Facilitating sulfur reduction reaction(SRR)is a promising pathway to tackle the polysulfide shuttle effect and enhance the electrochemical performance of lithium-sulfur(Li-S)batteries.Catalysts with a solo active site...Facilitating sulfur reduction reaction(SRR)is a promising pathway to tackle the polysulfide shuttle effect and enhance the electrochemical performance of lithium-sulfur(Li-S)batteries.Catalysts with a solo active site can reduce a reaction barrier of a certain transition-intermediate,but the linear scaling relationship between multi-intermediates still obstructs overall SRR.Herein,we construct tandem Co–O dual sites with accelerating SRR kinetics by loading highly dispersed cobalt sulfide clusters on halloysite.This catalyst features Co with upshifted d-orbital and O with downshifted p-orbital,which cooperatively adsorb long-chain polysulfide and dissociate an S–S bond,thus achieving both optimal adsorption–desorption strength and reduced conversion energy barrier of multi-intermediates in SRR.The Li-S coin batteries using the electrocatalyst endows a high specific capacity of 1224.3 m Ah g^(-1)at 0.2 C after 200cycles,and enhances cycling stability with a low-capacity decay rate of 0.03%per cycle at 1 C after1000 cycles.Moreover,the strategy of the tandem Co–O dual sites is further verified in a practical Li-S pouch battery that realizes 1014.1 m Ah g^(-1)for 100 cycles,which opens up a novel avenue for designing electrocatalysts to accelerate multi-step reactions.展开更多
A simple and general method for the synthesis of bi(acyl)disulfides is reported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfide at 65℃ under PTC,which can react with acyl halides to afford b...A simple and general method for the synthesis of bi(acyl)disulfides is reported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfide at 65℃ under PTC,which can react with acyl halides to afford bi(acyl)disulfides in good to excellent isolated yields.The effects of solvents and phase transfer catalysts are discussed.展开更多
Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyze...Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyzes the effect of the electrolyte-to-sulfur(E/S) ratios on battery energy density and the challenges for sulfur reduction reactions(SRR) under lean electrolyte conditions. Accordingly, we review the use of various polar transition metal sulfur hosts as corresponding solutions to facilitate SRR kinetics at low E/S ratios(< 10 μL mg~(-1)), and the strengths and limitations of different transition metal compounds are presented and discussed from a fundamental perspective. Subsequently, three promising strategies for sulfur hosts that act as anchors and catalysts are proposed to boost lean electrolyte Li–S battery performance. Finally, an outlook is provided to guide future research on high energy density Li–S batteries.展开更多
The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of io...The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of ion/electron-conductive and defect-rich networks on the threedimension carbon cathode,leading to its tunable activity for both relieving the shuttle phenomenon and accelerating the sulfur redox reaction kinetics.As expected,the defective carbon cathode harvests a high rate capacity of 1217.8 mAh g^(-1)at 0.2 C and a superior capacity retention of61.7%at 2 C after 500 cycles.Even under the sulfur mass loading of 11.1 mg cm^(-2),the defective cathode still holds a remarkable areal capacity of 8.5 mAh cm^(-2).展开更多
The practical application of lithium-sulfur(Li-S)batteries is greatly hindered by soluble polysulfides shuttling and sluggish sulfur redox kinetics.Rational design of multifunctional hybrid materials with superior ele...The practical application of lithium-sulfur(Li-S)batteries is greatly hindered by soluble polysulfides shuttling and sluggish sulfur redox kinetics.Rational design of multifunctional hybrid materials with superior electronic conductivity and high electrocatalytic activity,e.g.,heterostructures,is a promising strategy to solve the above obstacles.Herein,a binary metal sulfide MnS-MoS_(2) heterojunction electrocatalyst is first designed for the construction of high-sulfur-loaded and durable Li-S batteries.The MnS-MoS_(2) p-n heterojunction shows a unique structure of MoS_(2) nanosheets decorated with ample MnS nanodots,which contributes to the formation of a strong built-in electric field at the two-phase interface.The MnS-MoS_(2) hybrid host shows strong soluble polysulfide affinity,enhanced electronic conductivity,and exceptional catalytic effect on sulfur reduction.Benefiting from the synergistic effect,the as-derived S/MnS-MoS_(2) cathode delivers a superb rate capability(643 m A h g^(-1)at 6 C)and a durable cyclability(0.048%decay per cycle over 1000 cycles).More impressively,an areal capacity of 9.9 m A h cm^(-2)can be achieved even under an extremely high sulfur loading of 14.7 mg cm^(-2)and a low electrolyte to sulfur ratio of 2.9μL mg^(-1).This work provides an in-depth understanding of the interfacial catalytic effect of binary metal compound heterojunctions on sulfur reaction kinetics.展开更多
The polysulfide shuttling effect is the primary bottleneck restricting the industrial application of Li-S batteries,and the electrocatalytic sulfur reduction reaction(SRR)has emerged as an effective solution.Carbon-ba...The polysulfide shuttling effect is the primary bottleneck restricting the industrial application of Li-S batteries,and the electrocatalytic sulfur reduction reaction(SRR)has emerged as an effective solution.Carbon-based singleatom catalysts(SACs),which promotes SRR,show great potential in inhibiting the shuttling effect of polysulfides.Meanwhile,the optimization and rational design of such catalysts requires a deep understanding to the fundamental SRR mechanism and remains highly nontrivial.In this work,we construct a comprehensive database of carbon-based SACs,covering different coordination patterns,heteroatoms,and transition metals.The SRR activities are determined using density functional theory calculations,revealing a synergistic effect between the p orbital of the heteroatom and the d orbital of the transition metal.This interplay underscores the critical importance of the coordination environment for SRR under the ortho-P_(2)C_(2)structure.Regardless of the transition metal type,the ortho-P_(2)C_(2)coordination pattern significantly enhances the SRR performance of SACs,surpassing the widely reported N_(3)C_(1)and N_(4)coordinated graphene-based SACs.Furthermore,heteroatoms with ortho-P_(2)C_(2)may exhibit SRR activity.In a word,by using this comprehensive dataset and data-driven framework,we propose a promising novel class of coordination structure(ortho-P_(2)C_(2)structure)and neglected design principle.展开更多
Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which ...Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.展开更多
Lithium–sulfur(Li–S)batteries have been recognized as promising substitutes for current energy-storage technologies owing to their exceptional advantages in very high-energy density and excellent material sustainabi...Lithium–sulfur(Li–S)batteries have been recognized as promising substitutes for current energy-storage technologies owing to their exceptional advantages in very high-energy density and excellent material sustainability.The cathode with high sulfur areal loading is vital for the practical applications of Li–S batteries with very high energy density.However,the high sulfur loading in an electrode results in poor rate and cycling performances of batteries in most cases.Herein,we used diameters of 5.0(D5)and 13.0(D13)mm to probe the effect of electrodes with different sizes on the rate and cycling performances under a high sulfur loading(4.5 mg cm^-2).The cell with D5 sulfur cathode exhibits better rate and cycling performances comparing with a large(D13)cathode.Both the high concentration of lithium polysulfides and corrosion of lithium metal anode impede rapid kinetics of sulfur redox reactions,which results in inferior battery performance of the Li–S cell with large diameter cathode.This work highlights the importance of rational matching of the large sulfur cathode with a high areal sulfur loading,carbon modified separators,organic electrolyte,and Li metal anode in a pouch cell,wherein the sulfur redox kinetics and lithium metal protection should be carefully considered under the flooded lithium polysulfide conditions in a working Li–S battery.展开更多
Lithium-sulfur(Li-S)battery is highly regarded as a promising next-generation energy storage device but suffers from sluggish sulfur redox kinetics.Probing the behavior and mechanism of the sulfur species on electroca...Lithium-sulfur(Li-S)battery is highly regarded as a promising next-generation energy storage device but suffers from sluggish sulfur redox kinetics.Probing the behavior and mechanism of the sulfur species on electrocatalytic surface is the first step to rationally introduce polysulfide electrocatalysts for kinetic promotion in a working battery.Herein,crystalline lithium sulfide(Li_(2)S)is exclusively observed on electrocatalytic surface with uniform spherical morphology while Li_(2)S on non-electrocatalytic surface is amorphous and irregular.Further characterization indicates the crystalline Li_(2)S preferentially participates in the discharge/charge process to render reduced interfacial resistance,high sulfur utilization,and activated sulfur redox reactions.Consequently,crystalline Li_(2)S is proposed with thermodynamic and kinetic advantages to rati on alize the superior performances of Li-S batteries.The evoluti on of solid Li_(2)S on electrocatalytic surface not only addresses the polysulfide electrocatalysis strategy,but also inspires further investigation into the chemistry of energy-related processes.展开更多
This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and ...This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and status are investigated.A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio(72%S).In contrast,a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio(44%S).In carbonate ester electrolyte,only the sulfur trapped in porous structures is active via‘solid-solid’behavior during cycling.The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents.To improve the capacity of the sulfur-rich cathode,ether electrolyte with NaNO_(3) additive is explored to realize a‘solid-liquid’sulfur redox process and confine the shuttle effect of the dissolved polysulfides.As a result,the sulfur-rich cathode achieved high reversible capacity(483 mAh g^(−1)),corresponding to a specific energy of 362 Wh kg^(−1) after 200 cycles,shedding light on the use of ether electrolyte for high-loading sulfur cathode.展开更多
The sluggish kinetics in multistep sulfur redox reaction with different energy requirements for each step,is considered as the crucial handicap of lithium–sulfur(Li–S)batteries.Designing an electron reservoir,which ...The sluggish kinetics in multistep sulfur redox reaction with different energy requirements for each step,is considered as the crucial handicap of lithium–sulfur(Li–S)batteries.Designing an electron reservoir,which can dynamically release electron to/accept electron from sulfur species during dis-charge/charge,is the ideal strategy for realizing stepwise and dual-directional polysulfide electrocatalysis.Herein,a single Tb^(3+/4+)oxide with moderate unfilled f orbital is synthetized as an electron reservoir to optimize polysulfide adsorption via Tb–S and N…Li bonds,reduce activation energy barrier,expe-dite electron/Li+transport,and selectively catalyze both long-chain and short-chain polysulfide conversions during charge and discharge.As a result,Tb electron reservoir enables stable operation of low-capacity decay(0.087%over 500 cycles at 1 C),high sulfur loading(5.2 mg cm^(2))and electrolyte-starved(7.5μL mg^(-1))Li–S batteries.This work could unlock the potential of f orbital engineering for high-energy battery systems.展开更多
Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, ste...Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.展开更多
Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically requir...Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically require the use of either unstable sulfonimidoyl chlorides,toxic and corrosive sulfur fluorides,or expensive electrophilic fluorinating agents.Herein,we report an electrochemistry-enabled oxidative nucleophilic fluorination of readily available and bench-stable sulfinamides using a commercially available and easy-to-handle triethylamine trihydrofluoride.With other nucleophilic agents,this electrochemical approach also serves as a general approach to diverse sulfonimidoyl derivatives,including sulfonimidoyl azides and acetates.展开更多
Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been suc...Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.展开更多
Rationally designing sulfur hosts with the functions of confining lithium polysulfides(LiPSs)and promoting sulfur reaction kinetics is critically important to the real implementation of lithium-sulfur(Li-S)batteries.H...Rationally designing sulfur hosts with the functions of confining lithium polysulfides(LiPSs)and promoting sulfur reaction kinetics is critically important to the real implementation of lithium-sulfur(Li-S)batteries.Herein,the defect-rich carbon black(CB)as sulfur host was successfully constructed through a rationally regulated defect engineering.Thus-obtained defect-rich CB can act as an active electrocatalyst to enable the sulfur redox reaction kinetics,which could be regarded as effective inhibitor to alleviate the LiPS shuttle.As expected,the cathode consisting of sulfur and defect-rich CB presents a high rate capacity of 783.8 mA·h·g^−1 at 4 C and a low capacity decay of only 0.07% per cycle at 2 C over 500 cycles,showing favorable electrochemical performances.The strategy in this investigation paves a promising way to the design of active electrocatalysts for realizing commercially viable Li-S batteries.展开更多
To meet the ever-increasing energy demands, advanced electrode materials are strongly requested for the exploration of advanced energy storage and conversion technologies, such as Li-ion batteries, Li-S batteries, Li-...To meet the ever-increasing energy demands, advanced electrode materials are strongly requested for the exploration of advanced energy storage and conversion technologies, such as Li-ion batteries, Li-S batteries, Li-]Zn-air batteries, supercapacitors, dye-sensitized solar cells, and other electrocatalysis process (e.g., oxygen reductionlevolution reaction, hydrogen evolution reaction). Transition metal chalcogenides (TMCs, Le., sulfides and selenides) are forcefully considered as an emerging candidate, owing to their unique physical and chemical properties. Moreover, the integration of TMCs with conductive graphene host has enabled the significant improvement of electrochemical performance of devices. In this review, the recent research progress on TMC]graphene composites for applications in energy storage and conversion devices is summarized. The preparation process of TMC]graphene nanocomposites is also included. In order to promote an in-depth understanding of performance improvement for TMC/graphene materials, the operating principle of various devices and technologies are briefly presented. Finally, the perspectives are given on the design and construction of advanced electrode materials.展开更多
This letter describes a simple and efficient synthesis of 3-(cyclohexylamino)-7-hydroxy-2-arylimi- dazo[1,2-c]pyrimidin-5(6H)-one via a one-pot three-component reaction of cyclohexyl isocyanide, an aldehyde, and 4...This letter describes a simple and efficient synthesis of 3-(cyclohexylamino)-7-hydroxy-2-arylimi- dazo[1,2-c]pyrimidin-5(6H)-one via a one-pot three-component reaction of cyclohexyl isocyanide, an aldehyde, and 4-amiopyrimidine-2,6-diol in the presence of a catalytic amount of SSA.展开更多
Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)...Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,the limited active sites on the interface of the heterostructure offer unsatisfactory LiPSs conversion capability,rendering sluggish reaction kinetics.Herein,we have designed abnormal step-scheme nano-heterointerfaces,containing P-N,N-semimetal,and P-semimetal heterostructures as sulfur electrocatalysts to regulate the LiPSs catalytic conversion behavior,which demonstrates efficient catalytic activity and robust structural stability.The excellent electron-confinement contributed by the step-scheme barrier endows the electron gathering at the nano-heterointerfaces,conferring high selectivity and durability of electrocatalyst for an accelerated sulfur reduction reaction.The unique robust structure design further bestows the sulfur composite with favored ion/mass transportation within the electrode.Attributed to these structural features,the Li-S cell delivers excellent performance under high areal capacity over 7 mAh cm^(−2) and lean electrolyte/sulfur ratio below 2.5μL mg^(−1),decent rate capability up to 8 C,remarkable cyclic stability over 500 cycles,and satisfactory energy density of 386.3 Wh kg^(−1) in a 7.5 Ah pouch cell.This nano-heterointerface structure design strategy endows a sulfur cathode with superior LiPSs catalytic activity,opening new insights into high-performance Li-S batteries.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars(51225403)the National Natural Science Foundation of China(52042403)+3 种基金the National Postdoctoral Program for Innovative Talents(BX2021276)the China Postdoctoral Science Foundation(2020M682519)the Strategic Priority Research Program of Central South University(ZLXD2017005)the“CUG Scholar"Scientific Research Funds at China University of Geosciences(Wuhan)(Project No.20222020110)。
文摘Facilitating sulfur reduction reaction(SRR)is a promising pathway to tackle the polysulfide shuttle effect and enhance the electrochemical performance of lithium-sulfur(Li-S)batteries.Catalysts with a solo active site can reduce a reaction barrier of a certain transition-intermediate,but the linear scaling relationship between multi-intermediates still obstructs overall SRR.Herein,we construct tandem Co–O dual sites with accelerating SRR kinetics by loading highly dispersed cobalt sulfide clusters on halloysite.This catalyst features Co with upshifted d-orbital and O with downshifted p-orbital,which cooperatively adsorb long-chain polysulfide and dissociate an S–S bond,thus achieving both optimal adsorption–desorption strength and reduced conversion energy barrier of multi-intermediates in SRR.The Li-S coin batteries using the electrocatalyst endows a high specific capacity of 1224.3 m Ah g^(-1)at 0.2 C after 200cycles,and enhances cycling stability with a low-capacity decay rate of 0.03%per cycle at 1 C after1000 cycles.Moreover,the strategy of the tandem Co–O dual sites is further verified in a practical Li-S pouch battery that realizes 1014.1 m Ah g^(-1)for 100 cycles,which opens up a novel avenue for designing electrocatalysts to accelerate multi-step reactions.
文摘A simple and general method for the synthesis of bi(acyl)disulfides is reported.Sulfur is allowed to react with sodium hydroxide to give sodium disulfide at 65℃ under PTC,which can react with acyl halides to afford bi(acyl)disulfides in good to excellent isolated yields.The effects of solvents and phase transfer catalysts are discussed.
基金the Research Foundation-Flanders (FWO) for a Research Project (G0B3218N)the financial support by the National Natural Science Foundation of China (22005054)+3 种基金Natural Science Foundation of Fujian Province (2021J01149)State Key Laboratory of Structural Chemistry (20200007)Sichuan Science and Technology Program (project No.: 2022ZYD0016 and 2023JDRC0013)the National Natural Science Foundation of China (project No. 21776120)。
文摘Lithium–sulfur(Li–S) batteries have received widespread attention, and lean electrolyte Li–S batteries have attracted additional interest because of their higher energy densities. This review systematically analyzes the effect of the electrolyte-to-sulfur(E/S) ratios on battery energy density and the challenges for sulfur reduction reactions(SRR) under lean electrolyte conditions. Accordingly, we review the use of various polar transition metal sulfur hosts as corresponding solutions to facilitate SRR kinetics at low E/S ratios(< 10 μL mg~(-1)), and the strengths and limitations of different transition metal compounds are presented and discussed from a fundamental perspective. Subsequently, three promising strategies for sulfur hosts that act as anchors and catalysts are proposed to boost lean electrolyte Li–S battery performance. Finally, an outlook is provided to guide future research on high energy density Li–S batteries.
基金supported by the National Natural Science Foundation of China(52172239)Project of State Key Laboratory of Environment-Friendly Energy Materials+2 种基金Southwest University of Science and Technology(Grant Nos.21fksy24 and 18ZD320304)Chongqing Talents:Exceptional Young Talents Project(Grant No.CQYC201905041)Natural Science Foundation of Chongqing China(Grant No.cstc2021jcyj-jqX0031)。
文摘The defect chemistry is successfully modulated on free-standing and binder-free carbon cathodes for highly efficient Li-S redox reactions.Such rationally regulated defect engineering realizes the synchronization of ion/electron-conductive and defect-rich networks on the threedimension carbon cathode,leading to its tunable activity for both relieving the shuttle phenomenon and accelerating the sulfur redox reaction kinetics.As expected,the defective carbon cathode harvests a high rate capacity of 1217.8 mAh g^(-1)at 0.2 C and a superior capacity retention of61.7%at 2 C after 500 cycles.Even under the sulfur mass loading of 11.1 mg cm^(-2),the defective cathode still holds a remarkable areal capacity of 8.5 mAh cm^(-2).
基金financial support from the National Natural Science Foundation of China (NSFC,21875155,22032004)the support of the National Key Research and Development Program of China (2021YFA1201502)the support of the Nanqiang Young Top-notch Talent Fellowship in Xiamen University。
文摘The practical application of lithium-sulfur(Li-S)batteries is greatly hindered by soluble polysulfides shuttling and sluggish sulfur redox kinetics.Rational design of multifunctional hybrid materials with superior electronic conductivity and high electrocatalytic activity,e.g.,heterostructures,is a promising strategy to solve the above obstacles.Herein,a binary metal sulfide MnS-MoS_(2) heterojunction electrocatalyst is first designed for the construction of high-sulfur-loaded and durable Li-S batteries.The MnS-MoS_(2) p-n heterojunction shows a unique structure of MoS_(2) nanosheets decorated with ample MnS nanodots,which contributes to the formation of a strong built-in electric field at the two-phase interface.The MnS-MoS_(2) hybrid host shows strong soluble polysulfide affinity,enhanced electronic conductivity,and exceptional catalytic effect on sulfur reduction.Benefiting from the synergistic effect,the as-derived S/MnS-MoS_(2) cathode delivers a superb rate capability(643 m A h g^(-1)at 6 C)and a durable cyclability(0.048%decay per cycle over 1000 cycles).More impressively,an areal capacity of 9.9 m A h cm^(-2)can be achieved even under an extremely high sulfur loading of 14.7 mg cm^(-2)and a low electrolyte to sulfur ratio of 2.9μL mg^(-1).This work provides an in-depth understanding of the interfacial catalytic effect of binary metal compound heterojunctions on sulfur reaction kinetics.
基金supported by the Scientific Research Start-up Funds of Tsinghua SIGS(QD2021018C to Peng L)the National Natural Science Foundation of China(20231710015 and 22209096 to Peng L)+2 种基金GuangDong Basic and Applied Basic Research Foundation(2023A1515010059 to Peng L)Shenzhen Fundamental Research Program(JCYJ20220530143003008 to Peng L)Shenzhen Science and Technology Program(ZDSYS20230626091100001)。
文摘The polysulfide shuttling effect is the primary bottleneck restricting the industrial application of Li-S batteries,and the electrocatalytic sulfur reduction reaction(SRR)has emerged as an effective solution.Carbon-based singleatom catalysts(SACs),which promotes SRR,show great potential in inhibiting the shuttling effect of polysulfides.Meanwhile,the optimization and rational design of such catalysts requires a deep understanding to the fundamental SRR mechanism and remains highly nontrivial.In this work,we construct a comprehensive database of carbon-based SACs,covering different coordination patterns,heteroatoms,and transition metals.The SRR activities are determined using density functional theory calculations,revealing a synergistic effect between the p orbital of the heteroatom and the d orbital of the transition metal.This interplay underscores the critical importance of the coordination environment for SRR under the ortho-P_(2)C_(2)structure.Regardless of the transition metal type,the ortho-P_(2)C_(2)coordination pattern significantly enhances the SRR performance of SACs,surpassing the widely reported N_(3)C_(1)and N_(4)coordinated graphene-based SACs.Furthermore,heteroatoms with ortho-P_(2)C_(2)may exhibit SRR activity.In a word,by using this comprehensive dataset and data-driven framework,we propose a promising novel class of coordination structure(ortho-P_(2)C_(2)structure)and neglected design principle.
基金This work was supported by the Natural Science Foundation of China(22125902,21975243,U2032202,and U1932201)the National Program for Support of Topnotch Young Professionals,the DNL Cooperation Fund,CAS(DNL202020)+2 种基金the Anhui Science Fund for Distinguished Young Scholars(2208085J15)the National Key R&D Program of China(2022YFA1504101)Users with Excellence Program of Hefei Science Center CAS(2021HSC-UE002).
文摘Sulfur redox reactions render lithium–sulfur(Li–S)batteries with an energy density of>500Whkg−1 but suffer a low practical capacity and fast capacity fade due to sluggish sulfur redox reaction(SRR)kinetics,which lies in the complex reaction process that involves a series of reaction intermediates and proceeds via a cascade reaction.Here,we present a Pt–Cu dual-atom catalyst(Pt/Cu-NG)as an electrocatalyst for sulfur redox reactions.Pt/Cu-NG enabled the rapid conversion of soluble polysulfide intermediates into insoluble Li2S2/Li2S,and consequently,it prevented the accumulation and shuttling of lithium polysulfides,thus outperforming the corresponding single-atom catalysts(SACs)with individual Pt or Cu sites.Operando X-ray absorption spectroscopy and density functional theory calculations revealed that a synergistic effect between the paired Pt and Cu atoms modifies the electronic structure of the Pt site through d-orbital interactions,resulting in an optimal moderate interaction of the metal atom with the different sulfide species.This optimal interaction enhanced charge transfer kinetics and promoted sulfur redox reactions.Our work thus provides important insights on the atomic scale into the synergistic effects operative in dual-atom catalysts and will thus pave the way to electrocatalysts with enhanced efficiency for high-performance Li–S batteries.
基金supported by the National Key Research and Development Program(2016YFA0202500 and 2016YFA0200102)the National Natural Science Foundation of China(21776019,21805162,51772069,and U1801257)+1 种基金China Postdoctoral Science Foundation(2018M630165)Beijing Key Research and Development Plan(Z181100004518001)
文摘Lithium–sulfur(Li–S)batteries have been recognized as promising substitutes for current energy-storage technologies owing to their exceptional advantages in very high-energy density and excellent material sustainability.The cathode with high sulfur areal loading is vital for the practical applications of Li–S batteries with very high energy density.However,the high sulfur loading in an electrode results in poor rate and cycling performances of batteries in most cases.Herein,we used diameters of 5.0(D5)and 13.0(D13)mm to probe the effect of electrodes with different sizes on the rate and cycling performances under a high sulfur loading(4.5 mg cm^-2).The cell with D5 sulfur cathode exhibits better rate and cycling performances comparing with a large(D13)cathode.Both the high concentration of lithium polysulfides and corrosion of lithium metal anode impede rapid kinetics of sulfur redox reactions,which results in inferior battery performance of the Li–S cell with large diameter cathode.This work highlights the importance of rational matching of the large sulfur cathode with a high areal sulfur loading,carbon modified separators,organic electrolyte,and Li metal anode in a pouch cell,wherein the sulfur redox kinetics and lithium metal protection should be carefully considered under the flooded lithium polysulfide conditions in a working Li–S battery.
基金supported by the National Key Research and Development Program(2016YFA0202500 and 2016YFA0200102)the National Natural Scientific Foundation of China(21676160,21825501,and U1801257)the Tsinghua University Initiative Scientific Research Program.
文摘Lithium-sulfur(Li-S)battery is highly regarded as a promising next-generation energy storage device but suffers from sluggish sulfur redox kinetics.Probing the behavior and mechanism of the sulfur species on electrocatalytic surface is the first step to rationally introduce polysulfide electrocatalysts for kinetic promotion in a working battery.Herein,crystalline lithium sulfide(Li_(2)S)is exclusively observed on electrocatalytic surface with uniform spherical morphology while Li_(2)S on non-electrocatalytic surface is amorphous and irregular.Further characterization indicates the crystalline Li_(2)S preferentially participates in the discharge/charge process to render reduced interfacial resistance,high sulfur utilization,and activated sulfur redox reactions.Consequently,crystalline Li_(2)S is proposed with thermodynamic and kinetic advantages to rati on alize the superior performances of Li-S batteries.The evoluti on of solid Li_(2)S on electrocatalytic surface not only addresses the polysulfide electrocatalysis strategy,but also inspires further investigation into the chemistry of energy-related processes.
基金This research was supported by the Australian Research Council(ARC)(DE170100928,DP170101467)an Australian Renewable Energy Agency(ARENA)Project(G00849).The authors acknowledge the use of the facilities at the UOW Electron Microscopy Center(LE0882813 and LE0237478)and Dr.Tania Silver for critical reading of the manuscript.
文摘This work reports influence of two different electrolytes,carbonate ester and ether electrolytes,on the sulfur redox reactions in room-temperature Na-S batteries.Two sulfur cathodes with different S loading ratio and status are investigated.A sulfur-rich composite with most sulfur dispersed on the surface of a carbon host can realize a high loading ratio(72%S).In contrast,a confined sulfur sample can encapsulate S into the pores of the carbon host with a low loading ratio(44%S).In carbonate ester electrolyte,only the sulfur trapped in porous structures is active via‘solid-solid’behavior during cycling.The S cathode with high surface sulfur shows poor reversible capacity because of the severe side reactions between the surface polysulfides and the carbonate ester solvents.To improve the capacity of the sulfur-rich cathode,ether electrolyte with NaNO_(3) additive is explored to realize a‘solid-liquid’sulfur redox process and confine the shuttle effect of the dissolved polysulfides.As a result,the sulfur-rich cathode achieved high reversible capacity(483 mAh g^(−1)),corresponding to a specific energy of 362 Wh kg^(−1) after 200 cycles,shedding light on the use of ether electrolyte for high-loading sulfur cathode.
基金This research was funded in part by National Natural Science Foundation of China(Grant Nos.22109119,51972238 and U21A2081)Natural Science Foundation of Zhejiang Province(Grant Nos.LQ19B030006 and LQ22B030003)+1 种基金Major Scientific and Technological Inno-vation Project of Wenzhou City(Grant No.ZG2021013)Postgraduate Innovation Foundation of Wenzhou Uni-versity(Grant No.316202102051).
文摘The sluggish kinetics in multistep sulfur redox reaction with different energy requirements for each step,is considered as the crucial handicap of lithium–sulfur(Li–S)batteries.Designing an electron reservoir,which can dynamically release electron to/accept electron from sulfur species during dis-charge/charge,is the ideal strategy for realizing stepwise and dual-directional polysulfide electrocatalysis.Herein,a single Tb^(3+/4+)oxide with moderate unfilled f orbital is synthetized as an electron reservoir to optimize polysulfide adsorption via Tb–S and N…Li bonds,reduce activation energy barrier,expe-dite electron/Li+transport,and selectively catalyze both long-chain and short-chain polysulfide conversions during charge and discharge.As a result,Tb electron reservoir enables stable operation of low-capacity decay(0.087%over 500 cycles at 1 C),high sulfur loading(5.2 mg cm^(2))and electrolyte-starved(7.5μL mg^(-1))Li–S batteries.This work could unlock the potential of f orbital engineering for high-energy battery systems.
基金Project(2009CK2001) supported by the Science & Technology Development Key Program of Hunan Province STA of ChinaProject supported by the Young Teachers Program of Hunan University,China
文摘Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter(TWC) reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis(GRA), the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.
基金the National Natural Science Foundation of China(grant no.22171046)the Hundred-Talent Project of Fujian(grant no.50021113)is gratefully acknowledged.
文摘Sulfonimidoyl fluorides,the aza-bioisostere of sulfonyl fluorides,are emerging as a promising linkage agent in the sulfur(VI)fluoride exchange reaction(SuFEx).However,conventional synthetic approaches typically require the use of either unstable sulfonimidoyl chlorides,toxic and corrosive sulfur fluorides,or expensive electrophilic fluorinating agents.Herein,we report an electrochemistry-enabled oxidative nucleophilic fluorination of readily available and bench-stable sulfinamides using a commercially available and easy-to-handle triethylamine trihydrofluoride.With other nucleophilic agents,this electrochemical approach also serves as a general approach to diverse sulfonimidoyl derivatives,including sulfonimidoyl azides and acetates.
基金financially-supported by the National Natural Science Foundation of China(Nos.21677055,22006045 and 21407052)the National Key Technical Research and Development Program of China(No.2019YFC1805204)+1 种基金Leading Plan for Scientific and Technological Innovation of High-tech Industries of Hunan Province(No.2021GK4060)the Fundamental Research Funds for the Central Universities,HUST(No.2017KFXKJC004).
文摘Activation of(bi)sulfite(S(IV))by metal oxides is strongly limited by low electrons utilization.In this study,two carbon-supported cobalt ferrites spinels(CoFe^(2)O_(4) QDs-GO and CoFe^(2)O_(4) MOFs-CNTs)have been successfully synthesized by one-step solvothermal method.It was found that both catalysts could efficiently activate S(IV),with rapid reductive dechlorination and then oxidative degradation of a recalcitrant antibiotic chloramphenicol(CAP).Characterizations revealed that CoFe^(2)O_(4) spinels were tightly coated on the carbon bases(GO and CNTs),with effectiveness of the internal transfer of electrons.O_(2)˙−was identified for the reductive dechlorination of CAP,with simultaneously detection of both•OH and SO_(4)^(˙−)responsible for further oxidative degradation.The sulfur oxygen radical conversion reactions and molecular oxygen activation would occur together upon the carbon-based spinels.Spatial-separated interfacial reductive-oxidation of CAP would occur with dechlorination of CAP by O_(2)^(˙−)on the carbon bases,and oxidative degradation of intermediates by SO_(4)^(˙−/•)OH upon the CoFe^(2)O_(4) catalysts.
基金This work was financially supported by the National Key Research and Development Program of China(No.2017YFA0206703)the National Natural Science Foundation of China(No.21671183)the Project of State Key Laboratory of Environment-Friendly Energy Materials(SWUST,Nos.19FKSY16 and 18ZD320304).
文摘Rationally designing sulfur hosts with the functions of confining lithium polysulfides(LiPSs)and promoting sulfur reaction kinetics is critically important to the real implementation of lithium-sulfur(Li-S)batteries.Herein,the defect-rich carbon black(CB)as sulfur host was successfully constructed through a rationally regulated defect engineering.Thus-obtained defect-rich CB can act as an active electrocatalyst to enable the sulfur redox reaction kinetics,which could be regarded as effective inhibitor to alleviate the LiPS shuttle.As expected,the cathode consisting of sulfur and defect-rich CB presents a high rate capacity of 783.8 mA·h·g^−1 at 4 C and a low capacity decay of only 0.07% per cycle at 2 C over 500 cycles,showing favorable electrochemical performances.The strategy in this investigation paves a promising way to the design of active electrocatalysts for realizing commercially viable Li-S batteries.
基金supported by the National Key Research and Development Program(Nos.2016YFA0202500,2016YFA0200102)the National Natural Science Foundation of China(No.21676160)China Postdoctoral Science Foundation(No.2017M620049)
文摘To meet the ever-increasing energy demands, advanced electrode materials are strongly requested for the exploration of advanced energy storage and conversion technologies, such as Li-ion batteries, Li-S batteries, Li-]Zn-air batteries, supercapacitors, dye-sensitized solar cells, and other electrocatalysis process (e.g., oxygen reductionlevolution reaction, hydrogen evolution reaction). Transition metal chalcogenides (TMCs, Le., sulfides and selenides) are forcefully considered as an emerging candidate, owing to their unique physical and chemical properties. Moreover, the integration of TMCs with conductive graphene host has enabled the significant improvement of electrochemical performance of devices. In this review, the recent research progress on TMC]graphene composites for applications in energy storage and conversion devices is summarized. The preparation process of TMC]graphene nanocomposites is also included. In order to promote an in-depth understanding of performance improvement for TMC/graphene materials, the operating principle of various devices and technologies are briefly presented. Finally, the perspectives are given on the design and construction of advanced electrode materials.
基金the Research Council of Shahrood University of Technology for the financial support of this work
文摘This letter describes a simple and efficient synthesis of 3-(cyclohexylamino)-7-hydroxy-2-arylimi- dazo[1,2-c]pyrimidin-5(6H)-one via a one-pot three-component reaction of cyclohexyl isocyanide, an aldehyde, and 4-amiopyrimidine-2,6-diol in the presence of a catalytic amount of SSA.
基金supported by the Natural Science Foundation of China(grant no.22309179)Natural Science Foundation of Ningxia(grant no.2023AAC01003)Chinese Academy of Sciences,and the Foundation of State Key Laboratory of High Efficiency Utilization of Coal and Green Chemical Engineering(grant no.2022-K79)。
文摘Heterostructured sulfur electrocatalysts have long been heralded as an effective approach to settle the issues of the shuttle effect and sluggish reaction kinetics of lithium polysulfides(LiPSs)in lithium-sulfur(Li-S)batteries.However,the limited active sites on the interface of the heterostructure offer unsatisfactory LiPSs conversion capability,rendering sluggish reaction kinetics.Herein,we have designed abnormal step-scheme nano-heterointerfaces,containing P-N,N-semimetal,and P-semimetal heterostructures as sulfur electrocatalysts to regulate the LiPSs catalytic conversion behavior,which demonstrates efficient catalytic activity and robust structural stability.The excellent electron-confinement contributed by the step-scheme barrier endows the electron gathering at the nano-heterointerfaces,conferring high selectivity and durability of electrocatalyst for an accelerated sulfur reduction reaction.The unique robust structure design further bestows the sulfur composite with favored ion/mass transportation within the electrode.Attributed to these structural features,the Li-S cell delivers excellent performance under high areal capacity over 7 mAh cm^(−2) and lean electrolyte/sulfur ratio below 2.5μL mg^(−1),decent rate capability up to 8 C,remarkable cyclic stability over 500 cycles,and satisfactory energy density of 386.3 Wh kg^(−1) in a 7.5 Ah pouch cell.This nano-heterointerface structure design strategy endows a sulfur cathode with superior LiPSs catalytic activity,opening new insights into high-performance Li-S batteries.