Multifunctional Host Research Articles

FeF3·0.33H2O nanoparticles decorated Ti3C2 MXene as high-performance bifunctional sulfur host for lithium‑sulfur batteries

Lithium‑sulfur batteries are deemed as a potential next-generation energy storage system, but their development is hindered by the shuttle effect of lithium polysulfides. Design and synthesis of multifunctional sulfur host materials are expected to adsorb lithium polysulfides and catalyze their conversion during the lithiation process, thereby suppressing the shuttle effect. In this work, FeF3·0.33H2O nanoparticles is in situ grown on the surface of Ti3C2 nanosheets (FeF3@Ti3C2) and used as the bifunctional sulfur host for lithium‑sulfur batteries. Ti3C2 nanosheets not only provide two-dimensional (2D) conductive substrate for sulfur, but also strongly adsorb lithium polysulfides and suppress the shuttle effect. Meanwhile, FeF3 nanoparticles can accelerate the conversion reaction of lithium polysulfides, which also contributes to inhibiting the shuttle of lithium polysulfides. In addition, decorating Ti3C2 nanosheets with FeF3 nanoparticles can prevent the stacking of Ti3C2 nanosheets and enhance the interaction between Ti3C2 and lithium polysulfides. Therefore, sulfur-loaded FeF3@Ti3C2 (FeF3@Ti3C2@S) displays excellent electrochemical performance, such as a high reversible capacity of 687 mAh g−1 at 2C after 1000 cycles, and the capacity decay rate is only 0.023 %. This work paves a simple way for improving the performance of Ti3C2 as the sulfur host and expanding its application in lithium‑sulfur batteries.

3D lithiophilic collector coated by amorphous g-C3N4 enabling Ultra-Stable cycling Li metal batteries

Lithium metal batteries (LMB) are thought of the most promising candidates for the next generation of high energy density batteries, but the problems of interface instability and uncontrollable dendrite growth are key constraints to the commercial application. Herein, we constructed an amorphous graphitic carbon nitride (g-C3N4) “outerwear” modified lithiophilic 3D Au/CoO nanoarray matrix (CACM) as a multifunctional dual-layer host, achieving dendrite-free and cycling stabilized Li metal anode. The density functional theory (DFT) calculations show that the reaction between CACM and Li atoms has a strong binding energy and a large amount of charge transfer. The lithiophilic 3D host induces Li metal uniform deposition with a low nucleation barrier within the 3D skeleton. The amorphous g-C3N4 “outerwear” can effectively avoid direct contact between the electrolyte and Li and reduce the irreversible side reaction. Meanwhile, the g-C3N4 layer has abundant Li ion transport channels, which facilitated fast Li+ transfer and modulate the ion concentration over the anode surface. Thus, the half-cell equipped with the CACM electrode has ultra-high cyclic stability, maintaining a CE value of 99.6 % over 230 cycles at 1 mA cm−2 with 1 mAh cm−2. The symmetric-cell can maintain a low overpotential stable run 1300 cycles at 10 mA cm−2. Similarly, the full cell also showed outstanding long-term cycle stability (capacity maintained at 96.3 % after 400 cycles at 1C) and superior rate capability. The in-situ visualization cell test and ex-situ SEM also demonstrated that the multifunctional host inhibits volume expansion and the dendritic growth of Li.

Tailoring Versatile Cathodes and Induced Anodes for Zn-Se Batteries: Anisotropic Orientation of Tin-Based Materials within Bowl-In-Ball Carbon.

The advancement of Zn-Se batteries has been hindered by significant challenges, such as the sluggish kinetics of Se cathodes, limited Se loading, and uncontrollable formation of Zn dendrites. In this study, a bidirectional optimization strategy is devised for both cathode and anode to bolster the performance of Zn-Se batteries. A novel bowl-in-ball structured carbon (BIBCs) material is synthesized to serve as a nanoreactor, in which tin-based materials are grown and derived in situ to construct cathodes and anodes. Within the cathode, the multifunctional host material (SnSe@BIBCs) exhibits large adsorption capacity for selenium, and demonstrates supreme catalytic properties and spatially confined characteristics toward the selenium reduction reaction (SeRR). On the anode, Sn@BIBCs displays triple-induced properties, including the zincophilic of the internal metallic Sn, the homogenized spatial electric field from the 3D spatial structure, and the curvature effect of the bowl-shaped carbon. Collectively, these factors induce preferential nucleation of Zn, ensuring its uniform deposition. As a result, the integrated Zn-Se battery system achieves a remarkable specific capacity of up to 603 mAh g-1 and an impressive energy density of 581W kg-1, highlighting its tremendous potential for practical applications.

Recent advances in carbon-based sulfur host materials for lithium-sulfur batteries

Lithium-sulfur batteries (LSBs) have been brought into focus as the development direction of the next-generation power battery system due to their high energy density, eco-friendliness, and low cost, which has a broad application prospect in the field of energy storage. However, some problems are still unresolved in the sulfur cathode, e.g., poor electric conductivity, serious volume expansion of sulfur, shuttle effect caused by easy dissolution of lithium polysulfides in the electrolyte, and slow redox reaction kinetics of sulfur species. These issues lead to poor cycle stability and rate performance, making it hard to meet the requirement for LSBs in practical applications. Since the inherent nature of sulfur is the root cause of the above problems, reasonable design of functional sulfur hosts will be an effective way to break through the current bottlenecks of LSBs. The review covers the latest research progress on carbon-based sulfur host materials of LSBs, including structural design and functional optimization strategies, aiming to prepare multifunctional sulfur host materials by integrating physical confinement, chemical adsorption, and catalytic effect towards lithium polysulfides. The obstacles and future prospects of carbon-based sulfur hosts have also been brought forward, which provides in-depth guidance for practical application of LSBs.

Iodine-doped carbon nanotubes boosting the adsorption effect and conversion kinetics of lithium-sulfur batteries

Compared with lithium-ion batteries (LIBs), lithium-sulfur batteries (LSBs), based on electrochemical reactions involving multi-step 16-electron transformations provide higher specific capacity (1672 mAh g−1) and specific energy (2600 Wh kg−1), exhibiting great potential in the field of energy storage. However, the inherent insulation of sulfur, slow electrochemical reaction kinetics and detrimental shuttle-effect of lithium polysulfides (LiPSs) restrict the development of LSBs in practical applications. Herein, the iodine-doped carbon nanotubes (I-CNTs) is firstly reported as sulfur host material to the enhance the adsorption-conversion kinetics of LSBs. Iodine doping can significantly improve the polarity of I-CNTs. Iodine atoms with lone pair electrons (Lewis base) in iodine-doped CNTs can interact with lithium cations (Lewis acidic) in LiPSs, thereby anchoring polysulfides and suppressing subsequent shuttling behavior. Moreover, the charge transfer between iodine species (electron acceptor) and CNTs (electron donor) decreases the gap band and subsequently improves the conductivity of I-CNTs. The enhanced adsorption effect and conductivity are beneficial for accelerating reaction kinetics and enhancing electrocatalytic activity. The in-situ Raman spectroscopy, quasi in-situ electrochemical impedance spectroscopy (EIS) and Li2S potentiostatic deposition current–time (i-t) curves were conducted to verify mechanism of complex sulfur reduction reaction (SRR). Owing to above advantages, the I-CNTs@S composite cathode exhibits an ultrahigh initial capacity of 1326 mAh g−1 as well as outstanding cyclicability and rate performance. Our research results provide inspirations for the design of multifunctional host material for sulfur/carbon composite cathodes in LSBs.

Monolayer SrB8 as potential highly efficient electrocatalysts for lithium-sulfur batteries: First principle study

Lithium-sulfur batteries have extremely high theoretical specific capacity and energy density, but their commercial application has been hindered by the shuttle effect, poor cathode conductivity and sluggish reaction kinetics during charging and discharging. The proposed two-dimensional (2D) multifunctional sulfur host material is an effective strategy to solve the above problems. In this work, the anchoring and catalytic properties of SrB8 monolayer for S8 and Li2Sn (n = 1, 2, 4, 6, 8) were studied by means of density functional theory. The results show that SrB8 has moderate adsorption energy for lithium polysulfides (LiPSs), and can effectively prevent the dissolution of long-chain LiPSs into the electrolyte without destroying the integrity of the clusters. The metallic feature of the SrB8 monolayer is well preserved during the adsorption process, thus ensuring a high electric conductivity at the cathode. At the same time, the SrB8 monolayer has a lower decomposition barrier and diffusion barrier for Li2S molecules, which significantly improves the charge and discharge rate of lithium-sulfur batteries. The results show that SrB8 monolayer is a promising multifunctional host material for lithium-sulfur batteries.

Relay-Type Catalysis by a Dual-Metal Single-Atom System in a Waste Biomass Derivative Host for High-Rate and Durable Li-S Batteries.

An environmental-friendly and sustainable carbon-based host is one of the most competitive strategies for achieving high loading and practicality of Li-S batteries. However, the polysulfide conversion reaction kinetics is still limited by the nonuniform or monofunctional catalyst configuration in the carbon host. In this work, we propose a catalysis mode based on "relay-type" co-operation by adjacent dual-metal single atoms for high-rate and durable Li-S batteries. A discarded sericin fabric-derived porous N-doped carbon with a stacked schistose structure is prepared as the high-loading sulfur (84 wt %) host by a facile ionothermal method, which further enables the uniform anchoring of Fe/Co dual-metal single atoms. This multifunctional host enables superior lithiophilic-sulfiphilic and electrocatalytic capabilities contributed by the "relay-type" single-atom modulation effects on different conversion stages of liquid polysulfides and solid Li2S2/Li2S, leading to the suppression of the "shuttle effect", alleviation of nucleation and decomposition barriers of Li2Sx, and acceleration of polysulfide conversion kinetics. The corresponding Li-S batteries exhibit a high specific capacity of 1399.0 mA h g-1, high-rate performance up to 10 C, and excellent cycling stability over 1000 cycles. They can also endure the high sulfur loading of 8.5 mg cm-2 and the lean electrolyte condition and yield an areal capacity as high as 8.6 mA h cm-2. This work evidentially demonstrates the potential of waste biomass reutilization coupled with the design of a single-atom system for practical Li-S batteries with high energy density.

Highly dispersed cobalt clusters/nanoparticles embedded in cellulose nanocrystal derived carbon aerogel as efficient sulfur host for high performance lithium sulfur batteries

Exploring multifunctional sulfur host materials with high immobilization ability and catalytic activity is of great significance for realizing high-performance Lithium-sulfur (Li–S) batteries. Recently, cellulose nanocrystals (CNCs) receive extensive attention for advanced energy storage applications owing to their intrinsically exceptional physical/chemical properties and natural abundance. Herein, a highly dispersed cobalt clusters/nanoparticles embedded into CNC derived carbon aerogel composite (CA/Co-2) is for the first time synthesized. Benefiting from the interconnected hierarchical porous structure, homogeneously anchored Co clusters/nanoparticles and N-doped species, the designed CA/Co-2 could enable rapid electron/ion transport, efficient sulfur utilization, effective suppression of the shuttle effect and fast catalytic conversion of polysulfides, thereby contributing to outstanding electrochemical performance. Consequently, CA/Co-2@S cathode delivers high initial discharge capacity (1553.1 mAh g−1 at 0.1C) and superior cycle stability. Moreover, a remarkable rate performance of 681.4 mAh g−1 at 5.0C and exceptional long-term cycling stability with an ultralow capacity decay of 0.028 % per cycle at 5.0C over 1000 cycles could be achieved when coupled with carbon paper interlayer. This work develops a workable strategy for fabricating multifunctional sulfur host derived from the fascinating bio-nanomaterial of CNC, which provides valuable guidance for the future design of high-performance Li–S batteries.

Vacancy and Growth Modulation of Cobalt Hexacyanoferrate by Porous MXene for Zinc Ion Batteries

AbstractPrussian blue analogs (PBAs) featuring with 3D open framework are recognized as promising cathode candidates for Zinc‐ion batteries (ZIBs). However, challenges such as unsatisfactory active site utilization, low conductivity, and abundant structural vacancies have impeded fulfillment of their potential. In this work, a conductive in‐plane porous MXene is for the first time adopted as a multifunctional host material to enhance cobalt hexacyanoferrate (CoHCF) growth and crystallinity. Particularly, the uniform surface charges on MXene are identified to induce anisotropic and highly crystalline CoHCF, which are critical to alleviating the practical drawbacks associated with the PBAs family. Empowered by the targeted modification, the CoHCF nanotube/MXene composite realizes high surface area and low defectiveness, resulting in an impressive capacity of 197 mAh g−1 at 0.1 A g−1 and capacity retention of 95.3% over 3000 cycles at 2.0 A g−1. X‐ray spectroscopy and density functional theory (DFT) reveal that Co─C bonds in the heterostructure facilitate rapid electron/Zn‐ion transfer, enhancing Zn storage kinetics. To validate practical applicability, pouch cells incorporating Zn|CoHCF/MXene are further examined. This composition strategy, utilizing MXene as a multifunctional template, enhances the surface area, conductivity, and crystallinity of PBAs as cathodes for ZIBs, showcasing the significant potential for large‐scale energy storage applications.

BAG6 inhibits influenza A virus replication by inducing viral polymerase subunit PB2 degradation and perturbing RdRp complex assembly.

The interaction between influenza A virus (IAV) and host proteins is an important process that greatly influences viral replication and pathogenicity. PB2 protein is a subunit of viral ribonucleoprotein (vRNP) complex playing distinct roles in viral transcription and replication. BAG6 (BCL2-associated athanogene 6) as a multifunctional host protein participates in physiological and pathological processes. Here, we identify BAG6 as a new restriction factor for IAV replication through targeting PB2. For both avian and human influenza viruses, overexpression of BAG6 reduced viral protein expression and virus titers, whereas deletion of BAG6 significantly enhanced virus replication. Moreover, BAG6-knockdown mice developed more severe clinical symptoms and higher viral loads upon IAV infection. Mechanistically, BAG6 restricted IAV transcription and replication by inhibiting the activity of viral RNA-dependent RNA polymerase (RdRp). The co-immunoprecipitation assays showed BAG6 specifically interacted with the N-terminus of PB2 and competed with PB1 for RdRp complex assembly. The ubiquitination assay indicated that BAG6 promoted PB2 ubiquitination at K189 residue and targeted PB2 for K48-linked ubiquitination degradation. The antiviral effect of BAG6 necessitated its N-terminal region containing a ubiquitin-like (UBL) domain (17-92aa) and a PB2-binding domain (124-186aa), which are synergistically responsible for viral polymerase subunit PB2 degradation and perturbing RdRp complex assembly. These findings unravel a novel antiviral mechanism via the interaction of viral PB2 and host protein BAG6 during avian or human influenza virus infection and highlight a potential application of BAG6 for antiviral drug development.

Surface-coated AlF3 nanolayers enable polysulfide confinement within biomass-derived nitrogen-doped hierarchical porous carbon microspheres for improved lithium-sulfur batteries

The electrically insulating and volumetric deformation of sulfur and the shuttle effect of the intermediate lithium polysulfide (LiPSs) have severely hindered the development of lithium-sulfur batteries (LSBs). Herein, a synergistic strategy of hierarchical porous nitrogen-doped carbon microspheres (PNCM) derived from low-cost biomass with surface-coated AlF3 nanolayer as a multifunctional sulfur host (denoted as PNCM@S@AlF3) was developed. The PNCM not only possesses an abundant pore structure, large surface area, and high electrical conductivity but also features an intrinsic N-doped and fluorinated framework, which effectively enhances the physical adsorption and chemical anchoring to LiPSs. In addition, the AlF3 nanolayer protects the open surface of the porous carbon to isolate sulfur species from the electrolyte to reduce irreversible losses while accelerating the redox kinetics of LiPSs through strong polar adsorption and bonding. Hence, the PNCM@S@AlF3 cathode exhibits an initial capacity as high as 1176.2 mAh/g at 0.2C, and the cycling stability and rate capability are superior to that of PNCM@S without AlF3 coating. Impressively, the PNCM@S@AlF3 cathode delivers stable long-term cycling performance at a high rate of 2C, with 95.6% capacity retention after 500 cycles. This work presents a facile, sustainable, and efficient synergistic strategy for developing advanced LSBs.

Building composite of layered yttrium hydroxide and carbon nanotube as the sulfur host for high-performance lithium‑sulfur batteries

The commercialization of lithium‑sulfur batteries is still confronting with great challenges due to the sluggish redox kinetics of sulfur and the shuttle effect of lithium polysulfides (LiPS). Herein, two-dimensional (2D) layered yttrium hydroxide (LYH) nanosheets are in-situ grown on multiwalled carbon nanotubes (CNTs) and used as a multifunctional host material (LYH@CNT) for sulfur loading. The crosslinked CNTs provide a robust and conductive network for quick charge transfer and sufficient active site exposure, while LYH nanosheets demonstrate strong ability for anchor and catalytic conversion of lithium polysulfides. The theoretical calculation and adsorption experiment also confirm the strong adsorption of LYH for lithium polysulfides. Therefore, sulfur loaded on LYH@CNT exhibits excellent electrochemical performance, such as a good cycling stability with a capacity of 484 mAh g−1 after 800 cycles at 2C. This study opens a new avenue in the development of advanced sulfur hosts for lithium‑sulfur batteries.

A multifunctional layered Ti3C2Tx/VS2 composite sulfur host for promoting the conversion of lithium polysulfides in lithium–sulfur batteries

A multifunctional sulfur host, Ti3C2Tx/VS2, is developed by incorporating VS2 onto the surface of few-layer Ti3C2Tx using a self-assembly method. A 3D-printed Ti3C2Tx/VS2/S cathode with high sulfur loading achieves high areal capacity.

Hollow and Silver-Cored Carbon Nanospheres as Effective Sulfur Hosts for Lithium-Sulfur Batteries

Lithium sulfur (Li–S) batteries are considered to be one of the most promising “beyond lithium-ion” energy storage technologies and the development of alternative battery chemistries is required to alleviate our reliance on the burning of fossil fuels 1. The high theoretical specific capacity of sulfur (1672mAh g-1) leads to a theoretical specific energy of ~2510 Wh kg-1, which is significantly greater than the state-of-the-art lithium-ion batteries 2. Further to this, sulfur is environmentally benign, low cost, and Li–S batteries do not rely on cobalt, or manganese 3, which are expensive, toxic, and have known ethical implications associated with their extraction and refining 4.While Li–S batteries boast many theoretical advantages, their practical application has been plagued with an array of limitations, mainly attributed to the poor electrical conductivity of sulfur, the significant volumetric expansions (80%) that can occur during cycling, and the soluble polysulfide intermediates 5. To tackle this, current research efforts have focused on using porous carbon materials (PCMs) to prepare sulfur/carbon composite cathodes 6,7. PCMs offer improved electrical conductivity, a large specific surface area, and pore diameters that are less than 1nm—which may confine the soluble polysulfides within the cathode matrix 8.In this study, the synthesis of hollow and silver-cored carbon nanospheres (HCNS, Ag-CNS) is detailed and their use as a multifunctional sulfur host for Li–S batteries is assessed. Ag-CNS are synthesised via a hydrothermal procedure from a simple saccharide solution coupled with a silver precursor. These Ag-CNS are further processed to prepare HCNS by etching the internal silver nanoparticle with an acid solution. The hydrothermal procedure described in this study offers a simplification to traditional HCNS synthesis methods which typically require the removal of templates, such as silica nanospheres, through etching with hazardous chemicals such as hydrofluoric acid.In this work, the structural and physical properties of HCNS and Ag-CNS are characterised using transmission electron microscopy, scanning electron microscopy, nitrogen gas adsorption, X-ray diffraction, Raman spectroscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The electrochemical performance of these materials, when used as a sulfur host, is investigated through the preparation, and testing of half cells with lithium metal anodes. Electrochemical testes include cyclic voltammetry and galvanostatic cycling data at different C-rates.

Sandwich-type CoSe2-CNWs@NG as host for lithium-sulfur batteries with high sulfur loading, ultrahigh rate, and long lifespan

While lithium-sulfur batteries (LSBs) have tremendous potential in capacity and energy, their application in practice is limited by short cycle life, slow reaction kinetics, and underutilization of sulfur. To tackle these challenges, we have developed a multifunctional host consisting of sandwich-type CoSe2-CNWs@NG that were hydrothermally synthesized through self-assembly of CoSe2-embedded carbon nanowires (CoSe2-CNWs) with N-doped graphene (NG). Through the implementation of CoSe2-CNWs@NG as a host material, active sulfur can be effectively intercalated within the interlayer spaces of neighboring NG layers. The extensive contact area between sulfur and NG sheets facilitates rapid electron transfer, thereby maximizing sulfur utilization. N-doped graphene and polar CoSe2 provide sufficient chemisorption sites for polysulfides, while the catalytic activity of CoSe2 promotes polysulfide conversion. In addition to building a good conductivity structure for fast carrier transport and electrolyte diffusion, the sandwich structure of CoSe2-CNWs@NG physically restricts polysulfides and buffers substantial sulfur volume changes during cycling. As a result, the CoSe2-CNWs@NG/S cathode possessing high-load sulfur capacity (4.06 mg cm−2) exhibits superior cell performance at an ultrahigh rate as well as low E/S ratio. After 1000 cycles at 10 C, it achieves a remarkable reversible capacity of 314.4 mAh g−1 with an impressively low average fading rate of 0.023 % per cycle. Even at a low E/S ratio of 5 μL mg−1, the cathode exhibits remarkable performance, retaining a reversible capacity of 628.2 mAh g−1 after 150 cycles at the rate of 1 C.

DYRK1A is a multifunctional host factor that regulates coronavirus replication in a kinase-independent manner.

Coronaviruses (CoVs) pose a major threat to human and animal health worldwide, which complete viral replication by hijacking host factors. Identifying host factors essential for the viral life cycle can deepen our understanding of the mechanisms of virus-host interactions. Based on our previous genome-wide CRISPR screen of α-CoV transmissible gastroenteritis virus (TGEV), we identified the host factor dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A), but not DYRK1B, as a critical factor in TGEV replication. Rescue assays and kinase inhibitor experiments revealed that the effect of DYRK1A on viral replication is independent of its kinase activity. Nuclear localization signal modification experiments showed that nuclear DYRK1A facilitated virus replication. Furthermore, DYRK1A knockout significantly downregulated the expression of the TGEV receptor aminopeptidase N (ANPEP) and inhibited viral entry. Notably, we also demonstrated that DYRK1A is essential for the early stage of TGEV replication. Transmission electron microscopy results indicated that DYRK1A contributes to the formation of double-membrane vesicles in a kinase-independent manner. Finally, we validated that DYRK1A is also a proviral factor for mouse hepatitis virus, porcine deltacoronavirus, and porcine sapelovirus. In conclusion, our work demonstrated that DYRK1A is an essential host factor for the replication of multiple viruses, providing new insights into the mechanism of virus-host interactions and facilitating the development of new broad-spectrum antiviral drugs.IMPORTANCECoronaviruses, like other positive-sense RNA viruses, can remodel the host membrane to form double-membrane vesicles (DMVs) as their replication organelles. Currently, host factors involved in DMV formation are not well defined. In this study, we used transmissible gastroenteritis virus (TGEV) as a virus model to investigate the regulatory mechanism of dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) on coronavirus. Results showed that DYRK1A significantly inhibited TGEV replication in a kinase-independent manner. DYRK1A knockout (KO) can regulate the expression of receptor aminopeptidase N (ANPEP) and endocytic-related genes to inhibit virus entry. More importantly, our results revealed that DYRK1A KO notably inhibited the formation of DMV to regulate the virus replication. Further data proved that DYRK1A is also essential in the replication of mouse hepatitis virus, porcine deltacoronavirus, and porcine sapelovirus. Taken together, our findings demonstrated that DYRK1A is a conserved factor for positive-sense RNA viruses and provided new insights into its transcriptional regulation activity, revealing its potential as a candidate target for therapeutic design.

Graphene supported In2S3 nanostructure as electrode material for lithium sulfur batteries and supercapacitors

A facile one-pot fabrication of reduced graphene oxide (rGO) supported In2S3-rGO is presented here with improved electrochemical performance in lithium-sulfur (Li–S) batteries and supercapacitors (SCs). Increasing the concentration of rGO in the nanostructures successfully mitigated the conversation kinetics, polysulfide shuttle effect and improved the overall cyclability in Li–S batteries. A battery made from In2S3-rGO30 electrode loses only 8 % of its discharge capacity after 250 continuous charge-discharge cycles, compared to a 36 % loss from a bare In2S3 electrode. It presented a high discharge capacity of 947.3 mA h g−1 at 1C, superb rate performance of 821.65 mA h g−1 at 5C, excellent capacity retention and Columbic efficiency of ⁓100 % over 250 cycles are achieved. The In2S3-rGO30 electrode provides a specific capacitance of 645.2 F g−1 at a current density of 2 A g−1 for SC application. The electrode retains 96 % of its capacity after 1000 continuous discharge cycles at a higher current density of 5 A g−1, performing well and staying ahead of other nanocomposites. This study successfully demonstrates the integration of In2S3 with a two-dimensional conductive substrate as a multifunctional and cost-effective host for designing high-performance cathode for Li–S batteries and battery-type electrode material for SC application.

Platinum Electrocatalyst Promoting Redox Kinetics of Li2S and Regulating Li2S Nucleation for Lithium-Sulfur Batteries.

The development of lithium-sulfur batteries (LSBs) is impeded by the shuttle effect of polysulfides (LiPSs) and the sluggish nucleation of Li2S. To address these challenges, incorporating electrocatalysts into sulfur host materials represents an effective strategy for promoting polysulfide conversion, in tandem with the rational design of multifunctional sulfur host materials. In this study, Pt nanoparticles are integrated into biomass-derived carbon materials by solution deposition method. Pt, as an electrocatalyst, not only enhances the electrical conductivity of sulfur cathodes and effectively immobilizes LiPSs but also catalyzes the redox reactions of sulfur species bidirectionally. Additionally, Pt helps regulate the 3D deposition and growth of Li2S while reducing the reaction energy barrier. Consequently, this accelerates the conversion of LiPSs in LSBs. Furthermore, the catalytic ability of Pt for the redox reactions of sulfur species, along with its influence on the 3D deposition and growth of Li2S, is elucidated using electrochemical kinetic analyses and classical models of electrochemical deposition. The cathodes exhibit a high initial specific capacity of 1019.1mAhg-1 at 1C and a low decay rate of 0.045% over 1500 cycles. This study presents an effective strategy to regulate Li2S nucleation and enhance the kinetics of polysulfide conversion in LSBs.

In-situ construction of MoC quantum dots embedded in n-doped 2D nanocarbon as a multifunctional host for high-performance lithium sulfide cathode

Lithium–ion batteries using Li2S cathode are considered as an optimal alternative for current lithium–ion batteries since their high theoretical capacity (1166 mAh/g) and high energy density (2600 W h kg−1). However, low electronic/ionic conductivity, severe lithium polysulfides (LiPSs) shuttle, and sluggish electrochemical reaction kinetics are the three major challenges for the practical application of Li2S. Herein, we report a multifunctional host of MoC quantum dots embedded in N–doped 2D nanocarbon (MoC@2D–NNC) with high electronic/ionic conductivity, strong LiPSs capture ability and superior electrochemistry catalytic activation for Li2S electrode. Nano Li2S is successfully entered into the MoC@2D–NNC to form MoC@2D–NNC/Li2S composite via facile liquid–phase dissolution precipitation. The obtained MoC@2D–NNC/Li2S composite displays a high electronic conductivity of 0.1624 S cm−1, high initial discharge capacity of 1059 mAh/g, and long–term cycling performance over 1000 cycles. This reported MoC@2D–NNC/Li2S composite exhibits promising applications in advanced Li–S batteries.

Interfacial Engineering of Ru Nanocluster-Modified TiO2 Nanotube-Assisted Regulation of Lithium Polysulfide Reactions.

The inhibition of lithium polysulfide (LiPS) diffusion and the acceleration of reaction kinetics are two major challenges for the practical application of lithium-sulfur (Li-S) batteries. Herein, through an interface engineering strategy, a multifunctional sulfur host based on Ru nanocluster-modified TiO2 nanotubes (TiO2-Ru) was designed. The TiO2-Ru interface field effect, combined with the hollow nanotube structure and the strong chemical action of TiO2, enhanced the LiPS trapping ability and inhibited the "shuttle effect". Furthermore, the high catalytic activity of Ru nanoclusters reduced the energy barrier of multistep LiPS reactions, thus speeding up the electrode kinetics. As a result, the TiO2-Ru-based composite sulfur cathode delivered excellent electrochemical performance, including an extremely low capacity loss of ∼0.015% per cycle and an increased areal capacity of ∼6.1 mAh cm-2 at 4.8 mg cm-2. This work contributes to a better sulfur cathode design from insights into morphology and phase interface engineering.