In lithium-sulfur batteries(LSBs),the limited utilization of sulfur and the sluggish kinetics of redox reaction significantly hinder their electrochemical performance,especially under high rates and high sulfur loadin...In lithium-sulfur batteries(LSBs),the limited utilization of sulfur and the sluggish kinetics of redox reaction significantly hinder their electrochemical performance,especially under high rates and high sulfur loadings.Here,we propose a novel separator structure with an interlayer composed of a vermiculite nanosheet combined with Ketjen Black(VMT@KB)for LSBs,facilitating efficient adsorption and rapid catalytic conversion toward lithium polysulfides(LiPSs).The VMT@KB nanosheets with an electrical double-layer structure and electronic conductivity are obtained through a high-temperature peeling process and Li^(+)exchange treatment in LiCl solution,followed by a mechanical combination process with KB.The results demonstrate that incorporating VMT@KB as an interlayer on a conventional separator enhances the conductivity and limits the LiPSs in the cathode region.The Li-S cell with VMT@KB interlayer shows satisfactory cycle and rate performance,especially in high sulfur loading.It exhibits a remarkable initial discharge capacity of 1225 mAh g^(-1)at 0.5 C and maintains a capacity of 816 mAh g^(-1)after 500 cycles.Besides,the discharge capacity remains 462 mAh g^(-1)even at 6 C.Moreover,the cell with high sulfur loading(8.2 mg cm^(-2))enables stable cycling for 100 cycles at 0.1 C with a discharge capacity of over1000 mAh g^(-1).展开更多
Developing electrocatalysts to inhibit polysulfide shuttling and expedite sulfur species conversion is vital for the evolution of Lithium-sulfur(Li-S)batteries.This work provides a facile strategy to design an intimat...Developing electrocatalysts to inhibit polysulfide shuttling and expedite sulfur species conversion is vital for the evolution of Lithium-sulfur(Li-S)batteries.This work provides a facile strategy to design an intimate heterostructure of MIL-88A@CdS as a sulfur electrocatalyst combining high sulfur adsorption and accelerated polysulfide conversion.The MIL-88A can give a region of high-ordered polysulfide adsorption,whereas the CdS is an effective nanoreactor for the sulfur reduction reaction(SRR).Notedly,the significant size difference between MIL-88A and CdS enables the unique heterostructure interactions.The largesize MIL-88A ensures a uniform distribution of CdS nanoparticles as a substrate.This configuration facilitates control of the initial polysulfide adsorption position relative to its final deposition site as lithium sulfide.The heterostructure also demonstrates rapid transport and efficient conversion of lithium polysulfides.Consequently,the Li-S battery with MIL-88A@CdS heterostructure modified separator delivers exceptional performance,achieving an areal capacity exceeding 6 mAh cm^(−2),an excellent rate capability of 980 mAh g^(−1) at 5 C,and notable cycling stability in a 2 Ah pouch cell over 100 cycles.This work is significant for elucidating the relationship between heterostructure and electrocatalytic performance,providing great insights for material design aimed at highly efficient future electrocatalysts in practical applications.展开更多
Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-su...Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.展开更多
Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commo...Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commonly have limited catalytic abilities to improve battery performance.Herein,based on the Hume-Rothery rule and solvothermal method,the high-entropy sulfide NiCoCuTiVS_(x)derived from Co_(9)S_(8)was designed and synthesized,to realize the combination of small local strain and excellent catalytic performance.With all five metal elements(Ni,Co,Cu,Ti,and V)capable of chemical interactions with soluble polysulfides,NiCoCuTiVS_(x)exhibited strong chemical confinement of polysulfides and promoted fast kinetics for polysulfides conversion.Consequently,the S/NiCoCuTiVS_(x)cathode can maintain a high discharge capacity of 968.9 mA h g^(-1)after 200 cycles at 0.5 C and its capacity retention is 1.3 times higher than that of S/Co_(9)S_(8).The improved cycle stability can be attributed to the synergistic effect originating from the multiple metal elements,coupled with the reduced nucleation and activation barriers of Li_(2)S.The present work opens a path to explore novel electrocatalyst materials based on high entropy materials for the achievement of advanced Li-S batteries.展开更多
Developing effective heterostructure strategies to mitigate the shuttling effect and accelerate lithium polysulfide(Li PS)conversion remains a critical challenge in lithium–sulfur(Li–S)batteries.Here,we report the f...Developing effective heterostructure strategies to mitigate the shuttling effect and accelerate lithium polysulfide(Li PS)conversion remains a critical challenge in lithium–sulfur(Li–S)batteries.Here,we report the first carbon–free VO_(2)–VS_(2)heterostructure material synthesized via in situ sulfurization,applied as a modifier on a commercial polypropylene(PP)separator(denoted as VO_(2)–VS_(2)@PP).The as–prepared VO_(2)–VS_(2)nanorods synergistically combine the high absorptivity of VO_(2)with the efficient catalytic properties of VS_(2),simultaneously enhancing Li PS anchoring and promoting its conversion.We systematically investigate the influence of material composition on battery performance,leveraging these functional attributes,Li–S cells incorporating VO_(2)–VS_(2)@PP exhibit exceptional cycle stability(over 500cycles at 1C),impressive rate performance(807 m Ah.g^(–1)at 5C),desirable reversibility(49.9%capacity retention after 300 cycles at 5C)and exceptional pouch cell performance(3.65 m Ah.cm^(–2)after 50 stable cycles at 0.1C).This study underscores the potential of tailored heterostructures in realizing high–performance Li–S batteries,offering new insights for next–generation energy storage solutions.展开更多
The intrinsic clustering behavior and kinetically sluggish conversion process of lithium polysulfides seriously limit the electrochemical reversibility of sulfur redox reactions in lithium-sulfur(Li-S)batteries.Here,w...The intrinsic clustering behavior and kinetically sluggish conversion process of lithium polysulfides seriously limit the electrochemical reversibility of sulfur redox reactions in lithium-sulfur(Li-S)batteries.Here,we introduce molybdenum pentachloride(MoCl_(5))into the electrolyte which could coordinate with lithium polysulfides and inhibit their intrinsic clustering behavior,subsequently serving as an improved mediator with the bi-functional catalytic effect for Li_(2)S deposition and activation.Moreover,the coordination bonding and accelerated conversion reaction can also greatly suppress the dissolution and shuttling of polysulfides.Consequently,such polysulfide complexes enable the Li-S coin cell to exhibit good longterm cycling stability with a capacity decay of 0.078%per cycle after 400 cycles at 2 C,and excellent rate performance with a discharge capacity of 589 mAh/g at 4 C.An area capacity of 3.94 mAh/cm^(2)is also achieved with a high sulfur loading of 4.5mg/cm^(2)at 0.2 C.Even at-20℃,the modified cell maintains standard discharge plateaus with low overpotential,delivering a high capacity of 741 mAh/g at 0.2 C after 80 cycles.The low-cost and convenient MoCl_(5)additive opens a new avenue for the effective regulation of polysulfides and significant enhancement in sulfur redox conversion.展开更多
Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effe...Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effect of polysulfides and the growth of lithium dendrites greatly hinder their further development and commercial application.In this paper,cobalt-molybdenum bimetallic carbides heterostructure(Co_(6)Mo_(6)C_(2)@Co@NC)was successfully prepared through chemical etching procedure of ZIF-67 precursor with sodium molybdate and the subsequent high temperature annealing process.The obtained dodecahedral Co_(6)Mo_(6)C_(2)@Co@NC with hollow and porous structure provides large specific surface area and plentiful active sites,which speeds up the chemisorption and catalytic conversion of polysulfides,thus mitigating the shuttle effect of polysulfides and the generation of lithium dendrites.When applied as the LSBs separator modifier layer,the cell with modified separator present excellent rate capability and durable cycling stability.In particular,the cell with Co_(6)Mo_(6)C_(2)@Co@NC/PP separator can maintain the high capacity of 738 mAh/g at the current density of 2 C and the specific capacity of 782.6 mAh/g after 300 cycles at 0.5 C,with the coulombic efficiency(CE)near to 100%.Moreover,the Co_(6)Mo_(6)C_(2)@Co@NC/PP battery exhibits the impressive capacity of 431 mAh/g in high sulfur loading(4.096 mg/cm^(2))at 0.5 C after 200 cycles.This work paves the way for the development of bimetallic carbides heterostructure multifunctional catalysts for durable Li-S battery applications and reveals the synergistic regulation of polysulfides and lithium dendrites through the optimization of the structure and composition.展开更多
Lithium-sulfur batteries(LSBs)have already developed into one of the most promising new-generation high-energy density electrochemical energy storage systems with outstanding features including high-energy density,low...Lithium-sulfur batteries(LSBs)have already developed into one of the most promising new-generation high-energy density electrochemical energy storage systems with outstanding features including high-energy density,low cost,and environmental friendliness.However,the development and commercialization path of LSBs still presents significant limitations and challenges,particularly the notorious shuttle effect triggered by soluble longchain lithium polysulfides(LiPSs),which inevitably leads to low utilization of cathode active sulfur and high battery capacity degradation,short cycle life,etc.Substantial research efforts have been conducted to develop various sulfur host materials capable of effectively restricting the shuttle effect.This review firstly introduces the fundamental electrochemical aspects of LSBs,followed by a comprehensive analysis of the mechanism underlying the shuttle effect in Li–S batteries and its profound influence on various battery components as well as the overall battery performance.Subsequently,recent advances and strategies are systematically reviewed,including physical confinement,chemisorption,and catalytic conversion of sulfur hosts for restricting LiPSs shuttle effects.The interplay mechanisms of sulfur hosts and LiPSs are discussed in detail and the structural advantages of different host materials are highlighted.Furthermore,key insights for the rational design of advanced host materials for LSBs are provided,and the upcoming challenges and the prospects for sulfur host materials in lithium-sulfur batteries are also explored.展开更多
Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)ca...Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.展开更多
Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conduc...Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of LSBs.To solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb LiPSs.At the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction processes.The mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)calculations.The electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at 0.2C.And after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.展开更多
Lithium-sulfur(Li-S) batteries are considered one of the most promising next-generation secondary batteries owing to their ultrahigh theoretical energy density.However,practical applications are hindered by the shuttl...Lithium-sulfur(Li-S) batteries are considered one of the most promising next-generation secondary batteries owing to their ultrahigh theoretical energy density.However,practical applications are hindered by the shuttle effect of soluble lithium polysulfides(Li PSs) and sluggish redox kinetics,which result in low active material utilization and poor cycling stability.Various copper-based materials have been used to inhibit the shuttle effect of Li PSs,owing to the strong anchoring effect caused by the lithiophilic/sulphilic sites and the accelerated conversion kinetics caused by excellent catalytic activity.This study briefly introduces the working principles of Li-S batteries,followed by a summary of the synthetic methods for copper-based materials.Moreover,the recent research progress in the utilization of various copper-based materials in cathodes and separators of Li-S batteries,including copper oxides,copper sulfides,copper phosphides,copper selenides,copper-based metal-organic frameworks(MOFs),and copper single-atom,are systematically summarized.Subsequently,three strategies to improve the electrochemical performance of copper-based materials through defect engineering,morphology regulation,and synergistic effect of different components are presented.Finally,our perspectives on the future development of copper-based materials are presented,highlighting the major challenges in the rational design and synthesis of high-performance Li-S batteries.展开更多
Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,s...Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.展开更多
Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current s...Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.展开更多
For lithium-sulfur batteries(Li-S batteries),a high-content electrolyte typically can exacerbate the shuttle effect,while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion e...For lithium-sulfur batteries(Li-S batteries),a high-content electrolyte typically can exacerbate the shuttle effect,while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion efficiency,so achieving an appropriate electrolyte-to-sulfur ratio(E/S ratio)is essential for improving the battery cycling efficiency.A quasi-solid electrolyte(COF-SH@PVDF-HFP)with strong adsorption and high catalytic conversion was constructed for in situ covalent organic framework(COF)growth on highly polarized polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)fibers.COF-SH@PVDF-HFP enables efficient Li-ion conductivity with low-content liquid electrolyte and effectively suppresses the shuttle effect.The results based on in situ Fourier-transform infrared,in situ Raman,UV–Vis,X-ray photoelectron,and density functional theory calculations confirmed the high catalytic conversion of COF-SH layer containing sulfhydryl and imine groups for the lithium polysulfides.Lithium plating/stripping tests based on Li/COF-SH@PVDF-HFP/Li show excellent lithium compatibility(5 mAh cm^(-2) for 1400 h).The assembled Li-S battery exhibits excellent rate(2 C 688.7 mAh g^(-1))and cycle performance(at 2 C of 568.8 mAh g^(-1) with a capacity retention of 77.3%after 800 cycles).This is the first report to improve the cycling stability of quasi-solid-state Li-S batteries by reducing both the E/S ratio and the designing strategy of sulfhydryl-functionalized COF for quasi-solid electro-lytes.This process opens up the possibility of the high performance of solid-state Li-S batteries.展开更多
As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was design...As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was designed as the sulfur host, in which MoO_2 is inlaid on the surface of ordered mesoporous carbons that can store active materials and provide fast electron transfer channel due to its ordered pore structure. The MoO_2 can effectively prevent the migration of polysulfides through the chemical adsorption and promote the conversion of polysulfides towards Li-sulfur battery.展开更多
High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion ...High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion reaction kinetics immensely obstruct their commercial viability.Herein,a two-dimensional metallic 1T phase WS_(2)(1T-WS_(2))nanosheets modified functional separator is developed to improve the electrochemical performance.Meanwhile,the semiconducting bulk-WS_(2) crystals,and 2H phase WS_(2)(2H-WS_(2))nanosheets with more basal-plane Svacancy defects are also prepared to probe the contributions of the crystal structure(phase),S-vacancy defects,and edges to the Li–S batteries performance experimentally and theoretically.In merits of the synergistic effect of high ion and electron conductivity,enhanced binding ability to lithium polysulfides(LiPSs),and sufficient electrocatalytic active sites,the 1T-WS_(2) shows highly efficient electrocatalysis of LiPSs conversion and further improves Li–S battery performance.As expected,thus-fabricated cells with 1T-WS_(2) nanosheets present superior cycle stability that maintain capacity decline of 0.039%per cycle after 1000 cycles at 1.0 C.The strategy presented here offers a viable approach to reveal the critical factors for LiPSs catalytic conversion,which is beneficial to developing advanced Li–S batteries with enhanced properties.展开更多
Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish...Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish Na^(+)transport kinetics and polysulfides intermediates,have greatly affect their long cycle stability.Unfortunately,the majority of current studies only focus on the first two aspects,but lack of sufficient attention and insights into the effect of polysulfides intermediates.Here,a porous of CoS_(x)(P-CoS_(x))electrode material is fabricated as an example to investigate the influence of polysulfides on its cycling performance.The results show that polysulfides cause a slight loss of reversible capacity during the battery cycling,while the failure of the battery is due to its significant fluctuations in reversible capacity after extensive cycles.Detailed analyses demonstrate that the intense fluctuation in capacity originates from the faster growth of dendrites caused by the reaction of sodium polysulfides with sodium foil and/or the reaction of elemental sulfur with sodium foil to penetrate the separator,resulting in a local short circuit.To suppress these undesirable side reaction,N,S co-doped porous carbon tubes(N,S-PC)rich in C–S and C–N bonds have been added to adsorb polysulfides and alleviate their reaction with sodium foil.As a result,the capacity of the P-CoS_(x) electrode with N,S-PC(P-CoS_(x)/N,S-PC)remains stable without significant fluctuations for 1000 cycles,which is much better than that of the pure P-CoS_(x) electrode(intense fluctuation in capacity after 320 cycles).Our work offers insights into the crucial influence of polysulfides on the cycle performance of the P-CoS_(x) anode and provides a feasible strategy to prolong the cycle life of metal sulfide anode for SIBs.展开更多
Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrins...Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.展开更多
Lithium-sulfur(Li-S)battery has been considered as one of the most promising next generation energy storage technologies for its overwhelming merits of high theoretical specific capacity(1673 m Ah/g),high energy densi...Lithium-sulfur(Li-S)battery has been considered as one of the most promising next generation energy storage technologies for its overwhelming merits of high theoretical specific capacity(1673 m Ah/g),high energy density(2500 Wh/kg),low cost,and environmentally friendliness of sulfur.However,critical drawbacks,including inherent low conductivity of sulfur and Li2S,large volume changes of sulfur cathodes,undesirable shuttling and sluggish redox kinetics of polysulfides,seriously deteriorate the energy density,cycle life and rate capability of Li-S battery,and thus limit its practical applications.Herein,we reviewed the recent developments addressing these problems through iron-based nanomaterials for effective synergistic immobilization as well as conversion reaction kinetics acceleration for polysulfides.The mechanist configurations between different iron-based nanomaterials and polysulfides for entrapment and conversion acceleration were summarized at first.Then we concluded the recent progresses on utilizing various iron-based nanomaterials in Li-S battery as sulfur hosts,separators and cathode interlayers.Finally,we discussed the challenges and perspectives for designing high sulfur loading cathode architectures along with outstanding chemisorption capability and catalytic activity.展开更多
Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox react...Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm^(−2). This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.展开更多
基金financially supported by the National Natural Science Foundation of China(52172245)the Key Scientific and Technological Innovation Project of Shandong(2023CXGC010302)the Qingdao Flexible Materials Precision Die-cutting Technology Innovation Center。
文摘In lithium-sulfur batteries(LSBs),the limited utilization of sulfur and the sluggish kinetics of redox reaction significantly hinder their electrochemical performance,especially under high rates and high sulfur loadings.Here,we propose a novel separator structure with an interlayer composed of a vermiculite nanosheet combined with Ketjen Black(VMT@KB)for LSBs,facilitating efficient adsorption and rapid catalytic conversion toward lithium polysulfides(LiPSs).The VMT@KB nanosheets with an electrical double-layer structure and electronic conductivity are obtained through a high-temperature peeling process and Li^(+)exchange treatment in LiCl solution,followed by a mechanical combination process with KB.The results demonstrate that incorporating VMT@KB as an interlayer on a conventional separator enhances the conductivity and limits the LiPSs in the cathode region.The Li-S cell with VMT@KB interlayer shows satisfactory cycle and rate performance,especially in high sulfur loading.It exhibits a remarkable initial discharge capacity of 1225 mAh g^(-1)at 0.5 C and maintains a capacity of 816 mAh g^(-1)after 500 cycles.Besides,the discharge capacity remains 462 mAh g^(-1)even at 6 C.Moreover,the cell with high sulfur loading(8.2 mg cm^(-2))enables stable cycling for 100 cycles at 0.1 C with a discharge capacity of over1000 mAh g^(-1).
基金supported by the Natural Science Foundation of China(22309179)the Natural Science Foundation of China(12404049)+4 种基金Natural Science Foundation of Ningxia(2023AAC01003)Guangdong Basic and Applied Basic Research Foundation(2021A1515110156,2022A1515010724,2023A1515110521,2023B1515120095,2024A1515011260)Science and Technology Program of Guangzhou(No.2019050001)the Outstanding Youth Project of Guangdong Natural Science Foundation(2021B1515020051)Dalian Revitalization Talents Program(No.2022RG01).
文摘Developing electrocatalysts to inhibit polysulfide shuttling and expedite sulfur species conversion is vital for the evolution of Lithium-sulfur(Li-S)batteries.This work provides a facile strategy to design an intimate heterostructure of MIL-88A@CdS as a sulfur electrocatalyst combining high sulfur adsorption and accelerated polysulfide conversion.The MIL-88A can give a region of high-ordered polysulfide adsorption,whereas the CdS is an effective nanoreactor for the sulfur reduction reaction(SRR).Notedly,the significant size difference between MIL-88A and CdS enables the unique heterostructure interactions.The largesize MIL-88A ensures a uniform distribution of CdS nanoparticles as a substrate.This configuration facilitates control of the initial polysulfide adsorption position relative to its final deposition site as lithium sulfide.The heterostructure also demonstrates rapid transport and efficient conversion of lithium polysulfides.Consequently,the Li-S battery with MIL-88A@CdS heterostructure modified separator delivers exceptional performance,achieving an areal capacity exceeding 6 mAh cm^(−2),an excellent rate capability of 980 mAh g^(−1) at 5 C,and notable cycling stability in a 2 Ah pouch cell over 100 cycles.This work is significant for elucidating the relationship between heterostructure and electrocatalytic performance,providing great insights for material design aimed at highly efficient future electrocatalysts in practical applications.
基金supported by the Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.22JK0411)the Natural Science Basic Research Program of Shaanxi Province(No.2023-JC-QN-0165)the National Natural Science Foundation of China(No.21603109).
文摘Lithium-sulfur batteries are considered to be a new generation of high energy density batteries due to their non-toxicity,low cost and high theoretical specific capacity.However,the development of practical lithium-sulfur batteries is seriously impeded by the sluggish multi-electron redox reaction of sulfur species and obstinate shuttle effect of polysulfides.In this study,a porous lanthanum oxychloride(LaOCl)nanofiber is designed as adsorbent and electrocatalyst of polysulfides to regulate the redox kinetics and suppress shuttling of sulfur species.Benefiting from the porous architecture and luxuriant active site of LaOCl nanofibers,the meliorative polarization effect and sulfur expansion can be accomplished.The LaOCl/S electrode exhibits an initial discharge specific capacity of 1112.3 mAh/g at 0.1 C and maintains a superior cycling performance with a slight decay of 0.02%per cycle over 1000 cycles at 1.0 C.Furthermore,even under a high sulfur loading of 4.6mg/cm^(2),the S cathode with LaOCl nanofibers still retains a high reversible areal capacity of 4.2 mAh/cm^(2)at 0.2 C and a stable cycling performance.Such a porous host expands the application of rare earth based catalysts in lithium-sulfur batteries and provides an alternative approach to facilitate the polysulfides conversion kinetics.
基金financially supported by the National Natural Science Foundation of China(U22A20113,52261135543)。
文摘Lithium-sulfur(Li-S)batteries with high energy density suffer from the soluble lithium polysulfide species,Traditional metal sulfides containing a single metal element used as electrocatalysts for Li-S batteries commonly have limited catalytic abilities to improve battery performance.Herein,based on the Hume-Rothery rule and solvothermal method,the high-entropy sulfide NiCoCuTiVS_(x)derived from Co_(9)S_(8)was designed and synthesized,to realize the combination of small local strain and excellent catalytic performance.With all five metal elements(Ni,Co,Cu,Ti,and V)capable of chemical interactions with soluble polysulfides,NiCoCuTiVS_(x)exhibited strong chemical confinement of polysulfides and promoted fast kinetics for polysulfides conversion.Consequently,the S/NiCoCuTiVS_(x)cathode can maintain a high discharge capacity of 968.9 mA h g^(-1)after 200 cycles at 0.5 C and its capacity retention is 1.3 times higher than that of S/Co_(9)S_(8).The improved cycle stability can be attributed to the synergistic effect originating from the multiple metal elements,coupled with the reduced nucleation and activation barriers of Li_(2)S.The present work opens a path to explore novel electrocatalyst materials based on high entropy materials for the achievement of advanced Li-S batteries.
基金financially supported by Jilin province science and technology department(No.20230402059GH)Changchun Science and Technology Bureau(No.23YQ11)+4 种基金Jilin Province Science and Technology Department major science and technology project(Nos.20220301004GX and 20220301005GX)Key Subject Construction of Physical Chemistry of Northeast Normal University(No.2412022XK004)the National Natural Science Foundation of China(No.22102020)the Swedish Foundation for International Cooperation in Research and Higher Education(No.KO2017-7351)Swedish Energy Agency(No.P2020-90216)。
文摘Developing effective heterostructure strategies to mitigate the shuttling effect and accelerate lithium polysulfide(Li PS)conversion remains a critical challenge in lithium–sulfur(Li–S)batteries.Here,we report the first carbon–free VO_(2)–VS_(2)heterostructure material synthesized via in situ sulfurization,applied as a modifier on a commercial polypropylene(PP)separator(denoted as VO_(2)–VS_(2)@PP).The as–prepared VO_(2)–VS_(2)nanorods synergistically combine the high absorptivity of VO_(2)with the efficient catalytic properties of VS_(2),simultaneously enhancing Li PS anchoring and promoting its conversion.We systematically investigate the influence of material composition on battery performance,leveraging these functional attributes,Li–S cells incorporating VO_(2)–VS_(2)@PP exhibit exceptional cycle stability(over 500cycles at 1C),impressive rate performance(807 m Ah.g^(–1)at 5C),desirable reversibility(49.9%capacity retention after 300 cycles at 5C)and exceptional pouch cell performance(3.65 m Ah.cm^(–2)after 50 stable cycles at 0.1C).This study underscores the potential of tailored heterostructures in realizing high–performance Li–S batteries,offering new insights for next–generation energy storage solutions.
基金the National Natural Science Foundation of China(Nos.51904344,52172264)the Natural Science Foundation of Hunan Province of China(Nos.2021JJ10060 and 2022GK2033).
文摘The intrinsic clustering behavior and kinetically sluggish conversion process of lithium polysulfides seriously limit the electrochemical reversibility of sulfur redox reactions in lithium-sulfur(Li-S)batteries.Here,we introduce molybdenum pentachloride(MoCl_(5))into the electrolyte which could coordinate with lithium polysulfides and inhibit their intrinsic clustering behavior,subsequently serving as an improved mediator with the bi-functional catalytic effect for Li_(2)S deposition and activation.Moreover,the coordination bonding and accelerated conversion reaction can also greatly suppress the dissolution and shuttling of polysulfides.Consequently,such polysulfide complexes enable the Li-S coin cell to exhibit good longterm cycling stability with a capacity decay of 0.078%per cycle after 400 cycles at 2 C,and excellent rate performance with a discharge capacity of 589 mAh/g at 4 C.An area capacity of 3.94 mAh/cm^(2)is also achieved with a high sulfur loading of 4.5mg/cm^(2)at 0.2 C.Even at-20℃,the modified cell maintains standard discharge plateaus with low overpotential,delivering a high capacity of 741 mAh/g at 0.2 C after 80 cycles.The low-cost and convenient MoCl_(5)additive opens a new avenue for the effective regulation of polysulfides and significant enhancement in sulfur redox conversion.
基金supported by National Natural Science Foundation of China(Nos.52472194,52101243)Natural Science Foundation of Guangdong Province,China(No.2023A1515012619)the Science and Technology Planning Project of Guangzhou(No.202201010565).
文摘Lithium-sulfur batteries(LSBs)are considered as the most promising energy storage technologies owing to their large theoretical energy density(2500Wh/kg)and specific capacity(1675 mAh/g).However,the heavy shuttle effect of polysulfides and the growth of lithium dendrites greatly hinder their further development and commercial application.In this paper,cobalt-molybdenum bimetallic carbides heterostructure(Co_(6)Mo_(6)C_(2)@Co@NC)was successfully prepared through chemical etching procedure of ZIF-67 precursor with sodium molybdate and the subsequent high temperature annealing process.The obtained dodecahedral Co_(6)Mo_(6)C_(2)@Co@NC with hollow and porous structure provides large specific surface area and plentiful active sites,which speeds up the chemisorption and catalytic conversion of polysulfides,thus mitigating the shuttle effect of polysulfides and the generation of lithium dendrites.When applied as the LSBs separator modifier layer,the cell with modified separator present excellent rate capability and durable cycling stability.In particular,the cell with Co_(6)Mo_(6)C_(2)@Co@NC/PP separator can maintain the high capacity of 738 mAh/g at the current density of 2 C and the specific capacity of 782.6 mAh/g after 300 cycles at 0.5 C,with the coulombic efficiency(CE)near to 100%.Moreover,the Co_(6)Mo_(6)C_(2)@Co@NC/PP battery exhibits the impressive capacity of 431 mAh/g in high sulfur loading(4.096 mg/cm^(2))at 0.5 C after 200 cycles.This work paves the way for the development of bimetallic carbides heterostructure multifunctional catalysts for durable Li-S battery applications and reveals the synergistic regulation of polysulfides and lithium dendrites through the optimization of the structure and composition.
基金supported by the National Natural Science Foundation of China(Nos.52105575&52205593)the Fundamental Research Funds for the Central Universities(No.QTZX23063)+1 种基金the Proof of Concept Foundation of Xidian University Hangzhou Institute of Technology(Nos.GNYZ2023YL0302&GNYZ2023QC0401)the Aeronautical Science Foundation of China(No.2022Z073081001)。
文摘Lithium-sulfur batteries(LSBs)have already developed into one of the most promising new-generation high-energy density electrochemical energy storage systems with outstanding features including high-energy density,low cost,and environmental friendliness.However,the development and commercialization path of LSBs still presents significant limitations and challenges,particularly the notorious shuttle effect triggered by soluble longchain lithium polysulfides(LiPSs),which inevitably leads to low utilization of cathode active sulfur and high battery capacity degradation,short cycle life,etc.Substantial research efforts have been conducted to develop various sulfur host materials capable of effectively restricting the shuttle effect.This review firstly introduces the fundamental electrochemical aspects of LSBs,followed by a comprehensive analysis of the mechanism underlying the shuttle effect in Li–S batteries and its profound influence on various battery components as well as the overall battery performance.Subsequently,recent advances and strategies are systematically reviewed,including physical confinement,chemisorption,and catalytic conversion of sulfur hosts for restricting LiPSs shuttle effects.The interplay mechanisms of sulfur hosts and LiPSs are discussed in detail and the structural advantages of different host materials are highlighted.Furthermore,key insights for the rational design of advanced host materials for LSBs are provided,and the upcoming challenges and the prospects for sulfur host materials in lithium-sulfur batteries are also explored.
基金supported by the National Natural Science Foundation of China(22075091)the Natural Science Foundation of Hubei Province(Grant No.2021CFA066)。
文摘Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.
基金financially supported by the National Natural Science Foundation of China(No.52130101)the Project of Science and Technology Development Plan of Jilin Province in China(Nos.20210402058GH and 20220201114GX)。
文摘Lithium-sulfur batteries(LSBs)have attracted the attention of more and more researchers due to the advantages of high energy density,environmental friendliness,and low production cost.However,the low electronic conductivity of active material and shuttling effect of lithium polysulfides(LiPSs)limit the commercial development of LSBs.To solve these problems,we design a core-shell composite with nitrogen-doped carbon(NC)and two types of selenides(FeSe_(2)-NC@ZnSe-NC).The FeSe_(2)-NC@ZnSe-NC has a strong adsorption capacity,and can effectively adsorb LiPSs.At the same time,it also effectively alleviates the shuttling effect of LiPSs,and improves the utilization of the active substance during the charge/discharge reaction processes.The mechanism involved in FeSe_(2)-NC@ZnSe-NC is demonstrated by both experiments and density-functional theory(DFT)calculations.The electrochemical test results indicate that LSB with S/FeSe_(2)-NC@ZnSe-NC delivers an initial discharge capacity of 1260 mAh·g^(-1)at 0.2C.And after 500 cycles at 1C,the capacity decay rate per cycle is 0.031%,and the capacity retention rate is 85%.The FeSe_(2)-NC@ZnSe-NC core-shell structure verifies a rational strategy to construct an electrode material for high-performance LSBs.
基金supported by the National Natural Science Foundation of China (No.51962002)Natural Science Foundation of Guangxi (No.2022GXNSFAA035463)。
文摘Lithium-sulfur(Li-S) batteries are considered one of the most promising next-generation secondary batteries owing to their ultrahigh theoretical energy density.However,practical applications are hindered by the shuttle effect of soluble lithium polysulfides(Li PSs) and sluggish redox kinetics,which result in low active material utilization and poor cycling stability.Various copper-based materials have been used to inhibit the shuttle effect of Li PSs,owing to the strong anchoring effect caused by the lithiophilic/sulphilic sites and the accelerated conversion kinetics caused by excellent catalytic activity.This study briefly introduces the working principles of Li-S batteries,followed by a summary of the synthetic methods for copper-based materials.Moreover,the recent research progress in the utilization of various copper-based materials in cathodes and separators of Li-S batteries,including copper oxides,copper sulfides,copper phosphides,copper selenides,copper-based metal-organic frameworks(MOFs),and copper single-atom,are systematically summarized.Subsequently,three strategies to improve the electrochemical performance of copper-based materials through defect engineering,morphology regulation,and synergistic effect of different components are presented.Finally,our perspectives on the future development of copper-based materials are presented,highlighting the major challenges in the rational design and synthesis of high-performance Li-S batteries.
基金the financial support from the Australian Research Council (ARC) through Future Fellowship (FT210100298)DECRA Fellowship (DE230101068)+2 种基金Discovery Project (DP230100198 and DP210102215)Linkage Projects (LP220100088 and LP180100722)partially supported by AIIM FOR GOLD Grant (2017, 2018)
文摘Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.
基金supported in part by the Institute for Advanced Study of Central South University and the High Performance Computing Center of Central South Universitythe funding from Guangdong Natural Science Funds(No.2023A0505050107)。
文摘Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.
基金This research was supported by the National Natural Science Foundation of China(52202104)the Joint Funds of the Zhejiang Provincial Natural Science Foundation of China(LZY23B030002)+5 种基金the China Postdoctoral Science Foundation(2021T140433,2020M683408)the Quzhou Science and Technology Bureau Project(2022D015,2023D023)the International Cooperation Projects of Sichuan Provincial Department of Science and Technology(2021YFH0126)the Fundamental Research Funds for the Central Universities(ZYGX2020ZB016)the Key Research and Development Program of Yunnan Province China(202103AA080019)Yunnan Major Scientific and Technological Projects(202202AG050003).
文摘For lithium-sulfur batteries(Li-S batteries),a high-content electrolyte typically can exacerbate the shuttle effect,while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion efficiency,so achieving an appropriate electrolyte-to-sulfur ratio(E/S ratio)is essential for improving the battery cycling efficiency.A quasi-solid electrolyte(COF-SH@PVDF-HFP)with strong adsorption and high catalytic conversion was constructed for in situ covalent organic framework(COF)growth on highly polarized polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)fibers.COF-SH@PVDF-HFP enables efficient Li-ion conductivity with low-content liquid electrolyte and effectively suppresses the shuttle effect.The results based on in situ Fourier-transform infrared,in situ Raman,UV–Vis,X-ray photoelectron,and density functional theory calculations confirmed the high catalytic conversion of COF-SH layer containing sulfhydryl and imine groups for the lithium polysulfides.Lithium plating/stripping tests based on Li/COF-SH@PVDF-HFP/Li show excellent lithium compatibility(5 mAh cm^(-2) for 1400 h).The assembled Li-S battery exhibits excellent rate(2 C 688.7 mAh g^(-1))and cycle performance(at 2 C of 568.8 mAh g^(-1) with a capacity retention of 77.3%after 800 cycles).This is the first report to improve the cycling stability of quasi-solid-state Li-S batteries by reducing both the E/S ratio and the designing strategy of sulfhydryl-functionalized COF for quasi-solid electro-lytes.This process opens up the possibility of the high performance of solid-state Li-S batteries.
基金supported by the National Natural Science Foundation of China(Nos. U1710109 and 51702182)Shenzhen Basic Research Project(No.JCYJ20150529164918734)
文摘As polar materials, transition-metal oxides have shown great potentials to improve the adsorption of lithium polysulfides in lithium-sulfur batteries. Herein, a MoO_2-ordered mesoporous carbon (M-OMC)hybrid was designed as the sulfur host, in which MoO_2 is inlaid on the surface of ordered mesoporous carbons that can store active materials and provide fast electron transfer channel due to its ordered pore structure. The MoO_2 can effectively prevent the migration of polysulfides through the chemical adsorption and promote the conversion of polysulfides towards Li-sulfur battery.
基金supported by the National Natural Science Funds,China(No.21676198)the Program of Introducing Talents of Discipline to Universities,China(No.B06006)。
文摘High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion reaction kinetics immensely obstruct their commercial viability.Herein,a two-dimensional metallic 1T phase WS_(2)(1T-WS_(2))nanosheets modified functional separator is developed to improve the electrochemical performance.Meanwhile,the semiconducting bulk-WS_(2) crystals,and 2H phase WS_(2)(2H-WS_(2))nanosheets with more basal-plane Svacancy defects are also prepared to probe the contributions of the crystal structure(phase),S-vacancy defects,and edges to the Li–S batteries performance experimentally and theoretically.In merits of the synergistic effect of high ion and electron conductivity,enhanced binding ability to lithium polysulfides(LiPSs),and sufficient electrocatalytic active sites,the 1T-WS_(2) shows highly efficient electrocatalysis of LiPSs conversion and further improves Li–S battery performance.As expected,thus-fabricated cells with 1T-WS_(2) nanosheets present superior cycle stability that maintain capacity decline of 0.039%per cycle after 1000 cycles at 1.0 C.The strategy presented here offers a viable approach to reveal the critical factors for LiPSs catalytic conversion,which is beneficial to developing advanced Li–S batteries with enhanced properties.
基金supported by the National Natural Science Foundation of China(Grant Nos.22075064,21673065)。
文摘Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish Na^(+)transport kinetics and polysulfides intermediates,have greatly affect their long cycle stability.Unfortunately,the majority of current studies only focus on the first two aspects,but lack of sufficient attention and insights into the effect of polysulfides intermediates.Here,a porous of CoS_(x)(P-CoS_(x))electrode material is fabricated as an example to investigate the influence of polysulfides on its cycling performance.The results show that polysulfides cause a slight loss of reversible capacity during the battery cycling,while the failure of the battery is due to its significant fluctuations in reversible capacity after extensive cycles.Detailed analyses demonstrate that the intense fluctuation in capacity originates from the faster growth of dendrites caused by the reaction of sodium polysulfides with sodium foil and/or the reaction of elemental sulfur with sodium foil to penetrate the separator,resulting in a local short circuit.To suppress these undesirable side reaction,N,S co-doped porous carbon tubes(N,S-PC)rich in C–S and C–N bonds have been added to adsorb polysulfides and alleviate their reaction with sodium foil.As a result,the capacity of the P-CoS_(x) electrode with N,S-PC(P-CoS_(x)/N,S-PC)remains stable without significant fluctuations for 1000 cycles,which is much better than that of the pure P-CoS_(x) electrode(intense fluctuation in capacity after 320 cycles).Our work offers insights into the crucial influence of polysulfides on the cycle performance of the P-CoS_(x) anode and provides a feasible strategy to prolong the cycle life of metal sulfide anode for SIBs.
基金the National Natural Science Foundation of China(51773134)the Program for the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(51721091)+2 种基金the Sichuan Province Science and Technology Project(2019YFH0112)the Sichuan Province Youth Science and Technology Innovation Team(2017TD0006)the Fundamental Research Funds for the Central Universities(2017SCU04A14 and YJ201821)。
文摘Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.
基金financially supported by National Natural Science Foundation of China(Nos.51702362 and 21875282)Natural Science Foundation of Hunan Province(Nos.2022JJ30663,2022JJ40551)+1 种基金Scientific Research Project of National University of Defense Technology(No.ZK19–27)Significant Independent Research Projects for Young Talents of College of Aerospace Science and Engineering,National University of Defense Technology。
文摘Lithium-sulfur(Li-S)battery has been considered as one of the most promising next generation energy storage technologies for its overwhelming merits of high theoretical specific capacity(1673 m Ah/g),high energy density(2500 Wh/kg),low cost,and environmentally friendliness of sulfur.However,critical drawbacks,including inherent low conductivity of sulfur and Li2S,large volume changes of sulfur cathodes,undesirable shuttling and sluggish redox kinetics of polysulfides,seriously deteriorate the energy density,cycle life and rate capability of Li-S battery,and thus limit its practical applications.Herein,we reviewed the recent developments addressing these problems through iron-based nanomaterials for effective synergistic immobilization as well as conversion reaction kinetics acceleration for polysulfides.The mechanist configurations between different iron-based nanomaterials and polysulfides for entrapment and conversion acceleration were summarized at first.Then we concluded the recent progresses on utilizing various iron-based nanomaterials in Li-S battery as sulfur hosts,separators and cathode interlayers.Finally,we discussed the challenges and perspectives for designing high sulfur loading cathode architectures along with outstanding chemisorption capability and catalytic activity.
基金The authors appreciate support from the National Key Research and Development Program of China(No.2018YFE0124500)the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2020-11)the National Natural Science Foundation of China(Nos.51932005,U1710109).
文摘Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm^(−2). This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.
