Cathode Material For Lithium-sulfur Batteries Research Articles

Nitrogen-Doped Porous Nanofiber Aerogel-Encapsulated Staphylo-Ni3S2 Accelerating Polysulfide Conversion for Efficient Li-S Batteries.

The low conductivity of sulfur substances and the fussy effect of lithium polysulfides (LPS) limit the practical application of lithium-sulfur batteries (LSBs). In this work, Ni3S2 is in situ synthesized on N-doped 3D carbon nanofibers with an optimized pore structure as a cathode material for LSBs. The conductive carbon nanofiber skeleton with a hierarchical (micropore-mesopore-macropore) structure etched by Cd2+ can reduce the interface resistance of the cathode and remiss volume expansion during charge-discharge progress. The Ni was vulcanized and nitrogen-doped successively during the annealing process. In addition, the polar Ni3S2 and N-doped carbon structure can promote the catalytic conversion of LPS and regulate the 3D nucleation of Li2S, which could reduce the reaction energy barrier. Therefore, the NCF-Cd-Ni3S2-NC cathode can maintain a high initial capacity (1080.2 mAh g-1) and excellent stability at 0.1C. This work provides an important basis for the synthesis of high efficiency and inexpensive cathode carrier materials for LSBs.

Nitrogen-Doped Two-Dimensional Carbon Nanosheets for High-Sulfur-Loading Lithium-Sulfur Batteries via a Lignin-Based High-Internal-Phase Pickering Emulsion Strategy.

Attributable to sulfur's significant theoretical energy density, its affordability, and its environmentally friendly nature, lithium-sulfur batteries (LSBs) are recognized as advanced energy storage technologies with considerable potential. Nonetheless, the solubility and migration of polysulfides within the electrolyte substantially hinder their practical implementation. To address this issue, we developed a nitrogen-doped two-dimensional (2D) wavy carbon nanosheet material (NCN) by using the Pickering emulsion templating method. Nitrogen doping enhances the surface polarity of the two-dimensional carbon material, promoting electrolyte penetration and providing strong chemical adsorption of polysulfides. The distinctive two-dimensional wavy structure enhances lithium-ion transport and regulates polysulfide dissolution and diffusion throughout the electrochemical cycle, resulting in an enhanced electrochemical performance. Therefore, the S@NCN cathode shows a discharge specific capacity, reaching 936 mAh g-1 at 1 C. Despite a sulfur load reaching 7.2 mg cm-2, the S@NCN cathode achieves a specific capacity of 823 mAh g-1. These findings indicate that the NCN is a high-performance 2D carbon material for sulfur cathodes, effectively improving the electrochemical stability of LSBs and showing great potential for future applications as a cathode material in LSBs.

A review on sulfur-based composite cathode materials for lithium-sulfur batteries: Progress and prospects

A review on sulfur-based composite cathode materials for lithium-sulfur batteries: Progress and prospects

Constructing dual-atom catalysts by replacing N atoms with heteronuclear transition metals as efficient sulfur host materials for lithium-sulfur batteries: A first-principles study

Dual-atom catalysts (DACs) have shown remarkable electrochemical performance as cathode materials in lithium-sulfur batteries (LSBs), and carbon-nitrogen compounds are highly effective support materials for these catalysts. In previous studies, catalytic atoms were often introduced into the cavities of carbon-nitrogen compounds, but this structure generally lacked stability. This work employs first-principles calculations to investigate the application potential of DACs (TM-TM@g-C3N4) supported on monolayer g-C3N4 through atomic substitution in LSBs. Molecular dynamics simulations and electronic structure analyses indicate that TM-TM@g-C3N4 structures possess good structural stability and exhibit enhanced conductivity. Adsorption studies reveal that, due to the d-electron configuration of heteronuclear dual atoms, the constructed DACs display excellent anchoring performance for LiPSs (with adsorption energies ranging from -1.02 to -5.67eV). Notably, the strong hybridization of Mn and Co d-orbitals in Mn-Co@g-C3N4 at the Fermi level enhances its catalytic performance in the sulfur reduction reaction kinetics, particularly crossing the Fermi level. The reduction of Li2S2 to Li2S, the rate-limiting step, shows a low free energy barrier (-0.09eV). Additionally, weakened Li-S bonds facilitate the decomposition of Li2S on Mn-Co@g-C3N4 (0.77eV). With its suitable adsorption energy and superior catalytic activity in both directions, Mn-Co@g-C3N4 emerges as an optimal support material with strong application potential. This work paves the way for developing high-activity host materials for LiPSs and provides valuable insights for designing homonuclear and heteronuclear DACs in LSBs.

Synergistic mechanisms of nitrogen configurations in sulfur hosts and their enhancement of electrochemical performance in lithium‑sulfur batteries

Lithium‑sulfur batteries (LSBs) have attracted a lot of attention due to their high theoretical capacity and energy density. However, the cathode material for LSBs is limited by the low conductivity of sulfur and its products, as well as volume fluctuations during charging and discharging, and the shuttle effect of soluble lithium polysulfide. In this work, a cathode sulfur host material Nitrogen-doped porous carbon materials (N-PCM) was synthesized, doped with Pyridine N and Pyrrolic N, using melamine and glycine as nitrogen sources, silicon dioxide as template. The synthesis method characterized by controllable nitrogen content and nitrogen configurations. The results of the electrochemical performance test indicate that the composite N-PCM/S exhibits a higher capacity and enhanced cycling stability. At a rate of 0.1C, N-PCM/S demonstrates an initial discharge capacity of up to 1308 mAh/g. At 2C, the initial discharge capacity is 603 mAh/g, while maintaining a reversible capacity of 543 mAh/g after 400 cycles. The capacity decay rate is only 0.025 % per cycle, showcasing excellent cycle stability. Additionally, the N-PCM/S exhibits excellent electrochemical performance under electrolyte-poor conditions. The results showed that the synergistic effect of different nitrogen configurations significantly enhanced the adsorption and catalytic conversion of polysulfide by sulfur hosts, accelerate the reaction rate of polysulfide.

Long Chain Polysulfides Control via Ferroelectric (Ba0.9Sr0.1TiO3) Nanoparticles Doped Sulfur Cathode for High-Capacity Li-S Batteries

Lithium-sulfur (Li-S) batteries show promise in energy storage technology due to their high energy density and cost-effectiveness. However, practical application faces challenges, including low electrical conductivity of sulfur and discharge products, and the generation of insoluble compounds like Li2S during cycling. Soluble polysulfides can migrate, perpetuating a shuttle effect that leads to deposition of solid Li2S2 and Li2S on the anode, reducing efficiency and cycle life. Efforts to enhance cathode conductivity and suppress polysulfide loss during cycling are ongoing to overcome these challenges. In this study we are reporting electrochemical performance of Ba0.9Sr0.1TiO3 (BST) having polarization of 14.58 μC/cm2 doped sulfur/carbon black/polyvinylidene fluoride (S/BST/CB/PVDF) composite as cathode materials for Li-S batteries. The performance of S50BST30CB10PVDF10, and S40BST40CB10PVDF10 fabricated cathodes in terms of structural, electronic, morphological, and electrochemical response have been tested. X-ray diffraction spectra confirm tetragonal symmetry (c/a=1.0073), Raman spectroscopic study confirms Raman modes (A1(TO1), A1(TO2), A1(TO3) and A1(LO3)) of the tetragonal orientation for BST modified composites. All the compositional cations are observed from SEM images confirm homogeneous distribution of BST in the sulfur cathode system having grain sizes (1-1.5 μm) which is based on microscopic analysis. BST coupled C-S composite cathodes showing improved electrochemical performance in comparison to C-S composites. The high-capacity composites cathode in 1st cycle is S50BST30CB10PVDF10, tested @100 mA/g & 200 mA/g with polypropylene (PP) separator showing specific capacities ~820 mAh/g & ~540 mAh/g respectively, with improved capacity retention up to 60%. We observed that the hybrid composite cathode S40BST40CB10PVDF10 which was tested @100 mA/g showing specific capacity ~1080 mAh/g and remained up to 395 mAh/g after 100th cycle with capacity retention of 36%, very stable response till 100th cycles attributes polysulfide migration is effectively reducing due to ferroelectric particles doping in the composite cathode. Two plateaus were observed in between 2.3V to 2.0 V and 2.0 V to 1.5 V in the charge/discharge characteristics and high cyclic stability substantiate the superior performance of the designed ferroelectric nanoparticles doped S/CB composite cathode materials due to the efficient reduction in the polysulfide shuttle effect in these composite cathodes. Oxidation peaks for S50BST30CB10PVDF10 composite are at 2.6 V & 2.7 V and reduction peaks are at 2.0 V & 2.2V suggests an enhanced kinetics of the reduction reaction with the BST doped cathode as expected due to the alteration in the kinetics might be due to ferroelectric nanoparticles coupling & reversible transformation of Li2S to short/long chain LiPSs and finally to S8. In the case of symmetric cells with the positive and blocking electrodes. We have confirmed that the active material, sulfur, does not contribute to the resistance of the positive electrode, however due to inclusion of BST up to 20 & 30 wt% and applying RC(R)W circuit model for interfacial parameters. The observed values for S50BST30CB10PVDF10 are as Rs (2.688) C= 9.1 µF Rct (145 Ώ) and W (0.02312) showing the improved diffusion pathways for Lithium ions. Considering that polar substances have good affinity towards polysulfide and can provide more stable reacting environment in the cathodic site, to trap polysulfide intermediates via induced permanent dielectric polarizability. It is expected that spontaneous polarization induced by asymmetric crystal structure of ferroelectrics provide internal electric fields and increase chemisorption with heteropolar reactive.

MXene-CNT composite Ni12P5 for lithium-sulfur battery performance enhancement

Lithium-sulfur batteries have hindered industrialization due to their inherent defects. In this study, MXene and CNT composite Ni12P5 were used as cathode materials for lithium-sulfur batteries. MXene is known to have high specific surface area, while the CNT composite Ni12P5 has excellent electrical conductivity. The results show that MXene-CNT@ Ni12P5 composite can significantly improve the performance of lithium-sulfur batteries. The composite helps to mitigate the volume expansion and shuttle effect of the sulfur cathode, thereby improving the diffusion efficiency and cycling stability of the battery. In addition, the incorporation of the composite material enhances the electrical conductivity of the battery, reduces the secondary reaction with the electrolyte, and mitigates the deposition of polysulfides during lithium-ion charging and discharging, thereby further improving the lithium-ion diffusion efficiency. Therefore, this study presents a novel and convenient method to enhance the cathode material of lithium-sulfur batteries, which offers a broad prospect for its application in this field.

Accelerated Ion-Electron Transport in Bi-Heterostructures Constructed Based on Ohmic Contacts for Efficient Bi-Directional Catalysis of Lithium-Sulfur Batteries.

Although lithium-sulfur batteries have satisfactory theoretical specific capacity and energy density, they are difficult to further commercialize due to the shuttle effect of soluble polysulfides and slow sulfur oxidation kinetics. Based on this, in this work, the catalyst MXene-VS4-SnS2 (MVS), a dual heterostructured catalyst with ohmic contacts, is prepared by a one-step hydrothermal method and electrostatic self-adsorption for lithium-sulfur battery cathode materials. Experimental and theoretical results show that the ohmic contact induces spontaneous charge rearrangement, resulting in the formation of a fast charge transfer pathway at the MVS heterojunction interface, which helps to reduce the energy barrier for polysulfide reduction and Li2S oxidation during the discharge/charge process. In addition, the inherent sulfophilicity of VS4 and SnS2 promotes the conversion of S species, while the pleated MXene nanosheets not only provide a highly conductive network for the active sulfur but also retain a rich internal space to maintain the integrity of the cathode structure during the continuous cycling process. As a result, the MVS cathode exhibits excellent electrochemical performance even under high sulfur loading. The integration of excellent performance with a facile synthesis process provides a promising approach for designing highly efficient electrocatalysts suitable for the energy field.

Core-shell cobalt-iron@N-doped carbon: A high-performance cathode material for lithium-sulfur batteries.

Lithium-sulfur batteries hold great promise as energy storage systems, but the shuttle effect of lithium polysulfides (LiPS) and large volume variation limit their capacity and cycle life. We have developed CoFe alloy wrapped in N-doped porous carbon spheres (e-CF@NC) with a core-shell structure through simple copolymerization and pyrolysis. The nitrogen-doped porous carbon shell provides electron and ion transport channels and more active sites for electrolyte ion adsorption. The high chemically stable carbon can limit the segregation of polysulfides, further improving the battery cycling stability. Besides, the inside CoFe alloy particles catalyze the conversion between LiPS and Li2S, speeding up reaction kinetics and reducing solvation of active sites. Consequently, lithium-sulfur batteries with e-CF@NC-2 as the cathode display a high initial specific capacity of 1146 mA h g-1 at 0.1 C, excellent rate performance (891 mA h g-1 at 1 C, 741 mA h g-1 at 2 C), and satisfied cycle stability (average capacity decay rate of 0.033% per cycle at 1 C for 300 cycles), demonstrating significant application potential.

Asymmetrical TiSSe Monolayers as Catalytic Materials for Lithium-Sulfur Batteries: A DFT Study

Asymmetrical Janus TiSSe monolayers as cathode materials for lithium-sulfur batteries were studied by first-principles calculations, encompassing adsorption, catalytic, and conductive properties. The polarization effect, arising from the asymmetric arrangement of constituent elements, results in variability in adsorption energy and bonding processes across S/Se surfaces. The moderate adsorption energy of Lithium Polysulfides (LiPSs) on the TiSSe monolayer effectively mitigates the shuttle effect. The bond formation process investigated by charge transfer, physical/chemical adsorption, and projected crystal orbital Hamiltonian population (pCOHP), revealed its emergence in the early lithiation stage. The Gibbs free energies for the reduction reaction of sulfur on the S/Se surface demonstrate a significant enhancement in the transformation kinetics. The low decomposition and diffusion energy barriers for lithium atoms on the S/Se surface of the TiSSe monolayer indicate its catalytic potential in facilitating sulfur redox transformation. The TiSSe monolayer exhibits metallic properties before and after polysulfide absorption, thereby enhancing electron transport capacity in Li-S batteries. Therefore, the Janus TiSSe monolayer presents a new perspective for the selection of battery adsorption materials in lithium-sulfur batteries.

Design of Coatings for Sulfur-Based Cathode Materials in Lithium-Sulfur Batteries: A review.

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

Potassium Ion-Assisted Self-Assembled MXene-K-CNT Composite as High-Quality Sulfur-Loaded Hosts for Lithium-Sulfur Batteries.

We successfully synthesized hybrid MXene-K-CNT composites composed of alkalized two-dimensional (2D) metal carbide and carbon nanotubes (CNTs), which were employed as host materials for lithium-sulfur (Li-S) battery cathodes. The unique three-dimensional (3D) intercalated structure through electrostatic interactions by K+ ions in conjunction with the scaffolding effect provided by CNTs effectively inhibited the self-stacking of MXene nanosheets, resulting in an enhanced specific surface area (SSA) and ion transport capability. Moreover, the addition of CNTs and in situ-grown TiO2 considerably improved the conductivity of the cathode material. K+ ion etching created a more hierarchical porous structure in MXene, which further enhanced the SSA. The 3D framework effectively confined S embedded between nanosheet layers and suppressed volume changes of the cathode composite during charging/discharging processes. This combination of CNTs and alkalized nanosheets functioned as a physical and chemical dual adsorption system for lithium polysulfides (LiPSs). When subjected to a high current at 1.0C, S@MXene-K-0.5CNT with S-loaded of 1.2 mg cm-2 had an initial capacity of 919.6 mAh g-1 and capacity decay rate of merely 0.052% per cycle after 1000 cycles. Moreover, S@MXene-K-0.5CNT maintained good cycling stability even at a high current of up to 5.0C. These impressive results highlight the potential of alkalized 2D MXene nanosheets intercalated with CNTs as highly promising cathode materials for Li-S batteries. The study findings also have prospects for the development of next-generation Li-S batteries with high energy density and prolonged lifespans.

Flexible CNT-Interpenetrating Hierarchically Porous Sulfurized Polyacrylonitrile (CIHP-SPAN) Electrodes for High-Rate Lithium-Sulfur (Li-S) Batteries.

Sulfurized polyacrylonitrile (SPAN) is a promising cathode material for lithium-sulfur batteries owing to its reversible solid-solid conversion for high-energy-density batteries. However, the sluggish reaction kinetics of SPAN cathodes significantly limit their output capacity, especially at high cycling rates. Herein, a CNT-interpenetrating hierarchically porous SPAN electrode is developed by a simple phase-separation method. Flexible self-supporting SPAN cathodes with fast electron/ion pathways are synthesized without additional binders, and exceptional high-rate cycling performances are obtained even with substantial sulfur loading. For batteries assembled with this special cathode, an impressive initial discharge capacity of 1090 mAh g-1 and a retained capacity of 800 mAh g-1 are obtained after 1000 cycles at 1 C with a sulfur loading of 1.5 mg cm-2. Furthermore, by incorporating V2O5 anchored carbon fiber as an interlayer with adsorption and catalysis function, a high initial capacity of 614.8 mAh g-1 and a notable sustained capacity of 500 mAh g-1 after 500 cycles at 5 C are achieved, with an ultralow decay rate of 0.037% per cycle with a sulfur loading of 1.5 mg cm-2. The feasible construction of flexible SPAN electrodes with enhanced cycling performance enlists the current processing as a promising strategy for novel high-rate lithium-sulfur batteries and other emerging battery electrodes.

Insight into the effects of gas molecules-adsorbed on 2D-FeS2: A DFT study

Lithium-sulfur (Li-S) batteries are especially competitive in the energy sector due to their excellent performances, like preferable energy density and economic benefits. Studying the adsorption of gas molecules on electrode materials has potential engineering significance for Li-S batteries since they have a highly osmotic potential, which causes unavoidable damage to batteries. In this work, the adsorption phenomenon of common gas molecules (H2O, N2, H2, CO2, and O2) on the two-dimensional pyrite (2D-FeS2) cathode material surface, as well as the effects on the electronic and electrochemical properties, were investigated by the first-principles calculations. The adsorption capabilities were estimated by adsorption energy and Mulliken population analysis. Simulation results demonstrated that whole adsorption energies were less than -1.0 eV and larger than -0.6 eV, which shows a physisorption nature. Among them, the O-S bond of O2/2D-FeS2 has the strongest strength. Electronic structure calculations suggested that 2D-FeS2 maintained good conductivity after gas molecules were adsorbed, achieving efficient transfer between electron, lithium, and sulfur intermediates. Additionally, ab initio molecular dynamics (AIMD) simulations showed that Li+ exhibits excellent diffusion performance and low activation energy at different temperatures. 2D-FeS2 still has a stable electrochemical working window (1.87 ∼ 2.47 V), while the theoretical open current voltage is damaged by gas molecule adsorption. Consequently, this work theoretically reveals the effect of gas molecules on the cathode materials for Li-S batteries, which has guide meaning for engineering.

Sulfur Encapsulation into Carbon Nanospheres as an Effective Technique to Limit Sulfide Dissolution and Extend the Cycle Life of Lithium–Sulfur Batteries

Sulfur Encapsulation into Carbon Nanospheres as an Effective Technique to Limit Sulfide Dissolution and Extend the Cycle Life of Lithium–Sulfur Batteries

Theoretical screening of electrocatalytic performance of Fe@BNC materials in lithium-sulfur batteries

Advanced cathode materials can suppress the shuttle effect and improve the slow sulfur reduction kinetics during discharge in lithium-sulfur batteries. The catalytic performance of Fe@BNC single-atom catalysts as cathode materials was evaluated through simulations based on density functional theory in this article. By calculating the Gibbs free energy curve and adsorption energy of polysulfides on the substrate, it was found that Fe@BNC has a reasonable adsorption energy range and good catalytic activity. Moreover, calculations of reaction energy barriers indicate that Fe@B1N3 performs well in delithiation when charged. The Research investigates in detail the electrocatalytic properties and electronic structure properties of Fe@BNC as a cathode material for lithium-sulfur batteries. This paper highlights its potential to improve battery performance by reducing the shuttle effect and accelerating the redox kinetics.

Mixed valence Mo2C-MoC/C catalyst enhances polysulfides conversion kinetics in lithium–sulfur batteries

Lithium-sulfur batteries have received extensive attention in the field of electrochemical energy storage systems due to their extremely high theoretical energy density (2600 Wh·kg−1) and low cost. However, poor electrical conductivity, shuttle effect, and volume expansion effect still need to be addressed. Here, we controllably synthesized hollow spherical Mo2C-MoC/C structure as the cathode material for lithium-sulfur batteries. Through high-temperature calcination, the synthesis of graphitized reticular carbon matrix and the loading of Mo2C and MoC nanoparticles with mixed valence of Mo2+ and Mo3+ were simultaneously achieved. The two synergistically improved the electronic conductivity and ensured excellent battery performance. From the experimental results, Mo2C-MoC/C structure strongly adsorbed polysulfides and promoted the conversion of polysulfides to lithium sulfide, accelerating the reaction kinetics and enhancing the battery performance. The initial discharge specific capacity of Mo2C-MoC/C electrode with 57.12 wt% sulfur content was 870.4 mAh·g−1 at 0.2 C, and remained at 770.7 mAh·g−1 at 0.5 C, which was significantly better than that of Mo2C/C/S. The rational design of the Mo2C-MoC/C structure in this study can be generalized to the advanced electrode materials of other Mo-based nanomaterials.

Heterokaryotic transition-metal dimers embedded monolayer g-C3N3 as promising anchoring and electrocatalytic materials for lithium-sulfur battery: First-principles calculations

g-C3N3 not only has high content of pyridine nitrogen, but also has a special two-dimensional porous structure, which is an ideal diatomic catalytic host materials. In this work, homonuclear and heteronuclear dual-atom catalysts (DACs, TM-TM@g-C3N3, TM = Mn, Fe, Co, Ni) were constructed using single-layer g-C3N3 as the carrier material of DACs, and their potential as sulfur-hosting materials and electrocatalytic materials for lithium-sulfur batteries was explored through first principles comprehensively. The results show that the coupling between the two metal atoms in heteronuclear DACs can regulate the spin state of each other's d-electrons, so that the anchoring and catalytic effects of heteronuclear DACs on polysulfide are more excellent than that of homonuclear DACs. Co-Mn@g-C3N3, when utilized as the cathode material in lithium-sulfur batteries, offers exceptional properties due to the hybridization between Mn2+ high-spin state d electron and Co2+ half-filled dz2 orbital. This unique interaction not only enables the polysulfide to exhibit the lowest Gibbs free energy during conversion, but also results in the lowest reaction energy barrier of 0.26 eV for the conversion of Li2S2 to Li2S. Furthermore, it is found that when 3d transition metal atoms act as heteronuclear DACs, the coupling between metal ions with high-spin states at the active site and metal ions with empty orbitals or half-full d-electrons has the most significant catalytic effect on polysulfides.

Hybrid Organosulfur Network/MWCNT Composite Cathodes for Li-S Batteries.

Lithium-sulfur (Li-S) batteries hold a promising position as candidates for next-generation high-energy storage systems. Here, we combine inverse vulcanization of sulfur with multiwalled carbon nanotubes (MWCNTs) to increase the conductivity of cathode materials for Li-S batteries. The mixing process of inversely vulcanized sulfur copolymer networks with MWCNTs is aided by shear in a two-roll mill to take advantage of the soft nature of the copolymer. The high-throughput mixing method demands a source of conductive carbon that can be intimately mixed with the S copolymer, rendering MWCNTs an excellent choice for this purpose. The resulting sulfur copolymer network-MWCNTs composites were thoroughly characterized in terms of structure, chemical composition, thermal, and electronic transport properties, and finally evaluated by electrochemical benchmarking. These promising hybrids yielded electrodes with high sulfur content and demonstrate stable electrochemical performance exhibiting a specific capacity of ca. 550 mAh·gsulfur-1 (380 mAh·gelectrode-1) even after 500 charge-discharge cycles at specific current of 167 mA·g-1 (corresponds to 0.1C discharge rate), and thus are superior to melt-infiltrated reference samples.

Uniaxial tensile strain impact on 1T-NbS2 monolayers as cathode material for lithium-sulfur batteries.

The application of lithium-sulfur (Li-S) batteries as efficient energy storage systems is hindered by the polysulfide shuttle and expansion effects. To overcome these obstacles, we employed density functional theory (DFT) to explore the 1T-NbS2 monolayer as a cathode material for Li-S batteries, particularly focusing on the effects of uniaxial tensile strain. Our results indicate that the pristine 1T-NbS2 monolayer presents a balanced adsorption affinity for LiPSs, thereby mitigating the shuttle effect. The bond formation information is investigated through comprehensive analysis of charge transfer, physical/chemical adsorption, and projected crystal orbital Hamiltonian population (pCOHP). The projected density of states (PDOS) analysis reveals the role of sulfur atoms near the Fermi surface in the lithiation process. Notably, the system keeps superior metallic characteristics, alongside a diminished decomposition energy barrier (0.45 eV), lowered lithium-ion migration energy barrier (0.16 eV), and a diminished positive Gibbs free energy change (0.41 eV) during the sulfur reduction reaction (SSR). The imposition of uniaxial tensile strain on the 1T-NbS2 monolayer improves its adsorptive capacity for LiPSs and bolsters the retention of lithium-sulfur aggregates. These insights underscore the role of tensile strain in amplifying the efficiency of two-dimensional transition metal dichalcogenides as cathode materials of Li-S batteries.