With high energy density and low material cost,lithium sulfur batteries(LSBs)emerge quite expeditiously as a fascinating energy storage system over the past decade.Broad applications of LSBs ranging from electric vehi...With high energy density and low material cost,lithium sulfur batteries(LSBs)emerge quite expeditiously as a fascinating energy storage system over the past decade.Broad applications of LSBs ranging from electric vehicles to stationary grid storage seem rather bright in recent literatures.However,there still exist many pressing challenges to be addressed because we do not yet fully understand and control the electrode-electrolyte interface chemistries during battery operation,such as polysulide shuttling and poor utilization of active sulfur.Single-atom catalysts(SACs)pave new possibilities of tackling the tough issues due to their decent applicability in the atomic-level identification of structure-activity relationships and reaction mechanism,as well as their structural tunability with atomic precision.This review comprehensively summarizes the very recent advances in utilization of highly active SACs for LSBs by stating and discussing the related publications,which involves catalyst synthesis routes,battery pertormance,catalytic mechanisms,optimization strategies,and promises to achieve long-lite,high-energy LSBs.We see that endeavors to employ SACs to modify sulfur cathode have allowed efficient polysulfide conversion and confinement,leading to the minimization of shuttle effect.Parallel efforts are being devoted to extending the scope of SACs to cell separator and lithium metal anode in order to unlock the full potential of LSBs.We also obtain mechanistic insights into battery chemistries and nature of SACs in their strong interactions with polysulfides through advanced in situ characterizations documented.Overall,acceleration in the development of LSBs by introducing SACs is noticeable,and this cutting edge needs more attentions to further promoting the design of better LSBs.展开更多
Graphene, with unique two-dimensional form and numerous appealing properties, promises to remarkably increase the energy density and power density of electrochemical energy storage devices(EESDs),ranging from the popu...Graphene, with unique two-dimensional form and numerous appealing properties, promises to remarkably increase the energy density and power density of electrochemical energy storage devices(EESDs),ranging from the popular lithium ion batteries and supercapacitors to next-generation high-energy batteries. Here, we review the recent advances of the state-of-the-art graphene-based materials for EESDs,including lithium ion batteries, supercapacitors, micro-supercapacitors, high-energy lithium-air and lithium-sulfur batteries, and discuss the importance of the pore, doping, assembly, hybridization and functionalization of different nano-architectures in improving electrochemical performance. The major roles of graphene are highlighted as(1) a superior active material,(2) ultrathin 2D flexible support,and(3) an inactive yet electrically conductive additive. Furthermore, we address the enormous potential of graphene for constructing new-concept emerging graphene-enabled EESDs with multiple functionalities of lightweight, ultra-flexibility, thinness, and novel cell configurations. Finally, future perspectives and challenges of graphene-based EESDs are briefly discussed.展开更多
Lithium-sulfur(Li-S)batteries are one of the most promising candidates for high energy density rechargeable batteries beyond current Li-ion batteries.However,severe corrosion of Li metal anode and low Coulombic effici...Lithium-sulfur(Li-S)batteries are one of the most promising candidates for high energy density rechargeable batteries beyond current Li-ion batteries.However,severe corrosion of Li metal anode and low Coulombic efficiency(CE)induced by the unremitting shuttle of Li polysulfides immensely hinder the practical applications of Li-S batteries.Herein,a compact inorganic layer(CIL)formed by ex situ reactions between Li anode and ionic liquid emerged as an effective strategy to block Li polysulfides and suppress shuttle effect.A CE of 96.7%was achieved in Li-S batteries with CIL protected Li anode in contrast to 82.4%for bare Li anode while no lithium nitrate was employed.Furthermore,the corrosion of Li during cycling was effectively inhibited.While applied to working batteries,80.6%of the initial capacity after 100 cycles was retained in Li-S batteries with CIL-protected ultrathin(33μm)Li anode compared with 58.5%for bare Li anode,further demonstrating the potential of this strategy for practical applications.This study presents a feasible interfacial regulation strategy to protect Li anode with the presence of Li polysulfides and opens avenues for Li anode protection in Li-S batteries under practical conditions.展开更多
Lithium-sulfur(Li-S)batteries are considered as a highly promising energy storage system due to their ultrahigh theoretical energy density.However,the sluggish kinetics of the complex multi-electron sulfur redox react...Lithium-sulfur(Li-S)batteries are considered as a highly promising energy storage system due to their ultrahigh theoretical energy density.However,the sluggish kinetics of the complex multi-electron sulfur redox reactions seriously hinders the actual battery performance especially under practical working conditions.Homogeneous redox mediation,through elaborately designing the additive molecules,is an effective approach to promote the sulfur redox kinetics.Herein a promoter of mixed organodiselenides(mixed-Se)is proposed to comprehensively improve the sulfur redox kinetics following the redox comediation principles.Concretely,diphenyl diselenide promotes the liquid-liquid conversion between polysulfides and the solid-liquid conversion regarding lithium sulfide oxidation to polysulfides,while dimethyl diselenide enhances the liquid-solid conversion regarding lithium sulfide deposition.Consequently,the mixed-Se promoter endows a high discharge capacity of 1002 mAh g^(−1)with high sulfur loading of 4.0 mg cm^(−2),a high capacity retention of 81.6%after 200 cycles at 0.5 C,and a high actual energy density of 384 Wh kg^(−1)at 0.025 C in 1.5 Ah-level Li-S pouch cells.This work affords an effective kinetic promoter to construct high-energy-density Li-S batteries and inspires molecular design of kinetic promoters toward targeted energy-related redox reactions.展开更多
Due to the high specific capacity, low cost, and environmental friendliness, lithium-sulfur batteries hold great potential to become the mainsiay of next-generation energy storage system. Regarding the composition of ...Due to the high specific capacity, low cost, and environmental friendliness, lithium-sulfur batteries hold great potential to become the mainsiay of next-generation energy storage system. Regarding the composition of sulfur/carbon in cathode, flammable organic liquid electrolyte, and lithium metal anode, great concerns about the safety have been raised. Hence solid-electrolyte-based lithium-sulfur batteries, as one alternative route for safe batteries, are highly interested. This review highlights the recent research progress of lithium-sulfur batteries with solid electrolytes. Both sulfide solid electrolytes and oxide solid electrolytes are included. The sulfide solid electrolytes are mainly employed in all-solid-state lithium-sulfur batteries, while the oxide solid electrolytes are applied in hybrid electrolyte for lithium-sulfur batteries. The challenges and perspectives in this field are also featured on the basis of its current progress.展开更多
Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimiz...Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.展开更多
Lithium/sulfur （Li/S） cells have great potential to become mainstream secondary batteries due to their ultra-high theoretical specific energy. The major challenge for Li/S cells is the unstable cycling performance c...Lithium/sulfur （Li/S） cells have great potential to become mainstream secondary batteries due to their ultra-high theoretical specific energy. The major challenge for Li/S cells is the unstable cycling performance caused by the sulfur＇s insulating nature and the high-solubility of the intermediate polysulfide products. Several years of efforts to develop various fancy carbon nanostructures, trying to physically encapsulate the polysulfides, did not yet push the cell＇s cycle life long enough to compete with current Li ion cells. The focus of this review is on the recent progress in chemical bonding strategy for trapping polysulfides through employing functional groups and additives in carbon matrix. Research results on understanding the working mechanism of chemical interaction between polysulfides and functional groups （e.g. 0-, B-, N- and S-） in carbon matrix, metal-based additives, or polymer additives during charge/discharge are discussed.展开更多
Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical ...Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical properties, environmentally friendliness, and considerable economic value. Nature contributes to the biomass with bizarre microstructures with micropores, mesopores or hierarchical pores.Currently, it has been confirmed that biomass has great potential applications in energy storage devices,especially in lithium-sulfur(Li–S) batteries. In this article, the synthesis and function of BDNCs for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the carbons in Li-S batteries are discussed. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent BDNCs for Li–S batteries.展开更多
Comprehensive analyses on thermal runaway mechanisms are critically vital to achieve the safe lithium-sulfur(Li-S)batteries.The reactions between dissolved higher-order polysulfides and Li metal were found to be the o...Comprehensive analyses on thermal runaway mechanisms are critically vital to achieve the safe lithium-sulfur(Li-S)batteries.The reactions between dissolved higher-order polysulfides and Li metal were found to be the origins for the thermal runaway of 1.0 Ah cycled Li-S pouch cells.16-cycle pouch cell indicates high safety,heating from 30 to 300 ℃ without thermal runaway,while 16-cycle pouch cell with additional electrolyte undergoes severe thermal runaway at 147.9 ℃,demonstrating the key roles of the electrolyte on the thermal safety of batteries.On the contrary,thermal runaway does not occur for 45-cycle pouch cell despite the addition of the electrolyte.It is found that the higher-order polysulfides(Li_(2)S_(x) ≥ 6)are discovered in 16-cycle electrolyte while the sulfur species in 45-cycle electrolyte are Li_(2)S_(x) ≤ 4.In addition,strong exothermic reactions are discovered between cycled Li and dissolved higher-order polysulfide(Li_(2)S_(6) and Li_(2)S_(8))at 153.0 ℃,driving the thermal runaway of cycled Li-S pouch cells.This work uncovers the potential safety risks of Li-S batteries and negative roles of the polysulfide shuttle for Li-S batteries from the safety view.展开更多
The lithium-sulfur battery is considered one of the most promising candidates for portable energy storage devices due to its low cost and high energy density.However,many critical issues,including polysulfide shuttlin...The lithium-sulfur battery is considered one of the most promising candidates for portable energy storage devices due to its low cost and high energy density.However,many critical issues,including polysulfide shuttling,self-discharge,lithium dendritic growth,and thermal hazards need to be addressed before the commercialization of lithium-sulfur batteries.To this end,tremendous efforts have been made to explore battery configurations and components,such as electrodes,electrolytes,and separators,among which the separator plays an especially critical role in addressing aforementioned issues.Thus,this review analyzes the mechanisms and interactions of these critical issues and summarizes both the function of separators and recent progress made towards remedying such issues.Additionally,promising directions for the development of separators in lithium-sulfur batteries are proposed.展开更多
Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur （Li-S） batteries. Herein, porous bamboo bi...Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur （Li-S） batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur （BC-S） nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1,295 mA-h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA-h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency （995%）. This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteries.展开更多
The introduction of nitrogen heteroatoms into carbon materials is a facile and efficient strategy to regulate their reactivities and facilitate their potential applications in energy conversion and storage. However,mo...The introduction of nitrogen heteroatoms into carbon materials is a facile and efficient strategy to regulate their reactivities and facilitate their potential applications in energy conversion and storage. However,most of nitrogen heteroatoms are doped into the bulk phase of carbon without site selectivity, which significantly reduces the contacts of feedstocks with the active dopants in a conductive scaffold. Herein we proposed the chemical vapor deposition of a nitrogen-doped graphene skin on the 3D porous graphene framework and donated the carbon/carbon composite as surface N-doped grapheme（SNG）. In contrast with routine N-doped graphene framework（NGF） with bulk distribution of N heteroatoms, the SNG renders a high surface N content of 1.81 at%, enhanced electrical conductivity of 31 S cm^（-1）, a large surface area of 1531 m^2 g^（-1）, a low defect density with a low I_D/I_G ratio of 1.55 calculated from Raman spectrum, and a high oxidation peak of 532.7 ℃ in oxygen atmosphere. The selective distribution of N heteroatoms on the surface of SNG affords the effective exposure of active sites at the interfaces of the electrode/electrolyte, so that more N heteroatoms are able to contact with oxygen feedstocks in oxygen reduction reaction or serve as polysulfide anchoring sites to retard the shuttle of polysulfides in a lithium–sulfur battery. This work opens a fresh viewpoint on the manipulation of active site distribution in a conductive scaffolds for multi-electron redox reaction based energy conversion and storage.展开更多
Element sulfur is highly attractive due to their potentially low cost and environmental compatibility.However, polysulfides dissolution hinders the lithiumsulfur(Li-S) batteries toward commercialization. To overcome t...Element sulfur is highly attractive due to their potentially low cost and environmental compatibility.However, polysulfides dissolution hinders the lithiumsulfur(Li-S) batteries toward commercialization. To overcome these issues, in this work, lithium cobaltate as a commercial material, for the first time, was devoted to engineering the electrode structure and composition to improve the performance. When incorporated with 80% sulfur powder, the synergetic effects of cobalt atoms and interlayer spaces effectively enable the production of Li-S batteries with a relatively high discharge capacity of 1420 mAh·g-1at the low surface current density of 1 mA·cm-2and stable capacity retention of 650 mAh·g-1at high surface current density of 6 mA·cm-2. The introduction of lithium cobaltate is a viable approach for successfully developing practical Li-S batteries.展开更多
Lithium-sulfur(Li-S) battery has been considered as one of the most promising rechargeable batteries among various energy storage devices owing to the attractive ultrahigh theoretical capacity and low cost. However, t...Lithium-sulfur(Li-S) battery has been considered as one of the most promising rechargeable batteries among various energy storage devices owing to the attractive ultrahigh theoretical capacity and low cost. However, the performance of Li-S batteries is still far from theoretical prediction because of the inherent insulation of sulfur, shuttling of soluble polysulfides, swelling of cathode volume and the formation of lithium dendrites. Significant efforts have been made to trap polysulfides via physical strategies using carbon based materials, but the interactions between polysulfides and carbon are so weak that the device performance is limited. Chemical strategies provide the relatively complemented routes for improving the batteries' electrochemical properties by introducing strong interactions between functional groups and lithium polysulfides. Therefore, this review mainly discusses the recent advances in chemical absorption for improving the performance of Li-S batteries by introducing functional groups(oxygen, nitrogen, and boron, etc.) and chemical additives(metal, polymers, etc.) to the carbon structures, and how these foreign guests immobilize the dissolved polysulfides.展开更多
Inspired by high theoretical energy density(-2600 W h kg^(-1))and cost-effectiveness of sulfur cathode,lithium–sulfur batteries are receiving great attention and considered as one of the most promising next-generatio...Inspired by high theoretical energy density(-2600 W h kg^(-1))and cost-effectiveness of sulfur cathode,lithium–sulfur batteries are receiving great attention and considered as one of the most promising next-generation high-energy-density batteries.However,over the past decades,the energy density and reliable safety levels as well as the commercial progress of lithium-sulfur batteries are still far from satisfactory due to the disconnection and huge gap between fundamental research and practical application.展开更多
Despite promising characteristics such as high specific energy and low cost,current Li-S batteries fall short in cycle life.Improving the cycling stability of S cathodes requires immobilizing the lithium polysulfide ...Despite promising characteristics such as high specific energy and low cost,current Li-S batteries fall short in cycle life.Improving the cycling stability of S cathodes requires immobilizing the lithium polysulfide （LPS） intermediates as well as accelerating their redox kinetics.Although many materials have been explored for trapping LPS,the ability to promote LPS redox has attracted much less attention.Here,we report for the first time on transition metal phosphides as effective host materials to enhance both LPS adsorption and redox.Integrating MoP-nanoparticle-decorated carbon nanotubes with S deposited on graphene oxide,we enable Li-S battery cathodes with substantially improved cycling stability and rate capability.Capacity decay rates as low as 0.017% per cycle over 1,000 cycles can be realized.Stable and high areal capacity （〉 3 mAh＆#183;cm-2） can be achieved under high mass loading conditions.Comparable electrochemical performance can also be achieved with analogous material structures based on CoP,demonstrating the potential of metal phosphides for long-cycle Li-S batteries.展开更多
Lithium–sulfur(Li-S)batteries are promising next-generation energy storage systems with ultrahigh energy density.However,the intrinsic sluggish“solid–liquid–solid”reaction between S8 and Li2S causes unavoidable s...Lithium–sulfur(Li-S)batteries are promising next-generation energy storage systems with ultrahigh energy density.However,the intrinsic sluggish“solid–liquid–solid”reaction between S8 and Li2S causes unavoidable shuttling of polysulfides,severely limiting the practical energy density and cycling performance.Recently,the catalysis process has been introduced for the sulfur redox reaction to accelerate the conversion of polysulfides,providing a positive remedy for the polysulfides shuttling.Nevertheless,in-depth understanding of the catalyst evaluation criteria and catalytic mechanism still lies in the“black box”,and precise characterization technique is the key to unlock this puzzle.In this review,we provide a comprehensive overview of characterization techniques on the catalyst in Li-S batteries from two aspects of catalytic performance and catalytic mechanism,highlighting their significance and calling for more efforts to develop precise and fast techniques for Li-S catalysis.Moreover,we envision the future development of characterization for better understanding the catalysis toward practical Li-S battery.展开更多
Lithium-sulfur batteries(LSBs)have received much concern as emerging high-power energy storage system.Nevertheless,the low conductivity of sulfur and poly sulfide shuttle results in low rate capability and rapid capac...Lithium-sulfur batteries(LSBs)have received much concern as emerging high-power energy storage system.Nevertheless,the low conductivity of sulfur and poly sulfide shuttle results in low rate capability and rapid capacity decay,which seriously limit its commercial application.Here,facile,sustainable and cost-effective strategy for preparing heteroatom-doped porous activated carbon(PAC)derived from biomass palm kernel shell(PKS)was developed for high-performance LSB applications.The presence of N,P and S heteroatoms with modification of the surface polarity brings about large amounts of active sites and improved adsorption property compared to those of common carbon materials.The PAC sample possesses desirable specific surface area(SSA)(2760 m2·g-1)as well as pore volume(1.6 cm3·g-1).Besides,the good electrical conductivity of PAC endows the material with excellent rate performance.The PAC-S electrode with a 60%of sulfur loading has a desirable first discharge capacity(1045 mAh·g1,200 mA·g-1)with superb discharge capacity(869.8 mAh·g-1,100 th cycle)and cyclability(312.6 mAh·g-1,800 mA·g-1,1000 th cycle),which can be mainly ascribed to its unique porous properties and the good conductivity of PAC.展开更多
Low volumetric energy density is a bottleneck for the application of lithium-sulfur (Li-S)battery.The low- density sulfur cooperated with the light-weight carbon sub- strate realizes electrochemical cycle stability,bu...Low volumetric energy density is a bottleneck for the application of lithium-sulfur (Li-S)battery.The low- density sulfur cooperated with the light-weight carbon sub- strate realizes electrochemical cycle stability,but leads to worse volumetric energy density.Here,nickel ferrite (NiFe2O4)nanofibers as novel substrate for sulfur not only anchor lithium polysulfides to enhance the cycle stability of sulfur cathode,but also contribute to the high volumetric capacity of the S/nickel ferrite composite.Specifically,the S/ nickel ferrite composite presents an initial volumetric capacity of 1,281.7mA h cm^-3-composite at 0.1C rate,1.9times higher than that of S/carbon nanotubes,due to the high tap density of the S/nickel ferrite composite.展开更多
基金the National Key R&D Program of China(No.2018YFA0702003)the National Natural Science Foundation of China(Nos.21890383,21671117,21871159)+1 种基金the China Postdoctoral Science Foundation(No.2019M660607)Z.C.Z.acknowledges support from the Shuimu Isinghua Scholar Program.
文摘With high energy density and low material cost,lithium sulfur batteries(LSBs)emerge quite expeditiously as a fascinating energy storage system over the past decade.Broad applications of LSBs ranging from electric vehicles to stationary grid storage seem rather bright in recent literatures.However,there still exist many pressing challenges to be addressed because we do not yet fully understand and control the electrode-electrolyte interface chemistries during battery operation,such as polysulide shuttling and poor utilization of active sulfur.Single-atom catalysts(SACs)pave new possibilities of tackling the tough issues due to their decent applicability in the atomic-level identification of structure-activity relationships and reaction mechanism,as well as their structural tunability with atomic precision.This review comprehensively summarizes the very recent advances in utilization of highly active SACs for LSBs by stating and discussing the related publications,which involves catalyst synthesis routes,battery pertormance,catalytic mechanisms,optimization strategies,and promises to achieve long-lite,high-energy LSBs.We see that endeavors to employ SACs to modify sulfur cathode have allowed efficient polysulfide conversion and confinement,leading to the minimization of shuttle effect.Parallel efforts are being devoted to extending the scope of SACs to cell separator and lithium metal anode in order to unlock the full potential of LSBs.We also obtain mechanistic insights into battery chemistries and nature of SACs in their strong interactions with polysulfides through advanced in situ characterizations documented.Overall,acceleration in the development of LSBs by introducing SACs is noticeable,and this cutting edge needs more attentions to further promoting the design of better LSBs.
基金supported by the National Key Research and Development Program of China (2016YBF0100100, 2016YFA0200101, and 2016YFA0200200)the National Natural Science Foundation of China (51572259, 51325205, 51290273, and 51521091)+3 种基金the Natural Science Foundation of Liaoning Province (201602737)the Thousand Youth Talents Plan of China (Y5610121T3)China Postdoctoral Science Foundation (2016M601349)dedicated funds for methanol conversion from Dalian Institute of Chemical Physics, Chinese Academy of Sciences
文摘Graphene, with unique two-dimensional form and numerous appealing properties, promises to remarkably increase the energy density and power density of electrochemical energy storage devices(EESDs),ranging from the popular lithium ion batteries and supercapacitors to next-generation high-energy batteries. Here, we review the recent advances of the state-of-the-art graphene-based materials for EESDs,including lithium ion batteries, supercapacitors, micro-supercapacitors, high-energy lithium-air and lithium-sulfur batteries, and discuss the importance of the pore, doping, assembly, hybridization and functionalization of different nano-architectures in improving electrochemical performance. The major roles of graphene are highlighted as(1) a superior active material,(2) ultrathin 2D flexible support,and(3) an inactive yet electrically conductive additive. Furthermore, we address the enormous potential of graphene for constructing new-concept emerging graphene-enabled EESDs with multiple functionalities of lightweight, ultra-flexibility, thinness, and novel cell configurations. Finally, future perspectives and challenges of graphene-based EESDs are briefly discussed.
基金This work was supported by National Key Research and Development Program(2016YFA0202500 and 2015CB932500)National Natural Science Foundation of China(21676160,21825501,and U1801257)the Tsinghua University Initiative Scientific Research Program.
文摘Lithium-sulfur(Li-S)batteries are one of the most promising candidates for high energy density rechargeable batteries beyond current Li-ion batteries.However,severe corrosion of Li metal anode and low Coulombic efficiency(CE)induced by the unremitting shuttle of Li polysulfides immensely hinder the practical applications of Li-S batteries.Herein,a compact inorganic layer(CIL)formed by ex situ reactions between Li anode and ionic liquid emerged as an effective strategy to block Li polysulfides and suppress shuttle effect.A CE of 96.7%was achieved in Li-S batteries with CIL protected Li anode in contrast to 82.4%for bare Li anode while no lithium nitrate was employed.Furthermore,the corrosion of Li during cycling was effectively inhibited.While applied to working batteries,80.6%of the initial capacity after 100 cycles was retained in Li-S batteries with CIL-protected ultrathin(33μm)Li anode compared with 58.5%for bare Li anode,further demonstrating the potential of this strategy for practical applications.This study presents a feasible interfacial regulation strategy to protect Li anode with the presence of Li polysulfides and opens avenues for Li anode protection in Li-S batteries under practical conditions.
基金This work was supported by Beijing Natural Science Foundation(JQ20004)the National Natural Science Foundation of China(21776019)+1 种基金National Key Research and Development Program(2016YFA0202500)Scientific and Technological Key Project of Shanxi Province(20191102003).
文摘Lithium-sulfur(Li-S)batteries are considered as a highly promising energy storage system due to their ultrahigh theoretical energy density.However,the sluggish kinetics of the complex multi-electron sulfur redox reactions seriously hinders the actual battery performance especially under practical working conditions.Homogeneous redox mediation,through elaborately designing the additive molecules,is an effective approach to promote the sulfur redox kinetics.Herein a promoter of mixed organodiselenides(mixed-Se)is proposed to comprehensively improve the sulfur redox kinetics following the redox comediation principles.Concretely,diphenyl diselenide promotes the liquid-liquid conversion between polysulfides and the solid-liquid conversion regarding lithium sulfide oxidation to polysulfides,while dimethyl diselenide enhances the liquid-solid conversion regarding lithium sulfide deposition.Consequently,the mixed-Se promoter endows a high discharge capacity of 1002 mAh g^(−1)with high sulfur loading of 4.0 mg cm^(−2),a high capacity retention of 81.6%after 200 cycles at 0.5 C,and a high actual energy density of 384 Wh kg^(−1)at 0.025 C in 1.5 Ah-level Li-S pouch cells.This work affords an effective kinetic promoter to construct high-energy-density Li-S batteries and inspires molecular design of kinetic promoters toward targeted energy-related redox reactions.
基金supported by the National Key Research and Development Program (2016YFA0202500, 2015CB932500)the National Natural Science Foundation of China (21676160, 21776019)
文摘Due to the high specific capacity, low cost, and environmental friendliness, lithium-sulfur batteries hold great potential to become the mainsiay of next-generation energy storage system. Regarding the composition of sulfur/carbon in cathode, flammable organic liquid electrolyte, and lithium metal anode, great concerns about the safety have been raised. Hence solid-electrolyte-based lithium-sulfur batteries, as one alternative route for safe batteries, are highly interested. This review highlights the recent research progress of lithium-sulfur batteries with solid electrolytes. Both sulfide solid electrolytes and oxide solid electrolytes are included. The sulfide solid electrolytes are mainly employed in all-solid-state lithium-sulfur batteries, while the oxide solid electrolytes are applied in hybrid electrolyte for lithium-sulfur batteries. The challenges and perspectives in this field are also featured on the basis of its current progress.
基金We thank the National Basic Research Program of China （Nos. 2011CB932403 and 2015CB932300） and the National Natural Science Foundation of China （Nos. 21301144, 21390390, 21131005, 21333008, and 21420102001） for financial support.
文摘Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.
文摘Lithium/sulfur （Li/S） cells have great potential to become mainstream secondary batteries due to their ultra-high theoretical specific energy. The major challenge for Li/S cells is the unstable cycling performance caused by the sulfur＇s insulating nature and the high-solubility of the intermediate polysulfide products. Several years of efforts to develop various fancy carbon nanostructures, trying to physically encapsulate the polysulfides, did not yet push the cell＇s cycle life long enough to compete with current Li ion cells. The focus of this review is on the recent progress in chemical bonding strategy for trapping polysulfides through employing functional groups and additives in carbon matrix. Research results on understanding the working mechanism of chemical interaction between polysulfides and functional groups （e.g. 0-, B-, N- and S-） in carbon matrix, metal-based additives, or polymer additives during charge/discharge are discussed.
基金supported by the National Natural Science Foundation of China (U1832136 and 21303038)Think-Tank Union Funds for Energy Storage (Grant No.JZ2016QTXM1097)+3 种基金Open Funds of the State Key Laboratory of Rare Earth Resource Utilization (Grant No. RERU2016004)the Fundamental Research Funds for the Central Universities (JZ2016HGTA0690)Natural Science Foundation of Anhui province (1808085QE140)100 Talents Plan of Anhui
文摘Biomass, as the most widely used carbon sources, is the main ingredient in the formation of fossil fuels. Biomass-derived novel carbons(BDNCs) have attracted much attention because of its adjustable physical/chemical properties, environmentally friendliness, and considerable economic value. Nature contributes to the biomass with bizarre microstructures with micropores, mesopores or hierarchical pores.Currently, it has been confirmed that biomass has great potential applications in energy storage devices,especially in lithium-sulfur(Li–S) batteries. In this article, the synthesis and function of BDNCs for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the carbons in Li-S batteries are discussed. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent BDNCs for Li–S batteries.
基金supported by the National Key Research and Development Program(grant No.2021YFB2500300)National Natural Science Foundation of China(grant Nos.22179070,22075029,U1932220)+2 种基金Beijing Municipal Natural Science Foundation(grant No.Z200011)the Natural Science Foundation of Jiangsu Province(grant No.BK20220073)the Fundamental Research Funds for the Central Universities(grant No.2242022R10082).
文摘Comprehensive analyses on thermal runaway mechanisms are critically vital to achieve the safe lithium-sulfur(Li-S)batteries.The reactions between dissolved higher-order polysulfides and Li metal were found to be the origins for the thermal runaway of 1.0 Ah cycled Li-S pouch cells.16-cycle pouch cell indicates high safety,heating from 30 to 300 ℃ without thermal runaway,while 16-cycle pouch cell with additional electrolyte undergoes severe thermal runaway at 147.9 ℃,demonstrating the key roles of the electrolyte on the thermal safety of batteries.On the contrary,thermal runaway does not occur for 45-cycle pouch cell despite the addition of the electrolyte.It is found that the higher-order polysulfides(Li_(2)S_(x) ≥ 6)are discovered in 16-cycle electrolyte while the sulfur species in 45-cycle electrolyte are Li_(2)S_(x) ≤ 4.In addition,strong exothermic reactions are discovered between cycled Li and dissolved higher-order polysulfide(Li_(2)S_(6) and Li_(2)S_(8))at 153.0 ℃,driving the thermal runaway of cycled Li-S pouch cells.This work uncovers the potential safety risks of Li-S batteries and negative roles of the polysulfide shuttle for Li-S batteries from the safety view.
基金Fundamental Research Funds for the Chinese Central Universities,Grant/Award Number:ZYGX2017KYQD193National Natural Science Foundation of China,Grant/Award Numbers:51702040,21676064,21878063+3 种基金Taishan Scholar Program of Shandong Province,China,Grant/Award Number:tsqn201909119The work was supported by the Fundamental Research Funds for the Chinese Central Universities(Grant No.ZYGX2017KYQD193)the National Natural Science Foundation of China(Grant No.51702040,21676064 and 21878063)the Taishan Scholars Program of Shandong Province(Grant No.tsqn201909119).
文摘The lithium-sulfur battery is considered one of the most promising candidates for portable energy storage devices due to its low cost and high energy density.However,many critical issues,including polysulfide shuttling,self-discharge,lithium dendritic growth,and thermal hazards need to be addressed before the commercialization of lithium-sulfur batteries.To this end,tremendous efforts have been made to explore battery configurations and components,such as electrodes,electrolytes,and separators,among which the separator plays an especially critical role in addressing aforementioned issues.Thus,this review analyzes the mechanisms and interactions of these critical issues and summarizes both the function of separators and recent progress made towards remedying such issues.Additionally,promising directions for the development of separators in lithium-sulfur batteries are proposed.
文摘Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur （Li-S） batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur （BC-S） nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1,295 mA-h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA-h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency （995%）. This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteries.
基金supported by the National Key Research and Development Program(2016YFA0202500 and 2016YFA0200102)the Natural Scientific Foundation of China(21776019)
文摘The introduction of nitrogen heteroatoms into carbon materials is a facile and efficient strategy to regulate their reactivities and facilitate their potential applications in energy conversion and storage. However,most of nitrogen heteroatoms are doped into the bulk phase of carbon without site selectivity, which significantly reduces the contacts of feedstocks with the active dopants in a conductive scaffold. Herein we proposed the chemical vapor deposition of a nitrogen-doped graphene skin on the 3D porous graphene framework and donated the carbon/carbon composite as surface N-doped grapheme（SNG）. In contrast with routine N-doped graphene framework（NGF） with bulk distribution of N heteroatoms, the SNG renders a high surface N content of 1.81 at%, enhanced electrical conductivity of 31 S cm^（-1）, a large surface area of 1531 m^2 g^（-1）, a low defect density with a low I_D/I_G ratio of 1.55 calculated from Raman spectrum, and a high oxidation peak of 532.7 ℃ in oxygen atmosphere. The selective distribution of N heteroatoms on the surface of SNG affords the effective exposure of active sites at the interfaces of the electrode/electrolyte, so that more N heteroatoms are able to contact with oxygen feedstocks in oxygen reduction reaction or serve as polysulfide anchoring sites to retard the shuttle of polysulfides in a lithium–sulfur battery. This work opens a fresh viewpoint on the manipulation of active site distribution in a conductive scaffolds for multi-electron redox reaction based energy conversion and storage.
文摘Element sulfur is highly attractive due to their potentially low cost and environmental compatibility.However, polysulfides dissolution hinders the lithiumsulfur(Li-S) batteries toward commercialization. To overcome these issues, in this work, lithium cobaltate as a commercial material, for the first time, was devoted to engineering the electrode structure and composition to improve the performance. When incorporated with 80% sulfur powder, the synergetic effects of cobalt atoms and interlayer spaces effectively enable the production of Li-S batteries with a relatively high discharge capacity of 1420 mAh·g-1at the low surface current density of 1 mA·cm-2and stable capacity retention of 650 mAh·g-1at high surface current density of 6 mA·cm-2. The introduction of lithium cobaltate is a viable approach for successfully developing practical Li-S batteries.
基金supported by the National Natural Science Foundation of China (21303038)Open Funds of the State Key Laboratory of Rare Earth Resource Utilization (RERU2016004)+1 种基金Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education MinistryOne Hundred Talents Program of Anhui Province
文摘Lithium-sulfur(Li-S) battery has been considered as one of the most promising rechargeable batteries among various energy storage devices owing to the attractive ultrahigh theoretical capacity and low cost. However, the performance of Li-S batteries is still far from theoretical prediction because of the inherent insulation of sulfur, shuttling of soluble polysulfides, swelling of cathode volume and the formation of lithium dendrites. Significant efforts have been made to trap polysulfides via physical strategies using carbon based materials, but the interactions between polysulfides and carbon are so weak that the device performance is limited. Chemical strategies provide the relatively complemented routes for improving the batteries' electrochemical properties by introducing strong interactions between functional groups and lithium polysulfides. Therefore, this review mainly discusses the recent advances in chemical absorption for improving the performance of Li-S batteries by introducing functional groups(oxygen, nitrogen, and boron, etc.) and chemical additives(metal, polymers, etc.) to the carbon structures, and how these foreign guests immobilize the dissolved polysulfides.
基金This work is supported by National Natural Science Foundation of China(Grant No.51772272,51502263,and 51728204)Fundamental Research Funds for the Central Universities(Grant No.2018QNA4011),Qianjiang Talents Plan D(QJD1602029)+5 种基金Startup Foundation for Hundred-Talent Program of Zhejiang UniversityY.X.acknowledges the support by National Natural Science Foundation of China(21403196)Natural Science Foundation of Zhejiang Province(LY17E020010)W.Z.acknowledges the support by National Natural Science Foundation of China(51572240)Natural Science Foundation of Zhejiang Province(LY16E070004 and 2017C01035)H.H.acknowledges the support by Natural Science Foundation of Zhejiang Province(LY18B030008).
文摘Inspired by high theoretical energy density(-2600 W h kg^(-1))and cost-effectiveness of sulfur cathode,lithium–sulfur batteries are receiving great attention and considered as one of the most promising next-generation high-energy-density batteries.However,over the past decades,the energy density and reliable safety levels as well as the commercial progress of lithium-sulfur batteries are still far from satisfactory due to the disconnection and huge gap between fundamental research and practical application.
文摘Despite promising characteristics such as high specific energy and low cost,current Li-S batteries fall short in cycle life.Improving the cycling stability of S cathodes requires immobilizing the lithium polysulfide （LPS） intermediates as well as accelerating their redox kinetics.Although many materials have been explored for trapping LPS,the ability to promote LPS redox has attracted much less attention.Here,we report for the first time on transition metal phosphides as effective host materials to enhance both LPS adsorption and redox.Integrating MoP-nanoparticle-decorated carbon nanotubes with S deposited on graphene oxide,we enable Li-S battery cathodes with substantially improved cycling stability and rate capability.Capacity decay rates as low as 0.017% per cycle over 1,000 cycles can be realized.Stable and high areal capacity （〉 3 mAh＆#183;cm-2） can be achieved under high mass loading conditions.Comparable electrochemical performance can also be achieved with analogous material structures based on CoP,demonstrating the potential of metal phosphides for long-cycle Li-S batteries.
文摘Lithium–sulfur(Li-S)batteries are promising next-generation energy storage systems with ultrahigh energy density.However,the intrinsic sluggish“solid–liquid–solid”reaction between S8 and Li2S causes unavoidable shuttling of polysulfides,severely limiting the practical energy density and cycling performance.Recently,the catalysis process has been introduced for the sulfur redox reaction to accelerate the conversion of polysulfides,providing a positive remedy for the polysulfides shuttling.Nevertheless,in-depth understanding of the catalyst evaluation criteria and catalytic mechanism still lies in the“black box”,and precise characterization technique is the key to unlock this puzzle.In this review,we provide a comprehensive overview of characterization techniques on the catalyst in Li-S batteries from two aspects of catalytic performance and catalytic mechanism,highlighting their significance and calling for more efforts to develop precise and fast techniques for Li-S catalysis.Moreover,we envision the future development of characterization for better understanding the catalysis toward practical Li-S battery.
基金financially supported by the National Natural Science Foundation of China(Nos.21671170,21673203,21805136 and 21201010)the Natural Science Foundation of Jiangsu Province(No.BK20170999)+2 种基金Program for New Century Excellent Talents of the University in China(No.NCET-13-0645)the Six Talent Plan(No.2015-XCL-030)Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Lithium-sulfur batteries(LSBs)have received much concern as emerging high-power energy storage system.Nevertheless,the low conductivity of sulfur and poly sulfide shuttle results in low rate capability and rapid capacity decay,which seriously limit its commercial application.Here,facile,sustainable and cost-effective strategy for preparing heteroatom-doped porous activated carbon(PAC)derived from biomass palm kernel shell(PKS)was developed for high-performance LSB applications.The presence of N,P and S heteroatoms with modification of the surface polarity brings about large amounts of active sites and improved adsorption property compared to those of common carbon materials.The PAC sample possesses desirable specific surface area(SSA)(2760 m2·g-1)as well as pore volume(1.6 cm3·g-1).Besides,the good electrical conductivity of PAC endows the material with excellent rate performance.The PAC-S electrode with a 60%of sulfur loading has a desirable first discharge capacity(1045 mAh·g1,200 mA·g-1)with superb discharge capacity(869.8 mAh·g-1,100 th cycle)and cyclability(312.6 mAh·g-1,800 mA·g-1,1000 th cycle),which can be mainly ascribed to its unique porous properties and the good conductivity of PAC.
基金supported by the New Energy Project for Electric Vehicles in National Key Research and Development Program (2016YFB0100200)the National Natural Science Foundation of China (21573114 and 51502145)
文摘Low volumetric energy density is a bottleneck for the application of lithium-sulfur (Li-S)battery.The low- density sulfur cooperated with the light-weight carbon sub- strate realizes electrochemical cycle stability,but leads to worse volumetric energy density.Here,nickel ferrite (NiFe2O4)nanofibers as novel substrate for sulfur not only anchor lithium polysulfides to enhance the cycle stability of sulfur cathode,but also contribute to the high volumetric capacity of the S/nickel ferrite composite.Specifically,the S/ nickel ferrite composite presents an initial volumetric capacity of 1,281.7mA h cm^-3-composite at 0.1C rate,1.9times higher than that of S/carbon nanotubes,due to the high tap density of the S/nickel ferrite composite.
