Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery perf...Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery performance,however,their effect on the formation mechanism of the oxygen reduction product(NaO_(2))is still unclear.Here,we have investigated the formation mechanism of NaO_(2) during the discharge process in the presence of a redox mediator with the help of atomic/nano-scale in-situ characterization tools used in concert(e.g.atomic force microscope,electrochemical quartz crystal microbalance(EQCM)and laser nano-particle analyzer).As a result,real-time observations on different time scales show that by shuttling electrons to the electrolyte,the redox mediator enables formation of NaO_(2) in the solution-phase instead of within a finite region near the electrode surface.These findings provide new fundamental insights on the understanding of Na-O_(2) batteries and new consequently perspectives on designing high performance metal-O_(2) batteries and other related functions.展开更多
Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms lig...Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.展开更多
Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rap...Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.展开更多
A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface...A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.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
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 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
Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a no...Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.展开更多
Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from...Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.展开更多
Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two crit...Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.展开更多
Lithium-sulfur(Li-S)batteries require efficient catalysts to accelerate polysulfide conversion and mitigate the shuttle effect.However,the rational design of catalysts remains challenging due to the lack of a systemat...Lithium-sulfur(Li-S)batteries require efficient catalysts to accelerate polysulfide conversion and mitigate the shuttle effect.However,the rational design of catalysts remains challenging due to the lack of a systematic strategy that rationally optimizes electronic structures and mesoscale transport properties.In this work,we propose an autogenously transformed CoWO_(4)/WO_(2) heterojunction catalyst,integrating a strong polysulfide-adsorbing intercalation catalyst with a metallic-phase promoter for enhanced activity.CoWO_(4) effectively captures polysulfides,while the CoWO_(4)/WO_(2) interface facilitates their S-S bond activation on heterogenous catalytic sites.Benefiting from its directional intercalation channels,CoWO_(4) not only serves as a dynamic Li-ion reservoir but also provides continuous and direct pathways for rapid Li-ion transport.Such synergistic interactions across the heterojunction interfaces enhance the catalytic activity of the composite.As a result,the CoWO_(4)/WO_(2) heterostructure demonstrates significantly enhanced catalytic performance,delivering a high capacity of 1262 mAh g^(−1) at 0.1 C.Furthermore,its rate capability and high sulfur loading performance are markedly improved,surpassing the limitations of its single-component counterparts.This study provides new insights into the catalytic mechanisms governing Li-S chemistry and offers a promising strategy for the rational design of high-performance Li-S battery catalysts.展开更多
Lithium-sulfur battery(LSB) has high energy density but is limited by the polysulfides shuttle and dendrite growth during cycling. Herein, a free-standing cellulose nanofiber(CNF) separator is designed and fabricated ...Lithium-sulfur battery(LSB) has high energy density but is limited by the polysulfides shuttle and dendrite growth during cycling. Herein, a free-standing cellulose nanofiber(CNF) separator is designed and fabricated in isopropanol/water suspension through vacuum filtration progress. CNFs with abundant polar oxygen-containing functional groups can chemically immobilize the polysulfides, and suppress the formation of the dendrites by controlling the surface morphology of the SEI on lithium metal in LSB. The isopropanol content in a suspension can fine-tune the pore structure of the membrane to achieve optimal electrochemical performance. The prepared separator displays integrated advantages of an ultrathin thickness(19 μm), lightweight(0.87 mg cm^(-2)), extremely high porosity(98.05%), and decent electrolyte affinity. As a result, the discharge capacity of the LSB with CNF separator at the first and 100 th cycle is 1.4 and 1.3 times that of PP separator, respectively. Our research provides an environmentalfriendly and facile strategy for the preparation of multifunctional separators for LSBs.展开更多
Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-elect...Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-electron reaction between sulfur and lithium in liquid electrolyte makes the capacity much smaller than the theoretical value.Many methods were proposed for inhibiting the shuttle effect of polysulfide,improving corresponding redox kinetics and enhancing the integral performance of Li–S batteries.Here,we will comprehensively and systematically summarize the strategies for inhibiting the shuttle effect from all components of Li–S batteries.First,the electrochemical principles/mechanism and origin of the shuttle effect are described in detail.Moreover,the efficient strategies,including boosting the sulfur conversion rate of sulfur,confining sulfur or lithium polysulfides(LPS)within cathode host,confining LPS in the shield layer,and preventing LPS from contacting the anode,will be discussed to suppress the shuttle effect.Then,recent advances in inhibition of shuttle effect in cathode,electrolyte,separator,and anode with the aforementioned strategies have been summarized to direct the further design of efficient materials for Li–S batteries.Finally,we present prospects for inhibition of the LPS shuttle and potential development directions in Li–S batteries.展开更多
The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusi...The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.展开更多
Lithium–sulfur(Li-S)batteries have the advantages of high theoretical specific capacity(1675 mAh g^(−1)),rich sulfur resources,low production cost,and friendly environment,which makes it one of the most promising nex...Lithium–sulfur(Li-S)batteries have the advantages of high theoretical specific capacity(1675 mAh g^(−1)),rich sulfur resources,low production cost,and friendly environment,which makes it one of the most promising next-generation rechargeable energy storage devices.However,the“shuttle effect”of polysulfide results in the passivation of metal lithium anode,the decrease of battery capacity and coulombic efficiency,and the deterioration of cycle stability.To realize the commercialization of Li-S batteries,its serious“shuttle effect”needs to be suppress.The commercial separators are ineffective to suppress this effect because of its large pore size.Therefore,it is an effective strategy to modify the separator surface and introduce functional modified layer.In addition to the blocking strategy,the catalysis of polysulfide conversion reaction is also an important factor hindering the migration of polysulfides.In this review,the principles of separator modification,functionalization,and catalysis in Li-S batteries are reviewed.Furthermore,the research trend of separator functionalization and polysulfide catalysis in the future is prospected.展开更多
Multivalent metal-sulfur(M-S,where M=Mg,Al,Ca,Zn,Fe,etc.)batteries offer unique opportunities to achieve high specific capacity,elemental abundancy and cost-effectiveness beyond lithium-ion batteries(LIBs).However,the...Multivalent metal-sulfur(M-S,where M=Mg,Al,Ca,Zn,Fe,etc.)batteries offer unique opportunities to achieve high specific capacity,elemental abundancy and cost-effectiveness beyond lithium-ion batteries(LIBs).However,the slow diffusion of multivalent-metal ions and the shuttle of soluble polysulfide result in impoverished reversible capacity and limited cycle performance of M-S(Mg-S,Al-S,Ca-S,Zn-S,Fe-S,etc.)batteries.It is a necessity to optimize the electrochemical performance,while deepening the understanding of the unique electrochemical reaction mechanism,such as the intrinsic multi-electron reaction process,polysulfides dissoluti on and the in stability of metal an odes.To solve these problems,we have summarized the state-of-the-art progress of current M-S batteries,and sorted out the existing challen ges for different multivalent M-S batteries according to sulfur cathode,electrolytes,metallic an ode and current collectors/separators,respectively.In this literature,we have surveyed and exemplified the strategies developed for better M-S batteries to strengthen the application of green,cost-effective and high energy density M-S batteries.展开更多
Rechargeable lithium-oxygen(Li-O_(2))batteries are the next generation energy storage devices due to their ultrahigh theoretical capacity.Redox mediators(RMs)are widely used as a homogenous electrocatalyst in non-aque...Rechargeable lithium-oxygen(Li-O_(2))batteries are the next generation energy storage devices due to their ultrahigh theoretical capacity.Redox mediators(RMs)are widely used as a homogenous electrocatalyst in non-aqueous Li-O_(2)batteries to enhance their discharge capacity and reduce charge overpotential.However,the shuttle effect of RMs in the electrolyte solution usually leads to corrosion of the Li metal anode and uneven Li deposition on the anode surface,resulting in unwanted consumption of electrocatalysts and deterioration of the cells.It is therefore necessary to take some measures to prevent the shuttle effect of RMs and fully utilize the soluble electrocatalysts.Herein,we summarize the strategies to suppress the RM shuttle effect reported in recent years,including electrolyte additives,protective separators and electrode modification.The mechanisms of these strategies are analyzed and their corresponding requirements are discussed.The electrochemical properties of Li-O_(2)batteries with different strategies are summarized and compared.The challenges and perspectives on preventing the shuttle effect of RMs are described for future study.This review provides guidance for achieving shuttle-free redox mediation and for designing Li-O_(2)cells with a long cycle life,high energy efficiency and highly reversible electrochemical reactions.展开更多
According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-b...According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-biodegradable,thus they produce a mass of waste disposal and cause environmental pollution is-sue.For the purpose of transforming waste into wealth and reducing environmental pollution,nitrogen and sulfur co-doped carbon nanofiber/carbon black(N,S-CNF/CB)composite derived from the discarded cigarette filters is employed to modify glass fiber(GF)separator for the first time in this study.N,S-CNF improves binding ability towards sodium polysulfides(SPSs)by chemisorption.Non-polar CB limits the dissolution of SPSs in the liquid electrolyte by physisorption.The experiment and density functional theory calculation results indicate that a RT-Na/S battery with a N,S-CNF/CB+GF separator exhibits good cycling stability and rate performance.After 100 cycles at a low current rate of 0.1 C,a RT-Na/S battery with a sulfur mass fraction of 71%delivers a discharge capacity of 703 mAh g^(−1).In addition,at a high current rate of 0.5 C,a discharge capacity of 527 mAh g^(−1) is still maintained after 900 cycles with a very low capacity fading rate of 0.035%per cycle.展开更多
Polysulfide absorption in a micropore-rich structure has been reported to be capable of efficiently confining the shuttle effect for high-performance lithium-sulfur(Li–S)batteries.Here,a labyrinth maze-like spherical...Polysulfide absorption in a micropore-rich structure has been reported to be capable of efficiently confining the shuttle effect for high-performance lithium-sulfur(Li–S)batteries.Here,a labyrinth maze-like spherical honeycomb-like carbon with micropore-rich structure was synthesized,which is employed as a template host material of sulfur to study the shuttle effects.The results strongly confirm that a diffusion controlled process rather than an absorption resulted surface-controlled process occurs in an even micropore-rich cathode but still greatly inhibits the shuttle effect.Thus,the battery achieves a high initial discharge specific capacity of 1120 mAh g1 at 0.25 C and super cycling stability for 1635 cycles with only 0.035%capacity decay per cycle with 100%Coulombic efficiency.We would like to propose a new mechanism for shuttle effect inhibition in micropores.In terms of the diffusion control process in microporous paths of a labyrinth maze structure,polysulfides experience a long travel to realize continuous reductions of sulfur and polysulfides until formation of the final solid product.This efficiently prevents the polysulfides escaping to electrolyte.The labyrinth maze-like honeycomb structure also offers fast electron transfer and enhanced mass transport as well as robust mechanical strength retaining intact structure for long cycle life.This work sheds lights on new fundamental insights behind the shuttle effects with universal significance while demonstrating prominent merits of a robust labyrinth maze-like structure in high performance cathode for high-performance Li–S batteries.展开更多
Rechargeable aluminum-sulfur(Al-S)batteries have been considered as a highly potential energy storage system owing to the high theoretical capacity,good safety,abundant natural reserves,and low cost of Al and S.Howeve...Rechargeable aluminum-sulfur(Al-S)batteries have been considered as a highly potential energy storage system owing to the high theoretical capacity,good safety,abundant natural reserves,and low cost of Al and S.However,the research progress of Al-S batteries is limited by the slow kinetics and shuttle effect of soluble polysulfides intermediates.Herein,an interconnected free-standing interlayer of iron sin-gle atoms supported on porous nitrogen-doped carbon nanofibers(FeSAs-NCF)on the separator is developed and used as both catalyst and chemical barrier for Al-S batteries.The atomically dispersed iron active sites(Fe-N_(4))are clearly identified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption near-edge structure.The Al-S battery with the FeSAs-NCF shows an improved specific capacity of 780 mAh g^(−1)and enhanced cycle stability.As evidenced by experimental and theoretical results,the atomically dispersed iron active centers on the separator can chemically adsorb the polysulfides and accelerate reaction kinetics to inhibit the shuttle effect and promote the reversible conversion between aluminum polysulfides,thus improving the electrochemical performance of the Al-S battery.This work provides a new way that can not only promote the conversion of aluminum sulfides but also suppress the shuttle effect in Al-S batteries.展开更多
基金financially supported by Soft Science Research Project of Guangdong Province(No.2017B030301013)the Shenzhen Science and Technology Research(Grant No.JCYJ20170818085823773,ZDSYS201707281026184)+1 种基金China Postdoctoral Science Foundation(2019M660317)the National Science Foundation of China(No.U1864213)。
文摘Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery performance,however,their effect on the formation mechanism of the oxygen reduction product(NaO_(2))is still unclear.Here,we have investigated the formation mechanism of NaO_(2) during the discharge process in the presence of a redox mediator with the help of atomic/nano-scale in-situ characterization tools used in concert(e.g.atomic force microscope,electrochemical quartz crystal microbalance(EQCM)and laser nano-particle analyzer).As a result,real-time observations on different time scales show that by shuttling electrons to the electrolyte,the redox mediator enables formation of NaO_(2) in the solution-phase instead of within a finite region near the electrode surface.These findings provide new fundamental insights on the understanding of Na-O_(2) batteries and new consequently perspectives on designing high performance metal-O_(2) batteries and other related functions.
文摘Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.
基金supported by the Key Research and Development Projects of Anhui Province(No.202304a05020031).
文摘Lithium-sulfur batteries(LSBs)have attracted widespread attention due to their high theoretical energy density.However,the dissolution of long-chain polysulfides into the electrolyte(the“shuttle effect”)leads to rapid capacity decay.Therefore,finding suitable materials to mitigate the shuttle effect of polysulfides is crucial for enhancing the electrochemical performance of lithium-sulfur batteries.In this study,LSBs’separator is modified with Ni_(3)V_(2)O_(8)nanoparticles@carboxylated carbon nanotubes(Ni_(3)V_(2)O_(8)@CNTs)composite.There are abundant oxygen vacancies in Ni_(3)V_(2)O_(8)@CNTs composite which plays a synergistic effect on shuttle effect.The Ni_(3)V_(2)O_(8)can tightly anchor soluble polysulfides through oxygen vacancies,while the CNTs not only facilitate the transport of ions and electrons but also weaken the migration of polysulfides,limiting shuttle effect.As a result,the cycling stability of LSBs using Ni_(3)V_(2)O_(8)@CNTs-modified separator has been significantly improved(with a capacity decay rate of only 0.0334%after 1500 cycles at 4.0C).This study proposes a strategy to design modified separator for high-performance LSBs.
文摘A functional interlayer based on two-dimensional(2D)porous modified vermiculite nanosheets(PVS)was obtained by acid-etching vermiculite nanosheets.The as-obtained 2D porous nanosheets exhibited a high specific surface area of 427 m^(2)·g^(-1)and rich surface active sites,which help restrain polysulfides(LiPSs)through good physi-cal and chemical adsorption,while simultaneously accelerating the nucleation and dissolution kinetics of Li_(2)S,effec-tively suppressing the shuttle effect.The assembled lithium-sulfur batteries(LSBs)employing the PVS-based inter-layer delivered a high initial discharge capacity of 1386 mAh·g^(-1)at 0.1C(167.5 mAh·g^(-1)),long-term cycling stabil-ity,and good rate property.
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.
文摘Despite their high theoretical capacity and energy density,lithiumsulfur(Li–S)batteries still face challenges such as soluble lithium polysulfides(LiPSs)shuttling and sluggish redox kinetics.In this work,we used a novel MoS_(2)-Mo_(2)C heterostructure anchored on a carbon sponge(CS)as a Li_(2)S host to solve these problems.A simple hydrothermal process following carbothermal reduction was used to construct the MoS_(2)-Mo_(2)C heterostructure,enabling control of the phases and integration of MoS_(2) and Mo_(2)C.Structural characterization confirmed the coherent interface of the heterostructure with a precise orientation relationship between the two phases and their uniform distribution.An evaluation of the adsorption and catalytic performance of the material showed that it has an exceptional LiPSs adsorption capacity with faster conversion from Li_(2)S_(4) to Li_(2)S_(2).Density functional theory calculations further confirmed these results.As a result,the cathode had a high initial discharge capacity of 693 mAh g^(−1) at 0.2 C and achieved stable cycling at 2 C for 500 cycles with a low decay rate of 0.107%per cycle.The heterostructure design,coupled with the macroporous CS framework,effectively prevented the shuttling and increased sulfur utilization,offering a promising way to produce practical high-energydensity Li–S batteries.
基金supported by the financial support from the National Research Foundation,Singapore,under its Singapore-China Joint Flagship Project(Clean Energy).
文摘Aqueous Zn-iodine batteries(ZIBs)face the formidable challenges towards practical implementation,including metal corrosion and rampant dendrite growth on the Zn anode side,and shuttle effect of polyiodide species from the cathode side.These challenges lead to poor cycle stability and severe self-discharge.From the fabrication and cost point of view,it is technologically more viable to deploy electrolyte engineering than electrode protection strategies.More importantly,a synchronous method for modulation of both cathode and anode is pivotal,which has been often neglected in prior studies.In this work,cationic poly(allylamine hydrochloride)(Pah^(+))is adopted as a low-cost dual-function electrolyte additive for ZIBs.We elaborate the synchronous effect by Pah^(+)in stabilizing Zn anode and immobilizing polyiodide anions.The fabricated Zn-iodine coin cell with Pah^(+)(ZnI_(2) loading:25 mg cm^(−2))stably cycles 1000 times at 1 C,and a single-layered 3.4 cm^(2) pouch cell(N/P ratio~1.5)with the same mass loading cycles over 300 times with insignificant capacity decay.
基金the financial support from the Natural Science Foundation of Jiangsu Province(BK20231292)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(24)3091)+6 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25_1429)the National Key R&D Program of China(2024YFE0109200)the Fundamental Research Funds for the Central Universities(No.2024300440)Guangdong Basic and Applied Basic Research Foundation(2025A1515011098)the National Natural Science Foundation of China(12464032)the Natural Science Foundation of Jiangxi Province(20232BAB201032)Ji'an Science and Technology Plan Project(2024H-100301)。
文摘Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.
基金support of the National Natural Science Foundation of China(22075131 and 22078265)the Shaanxi Fundamental Science Research Project for Mathematics and Physics under Grants(No.22JSZ005)the State-Key Laboratory of Multiphase Complex Systems(No.MPCS-2021-A).
文摘Lithium-sulfur(Li-S)batteries require efficient catalysts to accelerate polysulfide conversion and mitigate the shuttle effect.However,the rational design of catalysts remains challenging due to the lack of a systematic strategy that rationally optimizes electronic structures and mesoscale transport properties.In this work,we propose an autogenously transformed CoWO_(4)/WO_(2) heterojunction catalyst,integrating a strong polysulfide-adsorbing intercalation catalyst with a metallic-phase promoter for enhanced activity.CoWO_(4) effectively captures polysulfides,while the CoWO_(4)/WO_(2) interface facilitates their S-S bond activation on heterogenous catalytic sites.Benefiting from its directional intercalation channels,CoWO_(4) not only serves as a dynamic Li-ion reservoir but also provides continuous and direct pathways for rapid Li-ion transport.Such synergistic interactions across the heterojunction interfaces enhance the catalytic activity of the composite.As a result,the CoWO_(4)/WO_(2) heterostructure demonstrates significantly enhanced catalytic performance,delivering a high capacity of 1262 mAh g^(−1) at 0.1 C.Furthermore,its rate capability and high sulfur loading performance are markedly improved,surpassing the limitations of its single-component counterparts.This study provides new insights into the catalytic mechanisms governing Li-S chemistry and offers a promising strategy for the rational design of high-performance Li-S battery catalysts.
基金supported by the National Key Research and Development Program(2018YFB1501500)the National Science Foundation for Excellent Young Scholars of China(21922815)+2 种基金the National Key Research and Development(R&D)Program of China(2020YFB1505800)the Research and Development Project of Key Core and Common Technology of Shanxi Province(2020XXX014)the Fundamental Research Program of Shanxi Province(20210302123008,20210302124101)。
文摘Lithium-sulfur battery(LSB) has high energy density but is limited by the polysulfides shuttle and dendrite growth during cycling. Herein, a free-standing cellulose nanofiber(CNF) separator is designed and fabricated in isopropanol/water suspension through vacuum filtration progress. CNFs with abundant polar oxygen-containing functional groups can chemically immobilize the polysulfides, and suppress the formation of the dendrites by controlling the surface morphology of the SEI on lithium metal in LSB. The isopropanol content in a suspension can fine-tune the pore structure of the membrane to achieve optimal electrochemical performance. The prepared separator displays integrated advantages of an ultrathin thickness(19 μm), lightweight(0.87 mg cm^(-2)), extremely high porosity(98.05%), and decent electrolyte affinity. As a result, the discharge capacity of the LSB with CNF separator at the first and 100 th cycle is 1.4 and 1.3 times that of PP separator, respectively. Our research provides an environmentalfriendly and facile strategy for the preparation of multifunctional separators for LSBs.
基金support from the “Joint International Laboratory on Environmental and Energy Frontier Materials”“Innovation Research Team of High-Level Local Universities in Shanghai”support from the National Natural Science Foundation of China (22209103)
文摘Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-electron reaction between sulfur and lithium in liquid electrolyte makes the capacity much smaller than the theoretical value.Many methods were proposed for inhibiting the shuttle effect of polysulfide,improving corresponding redox kinetics and enhancing the integral performance of Li–S batteries.Here,we will comprehensively and systematically summarize the strategies for inhibiting the shuttle effect from all components of Li–S batteries.First,the electrochemical principles/mechanism and origin of the shuttle effect are described in detail.Moreover,the efficient strategies,including boosting the sulfur conversion rate of sulfur,confining sulfur or lithium polysulfides(LPS)within cathode host,confining LPS in the shield layer,and preventing LPS from contacting the anode,will be discussed to suppress the shuttle effect.Then,recent advances in inhibition of shuttle effect in cathode,electrolyte,separator,and anode with the aforementioned strategies have been summarized to direct the further design of efficient materials for Li–S batteries.Finally,we present prospects for inhibition of the LPS shuttle and potential development directions in Li–S batteries.
基金financially supported by the National Key R&D Program of China(2016YFB0100100)the National Natural Science Foundation of China(Nos.21433013,U1832218)the support from China Scholarship Council
文摘The polysulfides shuttle effect represents a great challenge in achieving high capacity and long lifespan of lithium/sulfur(Li/S)cells.A comprehensive understanding of the shuttle-related sulfur speciation and diffusion process is vital for addressing this issue.Herein,we employed in situ/operando X-ray absorption spectroscopy(XAS)to trace the migration of polysulfides across the Li/S cells by precisely monitoring the sulfur chemical speciation at the cathodic electrolyte-separator and electrolyte-anode interfaces,respectively,in a real-time condition.After we adopted a shuttle-suppressing strategy by introducing an electrocatalytic layer of twinborn bismuth sulfide/bismuth oxide nanoclusters in a carbon matrix(BSOC),we found the Li/S cell showed greatly improved sulfur utilization and longer life span.The operando S Kedge XAS results revealed that the BSOC modification was bi-functional:trapping polysulfides and catalyzing conversion of sulfur species simultaneously.We elucidated that the polysulfide trapping-and-catalyzing effect of the BSOC electrocatalytic layer resulted in an effective lithium anode protection.Our results could offer potential stratagem for designing more advanced Li/S cells.
基金support of the National Natural Science Foundation of China(No.21773188,No.22179109)central universities fundamental research fund(XDJK2019AA002)Chongqing Natural Science fund(cstc2020jcyj-bshx0047,cstc2021jcyj-bsh0173).
文摘Lithium–sulfur(Li-S)batteries have the advantages of high theoretical specific capacity(1675 mAh g^(−1)),rich sulfur resources,low production cost,and friendly environment,which makes it one of the most promising next-generation rechargeable energy storage devices.However,the“shuttle effect”of polysulfide results in the passivation of metal lithium anode,the decrease of battery capacity and coulombic efficiency,and the deterioration of cycle stability.To realize the commercialization of Li-S batteries,its serious“shuttle effect”needs to be suppress.The commercial separators are ineffective to suppress this effect because of its large pore size.Therefore,it is an effective strategy to modify the separator surface and introduce functional modified layer.In addition to the blocking strategy,the catalysis of polysulfide conversion reaction is also an important factor hindering the migration of polysulfides.In this review,the principles of separator modification,functionalization,and catalysis in Li-S batteries are reviewed.Furthermore,the research trend of separator functionalization and polysulfide catalysis in the future is prospected.
基金supported by the National Natural Science Foundation of China (22075028)the Beijing Institute of Technology Research Fund Program for Young Scholars (2019CX04092).
文摘Multivalent metal-sulfur(M-S,where M=Mg,Al,Ca,Zn,Fe,etc.)batteries offer unique opportunities to achieve high specific capacity,elemental abundancy and cost-effectiveness beyond lithium-ion batteries(LIBs).However,the slow diffusion of multivalent-metal ions and the shuttle of soluble polysulfide result in impoverished reversible capacity and limited cycle performance of M-S(Mg-S,Al-S,Ca-S,Zn-S,Fe-S,etc.)batteries.It is a necessity to optimize the electrochemical performance,while deepening the understanding of the unique electrochemical reaction mechanism,such as the intrinsic multi-electron reaction process,polysulfides dissoluti on and the in stability of metal an odes.To solve these problems,we have summarized the state-of-the-art progress of current M-S batteries,and sorted out the existing challen ges for different multivalent M-S batteries according to sulfur cathode,electrolytes,metallic an ode and current collectors/separators,respectively.In this literature,we have surveyed and exemplified the strategies developed for better M-S batteries to strengthen the application of green,cost-effective and high energy density M-S batteries.
基金financially supported by the Tsinghua-Foshan Innovation Special Fund(Grant No.2018THFS0409)the China Postdoctoral Science Foundation(Grant No.2019M650668)the National Key Research and Development Program of China(Grant No.2016YFA0201003)。
文摘Rechargeable lithium-oxygen(Li-O_(2))batteries are the next generation energy storage devices due to their ultrahigh theoretical capacity.Redox mediators(RMs)are widely used as a homogenous electrocatalyst in non-aqueous Li-O_(2)batteries to enhance their discharge capacity and reduce charge overpotential.However,the shuttle effect of RMs in the electrolyte solution usually leads to corrosion of the Li metal anode and uneven Li deposition on the anode surface,resulting in unwanted consumption of electrocatalysts and deterioration of the cells.It is therefore necessary to take some measures to prevent the shuttle effect of RMs and fully utilize the soluble electrocatalysts.Herein,we summarize the strategies to suppress the RM shuttle effect reported in recent years,including electrolyte additives,protective separators and electrode modification.The mechanisms of these strategies are analyzed and their corresponding requirements are discussed.The electrochemical properties of Li-O_(2)batteries with different strategies are summarized and compared.The challenges and perspectives on preventing the shuttle effect of RMs are described for future study.This review provides guidance for achieving shuttle-free redox mediation and for designing Li-O_(2)cells with a long cycle life,high energy efficiency and highly reversible electrochemical reactions.
基金supported by the National Natural Science Foundation of China(Nos.51631004 and 52130101)the Basic Construction Fund in Jilin Province Budget for 2019(No.2019C042-8).
文摘According to a statistic,approximately 6 trillion cigarettes are smoked each year all over the world,which produces approximately 1.2 million tons of discarded cigarette butts.The discarded cigarette filters are non-biodegradable,thus they produce a mass of waste disposal and cause environmental pollution is-sue.For the purpose of transforming waste into wealth and reducing environmental pollution,nitrogen and sulfur co-doped carbon nanofiber/carbon black(N,S-CNF/CB)composite derived from the discarded cigarette filters is employed to modify glass fiber(GF)separator for the first time in this study.N,S-CNF improves binding ability towards sodium polysulfides(SPSs)by chemisorption.Non-polar CB limits the dissolution of SPSs in the liquid electrolyte by physisorption.The experiment and density functional theory calculation results indicate that a RT-Na/S battery with a N,S-CNF/CB+GF separator exhibits good cycling stability and rate performance.After 100 cycles at a low current rate of 0.1 C,a RT-Na/S battery with a sulfur mass fraction of 71%delivers a discharge capacity of 703 mAh g^(−1).In addition,at a high current rate of 0.5 C,a discharge capacity of 527 mAh g^(−1) is still maintained after 900 cycles with a very low capacity fading rate of 0.035%per cycle.
基金Supplementary data to this article can be found online at https://doi.org/10.1016/j.matre.2022.100159.
文摘Polysulfide absorption in a micropore-rich structure has been reported to be capable of efficiently confining the shuttle effect for high-performance lithium-sulfur(Li–S)batteries.Here,a labyrinth maze-like spherical honeycomb-like carbon with micropore-rich structure was synthesized,which is employed as a template host material of sulfur to study the shuttle effects.The results strongly confirm that a diffusion controlled process rather than an absorption resulted surface-controlled process occurs in an even micropore-rich cathode but still greatly inhibits the shuttle effect.Thus,the battery achieves a high initial discharge specific capacity of 1120 mAh g1 at 0.25 C and super cycling stability for 1635 cycles with only 0.035%capacity decay per cycle with 100%Coulombic efficiency.We would like to propose a new mechanism for shuttle effect inhibition in micropores.In terms of the diffusion control process in microporous paths of a labyrinth maze structure,polysulfides experience a long travel to realize continuous reductions of sulfur and polysulfides until formation of the final solid product.This efficiently prevents the polysulfides escaping to electrolyte.The labyrinth maze-like honeycomb structure also offers fast electron transfer and enhanced mass transport as well as robust mechanical strength retaining intact structure for long cycle life.This work sheds lights on new fundamental insights behind the shuttle effects with universal significance while demonstrating prominent merits of a robust labyrinth maze-like structure in high performance cathode for high-performance Li–S batteries.
基金financially supported by the National Natural Science Foundation of China (No.51874197)Natural Science Foundation of Shanghai (Nos.21ZR1429400,22ZR1429700)
文摘Rechargeable aluminum-sulfur(Al-S)batteries have been considered as a highly potential energy storage system owing to the high theoretical capacity,good safety,abundant natural reserves,and low cost of Al and S.However,the research progress of Al-S batteries is limited by the slow kinetics and shuttle effect of soluble polysulfides intermediates.Herein,an interconnected free-standing interlayer of iron sin-gle atoms supported on porous nitrogen-doped carbon nanofibers(FeSAs-NCF)on the separator is developed and used as both catalyst and chemical barrier for Al-S batteries.The atomically dispersed iron active sites(Fe-N_(4))are clearly identified by aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and X-ray absorption near-edge structure.The Al-S battery with the FeSAs-NCF shows an improved specific capacity of 780 mAh g^(−1)and enhanced cycle stability.As evidenced by experimental and theoretical results,the atomically dispersed iron active centers on the separator can chemically adsorb the polysulfides and accelerate reaction kinetics to inhibit the shuttle effect and promote the reversible conversion between aluminum polysulfides,thus improving the electrochemical performance of the Al-S battery.This work provides a new way that can not only promote the conversion of aluminum sulfides but also suppress the shuttle effect in Al-S batteries.
