Search Results (201)

Films of functionalised multiwalled carbon nanotubes (MWCNTs) were fabricated as interlayers (interfacial layers between the cathode and separator) in a lithium–sulfur battery (LSB). Phenylsulfonate functionalisation of commercial MWCNTs was achieved via diazotisation to attach lithium phenylsulfonate groups and was characterised by IR and XPS spectroscopies. SEM-EDX showed sulfur and oxygen colocations due to the sulfonate groups on the interlayer surface. However, CHNS elemental microstudies showed a low degree of functionalisation. Without an interlayer, the LSB produced stable cycling at a capacity of 600 mA h g⁻¹_sulfur at 0.05 C for 40 cycles. Using an unfunctionalised interlayer as a control gave a capacity of 1400 mA h g⁻¹_sulfur for the first cycle but rapidly decayed to the same 600 mA h g⁻¹_sulfur at the 40th cycle at 0.05 C, suggesting a high degree of polysulfide shuttling. Adding a lithium phenylsulfonated interlayer gave an initial capacity increase to 1100 mA h g⁻¹_sulfur that lowered to 800 mA h g⁻¹_sulfur at 0.05 C by the 40th cycle, showing an increase in charge storage (33%) relative to the other cells. This performance increase has been attributed to lessened polysulfide shuttling due to repulsion by the phenylsulfonate groups, increased conductivity at the separator-cathode interface and an increase in surface area. Full article

Lithium–sulfur batteries (LSBs), possessing excellent theoretical capacities, advanced theoretical energy densities, low cost, and nontoxicity, are one of the most promising energy storage battery systems. However, some issues, including poor conductivity of elemental S, the “shuttle effect” of high-order lithium polysulfides (LiPSs), and sluggish reaction kinetics, hinder the commercialization of LSBs. To solve these problems, various carbon-based aerogels with developed surface morphology, tunable pores, and electrical conductivity have been examined for immobilizing sulfur, mitigating its volume variation and enhancing its electrochemical kinetics. In this paper, an extensive generalization about the effective preparation methods of carbon-based aerogels comprising the combined method of carbonization with the gelation of precursors and drying processes (ambient pressure drying, freeze-drying, and supercritical drying) is proposed. And we summarize various carbon carbon-based aerogels, mainly including graphene aerogels (Gas) and carbon nanofiber (CNF) and carbon nanotube (CNT) aerogels as cathodes, separators, and interlayers in LSBs. In addition, the mechanism of action of carbon-based aerogels in LSBs is described. Finally, we conclude with an outlook section to provide some insights into the application of carbon-based aerogels in electrochemical energy storage devices. Based on the discussion and proposed recommendations, we provide more approaches on nanomaterials in high-performance liquid or state LSBs with high electrochemical performance in the future. Full article

Lithium–sulfur (Li-S) batteries are hindered by the sluggish electrochemical kinetics and poor reversibility of lithium polysulfides (LiPSs), which limits their practical energy density and cycle life. In order to address this issue, a novel Ni₃N/Nb₄N₅ heterostructure was synthesized via electrospinning and nitridation as a functional coating for polypropylene (PP) separators. Adsorption experiments were conducted in order to ascertain the heterostructure’s superior affinity for LiPSs, thereby effectively mitigating their shuttling. Studies of Li₂S nucleation demonstrated the catalytic role of the substance in accelerating the deposition kinetics of Li₂S. Consequently, Li-S cells that employed the Ni₃N/Nb₄N₅-modified separator were found to achieve significantly enhanced electrochemical performance, with the cells delivering an initial discharge capacity of 1294.4 mAh g⁻¹ at 0.2 C. The results demonstrate that, after 150 cycles, the cells retained a discharge capacity of 796.2 mAh g⁻¹, corresponding to a low capacity decay rate of only 0.25% per cycle. In addition, the rate capability of the cells was found to be improved in comparison to control cells with NiNb₂O₆-modified or pristine separators. Full article

The development of polymer binders with tailored functionalities and green manufacturing processes is highly needed for high-performance lithium–sulfur batteries. In this study, a readily hydrolyzable 3,9-divinyl-2,4,8,10-tetraoxaspiro-[5.5]-undecane is utilized to prepare a water-based binder. Specifically, the acrolein produced by hydrolysis undergoes in situ polymerization to form a linear polymer, while the other hydrolyzed product, pentaerythritol, physically crosslinks these polymer chains via hydrogen bonding, generating a network polymer (BTU). Additionally, gallic acid (GA), a substance derived from waste wood, is further introduced into BTU during slurry preparation, forming a biphenol-containing binder (BG) with a multi-hydrogen-bonded structure. This resilience and robust cathode framework effectively accommodate volumetric changes during cycling while maintaining efficient ion and electron transport pathways. Furthermore, the abundant polar groups in BG enable strong polysulfide adsorption. As a result, sulfur cathode with a high mass loading of 5.3 mg cm⁻² employing the BG (7:3) binder still retains an areal capacity of 4.7 mA h cm⁻² after 50 cycles at 0.1 C. This work presents a sustainable strategy for battery manufacturing by integrating renewable biomass-derived materials and eco-friendly aqueous processing to develop polymer binders, offering a green pathway to high-performance lithium–sulfur batteries. Full article

The “shuttle effect” caused by the shuttling of soluble long-chain polysulfides between the anode and cathode electrodes has persistently hindered lithium–sulfur batteries (LSBs) from achieving stable and high-capacity performance. Numerous materials have been explored to mitigate the adverse effects of this phenomenon, among which metal oxides and metal sulfides are regarded as promising solutions due to their strong adsorption capability toward lithium polysulfides (LiPSs). However, the poor electrical conductivity of the metal oxides and sulfides, coupled with their inherent morphological limitations, makes it challenging to sustainably suppress LiPS shuttling. In this study, we designed a heterostructured catalyst composed of a metal oxide–metal sulfide heterostructure integrated with carbon nanotubes (CNTs). This design addresses the low conductivity issue of metal oxides/sulfides while optimizing the material’s morphology, enabling persistent LiPSs adsorption. Furthermore, the composite successfully facilitates three-dimensional (3D) Li₂S deposition. The assembled battery exhibits stable and high-capacity performance, delivering an initial discharge capacity of 622.45 mAh g⁻¹ at 2C and retaining 569.5 mAh g⁻¹ after 350 cycles, demonstrating exceptional cycling stability. Full article

Lithium–sulfur batteries (LSBs) are favorable candidates for advanced energy storage, boasting a remarkable theoretical energy density of 2600 Wh kg⁻¹. Moreover, several challenges hinder their practical implementation, including sulfur’s intrinsic electrical insulation, the shuttle effect of lithium polysulfides (LiPSs), sluggish redox kinetics of Li₂S₂/Li₂S, and the uncontrolled growth of Li dendrites. These issues pose significant obstacles to the commercialization of LSBs. A viable strategy to address these challenges involves using MXene materials, 2D transition metal carbides, and nitrides (TMCs/TMNs) as hosts, functional separators, or interlayers. MXenes offer exceptional electronic conductivity, adjustable structural properties, and abundant polar functional groups, enabling strong interactions with both S cathodes and Li anodes. Despite their advantages, current MXene synthesis methods predominantly rely on acid etching, which is associated with environmental concerns, low production efficiency, and limited structural versatility, restricting their potential in LSBs. This review provides a comprehensive overview of traditional and environmentally sustainable MXene synthesis techniques, emphasizing their applications in developing S cathodes, Li anodes, and functional separators for LSBs. Additionally, it discusses the challenges and outlines future directions for advancing MXene-based solutions in LSBs technology. Full article

The advancement of lithium–sulfur (Li-S) batteries has been hindered by the shuttle effect of lithium polysulfides (LiPSs) and sluggish redox kinetics. The engineering of functional hybrid separators is a relatively simple and effective coping strategy. Layered transition-metal carbides, nitrides, and carbonitrides, a class of emerging two-dimensional materials termed MXenes, have gained popularity as catalytic materials for Li-S batteries due to their metallic conductivity, tunable surface chemistry, and terminal groups. Nonetheless, the self-stacking flaws and easy oxidation of MXenes pose disadvantages, and developing MXene-based heterostructures is anticipated to circumvent these issues and yield other remarkable physicochemical characteristics. Herein, recent advances in the construction of MXene-based heterostructured hybrid separators for improving the performance of Li-S batteries are reviewed. The diverse conformational forms of heterostructures and their constitutive relationships with LiPS conversion are discussed, and the general principles of MXene surface chemistry alterations and heterostructure designs for enhancing electrochemical performance are summarized. Lastly, tangible challenges are addressed, and advisable insights for future research are shared. This review aims to highlight the immense superiority of MXene-based heterostructures in Li-S battery separator modification and inspire researchers. Full article

Lithium–sulfur batteries (LSBs), with a high energy density (2600 $\mathrm{W}$$\mathrm{h}$ kg⁻¹) and theoretical specific capacity (1672 mA h g⁻¹), are considered the most promising next-generation rechargeable energy storage devices. However, polysulfide dissolution and the shuttle effect cause severe capacity fading and the rapid loss of the active material; hence, these must be addressed first. This review provides an overview of various strategies employed to immobilise polysulfides via polysulfide trapping and physical and chemical adsorption using porous cathode designs, heterostructures, functionalised separators, and polymer binders. The working mechanism of each strategy is reviewed and discussed, highlighting their advantages and disadvantages, and they are analysed through comparisons of the battery performance and limitations in terms of practical applications. Finally, the future prospects for the design and synthesis of LSBs to limit polysulfide dissolution are discussed. Full article

In this paper, the natural waste pinecone as a carbon precursor for the generation of satisfactory sulfur host materials in lithium–sulfur batteries was realized by introducing molybdenum carbide nanoparticles into the derived carbon structure. The conductive pinecone-derived carbon doped with N, O reveals an expansive specific surface area, facilitating the accommodation of a higher sulfur load. Moreover, the integration of Mo₂C nanoparticles also significantly enhances its chemical affinity and catalytic capacity for polysulfides (LiPSs) to alleviate the shuttle effect and accelerate sulfur redox conversion. As a result, the WPC-Mo₂C/S electrode displays excellent electrochemical performance, including a low capacity decay rate of 0.074% per cycle during 600 cycles at 1 C and an outstanding rate capacity (631.2 mAh g⁻¹ at 3 C). Moreover, with a high sulfur loading of 5.5 mg cm⁻², the WPC-Mo₂C/S electrode shows a high area capacity of 5.1 mAh cm⁻² after 60 cycles at 0.2 C. Full article

In this study, nitrogen- and sulfur-co-doped MXene (NS-MXene) was developed as a high-performance cathode material for lithium–sulfur (Li-S) batteries. Heterocyclic Se₂S₆ molecules were successfully confined within the NS-MXene structure using a simple melt impregnation method. The resulting NS-MXene exhibited a unique wrinkled morphology with a stable structure which facilitated rapid ion transport and provided a physical barrier to mitigate the shuttle effect of polysulfide. The introduction of nitrogen and sulfur heteroatoms into the MXene structure not only shifted the Ti d-band center towards the Fermi level but also significantly polarizes the MXene, enhancing the conversion kinetics and ion diffusion capability while preventing the accumulation of Li₂S₆. Additionally, the incorporation of Se and S in Se₂S₆ improved the conductivity compared to S alone, resulting in reduced polarization and enhanced electrical properties. Consequently, NS-MXene/Se₂S₆ exhibited excellent cycling stability, high reversible capacity, and reliable performance at high current densities and under extreme conditions, such as high sulfur loading and low electrolyte-to-sulfur ratios. This work presents a simple and effective strategy for designing heteroatom-doped MXene materials, offering promising potential for the development of high-performance, long-lasting Li-S batteries for practical applications. Full article

Lithium–sulfur (Li-S) batteries are recognized as a promising alternative in the energy storage domain due to their high theoretical energy density, environmental friendliness, and cost-effectiveness. However, challenges such as polysulfide dissolution, the low conductivity of sulfur, and limited cycling stability hinder their widespread application. To address these issues, the incorporation of heterostructured metallic substrates into Li-S batteries has emerged as a pivotal strategy, enhancing electrochemical performance by facilitating better adsorption and catalysis. This review delineates the modifications made to the cathode and separator of Li-S batteries through metallic heterostructures. We categorize the heterostructures into three classifications: single metals and metal compounds, MXene materials paired with metal compounds, and heterostructures formed entirely of metal compounds. Each category is systematically examined for its contributions to the electrochemical behavior and efficiency of Li-S batteries. The performance of these heterostructures is evaluated in both the cathode and separator contexts, revealing significant improvements in lithium-ion conductivity and polysulfide retention. Our findings suggest that the strategic design of metallic heterostructures can not only mitigate the inherent limitations of Li-S batteries but also pave the way for the development of high-performance energy storage systems. Full article

Lithium–sulfur (Li-S) batteries are promising candidates for next-generation energy storage due to their high energy density, cost-effectiveness, and environmental friendliness. However, their commercialization is hindered by challenges, such as the polysulfide shuttle effect, lithium dendrite growth, and low electrical conductivity of sulfur cathodes. Cellulose, a natural, renewable, and versatile biopolymer, has emerged as a multifunctional material to address these issues. In anode protection, cellulose-based composites and coatings mitigate dendrite formation and improve lithium-ion diffusion, extending cycle life and enhancing safety. As separators, cellulose materials exhibit high ionic conductivity, thermal stability, and excellent wettability, effectively suppressing the polysulfide shuttle effect and maintaining electrolyte stability. For the cathode, cellulose-derived carbon frameworks and binders improve sulfur loading, conductivity, and active material retention, resulting in higher energy density and cycling stability. This review highlights the diverse roles of cellulose in Li-S batteries, emphasizing its potential to enable sustainable and high-performance energy storage. The integration of cellulose into Li-S systems not only enhances electrochemical performance but also aligns with the goals of green energy technologies. Further advancements in cellulose processing and functionalization could pave the way for its broader application in next-generation battery systems. Full article

Lithium–sulfur batteries (LSBs) represent a promising next-generation energy storage technology due to their superior theoretical capacity and energy density compared to conventional lithium-ion batteries. Despite these advantages, their commercialization is hindered by intrinsic challenges such as sulfur’s low electrical conductivity, the polysulfide shuttle effect during cycling, and lithium dendrite formation. This mini-review examines recent advancements in leveraging biomass-derived activated carbon for LSB applications. The review categorizes biomass sources into animal- and plant-based precursors and highlights their respective synthesis processes. Furthermore, it discusses innovative strategies for utilizing these materials to mitigate the challenges of LSB performance and stability, paving the way for more sustainable and efficient energy storage systems. Full article

Lithium–sulfur batteries (LSBs) are gaining much attention because they offer a much higher theoretical energy density compared to traditional lithium-ion batteries. However, the cycling performance of LSBs with high sulfur mass loading is poor due to the shuttle effect, limiting the practical application of LSBs. In this work, a unique porous sulfur/Ti₃C₂T_x Mxene@selenium (S/Ti₃C₂T_x@Se) cathode of a LSB is synthesized by a simple hydrothermal method to address these challenges. In this composite, Ti₃C₂T_x forms a conductive framework and Se is tightly anchored on the framework. The Se inhibits the agglomeration of Ti₃C₂T_x and prevents the collapse of Ti₃C₂T_x. The S/Ti₃C₂T_x@Se composite can adsorb lithium polysulfides (LiPSs) and suppresses the shuttle effect and volume changes during cycling, improving the cycling stability of LSBs with high S loading. A high capacity of 812.2 mAh g⁻¹ at 0.1 C with 5.0 mg cm⁻² sulfur mass loading after 100 cycles is obtained. This work could inspire further research into high-performance S host materials for high-S-loading LSBs. Full article

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. Full article