Lithium Sulfur Research Articles

Nickel aerogel @ ultra-thin NiCo-LDH nanosheets integrated freestanding film as a collaborative adsorption and accelerated conversion cathode to improve the rate performance of lithium sulfur batteries

It is a great challenge to develop freestanding ultralight cathodes for lithium–sulfur battery exhibiting good electrochemical performances. Herein, ultrathin porous nickel–cobalt layered double hydroxide (NiCo-LDH) nanosheets were grown on the surface of ultra-light nickel microwire aerogels (NMWAs), and there is capillary action in the gaps formed by the ordered arrangement due to the presence of magnetic filed in the preparation process, which has the advantages of synergistic adsorption and accelerated conversion kinetics of lithium polysulfide. Because of the abundant hydrophilic hydroxyl groups on the surface of NiCo-LDH and the capillary action of NMWAs, the integrated freestanding film cathode sulfur host (NMWAs@NiCo-LDH/S) provides excellent rate performance as well as cycling stability. The film cathode has an ultra-high initial specific capacity of 1238.4 mAh/g at 0.1C and an excellent reversible capacity of 805.8 mAh/g at 5.0C. Even after 700cycles at a high current density of 5.0C, it still provides a reversible capacity of 647.1 mAh/g with a capacity decay rate of only 0.018 % per cycle. This work provides a simple and new way for the design of high rate lithium–sulfur battery film cathodes with good cycle stability.

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

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

Phosphorylated cellulose nanofibers establishing reliable ion-sieving barriers for durable lithium-sulfur batteries

Phosphorylated cellulose nanofibers establishing reliable ion-sieving barriers for durable lithium-sulfur batteries

Bridging the gap between academic research and industrial development in advanced all-solid-state lithium-sulfur batteries.

The energy storage and vehicle industries are heavily investing in advancing all-solid-state batteries to overcome critical limitations in existing liquid electrolyte-based lithium-ion batteries, specifically focusing on mitigating fire hazards and improving energy density. All-solid-state lithium-sulfur batteries (ASSLSBs), featuring earth-abundant sulfur cathodes, high-capacity metallic lithium anodes, and non-flammable solid electrolytes, hold significant promise. Despite these appealing advantages, persistent challenges like sluggish sulfur redox kinetics, lithium metal failure, solid electrolyte degradation, and manufacturing complexities hinder their practical use. To facilitate the transition of these technologies to an industrial scale, bridging the gap between fundamental scientific research and applied R&D activities is crucial. Our review will address the inherent challenges in cell chemistries within ASSLSBs, explore advanced characterization techniques, and delve into innovative cell structure designs. Furthermore, we will provide an overview of the recent trends in R&D and investment activities from both academia and industry. Building on the fundamental understandings and significant progress that has been made thus far, our objective is to motivate the battery community to advance ASSLSBs in a practical direction and propel the industrialized process.

Alveoli-Inspired Carbon Cathodes with Interconnected Porous Structure and Asymmetric Coordinated Vanadium Sites for Superior Li-S Batteries.

Accelerating sulfur conversion catalysis to alleviate the shuttle effect has become a novel paradigm for effective Li-S batteries. Although nitrogen-coordinated metal single-atom (M-N4) catalysts have been investigated, further optimizing its utilization rate and catalytic activities is urgently needed for practical applications. Inspired by the natural alveoli tissue with interconnected structure and well-distributed enzyme catalytic sites on the wall for the simultaneously fast diffusion and in-situ catalytic conversion of substrates, here, we proposed the controllable synthesis of bioinspired carbon cathode with interconnected porous structure and asymmetric coordinated V-S1N3 sites for efficient and stable Li-S batteries. The enzyme-mimetic V-S1N3 shows asymmetric electronic distribution and high tunability, therefore enhancing in-situ polysulfide conversion activities. Experimental and theoretical results reveal that the high charge asymmetry degree and large atom radius of S in V-S1N3 result in sloping adsorption for polysulfide, thereby exhibiting low thermodynamic energy barriers and long-range stability (0.076% decay over 600 cycles).

A Highly Effective Polysulfide-Trapping Approach for the Development of High Energy Density, Scalable Lithium-Sulfur Batteries

Abstract Lithium-sulfur (Li-S) batteries are identified as one of the most promising next-generation battery technologies owing to their high theoretical specific energy, sustainability, and affordability. However, the commercialization of Li-S batteries has been hindered by severe technical challenges, including the lithium polysulfide (PS) dissolution/shuttling effect, a major cause of fast capacity degradation over cycling. We demonstrated that nanolayer polymer coated high surface area porous carbons (NPCs) were coated directly on sulfur electrodes (NPC-S), which led to a high specific capacity of ~1,600 mAh/g approaching the theoretical specific capacity limit. The NPC-S based Li-S batteries maintained their large initial specific capacity gain compared with the Baseline-S based Li-S batteries (control) over extended cycles. Our experimental and computational results suggest that NPC coated on sulfur electrodes provides not only an effective and strong PS-trapping power but also an increased redox reaction kinetics during battery charge and discharge, rendering the realization of near-theoretical discharge specific capacity in the NPC-S based Li-S batteries. The findings presented in this study may inspire a new, simple, low-cost, and commercially scalable approach, without adding any appreciable dead weight or volume to the batteries, in the effort to tackle the technical challenges facing SOA Li-S batteries.

Regulating Sulfur Redox Kinetics by Coupling Photocatalysis for High-Performance Photo-Assisted Lithium-Sulfur Batteries.

Challenges such as shuttle effect have hindered the commercialization of lithium-sulfur batteries (LSBs), despite their potential as high-energy-density storage devices. To address these issues, we explore the integration of solar energy into LSBs, creating a photo-assisted lithium-sulfur battery (PA-LSB). The PA-LSB provides a novel and sustainable solution by coupling the photocatalytic effect to accelerate sulfur redox reactions. Herein, a perovskite quantum dot-loaded MOF material serves as a cathode for the PA-LSB, creating built-in electric fields at the micro-interface to extend the lifetime of photo-generated charge carriers. The band structure of the composite material aligns well with the electrochemical reaction potential of lithium-sulfur, enabling precise regulation of polysulfides in the cathode of the PA-LSB system. This is attributed to the selective catalysis of the liquid-solid reaction stage in the lithium-sulfur electrochemical process by photocatalysis. These contribute to the outstanding performance of PA-LSBs, particularly demonstrating a remarkably high reversible capacity of 679 mAh g-1 at 5 C, maintaining stable cycling for 1500 cycles with the capacity decay rate of 0.022% per cycle. Additionally, the photo-charging capability of the PA-LSB holds the potential to compensate for non-electric energy losses during the energy storage process, contributing to the development of lossless energy storage devices.

Asymmetric Sulfur Redox Paths in Sulfide-Based All-Solid-State Lithium–Sulfur Batteries

Asymmetric Sulfur Redox Paths in Sulfide-Based All-Solid-State Lithium–Sulfur Batteries

Mn-Based Mullites for Environmental and Energy Applications.

Mn-based mullite oxides AMn2O5 (A = lanthanide, Y, Bi) is a novel type of ternary catalyst in terms of their electronic and geometric structures. The coexistence of pyramid Mn3+-O and octahedral Mn4+-O makes the d-orbital selectively active toward various catalytic reactions. The alternative edge- and corner-sharing stacking configuration constructs the confined active sites and abundant active oxygen species. As a result, they tend to show superior catalytic behaviors and thus gain great attention in environmental treatment and energy conversion and storage. In environmental applications, Mn-based mullites have been demonstrated to be highly active toward low-temperature oxidization of CO, NO, volatile organic compounds (VOCs), etc. Recent research further shows that mullites decompose O3 and ozonize VOCs from -20°C to room temperature. Moreover, mullites enhance oxygen reduction reactions (ORR) and sulfur reduction reactions (SRR), critical kinetic steps in air-battery and Li-S batteries, respectively. Their distinctive structures also facilitate applications in gas-sensitive sensing, ionic conduction, high mobility dielectrics, oxygen storage, piezoelectricity, dehydration, H2O2 decomposition, and beyond. A comprehensive review from basic physicochemical properties to application certainly not only gains a full picture of mullite oxides but also provides new insights into designing heterogeneous catalysts.

Tailoring Solvation Solvent in Localized High-Concentration Electrolytes for Lithium||Sulfurized Polyacrylonitrile.

Sulfurized polyacrylonitrile (SPAN) is a promising cathode material for lithium-sulfur (Li-S) batteries due to its significantly reduced polysulfide (PS) dissolution compared to that of elemental S cathodes. Although conventional carbonate-based electrolytes are stable with SPAN electrodes, they are unstable with Li metal anodes. Recently, localized high-concentration electrolytes (LHCEs) have been developed to improve the stability of Li anodes. Here, we report a new strategy to further improve the performance of Li||SPAN batteries by replacing the conventional solvating solvent 1,2-dimethoxyethane (DME) in LHCEs with a new solvating solvent, 1,2-diethoxyethane (DEE). The new optimal DEE-LHCE exhibits less reactivity against Li2S2, alleviates PS dissolution, forms a better cathode-electrolyte interphase layer on the SPAN cathode, and enhances SPAN structural reversibility even at elevated temperatures (45 °C). Compared to DME-LHCE, DEE-LHCE with the same salt and diluent leads to better performance in Li||SPAN batteries (with 82.9% capacity retention after 300 cycles at 45 °C), preservation of the SPAN cathode structure, and suppression of volume change of the Li metal anode. A similar strategy on tailoring the solvating solvents in LHCEs can also be used in other rechargeable batteries to improve their electrochemical performances.

Atom-Level Tandem Catalysis in Lithium Metal Batteries.

High-energy-density lithium metal batteries (LMBs) are limited by reaction or diffusion barriers with dissatisfactory electrochemical kinetics. Typical conversion-type lithium sulfur battery systems exemplify the kinetic challenges. Namely, before diffusing or reacting in the electrode surface/interior, the Li(solvent)x + dissociation at the interface to produce isolated Li+, is usually a prerequisite fundamental step either for successive Li+ "reduction" or for Li+ to participate in the sulfur conversions, contributing to the related electrochemical barriers. Thanks to the ideal atomic efficiency (100 at%), single atom catalysts (SACs) have gained attention for use in LMBs toward resolving the issues caused by the five types of barrier-restricted processes, including polysulfide/Li2S conversions, Li(solvent)x + desolvation, and Li0 nucleation/diffusion. In this perspective, the tandem reactions including desolvation and reaction or plating and corresponding catalysis behaviors are introduced and analyzed from interface to electrode interior. Meanwhile, the principal mechanisms of highly efficient SACs in overcoming specific energy barriers to reinforce the catalytic electrochemistry are discussed. Lastly, the future development of high-efficiency atomic-level catalysts in batteries is presented.

Upcycling Spent Cathode Materials to Bifunctional Catalysts for High‐Stability Lithium–Sulfur Batteries

AbstractIn order to enhance the sluggish kinetics and suppress the polysulfide shuttle effect in high‐loading lithium–sulfur (Li–S) batteries, it is crucial to design and synthesize catalysts exhibiting both high conversion rate and strong anchoring effect toward polysulfide species. Herein, based on theoretical predictions, spent cathode materials (LiCoO2 and LiMn2O4) from spent lithium‐ion batteries are converted into a bifunctional catalyst (Co─MnO) for Li–S batteries through the high‐temperature shock method. Owing to the synergistic catalytic and anchoring effect of polysulfide species exhibit by Co─MnO, superior electrochemical performance, including excellent rate performance (707 mAh g−1 at 4C) and high stability (capacity fading of 0.058% per cycle over 400 cycles at 1C) can be delivered under a low areal catalyst loading (<0.5 wt%). This work not only offers a new design strategy for Li–S catalysts, but also proposes a promising approach to transform spent LIBs into highly efficient catalysts.

Decorating highly efficient VN quantum dots onto N-doped hollow carbon nanospheres enables effective inhibition of the shuttle effect and acceleration of LiPSs conversion in lithium–sulfur batteries

Decorating highly efficient VN quantum dots onto N-doped hollow carbon nanospheres enables effective inhibition of the shuttle effect and acceleration of LiPSs conversion in lithium–sulfur batteries

High-Energy SiO-Sulfur Battery with Preloaded Li3N in a Cathode as a Lithiation Reagent.

The practical use of lithium-sulfur batteries faces the "shuttle effect" and lithium dendrite growth. Employing SiO instead of Li metal can fundamentally solve the above problems. Nevertheless, selecting a convenient prelithiation method is essential for normal operation of the battery system. Hence, this work proposed a novel SiO-sulfur battery with preloaded Li3N in a cathode as a prelithiation reagent, which can thoroughly solve the dendrite problem and the side reaction with polysulfides of lithium anode. The S@KB-Li3N vs SiO full cell can obtain a high specific capacity of 790 mAh g-1 after the activation process and be maintained at 478 mAh g-1 after 100 cycles. Our design will provide a new prelithiation strategy for a high-specific-energy SiO-sulfur battery system.

Structural Engineering of Carbon Host Derived from Organic Pigment toward Physicochemically Confinement and Efficient Conversion of Polysulfide for Lithium-Sulfur Batteries.

Lithium-Sulfur Batteries (LSBs) have attracted significant attention as promising next-generation energy storage systems. However, the commercial viability of LSBs have been hindered due to lithium polysulfides (LiPSs) shuttle effect, resulting in poor cycling stability and low sulfur utilization. To address this issue, herein, the study prepares a sulfur host consisting of micro/mesopore-enriched activated carbonaceous materials with ultrahigh surface area using organic pigment via facile one-step activation. By varying the proportion of chemical agent, the pore size and volume of the activated carbonaceous materials are manipulated and their capabilities on the mitigation of LiPSs shuttle effect are investigated. Through the electrochemical measurements and spectroscopic analysis, it is verified that structural engineering of carbon hosts plays a pivotal role in effective physical confinement of LiPSs, leading to the mitigation of LiPSs shuttle effect and sulfur utilization. Additionally, nitrogen and oxygen-containing functional groups originated from PR show electrocatalytic activation sites, facilitating LiPSs conversion kinetics. The approach can reveal that rational design of carbon microstructures can improve trapping and suppression of LiPSs and shuttle effect, enhancing electrochemical performance of LSBs.

Multifunctional Vanadium Nitride-Modified Separator for High-Performance Lithium–Sulfur Batteries

Lithium–sulfur batteries (LSBs) are recognized as among the best potential alternative battery systems to lithium-ion batteries and have been widely investigated. However, the shuttle effect has severely restricted the advancement in their practical applications. Here, we prepare vanadium nitride (VN) nanoparticles grown in situ on a nitrogen-doped carbon skeleton (denoted as VN@NC) derived from the MAX phase and use it as separator modification materials for LSBs to suppress the shuttle effect and optimize electrochemical performance. Thanks to the outstanding catalytic performance of VN and the superior electrical conductivity of carbon skeleton derived from MAX, the synergistic effect between the two accelerates the kinetics of both lithium polysulfides (LiPSs) to Li2S and the reverse reaction, effectively suppresses the shuttle effect, and increases cathode sulfur availability, significantly enhancing the electrochemical performance of LSBs. LSBs constructed with VN@NC-modified separators achieve outstanding rate performance and cycle stability. With a capacity of 560 mAh g−1 at 4 C, it exhibits enhanced structural and chemical stability. At 1 C, the device has an incipient capacity of 1052.4 mAh g−1, and the degradation rate averaged only 0.085% over 400cycles. Meanwhile, the LSBs also show larger capacities and good cycling stability at a low electrolyte/sulfur ratio and high surface-loaded sulfur conditions. Thus, a facile and efficient way of preparing modified materials for separators is provided to realize high-performance LSBs.

Illuminating Polysulfide Distribution in Lithium Sulfur Batteries; Tracking Polysulfide Shuttle Using Operando Optical Fluorescence Microscopy.

High-energy-density lithium sulfur (Li-S) batteries suffer heavily from the polysulfide shuttle effect, a result of the dissolution and transport of intermediate polysulfides from the cathode, into the electrolyte, and onto the anode, leading to rapid cell degradation. If this primary mechanism of cell failure is to be overcome, the distribution, dynamics, and degree of polysulfide transport must first be understood in depth. In this work, operando optical fluorescence microscope imaging of optically accessible Li-S cells is shown to enable real-time qualitative visualization of the spatial distribution of lithium polysulfides, both within the electrolyte and porous cathode. Quantitative determinations of spatial concentration are also possible at a low enough concentration. The distribution throughout cycling is monitored, including direct observation of polysulfide shuttling to the anode and consequent dendrite formation. This was enabled through the optimization of a selective fluorescent dye, verified to fluoresce proportionally with concentration of polysulfides within Li-S cells. This ability to directly and conveniently track the spatial distribution of soluble polysulfide intermediates in Li-S battery electrolytes, while the cell operates, has the potential to have a widespread impact across the field, for example, by enabling the influence of a variety of polysulfide mitigation strategies to be assessed and optimized, including in this work the LiNO3 additive.

Theoretical Investigation of Nonmetallic Single-Atom Catalysts for Polysulfide Immobilization and Kinetic Enhancement in Lithium–Sulfur Batteries

Theoretical Investigation of Nonmetallic Single-Atom Catalysts for Polysulfide Immobilization and Kinetic Enhancement in Lithium–Sulfur Batteries

MXene-Bimetallic Hybrids via Mixed Molten Salts Etching for Kinetics-Enhanced and Dendrite-Free Lithium-Sulfur Batteries.

Lithium-sulfur (Li-S) batteries with high theoretical energy density (2600Whkg-1) are considered to be one of the most promising secondary batteries. However, the practical application of Li-S batteries is limited by the polysulfides shuttling and unstable lithium metal anodes. Herein, an asymmetric separator (CACNM@PP), composed of Co-Ni/MXene (CNM) on the cathode and Cu-Ag/MXene (CAM) on the anode for high-performance Li-S batteries is reported. For the cathode, CNM provides a synergistic effect by integrating Co, Ni, and MXene, resulting in strong chemical interactions and fast conversion kinetics for polysulfides. For the anode, CAM with abundant lithiophilicity active sites can lower the nucleation barrier of Li. Moreover, LiCl/LiF layers are generated in situ as an ion conductor layer during charging and discharging, inducing a uniform deposition of Li. Therefore, the assembled cells with the CACNM@PP separators harvest excellent electrochemical performance. This work provides novel insights into the development of commercially available high-energy density Li-S batteries with asymmetric separators.

Ultrafine Iron Boride as a Highly Efficient Nanocatalyst Expedites Sulfur Redox Electrochemistry for High‐Performance Lithium‐Sulfur Batteries

Lithium‐sulfur (Li‐S) batteries have garnered significant interest as a strong contender for future energy storage, characterized by their remarkable energy density and cost‐effectiveness. However, the sluggish conversion kinetics of the polysulfide intermediates, compounded with their shuttling behaviors, pose considerable challenges in sulfur electrochemistry. Herein, we develop a novel iron monoboride (FeB) electrocatalyst for boosting sulfur reactions and enhancing Li‐S battery performance. The ultrafine powdery FeB affords abundant and fully exposed active interfaces for host‐guest interactions. Meanwhile, the intrinsic high conductivity of FeB, combined with its strong adsorption and catalytic activity to polysulfides, enables substantial inhibition of the shuttle effect and enhancement of conversion kinetics. As a result, sulfur electrodes equipped with the FeB nanocatalyst realize excellent cyclability with a minimal capacity fading of 0.04 % per cycle over 500 cycles, as well as favorable rate capability up to 7 C. Moreover, decent areal capacity and cycling stability can be also achieved under high‐loading (5.1 mg cm‐2) and limited‐electrolyte (7.0 mL g‐1) configurations. This study presents a facile approach and insightful perspective on nanostructured metal boride for highly efficient sulfur electrocatalysis, holding good promise for the advancement of high‐performance Li‐S batteries.