High-performance Lithium-sulfur Batteries Research Articles

Enhanced Basal-Plane Catalytic Activity of MoS2 by Constructing an Electron Bridge for High-Performance Lithium-Sulfur Batteries.

MoS2 is a promising sulfur host material for lithium-sulfur (Li-S) batteries, but its low conductivity and limited active edge sites largely inhibit the catalytic activity toward the conversion of lithium polysulfides (LiPSs). Herein, we propose an electron bridge strategy by combining interlayer structure modification and electronic modulation to activate the basal-plane catalytic activity of MoS2 for the highly efficient catalytic conversion of LiPSs. As validated by experimental characterizations and theoretical calculations, the proposed strategy not only creates a conductive network but also induces delocalized electron redistribution within the MoS2 basal planes, leading to facilitated interfacial charge transfer kinetics and accelerated LiPSs redox kinetics. Because of these advantages, the Li-S batteries assembled with regulated MoS2 demonstrate outstanding electrochemical performance even under practical conditions. This work demonstrates the effectiveness and potential of regulating the intrinsic basal-plane catalytic activity of transition-metal dichalcogenides for Li-S batteries and beyond.

Mg2+/S Co-Decorated V, O Sites to Construct Multi-Defect V2O5 as a Sulfur-Wrapped Matrix for High-Performance Lithium–Sulfur Batteries

Mg²⁺/S Co-Decorated V, O Sites to Construct Multi-Defect V₂O₅ as a Sulfur-Wrapped Matrix for High-Performance Lithium–Sulfur Batteries

Ion selective rapid transport enabled by functionalized CeO2/LiX zeolite modified separator in high performance lithium sulfur batteries

With regard to the issues in the application of lithium sulfur batteries (LSBs), for instance, the low-rate performance due to the difficulty in Li+/S2-n diffusion, and the poor cycling stability caused by lithium dendrites and polysulfide shuttle. This work reports a unique strategy for protecting lithium anode, that is, using the “size sieving” and “Donnan effect” of CeO2/LiX modified separator to simultaneously regulate the transfer behavior of Li+/S2-n based on the differences in size and charge. The CeO2, which is carefully constructed with oxygen defects, together with the negatively charged properties of zeolite framework, exhibits a synergistic relationship in controlling the flux and diffusion rate of Li+ and suppressing the polysulfide shuttling, which is confirmed by the experimental and theoretical investigations. As a result, the symmetric cell assembled with CeO2/LiX modified separator achieves stable cycling for 5000 h at 5 mA cm−2 and 5 mA h cm−2, and a deep Li stripping/plating for more than 2000 h at 10 mA h cm−2. The corresponding full battery shows a competitive areal capacity of 4.7 mA h cm−2 under a high sulfur loading of 4.0 mg cm−2. This strategy offers a low-cost solution to achieve the practical application of LSBs.

Defect-riched prussian blue analogues with superior adsorption-catalysis toward lithium polysulfides for high performance lithium-sulfur batteries

Lithium‑sulfur batteries (LiS) garner significant interest within the energy storage industry, because of their exceptional theoretical energy density coupled with employment of environmental materials. Nevertheless, the broader implementation of LiS batteries faces challenges, primarily due to the lithium polysulfide (LiPSs) shuttle effect and the sluggish conversion kinetics associated with LiPSs. In this work, we introduce a reduction-induced dissolution process to fabricate a mesoporous CoFePB rich in crystal defects via a facile solvothermal method. The experimental results indicate that the abundance of crystal defects originate from the phase transition from Co3[FeIII(CN)6]2 to Co2[FeII(CN)6]. The subsequent adsorption tests and electrochemical evaluations have shown that the defect-rich CoFePB possesses enhanced LiPSs absorption capacity and improved cycling performance in contrast to the pristine CoFePB, which is primarily ascribed to proliferation of active sites emerging as a result of the crystal defects. Consequently, the D-CoFePB-S cathode demonstrates remarkable rate performance with 583 mAh g−1 at a substantial 5C current rate, superior long-term stability with capacity retention of 64.3 % over 2000 cycles at current rate of 2C and outstanding areal capacity of 4.9 mAh cm−2 at 0.1C, even under a substantial sulfur loading of 5.0 mg cm−2.

Coupling 5 d metallic and conductive Network for promoting polysulfide conversion

The reaction kinetics of lithium-sulfur (Li-S) battery mainly depends on the capture and catalytic conversion efficiency of lithium polysulfide (LiPSs). The unique electron configuration of the 5d metal and the high electrical conductivity of MXene can enhance the interaction between the catalyst and LiPSs. However, the challenge of enhancing the adsorption of LiPSs by regulating the electronic structure of the catalyst with 5d metal and MXene remains unresolved and obscure. In this work, we have developed molybdenum disulfide (MoS2)-tungsten disulfide (WS2) @MXene (MoS2-WS2@MX) heterostructure catalysts for separator coatings in Li-S batteries by introducing W and MXene for the first time. Theoretical calculations demonstrate that the 5 d metallic and conductive MXene coupling effectively modulate the orbital hybridization degree between the catalyst and LiPSs, thereby reducing the energy barrier for LiPSs conversion. Electrochemical test and in situ tests verify the effectiveness of the strategy on the adsorption and conversion of LiPSs. Consequently, the MoS2-WS2@MX based batteries exhibit high initial reversible capacity of 950.3 mAh g−1 and low capacity decay of 0.066 % per cycle over 500 cycles at 2 C, which is superior to most reported catalysts. This study provides a dual regulatory strategy for enhancing catalytic activity, offering valuable insights for the advancement of high-performance Li-S batteries.

Entropy Engineering-Modulated D-Band Center of Transition Metal Nitrides for Catalyzing Polysulfide Conversion in Lithium-Sulfur Batteries.

The sluggish sulfur redox kinetics and severe polysulfide shuttle effect seriously restrict the cycling stability and lower the sulfur utilization of lithium-sulfur (Li-S) batteries. Efficient catalytic conversion of polysulfides is deemed a crucial strategy to address these issues, but still suffers from an unclear electronic structure-activity relationship and a limited catalysis performance. Herein, entropy engineering-induced electronic state modulation of metal nitride nanoparticles embedded within hollow N-doped carbon (HNC) polyhedra are theoretically and experimentally constructed as a catalyst to accelerate the redox process of sulfur and suppress polysulfide migration in Li-S batteries. By introducing V, Cr, and Nb elements to engineer the entropy of TiN, the metal d-band center is optimized to approach the Fermi level, significantly facilitating the conversion of sulfur species. Accordingly, the TiVCrNbN@HNC catalyst enables Li-S batteries to achieve a high initial capacity (1299 mAh g-1 at 0.1C) and excellent cycling stability with a low capacity decay rate of 0.086% per cycle after 500 cycles. This work may provide a new insight into entropy engineering in catalyst design for high-performance Li-S batteries.

Pyridinic-N-rich single-atom vanadium catalysts boost conversion kinetics of polysulfides for high performance lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries are promising next-generation energy storage devices possessing a high theoretical energy density, but their practical deployment has been hindered by the notorious shuttle effect and sluggish conversion kinetics of soluble lithium polysulfides (LiPSs). In this work, single-atom vanadium catalysts (V-SACs) embedded in pyridinic-N-rich carbon are developed through a simple one-step polymer-assisted pyrolysis approach, which can effectively adsorb LiPSs and remarkably boost the kinetics of LiPSs conversion. The Li-S cells comprising pyridinic-N-rich V-SACs as the sulfur host display an initial discharge capacity of 921.1 mAh g−1 at 1 C and retain a capacity of 605.8 mAh g−1 after 500 cycles, showing a low decay rate of 0.068 % per cycle. Even with a high sulfur loading of 6.5 mg cm−2 and a low electrolyte/sulfur ratio of 7.5 μL mg−1, the cell still delivers a high initial areal capacity of 8.1 mAh cm−2 at 0.05 C. Comprehensive experimental studies and density functional theory (DFT) calculations demonstrate that the abundant pyridinic-N sites and vanadium single atoms afford more chemisorption sites for LiPSs and synergistically promote LiPSs conversion kinetics, resulting in enhanced electrochemical performance compared to the Li-S cells without V-SACs.

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

N-doped carbon nanotubes and CoS@NC composites as a multifunctional separator modifier for advanced lithium-sulfur batteries

Lithium-sulfur batteries (LSBs), with their high theoretical energy density and specific capacity, are considered optimal candidates for next-generation energy storage systems. However, significant challenges remain in their cycle life and efficiency for practical applications, primarily due to the shuttle effect of lithium polysulfides (LiPSs) and the poor electrical conductivity of sulfur materials. The key to addressing these challenges lies in designing materials with excellent dispersion, good electrical conductivity, and high catalytic activity. In this work, we have designed and successfully synthesized a unique structural material consisting of in-situ grown cobalt sulfide nanoparticles embedded in zeolite imidazolate frameworks (ZIFs), which are derived from N-doped carbon wrapped around polypyrrole-derived N-doped carbon nanotubes (CoS@NC/NCNT). This design effectively mitigates the shuttle effect of lithium polysulfides (LiPSs) and enhances the conductivity of the material. As a result, batteries with CoS@NC/NCNT-modified separators achieved a high specific discharge capacity of 1518 mAh g−1 at 0.1 C. This work provides a reliable design strategy for synthesizing N-doped carbon nanotube/high-activity transition metal sulfide composite materials and opens new avenues for enhancing the modification and separation of high-performance lithium-sulfur batteries (LSBs).

Natural Polyphenol-Reinforced Ion-Selective Separators for High-Performance Lithium-Sulfur Batteries with High Sulfur Loading and Lean Electrolyte.

Ion-selective separators are promising to inhibit soluble intermediates shuttle in practical lithium-sulfur (Li-S) batteries. However, designing and fabricating such high-performance ion-selective separators using cost-effective, eco-friendly, and versatile methods remains a formidable challenge. Here we present ion-selective separators fabricated via the spontaneous deposition of green tea-derived polyphenols onto a polypropylene separator, aimed at enhancing the stability of Li-S batteries. The resulting natural polyphenol-reinforced ion-selective (NPRIS24) separators exhibit rapid Li ion transport and high soluble intermediates inhibition capability with an ultralow shuttle rate of 0.67 % for Li2S4, 0.19 % for Li2S6 and 0.10 % for Li2S8. This superior ion-selectivity arises from the high electronegativity and strong lithiophilic nature of the phenolic compounds. Consequently, we have achieved high-performance Li-S batteries that are steadily cyclable under the challenging conditions of an S loading of 5.7 mg cm-2, an electrolyte-to-S ratio of 5.1 μL mg-1, and a 50 μm Li foil anode. Furthermore, the NPRIS24 separator enhances the performance of other Li metal batteries utilizing commercial LiFePO4 (5.3 mg cm-2) and LiNi0.5Co0.2Mn0.3O2 (9.9 mg cm-2) cathodes. This work underscores the potential of utilizing natural polyphenols for the design of advanced ion-selective separators in energy storage 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.

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

Cyclodextrin Metal-Organic Framework Functionalized Carbon Materials with Optimized Interface Electronics and Selective Supramolecular Channels for High-Performance Lithium-Sulfur Batteries.

During the reaction process in lithium-sulfur batteries, Lewis acidic lithium polysulfides (LiPSs) affect ion distribution and overall electrolyte stability, degrading battery performance and product distribution (e.g., Li2S). Here, a microenvironment regulation strategy with optimized interface electronics and selective supramolecular channels, is proposed to enhance LiPS reaction kinetics through Lewis basic γ-cyclodextrin metal-organic framework (γ-CDMOF). To validate this concept, γ-CDMOF is rapidly synthesized on 3D graphene foam (GF) via a microwave-assisted method, resulting in a γ-CDMOF/GF cathode for high-performance Li-S batteries. A range of analytical techniques combined with density functional theory (DFT) calculations confirm that introducing a Lewis basic supramolecular microenvironment mitigates the LiPSs shuttle effect, enhances polysulfide capture, and improves sulfur redox conversion. Additionally, COMSOL simulations reveal that the γ-CDMOF framework and oxygen sites significantly reduce volumetric expansion stress during the LiPS solid-liquid phase transition. Impressively, the γ-CDMOF/GF cathode exhibits exceptional performance, including a high specific capacity (1253.01 mAh g⁻¹ at 0.1C), excellent rate performance (589.68 mAh g⁻¹ at 5C), and long cycle life (over 1200 cycles). This study introduces a new concept of supramolecular microenvironment regulation and interfacial interaction strategy, offering a unique approach for the development of multifunctional electrode materials.

Rational Design of Two-Dimensional MA2Z4 Monolayers as Effective Anchoring Materials for Lithium-Sulfur Batteries.

Advances in lithium-sulfur batteries (LSBs) are impeded by the inefficiency of anchoring materials in facilitating long-term cycling and rate performance. To address this challenge, an exploration of two-dimensional MA2Z4 monolayers as potential anchoring materials for LSBs is proposed based on density functional theory calculations and machine learning (ML) techniques. Adsorption features, sulfur reduction reaction behaviors, and solvent interactions are assessed and analyzed; and MoGe2N4 and WGe2N4 are identified as the most promising candidates because they have optimal adsorption energies for lithium polysulfides to suppress the shuttle effect and exhibit enhanced catalytic activity. Meanwhile, ML analysis highlights the critical influence of the electronegativity of element Z in MA2Z4 on anchoring properties, providing valuable insights into future anchoring material design for high-performance LSBs.

A conjugated porous triazine-linked polyimide host with dual confinement of polysulfides for high-performance lithium-sulfur batteries

In the quest for next-generation energy storage solutions, lithium-sulfur (Li-S) batteries present exceptional potential due to their high energy density and cost-effectiveness. Nevertheless, significant challenges, such as the shuttle effect of lithium polysulfides (LiPSs) and inadequate sulfur utilization, have impeded their practical application. In this study, we report the design and synthesis of a novel covalent organic polymer that integrates a triazine-linked framework with carbonyl-enriched polyimide moieties, serving as a highly effective sulfur host for Li-S batteries. This engineered polymer not only provides abundant micropores for the physical confinement of LiPSs, but also facilitates robust chemical interaction through synergistic N-Li and O-Li bonding. The hierarchical porous architecture enhances sulfur loading, while the extended π-conjugation promotes rapid electron transport during LiPSs conversion. Consequently, the composite cathode achieves an impressive specific capacity of 1352 mAh/g at 0.1C, along with sustained cyclic stability (453 mAh/g after 400 cycles at 4C). These findings highlight the potential of multifunctional polymeric hosts in addressing critical limitations of Li-S batteries, offering a new blueprint for further developments in the field of high-performance energy storage systems.

Multifunctional Composite Separator Based on NiS2/NiSe2 Homologous Heterostructure Polyhedron Promotes Polysulfide Conversion for High Performance Lithium-Sulfur Batteries.

The shuttle effect significantly hinders the industrialization of high-energy-density lithium-sulfur batteries. To address this issue, NiS2/NiSe2 homologous heterostructure polyhedron (HHP) composite separators were developed to immobilize polysulfides and promote their swift conversion. An in-situ visualization symmetrical cell was specifically designed to show the rapid polysulfide adsorption capability of NiS2/NiSe2 HHP, while the electrolyte-separator interfacial contact behavior was simulated to elucidate the mechanism of action of the composite separator in affecting the homogeneous nucleation of lithium metal surfaces. The electrochemical experimental result highlights the substantial enhancement in the reaction kinetics of polysulfides facilitated by NiS2/NiSe2 HHP, owing to its high Li+ diffusion coefficient and Li2S deposition capacity. The NiS2/NiSe2 HHP cells demonstrate high initial specific capacity (1224.1 mAh g-1) at 0.2 C and minimal decay rates (0.073%) at 2 C. The NiS2/NiSe2 HHP separator has high electrochemical catalytic activity with multiple adsorption sites, enabling the rapid polysulfide conversion and contributing to the preparation of high-performance lithium-sulfur batteries.

Modification and Functionalization of Separators for High Performance Lithium-Sulfur Batteries.

Lithium-sulfur batteries (LSB) have been recognized as a prominent potential next-generation energy storage system, owing to their substantial theoretical specific capacity (1675 mAh g-1) and high energy density (2600 Wh kg-1). In addition, sulfur's abundance, low cost, and environmental friendliness make commercializing LSB feasible. However, challenges such as poor cycling stability and reduced capacity, stemming from the formation and diffusion of lithium polysulfides (LiPSs), hinder LSB's practical application. Introducing functional separators represents an effective strategy to surmount these obstacles and enhance the electrochemical performance of LSBs. Here, we have conducted a comprehensive review of recent advancements in functional separators for LSBs about various (i) carbon and metal compound materials, (ii) polymer materials, and (iii) novel separators in recent years. The detailed preparation process, morphology and performance characterization, and advantages and disadvantages are summarized, aiming to fundamentally understand the mechanisms of improving battery performance. Additionally, the development potential and future prospects of advanced separators are also discussed.

Tailoring eco-friendly siloxane-based electrolytes for high-performance lithium–sulfur batteries

Lithium–sulfur batteries (LSBs), with their ultra-high theoretical energy density (2600 Wh kg−1), are considered one of the most attractive high-energy batteries. However, the “shuttling effect” of polysulfides and the uncontrolled growth of lithium (Li) dendrites pose significant challenges to the practical implementation of LSBs. Herein, a lightweight and eco-friendly diethoxydimethylsilane (DEMS) is chosen as a multi-functional solvent for LSBs. The low polarity of DEMS promotes the “solid–solid” conversion of sulfurized polyacrylonitrile (SPAN) during charge–discharge processes, eliminating the shuttle effect of polysulfides. Moreover, the DEMS-based electrolyte enables highly reversible Li plating/stripping processes across a wide temperature range spanning from −20 to 60 °C. As a result, the Li/SPAN batteries using the DEMS electrolyte exhibit excellent cyclic stability at 0.2 C with retainable capacities of 524.4 mAh/g after 200 cycles, 598.8 mAh/g after 100 cycles, and 318.6 mAh/g after 50 cycles at 26, 60 and −20 °C, respectively. This study aims to identify low-cost and highly stable electrolytes through solvent screening to enhance the electrochemical performance of LSBs.

Insight into the polysulfides conversion kinetics and its activation energy relationship on ultrafine V8C7 in Li-S batteries

Catalytic conversion of lithium polysulfides (LiPSs) is regarded as an effective approach to boosting kinetics and suppressing shuttling effect in lithium-sulfur (Li-S) batteries, but developing efficient catalysts and understanding of its catalytic mechanism still remain challenges. Herein, the ultrafine V8C7 nanocrystals embedded into the porous N-doped carbon frameworks (V8C7/NC) was designed for accelerating the LiPSs catalytic-conversion kinetics toward high-performance Li-S batteries. We propose that the ultrafine V8C7 nanocrystals with abundant unsaturated coordination atoms increase the active sites for catalytic-conversion of LiPSs and also accelerate the corresponding kinetics by reducing its reaction activation energy, meanwhile the interlinked nano-channels of V8C7/NC can effectively confine LiPSs and also promote electron/ion transfer. These attributes enable the Li-S cell equipped with V8C7/NC to deliver a large discharge capacity of 1393.3 mAh g−1 at 0.2 C, excellent rate capability (496.0 mAh g−1 at 10 C), and robust cycling stability (1000 cycles with a negligible capacity decay rate of 0.019 % per cycle even at 5 C). The innovative concept of ultrafine V8C7 nanocrystals embedded into the porous carbon toward improved LiPSs catalytic-conversion kinetics could be extended to develop other electrocatalytic hosts for high-performance Li-S batteries.

Modulation of d-Orbital Interactions in Dual-Atom Catalysts for Enhanced Polysulfide Anchoring and Kinetics in Lithium-Sulfur Batteries.

Modulating the electronic structure is essential for improving the anchoring and catalytic capabilities of catalysts in lithium-sulfur batteries (LSBs). This study delves into the modulation of d-orbitals in transition metal dual-atom catalysts (DACs) supported by boron nitride and graphene (BNC) hybrid sheets for LSBs. This study reveals that the d-band center of the DACs, a key determinant of material chemical properties, is primarily determined by the electronic configuration of the dyz and dx2-y2 orbitals. Furthermore, the interaction between dz2 of transition metals and S_3 p orbitals is critical for the binding strength of LiPSs. By understanding these interactions, the functionality of DACs can be customized for optimal performance in LSBs. For example, the MnCrBNC catalyst with 10 d-electrons exhibits the optimal d-band center and demonstrates exceptional LiPSs binding capability, the lowest Li2S decomposition energy barrier, and the lowest Gibbs free energy of reaction for the rate-determining step of sulfur reduction. This study elucidates the fundamental mechanisms for designing high-performance LSB catalysts through electronic structure modulation.