Lithium Sulfur Research Articles

Modification strategies of molybdenum sulfide towards practical high-performance lithium-sulfur batteries: a review

Modification strategies of molybdenum sulfide towards practical high-performance lithium-sulfur batteries: a review

Engineering Triple-Phase Interfaces with Hierarchical Carbon Nanocages for High-Areal-Capacity All-Solid-State Li-S Batteries.

All-solid-state lithium-sulfur batteries (ASSLSBs) have garnered widespread attention due to their advantages of high energy density and enhanced safety. However, the typical composite structure composed of solid-state electrolyte (SE), discrete conducting carbon black, and microsized sulfur (μ-S) with long-range Li+/e- conducting path and huge volume changes, suffers from sluggish charge transport and severe electrochemical-mechanical failure. In this work, a unique hierarchical carbon nanocage (hCNC) is applied as a continuous conducting network where nanosized sulfur are confined. Due to the synergistic effects of multi-dimensional (particle, interface, and electrode) structural engineering, this new sulfur-carbon composite cathode (S@hCNC39) can achieve uniform distribution of sulfur and carbon, and efficiently constructs triple-phase interfaces, showing enhanced charge-carrier transport and improved electrochemical-mechanical stability. Remarkable cycling performance of 89% after 300 cycles at 0.2C at 30°C is realized in ASSLSBs assembled with S@hCNC39. Notably, ASSLSBs achieve an ultrahigh areal capacity of 9.95 mAh cm-2 with stable cycling at 60°C with high sulfur contents of 40% and high sulfur loadings of 6mg cm-2. These results provide critical insights into the design of rational sulfur-carbon composites and offer a viable approach to enhance the overall performance of ASSLSBs.

A Review of Advances in Heterostructured Catalysts for Li-S Batteries: Structural Design and Mechanism Analysis.

Lithium-sulfur (Li-S) batteries, acclaimed for their high energy density, cost-effectiveness, and environmental benefits, are widely considered as a leading candidate for the next-generation energy storage systems. However, their commercialization is impeded by critical challenges, such as the shuttle effect of lithium polysulfides and sluggish reaction kinetics. These issues can be effectively mitigated through the design of heterojunction catalysts. Despite the remarkable advancements in this field, a comprehensive elucidation of the underlying mechanisms and structure-performance relationships of heterojunction catalysts in sulfur electrocatalysis systems remains conspicuously absent. Here, it is expounded upon the mechanisms underlying heterostructure engineering in Li-S batteries and the latest advancements in heterostructure catalysts guided by these multifarious mechanisms are examined. Furthermore, it illuminates groundbreaking paradigms in heterostructure design, encompassing the realms of composition, structure, function, and application. Finally, the research trends and future development directions for the novel heterojunction materials are extensively deliberated. This study not only provides a comprehensive and profound understanding of heterostructure catalysts in Li-S batteries but also facilitates the exploration of new electrocatalyst systems.

Regulating Li2S Deposition and Accelerating Conversion Kinetics through Intracavity ZnS toward Low-Temperature Lithium-Sulfur Batteries.

The uncontrolled deposition behavior and sluggish conversion kinetics of the discharging product (solid Li2S) severely deteriorate the electrochemical performance of lithium-sulfur (Li-S) batteries, especially under high S loading and low-temperature conditions. Herein, a multifunctional S cathode host consisting of ZnS nanoparticles (NPs) confined in hollow porous carbon spheres (ZnS@HPCS) is synthesized via a unique capillary force-driven melting-diffusion strategy. The porous carbon shell of ZnS@HPCS provides a space-confined reservoir for soluble polysulfides and solid Li2S, while the intracavity ZnS NPs trap polysulfides, induce Li2S inside deposition, and accelerate conversion kinetics. Thus, Li-S batteries with ZnS@HPCS-S cathodes exhibit excellent electrochemical performance at both room and low temperatures (-40 °C) and high reversible capacities under high S loading (5.2 mg cm-2). Furthermore, Li2S nucleation/deposition, in situ Raman, and theoretical analyses reveal the underlying mechanism. This work offers fundamental insights into regulating Li2S deposition and designing S hosts for high-performance Li-S batteries.

Engineering Densely Packed Ion-Cluster Electrolytes for Wide-Temperature Lithium-Sulfurized Polyacrylonitrile Batteries.

The electrolyte plays an essential role in the advancement of lithium-sulfur batteries (LSBs), as it not only transports the charge carriers but also extensively influences sulfur conversion mechanisms and electrode-electrolyte interphases formed on the electrode surface, thereby directly impacting battery performance. However, the majority of existing electrolytes suffer from incompatibility with either the Li anode or the sulfur cathode. Here, we develop a densely packed ion-cluster electrolyte (DPIE) through the strategic combination of a weakly solvating solvent and an inert diluent, resulting in the self-assembly of abundant compact ion-pair aggregates within its structure. This peculiar solvation structure promotes fast Li+ desolvation, the formation of robust electrode-electrolyte interphases, and the suppression of polysulfide dissolution. Leveraging the tailored DPIE, room-temperature Li||sulfurized polyacrylonitrile (SPAN) batteries demonstrate 300 stable cycles with a capacity retention of 97.8% and a steady Coulombic efficiency exceeding 99.9%. Even under a limited negative/positive areal capacity ratio of four, the Li||SPAN cells exhibit good stability over 250 cycles with 97.1% capacity retention. Furthermore, Li||SPAN batteries show impressive stability over a wide temperature range spanning from -20 to 60 °C and exhibit reversibility at -10 °C over 200 cycles. This electrolyte design enables LSBs with prolonged operational lifetimes, rapid charging capabilities, and expanded temperature tolerance.

Tandemly promoting the sulfur redox kinetics through low concentration mixed organodiselenide and organoditelluride in Ah-level high-energy-density Li-S batteries

Tandemly promoting the sulfur redox kinetics through low concentration mixed organodiselenide and organoditelluride in Ah-level high-energy-density Li-S batteries

CeVO4/KB Nanoparticles on Shuttle Effect Inhibition in Lithium-Sulfur Battery Separator Modification.

Lithium-sulfur (Li-S) batteries display promise as redox-based batteries, where separators are an essential part of preventing short-circuiting of the positive and negative electrodes, while the shuttle effect is a critical issue of separators. Currently, commercial PP separators are weak in inhibiting the polysulfides shuttling, so modified separators are needed to inhibit it to improve the battery performance. This paper reports that CeVO4/KB composites act as separator materials. CeVO4/KB modified PP separators enhanced the adsorption of LiPSs, accelerated the rate of Li+ migration, and catalyzed the conversion of LiPSs. These bring about the effect that CeVO4/KB/PP batteries reach 1200.9 mAh g-1 in the first cycle with a capacity retention rate of 86.5 % after 100 cycles at 0.2 C and reach 882.7 mAh g-1 of the initial cycle with a capacity decay rate of 0.063 % after 1000 cycles at 3 C. This work introduces rare earth metal vanadates to modify the separator, adding new ideas for designing separators for good-performance batteries.

Multifunctional Ultrathin Ti3C2Tx MXene@CuCo2O4 /PE Separator for Ultra-High-Energy-Density and Large-Capacity Lithium-Sulfur Pouch Cells.

The shuttling of lithium polysulfides (LiPSs), sluggish reaction kinetics, and uncontrolled lithium deposition/stripping remain the main challenges in lithium-sulfur batteries (LSBs), which are aggravated under practical working conditions, i.e., high sulfur loading and lean electrolyte in large-capacity pouch cells. This study introduces a Ti3C2Tx MXene@CuCo2O4 (MCC) composite on a polyethylene (PE) separator to construct an ultrathin MXene@CuCo2O4/PE (MCCP) film. The MCCP functional separator can deliver superior LiPSs adsorption/catalysis capabilities via the MCC composite and regulate the Li+ deposition through a conductive Ti3C2Tx MXene framework, enhancing redox kinetics and cycling lifetime. When paired with sulfur/carbon (S/C) cathode and lithium metal anode, the resultant 10 Ah-level pouch cell with the ultrathin MCCP separator achieves an energy density of 417Wh kg-1 based on the whole cell and a stable running of 100 cycles under practical operation conditions (cathode loading = 10.0 mg cm-2, negative/positive areal capacity ratio (N/P ratio) = 2, and electrolyte/sulfur weight ratio (E/S ratio) = 2.6 µL mg-1). Furthermore, through a systematic evaluation of the as-prepared Li-S pouch cell, the study unveils the operational and failure mechanisms of LSBs under practical conditions. The achievement of ultrahigh energy density in such a large-capacity lithium-sulfur pouch cell will accelerate the commercialization of LSBs.

Balanced d-Band Model: A Framework for Balancing Redox Reactions in Lithium-Sulfur Batteries.

Managing the redox reactions of polysulfides is crucial for improving the performance of lithium-sulfur batteries (LSBs). Herein, we introduce a progressive theoretical framework: the balanced d-band model, which is based on classical d-band center theory. Specifically, by optimizing the position of the d-band center in the middle between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of each sulfur species, balanced and fast oxidation and reduction reactions of the sulfur species can be achieved simultaneously. To validate this theory, we synthesized a catalyst featuring an in situ phosphorized heterostructure (NOP) based on nickel oxide (NiO), which effectively optimizes the d-band center at the middle between the HOMO and LUMO of each sulfur species. Aided by the balanced oxidation and reduction kinetics of the sulfur species, the NOP-based cell achieved a high reversible capacity, superior cycling stability, and prolonged cycle life. This study extends the conventional d-band center theory and introduces an innovative theoretical model to expand our understanding of the internal reaction mechanisms in LSBs.

Highly Solvating Electrolytes with Core-Shell Solvation Structure for Lean-Electrolyte Lithium-Sulfur Batteries.

The practical energy density of lithium-sulfur batteries is limited by the low sulfur utilization at lean electrolyte conditions. The highly solvating electrolytes (HSEs) promise to address the issue at harsh conditions, but the conflicting challenges of long-term stability of radical-mediated sulfur redox reactions (SRR) and the poor stability with lithium metal anode (LMA) have dimmed the efforts. We now present a unique core-shell solvation structured HSE formulated with classical ether-based solvents and phosphoramide co-solvent. The unique core-shell solvation structure features confinement of the phosphoramide in the first solvation shell, which prohibits severe contact reactions with LMA and endows prolonged stability for [S3]•- radical, favoring a rapid radical-mediated solution-based SRR. The cell with the proposed electrolyte showing a high capacity of 864 mA h gsulfur-1 under high sulfur loading of 5.5 mgsulfur cm-2 and low E/S ratio of 4 µL mgsulfur-1. The strategy further enables steady cycling of a 2.71-A h pouch cell with a high specific energy of 307 W h kg-1. Our work highlights the fundamental chemical concept of tuning the solvation structure to simultaneously tame the SRR and LMA stability for metal-sulfur batteries wherein the electrode reactions are heavily coupled with electrolyte chemistry.

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.

Replenish the Electron-Deficient State of Carbonyl Carbon Atoms to Achieve Stable Li-S Battery.

Carbonate-based electrolytes are widely used in Li-ion batteries (LIBs) due to their safe, stable properties and wide operating temperature range. However, the nucleophilic attack at carbonyl carbon atoms by polysulfide anions and the low solubility of lithium nitrate (LiNO3<0.1m) in carbonate-based electrolytes seriously hinder the application of lithium-sulfur (Li-S) batteries in carbonate-based electrolytes. Herein, the electrophilicity of carbonyl carbon atoms is gradually reduced through solvent molecules redesign, eliminated the attack of polysulfide anions on carbonyl carbon atoms, and also changed the intermolecular interactions in the electrolyte, improving the solubility of LiNO3 (>1.0m) and forming stable LiNxOy-containing SEI on the surface of the lithium metal. The assembled Li-S battery with these designed solvent molecules delivers an initial discharge capacity of 1251.7mAhg-1 at 0.1C. In addition, the lithium-sulfur battery assembled with the designed solvent molecule has a discharge capacity of 631mAhg-1 after 420 cycles at 0.2 C, with a capacity retention of ≈60%. Moreover, the Li||Li symmetrical cell shows stable cycle performance over 1200h at 0.5mAcm-2 and 0.5mAhcm-2.

Hierarchical van der Waals heterostructure with dual-defect sites for bidirectionally catalyzing Li2S nucleation and decomposition in lithium-sulfur batteries

The lithium‑sulfur batteries hold a promising option for the next generation of energy storage systems. Nevertheless, the shuttle effect of soluble lithium polysulfides and their slow reaction kinetics lead to extremely low efficiency and poor stability, thereby limiting the commercial viability of lithium‑sulfur batteries. Herein, MoSe2/Ti3C2 van der Waals heterostructure is synthesized with a dual-defect strategy, and its electrocatalytic performance is further improved through solution coating treatment (SCT), which involves the addition of glucose during the hydrothermal process. The conductive Ti3C2 scaffold effectively inhibits the aggregation of MoSe2 nanoflakes, thereby validating a larger active surface area. Meanwhile, the nitrogen dopant and selenium vacancy dual-defects in MoSe2 provide abundant active sites for anchoring polysulfides and catalyzing their conversion. As a result, the synergistic interaction between MoSe2 and Ti3C2 bidirectionally catalyzes the Li2S nucleation and decomposition through a heterointerface effect. The lithium‑sulfur battery equipped with MoSe2/Ti3C2-SCT heterostructure modified separator exhibits outstanding discharge specific capacity of 1496.9 mAh g−1 at 0.1C, and a low decay rate per cycle of 0.059 % after 500 cycles at 1C. The discharge specific capacity recovers to 89.3 % of the initial capacity when the current density is decreased from 5C to 0.1C. This work highlights the potential of defect engineering in transition metal selenides to enhance the performance of lithium‑sulfur batteries. It offers a new approach to designing composite electrocatalysts for high-performance lithium‑sulfur batteries.

Review and prospect on Metal-organic framework-based Separators for Lithium–Sulfur Battery

With the continuous advancement of technology, wearable smart devices and electric vehicles (EVs) have become an integral part of our daily lives. The increasing demand for energy from these devices and vehicles has driven the pursuit of high-performance rechargeable battery technology. In particular, the widespread adoption of electric vehicles has set higher standards for the energy density and cycle life of batteries. However, the energy density of the widely used lithium-ion batteries is currently limited by the theoretical capacity of commercial cathode materials, and there are certain challenges in terms of safety and cost-effectiveness. Therefore, the development of a new generation of rechargeable batteries with higher energy density, better safety, and more economical cost is particularly urgent. Lithium-sulfur batteries, due to their high energy density, high economic benefits, and high environmental friendliness, are considered to be one of the most promising successors to the widely used lithium-ion batteries. However, in practical applications, the electrochemical performance of lithium-sulfur batteries still needs to be improved. In particular, the poor conductivity of sulfur/lithium and the shuttle effect of polysulfides make the cycle life of the battery less than ideal, and lithium-sulfur batteries (LSB) are still far from achieving large-scale commercialization. The separator used in lithium-sulfur batteries plays a crucial role in its cycle performance and safety. The current commercial separator lacks the ability to effectively regulate the shuttle of polysulfides and is prone to thermal runaway at high temperatures. Therefore, to improve these issues, various functional materials have been used to modify the separator. Among them, as a new type of porous coordination polymer, metal organic frameworks (MOFs) have become a promising material for modifying separators due to their large specific surface area and highly ordered tunable nano-holes.At the same time, their rich inorganic nodes and designable organic ligands allow for the customization of pore chemistry at the molecular level, which can interact with the electroactive components in lithium-sulfur batteries in a tunable manner. This article reviews the reaction mechanism of lithium-sulfur batteries and the structural advantages of MOFs in terms of pore chemistry and morphology and briefly introduces the research progress of MOF-based interfacial layers for the functionalization of LSB separators in recent years. It elaborates on the mechanisms by which various modified separators improve electrochemical performance and provides a prospect for the development prospects of the field.

Nanotechnology in Lithium-Sulfur Batteries: Addressing the Challenges in Battery Cycle Life and Safety

Lithium-sulfur (Li-S) batteries, with their high energy density and affordable material prices, are a viable alternative to ordinary lithium-ion batteries, especially for electric cars. Their actual application is limited by challenges such as substantial volume expansion, low electrical conductivity, and the polysulfide shuttle effect, despite their advantages. This research investigates how incorporating nanomaterials into Li-S battery cathodes, anodes, and electrolytes might improve battery performance and analyzes the potential of nanotechnology to address these problems. The application of metal oxides, graphene oxide, and carbon nanofibers to improve the stability and conductivity of sulfur cathodes is covered. Additionally, it examines anode protection strategies using nanocoating and protective layers to inhibit dendrite growth and improve safety. The incorporation of nanoparticles in electrolytes to improve ionic conductivity and reduce side reactions is also analyzed. Despite the progress, challenges such as the polysulfide shuttle effect and volume changes remain. The paper concludes with recommendations for future research to develop commercially viable Li-S batteries with higher capacity, longer lifespan, and improved safety.

HighSpin-State Modulation of Catalytic Centers by Weak Ligand Field for Promoting Sulfur Redox Reaction in Lithium-Sulfur Batteries.

The spin state of transition-metal compounds in lithium-sulfur batteries (LSBs) significantly impacts the electronic properties and the kinetics of sulfur redox reactions (SRR). However, accurately designing the spin state remains challenging, which is crucial for understanding the structure-performance relationship and developing high-performance electrocatalysts. Herein, the CoF2, specifically the Co2+ with 3d7 electrons in a high-spin state distribution (t2g5eg2), were tailored predictably for the first time through the weak coordination field effect of the F element. Both DFT calculations and experimental results confirm that the spin state of Co2+ transitions from low- to high-spin configurations and strongly interacts with sulfur species through Co-S and Li-F bonds during the SRR process. This interaction weakens the S-S bond, promoting its facile cleavage from both ends while also facilitating the rapid and uniform nucleation of Li2S2/Li2S, thus resulting in LSBs with a capacity of 447.7 mAh g-1 at 10 C rates and stable cycling for 1000 cycles, with an acceptable practical capacity of 585 mAh g-1 at a high sulfur loading mass of 10 mg cm-2. This work achieves rational control of the active Co2+ d electron state through the field effect and enriches the application of spin control to accelerate SRR in LSBs.

Tailoring-Orientated Deposition of Li2S for Extreme Fast-Charging Lithium-Sulfur Batteries.

Precipitation/dissolution of insulating Li2S has long been recognized as the rate-determining step in lithium-sulfur (Li-S) batteries, which dramatically undermines sulfur utilization at elevated charging rates. Herein, we present an orientated Li2S deposition strategy to achieve extreme fast charging (XFC, ≤15 min) through synergistic control of porosity, electronic conductivity, and anchoring sites of electrode substrate. Via magnesiothermic reduction of a zeolitic imidazolate framework, a nitrogen-doped and hierarchical porous carbon with highly graphitic phase was developed. This design effectively reduces interfacial resistance and ensures efficient sequestration of polysulfides during deposition, leading to (110)-preferred growth of Li2S nanocrystalline between (002)-dominated graphitic layers. Our approach directs an alternative Li2S deposition pathway to the commonly reported lateral growth and 3D thickening growth mode, ameliorating the electrode passivation. Therefore, a Li-S cell capable of charging/discharging at 5C (12 min) while maintaining excellent cycling stability (82% capacity retention) for 1000 cycles is demonstrated. Even under high S loading (8.3 mg cm-2) and low electrolyte/sulfur ratio (3.8 mL mg-1), the sulfur cathode still delivers a high areal capacity of >7 mAh cm-2 for 80 cycles.

Enhanced Performance of Lithium-Sulfur Batteries Using Construction Wastes: A Sustainable Approach to High-Loading Sulfur Cathodes.

Advancing lithium-sulfur battery technology requires addressing both extrinsic cell-fabrication and intrinsic material challenges to improve efficiency, cyclability, and environmental sustainability. A key challenge is the low conductivity of sulfur cathodes, which is typically managed by incorporating conductive carbon materials. These materials enhance the performance of sulfur cathodes by facilitating high sulfur loading and improving polysulfide retention. In line with green chemistry principles and circular economy concepts, this study explores the use of recycled materials-specifically recycled quartz and board-as substrates for graphene coatings in lithium-sulfur cells. Recycled quartz bricks and blocks, predominantly SiO2, and recycled shelf boards, rich in Al2O3, are successfully coated with graphene, which significantly improves polysulfide adsorption and overall battery performance. The graphene-coated quartz exhibits high sulfur loading (8 mg cm-2), exceptional charge-storage capacity (1,114 mA·h g-1), and long cycle stability (200 cycles) with an energy density of 19 mW·h cm-2. This approach enhances the electrochemical performance of the lithium-sulfur cells and also aligns with sustainability goals by repurposing waste materials and minimizing environmental impact. This novel methodology demonstrates that integrating recycled materials can effectively address key challenges in lithium-sulfur battery technology, advancing both performance and environmental sustainability.

Novel Resveratrol-Derived Sulfur-Rich Polymers: Advanced Materials for Silver Capture and High-Performance Lithium–Sulfur Battery Cathodes

Novel Resveratrol-Derived Sulfur-Rich Polymers: Advanced Materials for Silver Capture and High-Performance Lithium–Sulfur Battery Cathodes

Progress in Carbon Cathodic Host Matrices for Lithium–Sulfur Cells: A Meta Analysis

Progress in Carbon Cathodic Host Matrices for Lithium–Sulfur Cells: A Meta Analysis