Lithium-sulfur(Li-S)system coupled with thin-film solid electrolyte as a novel high-energy micro-battery has enormous potential for complementing embedded energy harvesters to enable the autonomy of the Internet of Th...Lithium-sulfur(Li-S)system coupled with thin-film solid electrolyte as a novel high-energy micro-battery has enormous potential for complementing embedded energy harvesters to enable the autonomy of the Internet of Things microdevice.However,the volatility in high vacuum and intrinsic sluggish kinetics of S hinder researchers from empirically integrating it into allsolid-state thin-film batteries,leading to inexperience in fabricating all-solid-state thin-film Li-S batteries(TFLSBs).Herein,for the first time,TFLSBs have been successfully constructed by stacking vertical graphene nanosheets-Li2S(VGsLi2S)composite thin-film cathode,lithium-phosphorous-oxynitride(LiPON)thin-film solid electrolyte,and Li metal anode.Fundamentally eliminating Lipolysulfide shuttle effect and maintaining a stable VGs-Li2S/LiPON interface upon prolonged cycles have been well identified by employing the solid-state Li-S system with an“unlimited Li”reservoir,which exhibits excellent longterm cycling stability with a capacity retention of 81%for 3,000 cycles,and an exceptional high temperature tolerance up to 60℃.More impressively,VGs-Li2S-based TFLSBs with evaporated-Li thin-film anode also demonstrate outstanding cycling performance over 500 cycles with a high Coulombic efficiency of 99.71%.Collectively,this study presents a new development strategy for secure and high-performance rechargeable all-solid-state thin-film batteries.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
High energy density and low cost made lithium–sulfur(Li–S)batteries appealing for the next-generation energy storage devices.However,their commercial viability is seriously challenged by serious polysulfide shuttle ...High energy density and low cost made lithium–sulfur(Li–S)batteries appealing for the next-generation energy storage devices.However,their commercial viability is seriously challenged by serious polysulfide shuttle effect,sluggish sulfur kinetics,and uncontrollable dendritic Li growth.Herein,a dual-functional electrolyte additive,diphenyl ditelluride(DPDTe)is reported for Li–S battery.For sulfur cathodes,DPDTe works as a redox mediator to accelerate redox kinetics of sulfur,in which Te radical-mediated catalytic cycle at the solid–liquid interface contributes significantly to the whole process.For lithium anodes,DPDTe can react with lithium metal to form a smooth and stable organic–inorganic hybrid solid-electrolyte interphase(SEI),enabling homogeneous lithium deposition for suppressing dendrite growth.Consequently,the Li–S battery with DPDTe exhibits remarkable cycling stability and superb rate capability,with a high capacity up to 1227.3 mAh g^(-1)and stable cycling over 300 cycles.Moreover,a Li–S pouch cell with DPDTe is evaluated as the proof of concept.This work demonstrates that organotelluride compounds can be used as functional electrolyte additives and offers new insights and opportunities for practical Li–S batteries.展开更多
Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trode...Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trodes and low electrolyte/sulfur(E/S)ratios.The sluggish reaction in the low E/S ratio induces poor LiPS solubility and unstable Li_(2)S electrodeposition,resulting in limited sulfur utilization,especially under high-loading sulfur electrode.In this study,we report on salt concentration effects that improve sulfur utilization with a high-loading cathode(6 mgs ulfurcm^(-2)),a high sulfur content(80 wt%)and a low E/S ratio(5 m L gs ulfur^(-1)).On the basis of the rapid LiPS dissolving in a low concentration electrolyte,we estab-lished that the quantity of Li_(2)S electrodeposition from a high Li+diffusion coefficient,referring to the reduction of LiPS precipitation,was significantly enhanced by a faster kinetic.These results demonstrate the importance of kinetic factors for the rate capability and cycle life stability of Li-S battery electrolytes through high Li_(2)S deposition under high-loading sulfur electrode.展开更多
Severe capacity fading and poor high rate performance of lithium sulfur(Li–S) battery caused by "shuttle effect" and low conductivity of sulfur hampers its further developments and applications. Li_4Ti_5O_(...Severe capacity fading and poor high rate performance of lithium sulfur(Li–S) battery caused by "shuttle effect" and low conductivity of sulfur hampers its further developments and applications. Li_4Ti_5O_(12) (LTO)possesses high lithium ion conductivity, and it is also can be used as an active adsorbent for polysulfide. Herein, fine LTO particle coated carbon nanofibers(CNF) were prepared and a conductive network both for electron and lithium ion was built, which can greatly promote the electrochemical conversion of polysulfide and improve the rate performance of Li–S batteries. Meanwhile, a quantity of adsorption sites is constructed by defects of the surface of LTO-CNF membrane to effectively immobilize polysulfide. The multifunctional LTO-CNF interlayer could impede the shuttle effect and enhance comprehensive electrochemical performance of Li–S batteries, especially high rate performance. With such LTO-CNF interlayer,the Li–S battery presents a specific capacity of 641.9 mAh/g at 5 C rate. After 400 cycles at 1 C, a capacity of 618.0 mAh/g is retained. This work provides a feasible strategy to achieve high performance of Li–S battery for practical utilization.展开更多
Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercia...Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur batteries.In this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur host.The assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 C.The polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling effect.Meanwhile,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li ions.Polysulfide adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.展开更多
The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite fo...The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation.All-solid-state lithium-sulfur batteries have been proposed to solve the shuttle effect and prevent short circuits.However,solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain,which could result in the limited electrochemical performances.In this work,the cathode of all-solid-state lithium-sulfur batteries is prepared by depositing sulfur on the surface of the carbon nanotubes(CNTs@S)and further mixing with Li10GeP2S12 electrolyte and acetylene black agents.At 60℃,CNTs@S electrode exhibits superior electrochemical performance,delivering the reversible discharge capacities of 1193.3,959.5,813.1,569.6 and 395.5 mAhg^-1 at the rate of 0.1,0.5,1,2 and 5 C,respectively.Moreover,the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAhg^-1 and cycling stability of 400 cycles at a high rate of 1.0 C.Such uniform distribution of the CNTs,S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.展开更多
Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific capacity.However,the growth of lithium dendrites could result in a short lifespan,low coulombic effici...Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific capacity.However,the growth of lithium dendrites could result in a short lifespan,low coulombic efficiency,and potential safety hazards during the progress of lithium plating/stripping.These factors drastically hinder its application in lithium metal batteries.This review focuses on the use of three dimensional(3D)porous host frameworks to improve Li plating/stripping behaviors,accommodate the change in volume,and suppress or block lithium dendrite growth.Various 3D porous frameworks,including the conductive carbon-based,metal-based,and lithiophilic inorganic-compound frameworks are introduced and summarized in detail.The particular functions,relative developments,and optimized strategies of various 3D porous frameworks for lithium deposition/dissolution behaviors are discussed.Moreover,the challenges and promising developments in the field of Li metal anodes will be discussed at the end of this review.展开更多
Owing to their low cost,high energy densities,and superior performance compared with that of Li-ion batteries,Li–S batteries have been recognized as very promising next-generation batteries.However,the commercializat...Owing to their low cost,high energy densities,and superior performance compared with that of Li-ion batteries,Li–S batteries have been recognized as very promising next-generation batteries.However,the commercialization of Li–S batteries has been hindered by the insulation of sulfur,significant volume expansion,shuttling of dissolved lithium polysulfides(Li PSs),and more importantly,sluggish conversion of polysulfide intermediates.To overcome these problems,a state-of-the-art strategy is to use sulfur host materials that feature chemical adsorption and electrocatalytic capabilities for Li PS species.In this review,we comprehensively illustrate the latest progress on the rational design and controllable fabrication of materials with chemical adsorbing and binding capabilities for Li PSs and electrocatalytic activities that allow them to accelerate the conversion of Li PSs for Li–S batteries.Moreover,the current essential challenges encountered when designing these materials are summarized,and possible solutions are proposed.We hope that this review could provide some strategies and theoretical guidance for developing novel chemical anchoring and electrocatalytic materials for high-performance Li–S batteries.展开更多
Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic...Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic Li exists in the cells. Pairing lithium sulfide (Li2S) cathode with currently available metallic Lifree high-capacity anodes offers an alternative solution to this challenge. However, the performance of Li2S cathode is primarily restricted by high activation barrier upon initial charge, low active mass utilization and sluggish redox kinetics. Herein, a MXene-induced multifunctional collaborative interface is proposed to afford superb activity towards redox solid-liquid/liquid-liquid phase transformation, strong chemisorption, high conductivity and fast ionic/charge transport in high Li2S loading cathode. Applying collaborative interface effectively reduces initial voltage barrier of Li2S activation and regulates the kinetic behavior of redox polysulfide conversion. Therefore, stable operation of additive-free Li2S cathode with high areal capacities at high Li2S loading up to 9 mg cm^-2 can be achieved with less sacrifice of high capacity and rate capability in Li-S batteries. Rechargeable metallic Li-free batteries are successfully constructed by pairing this high-performance Li2S cathode with high-capacity metal oxide anodes, which delivers superior energy density to current Li-ion batteries.展开更多
Lithium–sulfur batteries are one of the attractive next-generation energy storage systems owing to theienvironmental friendliness,low cost,and high specific energy densities.However,the low electrical conductivity of...Lithium–sulfur batteries are one of the attractive next-generation energy storage systems owing to theienvironmental friendliness,low cost,and high specific energy densities.However,the low electrical conductivity of sulfur,shuttling of soluble intermediate polysulfides between electrodes,and low capacitretention have hampered their commercial use.To address these issues,we use a halloysitemodulated(H-M)separator in a lithium–sulfur battery to mitigate the shuttling problem.The H-M separator acts as a mutual Coulombic repulsion in lithium-sulfur batteries,thereby selectively permitting Lions and efficiently suppressing the transfer of undesired lithium polysulfides to the Li anode sideMoreover,the use of halloysite switches the surface of the separator from hydrophobic to hydrophilicconsequently improving the electrolyte wettability and adhesion between the separator and cathodeWhen sulfur-multi-walled carbon nanotube(S-MWCNT)composites are used as cathode active materialsa lithium–sulfur battery with an H-M separator exhibits first discharge and charge capacities of 1587 an1527 m Ah g-1,respectively.Moreover,there is a consistent capacity retention up to 100 cyclesAccordingly,our approach demonstrates an economical and easily accessible strategy for commercialization of lithium–sulfur batteries.展开更多
Tremendous effort has been devoted to lithium‐sulfur batteries,where flooded electrolytes have been employed ubiquitously.The use of lean electrolytes albeit indispensable for practical applications often causes low ...Tremendous effort has been devoted to lithium‐sulfur batteries,where flooded electrolytes have been employed ubiquitously.The use of lean electrolytes albeit indispensable for practical applications often causes low capacity and fast capacity fading of the sulfur cathode;thus,the electrolyte/sulfur active mass ratios below 5μL/mg have been rarely reported.Herein,we demonstrate that ZnS coating transforms sulfur cathode materials electrolyte‐philic,which tremendously promotes the performance in lean electrolytes.The ZnS‐coated Li2S@graphene cathode delivers an initial discharge capacity of 944mAh/g at an E/S ratio of 2μL/mg at the active mass loading of 5.0 mg Li2S/cm^2,corresponding to an impressive specific energy of 500Wh/kg based on the mass of cathode,electrolyte,and the assumed minimal mass of lithium metal anode.Density functional theory calculations reveal strong binding between ZnS crystals and electrolyte solvent molecules,explaining the better wetting properties.We also demonstrate the reversible cycling of a hybrid cathode of ZnS‐coated Li2S@graphene mixed with VS2 as an additive at an E/AM(active mass)ratio of 1.1μL/mg,equivalent to the specific energy of 432 Wh/kg on the basis of the mass of electrodes and electrolyte.展开更多
锂硫电池正极活性物质理论比容量高达1 675 m Ah/g,单质硫具有环境友好,资源丰富,价格低廉等优点,因此,锂硫电池最有希望成为下一代二次电池的有力竞争者。硝酸锂是抑制锂硫电池飞梭的常用添加剂,会随着电池循环不断被消耗。不断消耗的...锂硫电池正极活性物质理论比容量高达1 675 m Ah/g,单质硫具有环境友好,资源丰富,价格低廉等优点,因此,锂硫电池最有希望成为下一代二次电池的有力竞争者。硝酸锂是抑制锂硫电池飞梭的常用添加剂,会随着电池循环不断被消耗。不断消耗的硝酸锂难以长期抑制硫负载量较高电池的飞梭。有研究表明锂离子选择透过性聚合物电解质膜能够有效抑制飞梭效应。将聚偏氟乙烯(PVDF)和SiO_2改性并与Celgard膜复合的全氟磺酸双氰胺锂(LiPFSD)单离子聚合物电解质膜应用于锂硫电池中,研究了电解液中无硝酸锂条件下,复合膜对电池性能的影响。膜的厚度为15μm,膜内添加20%PVDF和10%SiO_2,正极硫负载量3.5 mg/cm2的锂硫电池,其首次放电比容量为995 m Ah/g,0.1 C下50次循环后放电比容量为798 m Ah/g,库仑效率维持80%以上。展开更多
Lithium–sulfur(Li–S)batteries stand out the energy storage systems because of extremely high energy density(2600 W h Kg−1)and low-cost sulfur cathode.Unfortunately,the sluggish deposition from liquid Li polysulfides...Lithium–sulfur(Li–S)batteries stand out the energy storage systems because of extremely high energy density(2600 W h Kg−1)and low-cost sulfur cathode.Unfortunately,the sluggish deposition from liquid Li polysulfides(LiPSs)to solid Li2S leads to mild power density and short cycle life.Understanding and regulating Li_(2)S_(2)/Li2S deposition are conceived to be importance to deliver second-plateau capacity in acceptable kinetics,which has the potential to operation Li–S batteries under electrolyte-lean conditions.This perspective aims to summarize the proposed models that can describe the nucleation and propagation of three-dimensional Li_(2)S_(2)/Li2S,as well as affords critical views how electrolyte dictates LiPS conversion from liquid to solid.It hopes to encourage necessary scaffold strategies and electrolyte formulations to further improve energy density and life span of Li–S batteries.展开更多
Lithium–sulfur batteries have been attracting considerable research attention due to their high energy densities and low costs. However, one of their main challenges is the undesired shuttling of polysulfides, causin...Lithium–sulfur batteries have been attracting considerable research attention due to their high energy densities and low costs. However, one of their main challenges is the undesired shuttling of polysulfides, causing rapid capacity degradation. Herein, we report the first example of sulfiphilic VSe2 ultrafine nanocrystals immobilized on nitrogen-doped graphene to modify the battery separator for alleviating the shuttling problem. VSe2 nanocrystals provide numerous active sites for chemisorption of polysulfides as well as benefit the nucleation and growth of Li2S. Furthermore, the kinetic reactions are accelerated which is confirmed by higher exchange current density and higher lithium ion diffusion coefficient. And the first-principles calculations further show that the exposed sulfiphilic planes of VSe2 boost the redox of Li2S. When used as separators within the lithium sulfur batteries, the cell indicates greatly enhanced electrochemical performances with excellent long cycling stability and exceptional rate capability up to 8 C. Moreover, it delivers a higher areal capacity of 4.04 mAh·cm^−2 as well as superior cycling stability with sulfur areal loading up to 6.1 mg·cm^−2. The present strategy can encourage us in engineering novel multifunctional separators for energy-storage devices.展开更多
基金supported by National Natural Science Foundation of China(No.U22A20118)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR146,2021ZZ122)Award Program for Fujian Minjiang Scholar Professorship。
文摘Lithium-sulfur(Li-S)system coupled with thin-film solid electrolyte as a novel high-energy micro-battery has enormous potential for complementing embedded energy harvesters to enable the autonomy of the Internet of Things microdevice.However,the volatility in high vacuum and intrinsic sluggish kinetics of S hinder researchers from empirically integrating it into allsolid-state thin-film batteries,leading to inexperience in fabricating all-solid-state thin-film Li-S batteries(TFLSBs).Herein,for the first time,TFLSBs have been successfully constructed by stacking vertical graphene nanosheets-Li2S(VGsLi2S)composite thin-film cathode,lithium-phosphorous-oxynitride(LiPON)thin-film solid electrolyte,and Li metal anode.Fundamentally eliminating Lipolysulfide shuttle effect and maintaining a stable VGs-Li2S/LiPON interface upon prolonged cycles have been well identified by employing the solid-state Li-S system with an“unlimited Li”reservoir,which exhibits excellent longterm cycling stability with a capacity retention of 81%for 3,000 cycles,and an exceptional high temperature tolerance up to 60℃.More impressively,VGs-Li2S-based TFLSBs with evaporated-Li thin-film anode also demonstrate outstanding cycling performance over 500 cycles with a high Coulombic efficiency of 99.71%.Collectively,this study presents a new development strategy for secure and high-performance rechargeable all-solid-state thin-film batteries.
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 Sci-ence Foundation of China(Nos.21975087,U1966214)the Certificate of China Postdoctoral Science Foundation Grant(2020M672337).
文摘High energy density and low cost made lithium–sulfur(Li–S)batteries appealing for the next-generation energy storage devices.However,their commercial viability is seriously challenged by serious polysulfide shuttle effect,sluggish sulfur kinetics,and uncontrollable dendritic Li growth.Herein,a dual-functional electrolyte additive,diphenyl ditelluride(DPDTe)is reported for Li–S battery.For sulfur cathodes,DPDTe works as a redox mediator to accelerate redox kinetics of sulfur,in which Te radical-mediated catalytic cycle at the solid–liquid interface contributes significantly to the whole process.For lithium anodes,DPDTe can react with lithium metal to form a smooth and stable organic–inorganic hybrid solid-electrolyte interphase(SEI),enabling homogeneous lithium deposition for suppressing dendrite growth.Consequently,the Li–S battery with DPDTe exhibits remarkable cycling stability and superb rate capability,with a high capacity up to 1227.3 mAh g^(-1)and stable cycling over 300 cycles.Moreover,a Li–S pouch cell with DPDTe is evaluated as the proof of concept.This work demonstrates that organotelluride compounds can be used as functional electrolyte additives and offers new insights and opportunities for practical Li–S batteries.
基金supported by a grant from the Korea Evaluation Institute of Industrial Technology(KEIT)funded by the Ministry of Trade,Industry and Energy(MOTIE)(No.20012341)。
文摘Sulfur utilization improvement and control of dissolved lithium polysulfide(LiPS;Li_(2)S x,2<x≤8)are cru-cial aspects of the development of lithium-sulfur(Li-S)batteries,especially in high-loading sulfur elec-trodes and low electrolyte/sulfur(E/S)ratios.The sluggish reaction in the low E/S ratio induces poor LiPS solubility and unstable Li_(2)S electrodeposition,resulting in limited sulfur utilization,especially under high-loading sulfur electrode.In this study,we report on salt concentration effects that improve sulfur utilization with a high-loading cathode(6 mgs ulfurcm^(-2)),a high sulfur content(80 wt%)and a low E/S ratio(5 m L gs ulfur^(-1)).On the basis of the rapid LiPS dissolving in a low concentration electrolyte,we estab-lished that the quantity of Li_(2)S electrodeposition from a high Li+diffusion coefficient,referring to the reduction of LiPS precipitation,was significantly enhanced by a faster kinetic.These results demonstrate the importance of kinetic factors for the rate capability and cycle life stability of Li-S battery electrolytes through high Li_(2)S deposition under high-loading sulfur electrode.
基金supported by the National Key Basic Research Program of China (2014CB932400)the National Natural Science Foundation of China (51672156 and 51232005)+3 种基金Guangdong special support program (2015TQ01N401)Guangdong Province Technical Plan Project (2017B010119001 and 2017B090907005)Dongguan City (2015509119213)Shenzhen Technical Plan Project (JCYJ20170817161221958, JCYJ20170412170706047, JCYJ20170307153806471, and GJHS20170314165324888)
文摘Severe capacity fading and poor high rate performance of lithium sulfur(Li–S) battery caused by "shuttle effect" and low conductivity of sulfur hampers its further developments and applications. Li_4Ti_5O_(12) (LTO)possesses high lithium ion conductivity, and it is also can be used as an active adsorbent for polysulfide. Herein, fine LTO particle coated carbon nanofibers(CNF) were prepared and a conductive network both for electron and lithium ion was built, which can greatly promote the electrochemical conversion of polysulfide and improve the rate performance of Li–S batteries. Meanwhile, a quantity of adsorption sites is constructed by defects of the surface of LTO-CNF membrane to effectively immobilize polysulfide. The multifunctional LTO-CNF interlayer could impede the shuttle effect and enhance comprehensive electrochemical performance of Li–S batteries, especially high rate performance. With such LTO-CNF interlayer,the Li–S battery presents a specific capacity of 641.9 mAh/g at 5 C rate. After 400 cycles at 1 C, a capacity of 618.0 mAh/g is retained. This work provides a feasible strategy to achieve high performance of Li–S battery for practical utilization.
基金National Natural Science Foundation of China(No.51974209)the Natural Science Foundation of Hubei Province of China(Nos.2013CFA021,2017CFB401,2018CFA022)。
文摘Several challenging issues,such as the poor conductivity of sulfur,shuttle effects,large volume change of cathode,and the dendritic lithium in anode,have led to the low utilization of sulfur and hampered the commercialization of lithium–sulfur batteries.In this study,a novel three-dimensionally interconnected network structure comprising Co9 S8 and multiwalled carbon nanotubes(MWCNTs)was synthesized by a solvothermal route and used as the sulfur host.The assembled batteries delivered a specific capacity of1154 m Ah g-1 at 0.1 C,and the retention was 64%after 400 cycles at 0.5 C.The polar and catalytic Co9 S8 nanoparticles have a strong adsorbent effect for polysulfide,which can effectively reduce the shuttling effect.Meanwhile,the three-dimensionally interconnected CNT networks improve the overall conductivity and increase the contact with the electrolyte,thus enhancing the transport of electrons and Li ions.Polysulfide adsorption is greatly increased with the synergistic effect of polar Co9 S8 and MWCNTs in the three-dimensionally interconnected composites,which contributes to their promising performance for the lithium–sulfur batteries.
基金supported by the National Key R&D Program of China (Grant no. 2016YFB0100105)the National Natural Science Foundation of China (Grant no. 51872303)+1 种基金Zhejiang Provincial Natural Science Foundation of China (Grant no. LD18E020004, LQ16E020003, LY18E020018, LY18E030011)Youth Innovation Promotion Association CAS (2017342)
文摘The main challenges in development of traditional liquid lithium-sulfur batteries are the shuttle effect at the cathode caused by the polysulfide and the safety concern at the Li metal anode arose from the dendrite formation.All-solid-state lithium-sulfur batteries have been proposed to solve the shuttle effect and prevent short circuits.However,solid-solid contacts between the electrodes and the electrolyte increase the interface resistance and stress/strain,which could result in the limited electrochemical performances.In this work,the cathode of all-solid-state lithium-sulfur batteries is prepared by depositing sulfur on the surface of the carbon nanotubes(CNTs@S)and further mixing with Li10GeP2S12 electrolyte and acetylene black agents.At 60℃,CNTs@S electrode exhibits superior electrochemical performance,delivering the reversible discharge capacities of 1193.3,959.5,813.1,569.6 and 395.5 mAhg^-1 at the rate of 0.1,0.5,1,2 and 5 C,respectively.Moreover,the CNTs@S is able to demonstrate superior high-rate capability of 660.3 mAhg^-1 and cycling stability of 400 cycles at a high rate of 1.0 C.Such uniform distribution of the CNTs,S and Li10GeP2S12 electrolyte increase the electronic and ionic conductivity between the cathode and the electrolyte hence improves the rate performance and capacity retention.
基金the National Natural Science Foundation of China(51521001,51832004 and 51602239)the National Natural Science Fund for Distinguished Young Scholars(51425204)+1 种基金the Programme of Introducing Talents of Discipline to Universities(B17034)the Yellow Crane Talent(Science&Technology)Program of Wuhan City.
文摘Lithium metal is a promising anode material owing to its very low electrochemical potential and ultrahigh specific capacity.However,the growth of lithium dendrites could result in a short lifespan,low coulombic efficiency,and potential safety hazards during the progress of lithium plating/stripping.These factors drastically hinder its application in lithium metal batteries.This review focuses on the use of three dimensional(3D)porous host frameworks to improve Li plating/stripping behaviors,accommodate the change in volume,and suppress or block lithium dendrite growth.Various 3D porous frameworks,including the conductive carbon-based,metal-based,and lithiophilic inorganic-compound frameworks are introduced and summarized in detail.The particular functions,relative developments,and optimized strategies of various 3D porous frameworks for lithium deposition/dissolution behaviors are discussed.Moreover,the challenges and promising developments in the field of Li metal anodes will be discussed at the end of this review.
基金supported by the National Natural Science Foundation of China(No.51403094)Program of Liaoning Education Department of China(No.LJ2017FBL002)Australian Research Council through the Discovery Early Career Researcher Award(DECRA,No.DE170100871)Program.
文摘Owing to their low cost,high energy densities,and superior performance compared with that of Li-ion batteries,Li–S batteries have been recognized as very promising next-generation batteries.However,the commercialization of Li–S batteries has been hindered by the insulation of sulfur,significant volume expansion,shuttling of dissolved lithium polysulfides(Li PSs),and more importantly,sluggish conversion of polysulfide intermediates.To overcome these problems,a state-of-the-art strategy is to use sulfur host materials that feature chemical adsorption and electrocatalytic capabilities for Li PS species.In this review,we comprehensively illustrate the latest progress on the rational design and controllable fabrication of materials with chemical adsorbing and binding capabilities for Li PSs and electrocatalytic activities that allow them to accelerate the conversion of Li PSs for Li–S batteries.Moreover,the current essential challenges encountered when designing these materials are summarized,and possible solutions are proposed.We hope that this review could provide some strategies and theoretical guidance for developing novel chemical anchoring and electrocatalytic materials for high-performance Li–S batteries.
基金supported by the National Natural Science Foundation of China (NSFC, No. 51522203, 51772040)Fok Ying Tung Education Foundation (No. 151047)+2 种基金the Recruitment Program of Global Youth ExpertsXinghai Scholarship of Dalian University of Technologythe Fundamental Research Funds for the Central Universities (No. DUT18LAB19)
文摘Use of metallic Li anode raises serious concerns on the safety and operational performance of Li-S batteries due to uncontrolled hazard of Li dendrite formation, which is difficultly eliminated as long as the metallic Li exists in the cells. Pairing lithium sulfide (Li2S) cathode with currently available metallic Lifree high-capacity anodes offers an alternative solution to this challenge. However, the performance of Li2S cathode is primarily restricted by high activation barrier upon initial charge, low active mass utilization and sluggish redox kinetics. Herein, a MXene-induced multifunctional collaborative interface is proposed to afford superb activity towards redox solid-liquid/liquid-liquid phase transformation, strong chemisorption, high conductivity and fast ionic/charge transport in high Li2S loading cathode. Applying collaborative interface effectively reduces initial voltage barrier of Li2S activation and regulates the kinetic behavior of redox polysulfide conversion. Therefore, stable operation of additive-free Li2S cathode with high areal capacities at high Li2S loading up to 9 mg cm^-2 can be achieved with less sacrifice of high capacity and rate capability in Li-S batteries. Rechargeable metallic Li-free batteries are successfully constructed by pairing this high-performance Li2S cathode with high-capacity metal oxide anodes, which delivers superior energy density to current Li-ion batteries.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2018R1C1B6004689)the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(No.2020R1I1A306182111)the Electronics and Telecommunications Research Institute(ETRI)grant funded by the Korean government(21ZB1200,Development of ICT Materials,Components and Equipment Technologies)。
文摘Lithium–sulfur batteries are one of the attractive next-generation energy storage systems owing to theienvironmental friendliness,low cost,and high specific energy densities.However,the low electrical conductivity of sulfur,shuttling of soluble intermediate polysulfides between electrodes,and low capacitretention have hampered their commercial use.To address these issues,we use a halloysitemodulated(H-M)separator in a lithium–sulfur battery to mitigate the shuttling problem.The H-M separator acts as a mutual Coulombic repulsion in lithium-sulfur batteries,thereby selectively permitting Lions and efficiently suppressing the transfer of undesired lithium polysulfides to the Li anode sideMoreover,the use of halloysite switches the surface of the separator from hydrophobic to hydrophilicconsequently improving the electrolyte wettability and adhesion between the separator and cathodeWhen sulfur-multi-walled carbon nanotube(S-MWCNT)composites are used as cathode active materialsa lithium–sulfur battery with an H-M separator exhibits first discharge and charge capacities of 1587 an1527 m Ah g-1,respectively.Moreover,there is a consistent capacity retention up to 100 cyclesAccordingly,our approach demonstrates an economical and easily accessible strategy for commercialization of lithium–sulfur batteries.
基金Office of Energy Efficiency and Renewable Energy,Grant/Award Number:DE‐FOA‐0001629U.S.Department of Energy,Grant/Award Number:DE‐AC02‐06CH11357。
文摘Tremendous effort has been devoted to lithium‐sulfur batteries,where flooded electrolytes have been employed ubiquitously.The use of lean electrolytes albeit indispensable for practical applications often causes low capacity and fast capacity fading of the sulfur cathode;thus,the electrolyte/sulfur active mass ratios below 5μL/mg have been rarely reported.Herein,we demonstrate that ZnS coating transforms sulfur cathode materials electrolyte‐philic,which tremendously promotes the performance in lean electrolytes.The ZnS‐coated Li2S@graphene cathode delivers an initial discharge capacity of 944mAh/g at an E/S ratio of 2μL/mg at the active mass loading of 5.0 mg Li2S/cm^2,corresponding to an impressive specific energy of 500Wh/kg based on the mass of cathode,electrolyte,and the assumed minimal mass of lithium metal anode.Density functional theory calculations reveal strong binding between ZnS crystals and electrolyte solvent molecules,explaining the better wetting properties.We also demonstrate the reversible cycling of a hybrid cathode of ZnS‐coated Li2S@graphene mixed with VS2 as an additive at an E/AM(active mass)ratio of 1.1μL/mg,equivalent to the specific energy of 432 Wh/kg on the basis of the mass of electrodes and electrolyte.
文摘锂硫电池正极活性物质理论比容量高达1 675 m Ah/g,单质硫具有环境友好,资源丰富,价格低廉等优点,因此,锂硫电池最有希望成为下一代二次电池的有力竞争者。硝酸锂是抑制锂硫电池飞梭的常用添加剂,会随着电池循环不断被消耗。不断消耗的硝酸锂难以长期抑制硫负载量较高电池的飞梭。有研究表明锂离子选择透过性聚合物电解质膜能够有效抑制飞梭效应。将聚偏氟乙烯(PVDF)和SiO_2改性并与Celgard膜复合的全氟磺酸双氰胺锂(LiPFSD)单离子聚合物电解质膜应用于锂硫电池中,研究了电解液中无硝酸锂条件下,复合膜对电池性能的影响。膜的厚度为15μm,膜内添加20%PVDF和10%SiO_2,正极硫负载量3.5 mg/cm2的锂硫电池,其首次放电比容量为995 m Ah/g,0.1 C下50次循环后放电比容量为798 m Ah/g,库仑效率维持80%以上。
基金the National Natural Science Foundation of China(grant No.22379121)Shenzhen Foundation Research Fund(grant No.JCYJ20220530112812028)+2 种基金Fundamental Research Funds of Shaanxi Key Laboratory of Artificially Structured Functional Materials and Devices(grant No.AFMD-KFJ-22204)Fundamental Research Funds for the Central Universities(grant No.G2022KY0606)Open Project of State Key Laboratory of Environment-friendly Energy Materials(grant No.22kfhg05).
文摘Lithium–sulfur(Li–S)batteries stand out the energy storage systems because of extremely high energy density(2600 W h Kg−1)and low-cost sulfur cathode.Unfortunately,the sluggish deposition from liquid Li polysulfides(LiPSs)to solid Li2S leads to mild power density and short cycle life.Understanding and regulating Li_(2)S_(2)/Li2S deposition are conceived to be importance to deliver second-plateau capacity in acceptable kinetics,which has the potential to operation Li–S batteries under electrolyte-lean conditions.This perspective aims to summarize the proposed models that can describe the nucleation and propagation of three-dimensional Li_(2)S_(2)/Li2S,as well as affords critical views how electrolyte dictates LiPS conversion from liquid to solid.It hopes to encourage necessary scaffold strategies and electrolyte formulations to further improve energy density and life span of Li–S batteries.
基金The authors acknowledge the financial supports provided by the National Natural Science Foundation of China(Nos.21871164,21803036,and U1764258)the Taishan Scholar Project Foundation of Shandong Province(Nos.ts20190908 and ts201511004)the National Science Foundation of Shandong Province(No.ZR2019MB024).The theoretical calculations in this work were performed on the HPC Cloud Platform of Shandong University.We also thank Anhui Kemi Machinery Technology Co,Ltd for providing Teflon-lined stainless steel autoclave.
文摘Lithium–sulfur batteries have been attracting considerable research attention due to their high energy densities and low costs. However, one of their main challenges is the undesired shuttling of polysulfides, causing rapid capacity degradation. Herein, we report the first example of sulfiphilic VSe2 ultrafine nanocrystals immobilized on nitrogen-doped graphene to modify the battery separator for alleviating the shuttling problem. VSe2 nanocrystals provide numerous active sites for chemisorption of polysulfides as well as benefit the nucleation and growth of Li2S. Furthermore, the kinetic reactions are accelerated which is confirmed by higher exchange current density and higher lithium ion diffusion coefficient. And the first-principles calculations further show that the exposed sulfiphilic planes of VSe2 boost the redox of Li2S. When used as separators within the lithium sulfur batteries, the cell indicates greatly enhanced electrochemical performances with excellent long cycling stability and exceptional rate capability up to 8 C. Moreover, it delivers a higher areal capacity of 4.04 mAh·cm^−2 as well as superior cycling stability with sulfur areal loading up to 6.1 mg·cm^−2. The present strategy can encourage us in engineering novel multifunctional separators for energy-storage devices.
