Lithium Sulfur Research Articles

Spontaneous built-in electric field in W-W2C@C heterostructure: Accelerating Sn2- directed migration in Li-S batteries

The commercialization of Li-S batteries is severely hindered by shuttle effect and sluggish redox reaction kinetics of LiPSs. Heterostructure can resolve the above shortcomings through the synergistic effect of adsorption and catalysis. However, long-chain LiPSs dissolving in electrolyte tend to cluster, resulting in low sulfur utilization and preventing kinetic conversion Thus, it is necessary to regulate the diffusion of Sn2− to achieve the directional diffusion from adsorbent to catalyst. Nevertheless, the design principle has not yet been clarified. W-W2C@C heterostructure with W of strong adsorption ability and high work function and W2C of excellent catalytic activity and low work function is designed by theoretical screening. Due to work function difference, this heterostructure controls the direction of the interface built-in electric field (BIEF), realizing the directional migration process of Sn2− from adsorptive W to catalytic W2C, thereby achieving a continuous “trapping-directional migration-conversion” reaction mechanism. The batteries have an excellent Li+ diffusion rate, high initial discharge specific capacity (1400.6 mAh/g at 0.2C), excellent rate capability (853.2 mAh/g at 2C), high reversible capacity (977.9 mAh/g after 150 cycles at 0.2C) and an extremely low capacity decay rate of 0.09 % per cycle after 300 cycles at 1C.

Incorporation of Mo2C nanoparticles to pollen-derived 3D porous carbon as electrocatalyst for high performance lithium-sulfur batteries

The practical application and development of lithium‑sulfur (LiS) batteries are limited by the slow redox reaction kinetics and shuttle effect of polysulfide lithium (LiPSs). To address these issues, three-dimensional porous carbon (PC, derived from rapeseed pollen) modified with molybdenum carbide (Mo2C) nanoparticles is prepared by a simple and environment-friendly method. On the one hand, the PC-Mo2C host material can facilitate the uniform loading of sulfur and reduce its volume expansion due to its porous carbon structure. On the other hand, it mitigates the shuttle effect by effective chemical adsorption of LiPSs to form strong physical confinement and catalyze the conversion of LiPSs via the aid of the decorated Mo2C nanoparticles. Density functional theoretical calculations also illustrate the Mo2C nanoparticles are capable of inhibiting the shuttle of LiPSs and further improving the cycling stability. The results show that the PC-Mo2C/S electrode exhibits excellent electrochemical performance with high cycle stability (fading rate of 0.066 % per cycle at 0.2C and 0.054 % per cycle at 1C) and outstanding rate capacity (623.2 mAh g−1 at 5C).

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

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

High-entropy sulfides enhancing adsorption and catalytic conversion of lithium polysulfides for lithium-sulfur batteries

High-entropy sulfides enhancing adsorption and catalytic conversion of lithium polysulfides for lithium-sulfur batteries

Optimal liquid sulfur deposition dynamics for fast-charging Li-S batteries

Optimal liquid sulfur deposition dynamics for fast-charging Li-S batteries

In Situ Synthesis of CoMoO4 Microsphere@rGO as a Matrix for High-Performance Li-S Batteries at Room and Low Temperatures.

Lithium-sulfur batteries (Li-S batteries) have attracted wide attention due to their high theoretical energy density and the low cost of sulfur cathode material. However, the poor conductivity of the sulfur cathode, the polysulfide shuttle effect, and the slow redox kinetics severely affect their cycling performance and Coulombic efficiencies, especially under low-temperature conditions, where these effects are more exacerbated. To address these issues, this study designs and synthesizes a microspherical cobalt molybdate@reduced graphene oxide (CoMoO4@rGO) composite material as the cathode material for Li-S batteries. By growing CoMoO4 nanoparticles on the rGO surface, the composite material not only provides a good conductive network but also significantly enhances the adsorption capacity to polysulfides, effectively suppressing the shuttle effect. After 100 cycles at room temperature with a current density of 1 C, the reversible specific capacity of the battery stabilizes at 805 mAh g-1. Notably, at -20 °C, the S/CoMoO4@rGO composite achieves a reversible specific capacity of 840 mAh g-1. This study demonstrates that the CoMoO4@rGO composite has significant advantages in suppressing polysulfide diffusion and expanding the working temperature range of Li-S batteries, showing great potential for applications in next-generation high-performance Li-S batteries.

Copper-nickel MOF-coated electrospun polyacrylonitrile membranes for Li–S batteries: Mitigating the shuttle effect and enhancing stability

Cu–Ni MOF nanoparticles were synthesized as coating materials for lithium–sulfur battery membranes, and the performance of batteries employing Cu–Ni MOF/PAN (CNMP) electrospinning membranes were examined. The modified membrane efficiently suppresses the shuttle effect, leveraging the synergistic catalysis and adsorption capabilities of the Cu–Ni MOF nanoparticles. The modified membrane exhibited relatively high porosity and outstanding electrolyte absorption capacity. The CNMP membrane battery demonstrated a remarkable first-cycle discharge capacity of 1529 mA h g⁻¹. The battery maintained an exceptional discharge capacity with 85.2 % retention and a minimal capacity decay rate of just 0.074 % per cycle after 200 cycles at 0.5 C. The capacity retention of the modified membrane battery remained at 74.6 % even after 2000 cycles at 2 C. The excellent performance of the modified membrane battery was due to the physical entrapment and strong chemical adsorption of lithium polysulfides by Cu–Ni MOF nanoparticles, significantly preventing the shuttle effect and facilitating rapid oxidation–reduction kinetics based on strong catalytic conversion.

Solid‐State Electrolytes for Lithium Metal Batteries: State‐of‐the‐Art and Perspectives

AbstractThe use of all‐solid‐state lithium metal batteries (ASSLMBs) has garnered significant attention as a promising solution for advanced energy storage systems. By employing non‐flammable solid electrolytes in ASSLMBs, their safety profile is enhanced, and the use of lithium metal as the anode allows for higher energy density compared to traditional lithium‐ion batteries. To fully realize the potential of ASSLMBs, solid‐state electrolytes (SSEs) must meet several requirements. These include high ionic conductivity and Li+ transference number, smooth interfacial contact between SSEs and electrodes, low manufacturing cost, excellent electrochemical stability, and effective suppression of dendrite formation. This paper delves into the essential requirements of SSEs to enable the successful implementation of ASSLMBs. Additionally, the representative state‐of‐the‐art examples of SSEs developed in the past 5 years, showcasing the latest advancements in SSE materials and highlighting their unique properties are discussed. Finally, the paper provides an outlook on achieving balanced and improved SSEs for ASSLMBs, addressing failure mechanisms and solutions, highlighting critical challenges such as the reversibility of Li plating/stripping and thermal runaway, advanced characterization techniques, composite SSEs, computational studies, and potential and challenges of ASS lithium–sulfur and lithium–oxygen batteries. With this consideration, balanced and improved SSEs for ASSLMBs can be realized.

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.

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.

Encapsulation Engineering of Sulfur into Magnesium Oxide for High Energy Density Li-S Batteries.

This study addresses the persistent challenge of polysulfide dissolution in lithium-sulfur (Li-S) batteries by introducing magnesium oxide (MgO) nanoparticles as a novel additive. MgO was integrated with sulfur using a scalable process involving solid-state melt diffusion treatment followed by planetary ball milling. XRD measurements confirmed that sulfur (S8) retains its orthorhombic crystalline structure (space group Fddd) following the MgO incorporation, with minimal peak shifts indicating slight lattice distortion, while the increased peak intensity suggests enhanced crystallinity due to MgO acting as a nucleation site. Additionally, Raman spectroscopy demonstrated sulfur's characteristic vibrational modes consistent with group theory (point group D2h) and highlighted multiwalled carbon nanotube (MWCNT's) D, G, and 2D bands, with a low ID/IG ratio (0.47), which indicated low defects and high crystallinity in the prepared cathode. The S-MgO composite cathode exhibited superior electrochemical behavior, with an initial discharge capacity (950 mA h g-1 at 0.1 C), significantly improved compared to pristine sulfur's. The presence of MgO effectively mitigated the polysulfide shuttle effect by trapping polysulfides, leading to enhanced stability over 400 cycles and the consistent coulombic efficiency of over 99.5%. After 400 cycles, EDS and SEM analyses confirmed the structural integrity of the electrode, with only minor fractures and slight sulfur content loss. Electrochemical impedance spectroscopy further confirmed the enhanced performance.

Exploration of Optimization Strategies for Locking Sulfur in 2D Layered/Polymer-Enveloped Cathode Composite for High Power Li-S Batteries.

In Lithium sulfur (Li-S) batteries the sulfur host material is a significant area of research that could impart enhanced conductivity and alleviate the shuttling of polysulfides. In the present study, graphene oxide- sulfur, GO-S was synthesized in melt diffusion method by exploring the two different strategies: Ambient (G2-M) and Inert (G2-T) conditions. Within the cathode, efficient storage of S with sufficient space in GO interlayers was outperformed by G2-T method. Further with PEDOT nanostructures enveloped by oxidative polymerisation proves to be a robust conductive layer and an adsorbing agent. It is evidenced physicochemically by XRD, FTIR, TGA, HR-SEM. Moreover, in addition to the supporting studies, high binding energies of 168.3 and 169.5 eV confirms the superior performance of PEDOT/GO-S (G3-T) as most suitable cathode within the system. The electrochemical behaviour of G3-T possess very low cell impedance with an excellent cyclic reversibility in CV during (de)lithiation process. At 0.1 C, an initial discharge capacity of 868 mAh g-1 has been achieved confirming a high catalytic activity with a low polarisation potential of (ΔE=0.25) inducing fast reaction kinetics. Thus potential locking of sulfur under inert condition is explored with a proven OCV of 2.3 V with red LED glow.

Electronic Modulation and Symmetry-Breaking Engineering of Single-Atom Catalysts Driving Long-Cycling Li-S Battery.

Developing efficient and durable single-atom catalysts is vitally important for the sulfur redox reaction (SROR) in Li-S battery, while it remains enormous challenging. Herein, undercoordinated Ni-N3 moieties anchored on N,S-codoped porous carbon (Ni-NSC) is obtained to enhance the SROR. The experiments and theoretical calculations indicate that the symmetry-breaking charge transfer in Ni single-atom catalyst originates from tuning effect of sulfur atoms mediated Ni-N3 moieties, which can both facilitate the chemical adsorption by formation of N-Ni⋯Sn2-, and achieve a rapid redox conversion of polysulfides because of the enhanced electron transfer. As results, the Ni-NSC based Li-S battery delivers a very high initial reversible capacity (1025 mAh g-1 at 1 C), as well as outstanding cycling-stability for 2400 cycles at 2 C and 3 C, respectively. Noteworthy, the areal capacity can reach 7.8 mAh cm-2 at 0.05 C and a retention capacity of 4.7 mAh cm-2 after 100 cycles at 0.2 C for Ni-NSC based Li-S battery with sulfur loading of 5.88 mg cm-2. This work provides profound insight for rational optimizing microscopic electronic density of active site to promoting SROR in metal-sulfur batteries.

Advanced Li-S Battery Configuration Featuring Sulfur-Coated Separator and Interwoven rGO/CNT Fabric Current Collector.

The development of lithium-sulfur batteries (LSBs) marks a crucial milestone in advancing energy storage solutions essential for sustainable energy transitions. With high theoretical specific capacity, cost-effectiveness, and reduced ecological footprint, LSBs promise to enhance electric vehicle ranges, extend portable electronics' operational times, and stabilize grids integrated with renewable energy. However, challenges like complex processing, electrode instability, and poor cycling stability hinder their commercialization. This study introduces a novel battery design that addresses these issues by coating sulfur directly onto the separator instead of the current collector, demonstrating that active sulfur can be effectively utilized without being incorporated into the electrode structure. Using an interwoven substrate made from carbon nanotube (CNT) fabric adorned with reduced graphene oxide (rGO), this setup enhances manufacturing scalability, supports optimal sulfur utilization, and improves battery performance. The rGO decoration provides multiple highly conductive polysulfide trapping sites, enhancing active material reutilization, while the flexibility and mechanical strength of CNT fabric contribute to electrode integrity. This combination boosts electrical conductivity and polysulfide-capturing capability, effectively managing migrating sulfur species during charge-discharge cycles and mitigating sulfur loss and polysulfide shuttling. The results demonstrate superior cycling stability and efficiency, highlighting the potential of this approach in advancing LSB technology.

Dual-Functional Additive Bipyridine Cobalt Complex for Highly Efficient Kinetics and Lithium Regulation in Lithium–Sulfur Batteries

Dual-Functional Additive Bipyridine Cobalt Complex for Highly Efficient Kinetics and Lithium Regulation in Lithium–Sulfur Batteries

Melamine-based nanoscale porous organic frameworks as multifunctional separator modifiers to mitigate the polysulfide shuttle effect in lithium–Sulfur batteries

The shuttling of polysulfides between electrodes in lithium-sulfur (Li-S) batteries significantly impairs cycle stability. This study explores the use of melamine-based nanoscale porous organic frameworks (POFs) as polysulfide reservoirs to modify glass fiber (GF) separators. Melamine was reacted with dibromoalkanes of varying carbon chain lengths (n = 4, 8, and 12) to produce a series of POF materials, POF-Cn, with different nanoscale pore sizes and solubilities. The POF composites, POF-Cn/SP/PVP, which include conductive carbon Super P (SP) and a polyvinylpyrrolidone (PVP) binder, were coated onto GF membranes to create modified separators for Li-S batteries. Batteries with these modified GF separators exhibited higher initial capacities, improved rate performance, and better long-term cycle stability compared to those with non-modified separators. Among the POF composites, POF-C8/SP/PVP exhibited the best performance, with an initial specific capacity of 1392 mAh g-1 at 0.1C and a high capacity retention of 90% after 300 cycles at 0.5C. The enhanced capacity, stability, and rate performance are attributed to the nanoporous structure of POF-C8 and its high nitrogen content, which effectively traps soluble LiPSs and reduces their diffusion toward the Li anode. The good solubility of POF-C8 facilitates uniform dispersion in the modifying layer, promoting efficient polysulfide trapping and maximizing their utilization in electrochemical reactions, aided by the conductive SP in the composite.

A Review on Architecting Rationally Designed Metal-Organic Frameworks for the Next-Generation Li-S Batteries.

The modern era demands the development of energy storage devices with high energy density and power density. There is no doubt that lithium‒sulfur batteries (Li‒S) claim high theoretical energy density and have attracted great attention from researchers, but fundamental exploration and practical applications cannot converge to utilize their maximum potential. The design parameters of Li-S batteries involve various complex mechanisms, and their obliviousness has resulted in failure at the commercial level. This article presents a review on rationally designed metal-organic frameworks (MOFs) for improving next-generation Li-S batteries. The use of MOFs in Li-S batteries is of great interest because of their large surface area, porous structure, and selective permeability for ions. The working principles of Li-S batteries, the commercialization of Li-S batteries, and the use of MOFs as electrodes, electrolytes, and separators are critically examined. Finally, designed strategies (host structure, binder improvement, separator modification, lithium metal protection, and electrolyte optimization) are developed to increase the performance of Li-S batteries.

Construction of Ordered and Fast Lithium Ion Channels in Gel Electrolytes for Li-SPAN Batteries.

As one of the most promising battery systems, the lithium sulfur battery is expected to be widely used in fields of high energy density demands. Owing to the unique solid-solid conversion mechanism, there is no shuttle effect for the Li-SPAN (sulfurized polyacrylonitrile) battery. However, the compatibility between Li anode and carbonate electrolyte has not been resolved, which prevents the SPAN from practical applications. Herein, an organic-inorganic gel carbonate electrolyte is proposed to stabilize interphases and structures of both the anode and cathode, where polyimide (PI) is used for electrolyte gelation, which can assist in the uniform distribution of inorganic components at the electrolyte interface. Furthermore, ZnS nanodots loaded on two-dimensional MoS2 flakes provide abundant Li-ion diffusion paths, improve the transfer kinetic of Li ions, and induce uniform nucleation and deposition of Li. This gel electrolyte ensures Li symmetric cells a long-term cycle life of more than 900 h under the condition of deep lithium plating/stripping at 5 mAh cm-1. Li∥Cu cells exhibit a prolonged lifespan of 800 h with a CE of 98.3%. Furthermore, the Li-SPAN battery shows stability of more than 850 cycles, with the capacity retention of 85.1%. This work provides an approach for high-energy Li-SPAN batteries with carbonate-based electrolytes.

Spherical NiS2/Ni17S18–C accelerates ion transport and enhances kinetics for lithium-sulfur battery host material

Transition metal sulfides exhibit notable catalytic activity and possess a high theoretical specific capacity as host materials in lithium-sulfur batteries. However, their restricted conductivity and sluggish Li+ transport hinder their broader application. In this research, we developed a Ni-based metal-organic framework (Ni-MOF) using nitrogen-containing benzimidazole and coupled it with a highly conductive carbon nanotube (CNT) to form NixSy (NiS2–Ni17S18)–C/CNT. The N-doped carbon skeleton derived from the MOF enhances the adsorption and chemical anchoring of polysulfides, while the even distribution of NiS2 and Ni17S18 enhances the redox reaction kinetics. Additionally, the conductive CNT networks aid in rapid electron transport, resulting in improved sulfur utilization. Consequently, the NixSy-C/CNT@S electrode demonstrates an impressive initial specific capacity of 1468 mAh g−1 at 0.2C and maintains 904.4 mAh g−1 after 200 cycles. Moreover, NixSy-C/CNT@S displays exceptional cycle stability, with a capacity retention of 76.20 % and a decay rate of only 0.05 % per cycle after 500 cycles at 0.5C. This study paves the way for the development and synthesis of cathode materials with outstanding electrochemical performance in LSBs.

Study of the Activator Effects on the Specific Surface Area of Porous Carbon and its Performance as Lithium-Sulfur Battery Cathode

A study was conducted to investigate the effect of activator types KOH, ZnCl2, and H3PO4 on the specific surface area of porous carbon and its performance as a Li-S battery. Porous carbon was synthesized from candlenut shells through a carbonization process at 700 °C using three types of activator solutions with a concentration of 0.36 M. The porous carbon activated with KOH achieved the best results, with a specific surface area of 681 m²g-1. The porous carbon candlenut shell-sulfur (PCCS-S) composite was obtained by the solid-state reaction method in a ratio of 1:2.5 w% and heat-treated at 155 °C to form the PCCS-S composite. The PCCS-S composite was then made into a slurry and coated onto Al-foil to obtain a layer of electrodes with a thickness of 200 µm. The PCCS-S cathode was then assembled into a coin battery with lithium metal as the anode and an electrolyte of 1.0 M LiTFSi solution dissolved in 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) (v/v, 1:1). Charge-discharge characterization was carried out at a charge rate of 1 C for 50 cycles. Characterization shows that the performance of the PCCS-S KOH composite cathode Li-S battery is stable at a specific capacity of 324 mAhg-1 after the first 10 cycles, with an average Coulombic efficiency of around 86.8 %.