−1 with decent durability, showing great application prospects in lean-electrolyte Li-S batteries.

Building a High-Potential Silver-Sulfur Redox Reaction Based on the Hard-Soft Acid-Base Theory.

Sulfur holds immense promise for battery applications owing to its abundant availability, low cost, and high capacity. Currently, sulfur is commonly combined with alkali or alkaline earth metals in metal-sulfur batteries. However, these batteries universally face challenges in cycling stability due to the inevitable issue of polysulfide dissolution and shuttling. Additionally, the inferior stability of metal sulfide discharge compounds results in low S0/S2- redox potentials (<-0.41 V vs SHE). Herein, we leverage the principle of the hard-soft acid-base theory to introduce a novel silver-sulfur (Ag-S) battery system, which operates on the reaction between the soft acid of Ag+ and the soft base of S2-. Due to their high reaction affinity, the discharge compound of silver sulfide (Ag2S) is intrinsically insoluble and fundamentally stable. This not only resolves the polysulfide dissolution issue but also leads to a predominantly high S0/S2- redox potential (+1.0 V vs. SHE). We thus exploit the Ag-S reaction for a primary zinc battery application, which exhibits a high capacity of ∼620 mAh g-1 and a high voltage of ∼1.45 V. This work offers valuable insights into the application of classic chemistry theories in the development of innovative energy storage devices.

Universal, minute-scale synthesis of transition metal compound nanocatalysts via graphene-microwave system for enhancing sulfur kinetics in lithium-sulfur batteries

The application of Li-S batteries on large scale is held back by the sluggish sulfur kinetics and low synthesis efficiency of sulfur host. In addition, the preparation of catalysts that promote polysulfide redox kinetics is complex and time-consuming, reducing the cost of raw materials in Li-S. Here, a universal synthetic strategy for rapid fabrication of sulfur cathode and metal compounds nanocatalysts is reported based on microwave heating of graphene. Heat-sensitive materials can achieve rapid heating due to graphene reaching 500 ℃ within 4 s via microwave irradiation. The MoP-MoS2/rGO catalyst demonstrated in this work was synthesized within 60 s. When used for catalysts for Li-S batteries whose graphene/sulfur cathodes were also synthesized by microwave heating, enhanced catalytic effect for sulfur redox reaction was verified via experimental and DFT theoretical results. Benefiting from fast redox reaction (MoP), smooth Li+ diffusion pathways (MoS2), and large conductive network (rGO), the assembled Li-S battery with MoP-MoS2/rGO-Add@CS displays a remarkable initial specific capacity, stable lithium anode and good cycle stability (in pouch cells) using this two-pronged strategy. The work provides a practical strategy for advanced Li-S batteries toward a wide range of applications.

Regulating Sulfur Redox Kinetics by Coupling Photocatalysis for High-Performance Photo-Assisted Lithium-Sulfur Batteries.

Challenges such as shuttle effect have hindered the commercialization of lithium-sulfur batteries (LSBs), despite their potential as high-energy-density storage devices. To address these issues, we explore the integration of solar energy into LSBs, creating a photo-assisted lithium-sulfur battery (PA-LSB). The PA-LSB provides a novel and sustainable solution by coupling the photocatalytic effect to accelerate sulfur redox reactions. Herein, a perovskite quantum dot-loaded MOF material serves as a cathode for the PA-LSB, creating built-in electric fields at the micro-interface to extend the lifetime of photo-generated charge carriers. The band structure of the composite material aligns well with the electrochemical reaction potential of lithium-sulfur, enabling precise regulation of polysulfides in the cathode of the PA-LSB system. This is attributed to the selective catalysis of the liquid-solid reaction stage in the lithium-sulfur electrochemical process by photocatalysis. These contribute to the outstanding performance of PA-LSBs, particularly demonstrating a remarkably high reversible capacity of 679 mAh g-1 at 5 C, maintaining stable cycling for 1500 cycles with the capacity decay rate of 0.022 % per cycle. Additionally, the photo-charging capability of the PA-LSB holds the potential to compensate for non-electric energy losses during the energy storage process, contributing to the development of lossless energy storage devices.

Regulating Sulfur Redox Kinetics by Coupling Photocatalysis for High‐Performance Photo‐Assisted Lithium‐Sulfur Batteries

AbstractChallenges such as shuttle effect have hindered the commercialization of lithium‐sulfur batteries (LSBs), despite their potential as high‐energy‐density storage devices. To address these issues, we explore the integration of solar energy into LSBs, creating a photo‐assisted lithium‐sulfur battery (PA‐LSB). The PA‐LSB provides a novel and sustainable solution by coupling the photocatalytic effect to accelerate sulfur redox reactions. Herein, a perovskite quantum dot‐loaded MOF material serves as a cathode for the PA‐LSB, creating built‐in electric fields at the micro‐interface to extend the lifetime of photo‐generated charge carriers. The band structure of the composite material aligns well with the electrochemical reaction potential of lithium‐sulfur, enabling precise regulation of polysulfides in the cathode of the PA‐LSB system. This is attributed to the selective catalysis of the liquid‐solid reaction stage in the lithium‐sulfur electrochemical process by photocatalysis. These contribute to the outstanding performance of PA‐LSBs, particularly demonstrating a remarkably high reversible capacity of 679 mAh g−1 at 5 C, maintaining stable cycling for 1500 cycles with the capacity decay rate of 0.022 % per cycle. Additionally, the photo‐charging capability of the PA‐LSB holds the potential to compensate for non‐electric energy losses during the energy storage process, contributing to the development of lossless energy storage devices.

Chemomechanics Engineering Promotes the Catalytic Activity of Spinel Oxides for Sulfur Redox Reaction

AbstractCooperative catalysis is a promising approach to enhance the sluggish redox kinetics of lithium polysulfides (LiPSs) for practical lithium–sulfur (Li–S) batteries. However, the elusory synergistic effect among multiple active sites makes it challenging to accurately customize the electronic structure of catalysts. Herein, a strategy of precisely tailoring eg orbitals of spinel oxides through chemomechanics engineering is porposed to regulate LiPSs retention and catalysis. By manipulating the regulable cations in MnxCo3‐xO4, it is theoretically and experimentally revealed that the lattice strain induced by the Jahn–Teller active and high‐spin Mn3+ at octahedral (Oh) sites can increase the eg occupancy of low‐spin Co3+Oh, which effectively regulates the chemical affinity toward LiPSs and establishes an unblocked channel for intrinsic charge transfer. This leads to a volcano‐type correlation between the eg occupancy at Oh sites and sulfur redox activity. Benefitting from the cooperative catalysis of dual‐active sites, MnCo2O4 with an average eg occupancy of 0.45 affords the most appropriate adsorption strength and rapid redox kinetics toward LiPSs, leading to remarkable rate performance and capacity retention for the assembled Li–S batteries. This work demonstrates the promise of chemomechanics engineering for optimizing the eg occupancy to achieve efficient sulfur redox catalysts.

Defect-rich porous graphitic phase carbon nitride layer grafted MXene as desolvation promoter for efficient sulfur conversion in extremely harsh conditions

Lithium-sulfur (Li-S) batteries exhibit superior theoretical capacity and energy density but are still hindered by the sluggish redox conversion kinetic of lithium polysulfides arising from the significant desolvation barrier, especially under high current density or low-temperature environments. Herein, a two-dimensional (2D) porous graphitic phase carbon nitride/MXene (CN-MX) heterostructure with intrinsic defects was designed via electrostatic adherence and in-situ thermal polycondensation. In the design, the defect-rich CN with abundant catalytic activity and porous structure could efficiently facilitate the lithium polysulfides capture, the dissociation of solvated lithium-ion (Li+), and fast Li+ diffusion. Concurrently, 2D MXene nanosheets with high electronic conductivity could act as charge transport channels and provide electrochemical active sites for sulfur redox reactions. The Li-S cells with CN-MX heterostructure modified separator demonstrated uncommon rate performance (945 mAh/g at 4.0 C) and satisfactory areal capacity (5.5 mAh cm−2 at 0.2 C). Most remarkably, even at 0 °C, the assembled Li-S batteries performed favorable cycle stability (91.6% capacity retention after 100 cycles at 0.5 C) and outstanding rate performance (695 mAh/g at 2.0 C), and superior high loading performance (5.1 mAh cm−2 at 0.1 C). This work offers exciting new insights to enable Li-S batteries to operate in extreme environments.

Synergistic coupling of optical field and built-in electric field for lithium-sulfur batteries with high cyclabilities and energy densities

Photo-assisted lithium sulfur batteries (PA-LSBs) provide vital and sustainable protocols for promoting sulfur redox reactions via powerful photoinduced effects. However, precise control of the stepwise adsorption, diffusion and photocatalytic conversion of polysulfides at the surface of photocatalysts is required to accelerate the photo-assisted process. Herein, optical field and built-in electric field synergistically-assisted LSBs are developed with a p-n junction of Co3O4-TiO2 on the carbon cloth, possessing a spontaneously generated built-in electric field and a well-matched energy band structure with sulfur redox reactions. Under light irradiation, the directional migration of soluble polysulfides and the space separation of photogenerated carriers are achieved with the synergistical coupling of the optical field and built-in electric field to precisely regulate the selective deposition of Li2S and inhibit the shuttle effect via an effective photocatalytic-promoted process, leading to a maximum capacity of 1087 mAh g−1 at 2 C and a low capacity attenuation of 0.068% per cycle at 5 C. A high areal capacity of 9.6 mAh cm−2 and a great potential photo-charge process can be realized with light irradiation. Furthermore, the stability of lithium metal anodes is improved accordingly. This work demonstrates a new insight to develop high-performance LSBs with a multifield synergistical coupling protocol.

FeSx/MoS2 heterostructure decorated S-coated hydroxylated carbon nanotubes for boosting catalytic activity and mitigating polysulfide shuttling in lithium-sulfur batteries

Heterostructure was widely study to figure out the inferior shuttle effect of intermediate lithium polysulfides and the sluggish kinetics of sulfur redox reaction in lithium-sulfur batteries (LSBs). However, they have low electrical conductivity and no clear discharge/charge catalytic mechanism as LSBs cathode. Combination of heterostructure and functional carbonaceous is a promising choice. Herein, FeSx/MoS2 heterostructure decorated S-coated hydroxylated carbon nanotubes (FSM/SHC) were successfully designed and the catalytic mechanism of FSM was elucidated by in-/ex- situ electrochemical characterizations. Compared to FeSx/MoS2 heterostructure decorated carbon nanotubes (FSM/C)-based sulfur cathode, the chemical adsorption capacity to anchor intermediate polysulfides and the Li-S conversion reaction kinetics of FSM/SHC has been enhanced ascribed to the introduction of polar bonds and functional groups. As a consequence, FSM/SHC-based sulfur modified cathode delivers a marked sulfur reversion (1280 mAh g−1 after 800 cycles at 0.2C and 1048 mAh g−1 after 300 cycles at 4C) and a high capacity retention of 6 mAh cm−2 over 70 cycles at 0.5C (8 mg cm−2). Moreover,the FSM heterostructuredemonstrates an accelerated electron transfer caused by the valence change of Fe0/Fe3+transition, Mo4+/Mo6+ transition and heterointerface, and thus facilitates the redox reaction kinetics of polysulfide. This work reveals the advantages of multi metal-based heterostructures and functional group modification in LSBs.

P-doped Mo2C nanoparticles embedded on carbon nanofibers as an efficient electrocatalyst for Li-S batteries

Designing a reliable sulfur host that can simultaneously catalyze sulfur redox reactions and suppress polysulfides shuttling is highly desired for the development of advancing Li-S batteries. In this work, P-doped Mo2C nanoparticles anchoring on carbon nanofibers (CNF) is prepared via an organic–inorganic nanohybridization process. The interwoven CNF networks establish continuous electrons transport pathways and provide a large surface area for loading P-Mo2C nanoparticles. The P dopant tunes the electronic structure of Mo2C, which endows P-Mo2C with enhanced polysulfides adsorption ability and improved sulfur redox kinetics. Leveraging these advantages, the Li-S battery shows excellent electrochemical properties, delivering a high specific capacity of 1174 mA·h·g−1 at 0.2 C, and maintaining over 1200 stable cycles at 1 C with a low capacity attenuation rate of 0.043 % per cycle. At a S loading of 4.88 mg·cm−2 and E/S ratio of 8.25 μL·mg−1, the Li-S battery attains an areal capacity of 6.50 mA·h·cm−2 at 0.05 C. These results highlight the promising application potential of P-Mo2C@CNF as an effective electrocatalyst for Li-S batteries.

Single-Atom Catalysts with Unsaturated Co–N2 Active Sites Based on a C2N 2D-Organic Framework for Efficient Sulfur Redox Reaction

Single-Atom Catalysts with Unsaturated Co–N₂ Active Sites Based on a C₂N 2D-Organic Framework for Efficient Sulfur Redox Reaction