Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)ca...Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.展开更多
Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,s...Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.展开更多
Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current s...Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.展开更多
Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of L...Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of Li_(2)S.To address these issues,a novel composite,using electrospinning technology,consisting of Fe_(3)Se_(4)and porous nitrogen-doped carbon nanofibers was designed for the interlayer of LSBs.The porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe_(3)Se_(4)material adsorbs lithium polysulfides(LiPSs)and accelerates its catalytic conversion process.Furthermore,the Fe_(3)Se_(4)material interacts with soluble LiPSs to generate a new polysulfide intermediate,Li_(x)FeS_(y)complex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of Li_(2)S,enhancing the reversibility of LSBs.The designed LSB demonstrates a high specific capacity of1529.6 mA h g^(-1)in the first cycle at 0.2 C.The rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g^(-1)at a high rate of 8 C.This investigation explores the mechanism of the interaction between the interlayer and LiPSs,and provides a new strategy to regulate the reaction kinetics and Li_(2)S deposition in LSBs.展开更多
Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish...Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish Na^(+)transport kinetics and polysulfides intermediates,have greatly affect their long cycle stability.Unfortunately,the majority of current studies only focus on the first two aspects,but lack of sufficient attention and insights into the effect of polysulfides intermediates.Here,a porous of CoS_(x)(P-CoS_(x))electrode material is fabricated as an example to investigate the influence of polysulfides on its cycling performance.The results show that polysulfides cause a slight loss of reversible capacity during the battery cycling,while the failure of the battery is due to its significant fluctuations in reversible capacity after extensive cycles.Detailed analyses demonstrate that the intense fluctuation in capacity originates from the faster growth of dendrites caused by the reaction of sodium polysulfides with sodium foil and/or the reaction of elemental sulfur with sodium foil to penetrate the separator,resulting in a local short circuit.To suppress these undesirable side reaction,N,S co-doped porous carbon tubes(N,S-PC)rich in C–S and C–N bonds have been added to adsorb polysulfides and alleviate their reaction with sodium foil.As a result,the capacity of the P-CoS_(x) electrode with N,S-PC(P-CoS_(x)/N,S-PC)remains stable without significant fluctuations for 1000 cycles,which is much better than that of the pure P-CoS_(x) electrode(intense fluctuation in capacity after 320 cycles).Our work offers insights into the crucial influence of polysulfides on the cycle performance of the P-CoS_(x) anode and provides a feasible strategy to prolong the cycle life of metal sulfide anode for SIBs.展开更多
High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion ...High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion reaction kinetics immensely obstruct their commercial viability.Herein,a two-dimensional metallic 1T phase WS_(2)(1T-WS_(2))nanosheets modified functional separator is developed to improve the electrochemical performance.Meanwhile,the semiconducting bulk-WS_(2) crystals,and 2H phase WS_(2)(2H-WS_(2))nanosheets with more basal-plane Svacancy defects are also prepared to probe the contributions of the crystal structure(phase),S-vacancy defects,and edges to the Li–S batteries performance experimentally and theoretically.In merits of the synergistic effect of high ion and electron conductivity,enhanced binding ability to lithium polysulfides(LiPSs),and sufficient electrocatalytic active sites,the 1T-WS_(2) shows highly efficient electrocatalysis of LiPSs conversion and further improves Li–S battery performance.As expected,thus-fabricated cells with 1T-WS_(2) nanosheets present superior cycle stability that maintain capacity decline of 0.039%per cycle after 1000 cycles at 1.0 C.The strategy presented here offers a viable approach to reveal the critical factors for LiPSs catalytic conversion,which is beneficial to developing advanced Li–S batteries with enhanced properties.展开更多
Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrins...Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.展开更多
Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox react...Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm^(−2). This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.展开更多
Room-temperature sodium-sulfur(RT Na-S)batteries hold great promise for large-scale energy storage applications owing to the high energy density and earth-abundance of Na and S.However,the dissolution and migration of...Room-temperature sodium-sulfur(RT Na-S)batteries hold great promise for large-scale energy storage applications owing to the high energy density and earth-abundance of Na and S.However,the dissolution and migration of sodium polysulfides,uncontrollable Na dendrite growth,and the lack of studies on Na electrodeposition kinetics have hindered the development of these batteries.Herein,we reveal the mechanism of sodium polysulfides on the Na plating/stripping kinetics using a three-electrode system.First,the kinetic behavior deviates from the commonly supposed Butler-Volmer model,which is well described by the Marcus model.In addition,the specific adsorption of polysulfides on the sodium electrode surface is a key factor influencing the kinetics.Higher-order polysulfides(S_(8)^(2-)and S_(6)^(2-))exhibit distinct specific adsorption behaviors because of their high adsorption energies compared to lower-order polysulfides(S_(4)^(2-)and S_(2)^(2-)).The electrostatic effect caused by specific adsorption can accelerate the kinetics,whereas the blocking effect can slow the kinetics.Thus,this competitive relationship enables low concentrations of high-order polysulfides to stimulate kinetics.This implies that a weak shuttle effect is beneficial for obtaining a stable Na deposition in RT Na-S batteries.An in-depth understanding of the Na electrodeposition kinetics provides beneficial clues for future metal sodium/electrolyte interface designs.展开更多
WS_(2)with layered graphite-like structure as anode for sodium ion batteries has high specific capacity.However,the poor cycling performance and rate capability of WS_(2)caused by the low electronic conductivity and s...WS_(2)with layered graphite-like structure as anode for sodium ion batteries has high specific capacity.However,the poor cycling performance and rate capability of WS_(2)caused by the low electronic conductivity and structure changes during cycles inhibit its practical application.Herein,metallic phase(1T)W_(x)Mo_(1−x)S2(x=1,0.9,0.8 and 0.6)with high electronic conductivity and expanded interlayer spacing of 0.95 nm was directly prepared via a simple hydrothermal method.Specially,1T W_(0.9)Mo_(0.1)S_(2)as anode for sodium ion batteries displays high capacities of 411 mAh g^(-1)at 0.1 A g^(-1)after 180 cycles and 262 mAh g^(-1)at 1 A g^(-1)after 280 cycles and excellent rate capability(245 mAh g^(-1)at 5 A g^(-1)).The full cell based on Na_(3)V_(2)(PO_(4))_(2)O_(2)F/C cathode and 1T W_(0.9)Mo_(0.1)S_(2)anode also exhibits high capacity and good cycling performance.The irreversible electrochemical reaction of 1T W_(0.9)Mo_(0.1)S_(2)with Na ions during first few cycles results in the main products of W-Mo alloy and S.The strong adsorption of W-Mo alloy with polysulfides can effectively suppress the dissolution and shuttle effect of polysulfides,which ensures the excellent cycling performance of 1T W_(0.9)Mo_(0.1)S_(2).展开更多
The slow redox dynamics and dissolution of polysulfides in lithium-sulfur(Li-S)batteries result in poor rate performance and rapid decay of battery capacity,thus limiting their practical application.Ferroelectric bari...The slow redox dynamics and dissolution of polysulfides in lithium-sulfur(Li-S)batteries result in poor rate performance and rapid decay of battery capacity,thus limiting their practical application.Ferroelectric barium titanate(BT)nanoparticles have been reported to effectively improve the electrochemical performance of Li-S batteries due to the inherent self-polarization and high adsorption capacity of the BT nanoparticles towards polysulfides.Here in this paper,BT nanoparticles,behave as highly efficient electrocatalyst and demonstrate much higher redox dynamics towards the conversion reaction of polysulfides and Li2S than TiO2,as shown by both electrochemical measurements and density functional theory calculation.The coupling of the sulfur host of the hollow and graphitic carbon flakes(HGCF)and the BT nanoparticles(HGCF/S-BT)enable excellent electrochemical performance of Li-S batteries,delivering a0.047%capacity decay per cycle in 1000 cycles at 1 C,788 mAh g^-1 at 2 C and a reversible capacity of613 mAh g^-1 after 300 cycles at a current density of 0.5 C at a S loading of 3.4 mg cm^-2.HGCF/S-BT also shows great promise for practical application in flexible devices as demonstrated on the soft-packaged Li-S batteries.展开更多
Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-elect...Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-electron reaction between sulfur and lithium in liquid electrolyte makes the capacity much smaller than the theoretical value.Many methods were proposed for inhibiting the shuttle effect of polysulfide,improving corresponding redox kinetics and enhancing the integral performance of Li–S batteries.Here,we will comprehensively and systematically summarize the strategies for inhibiting the shuttle effect from all components of Li–S batteries.First,the electrochemical principles/mechanism and origin of the shuttle effect are described in detail.Moreover,the efficient strategies,including boosting the sulfur conversion rate of sulfur,confining sulfur or lithium polysulfides(LPS)within cathode host,confining LPS in the shield layer,and preventing LPS from contacting the anode,will be discussed to suppress the shuttle effect.Then,recent advances in inhibition of shuttle effect in cathode,electrolyte,separator,and anode with the aforementioned strategies have been summarized to direct the further design of efficient materials for Li–S batteries.Finally,we present prospects for inhibition of the LPS shuttle and potential development directions in Li–S batteries.展开更多
Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batter...Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batteries.In this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(LiPSs)and solid lithium disulfide/sulfide(Li_(2)S_(2)/Li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of Li_(2)S_(2)/Li_(2)S.The selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)component.The Fe-Co alloy serves as a heterogeneous electrocatalyst to seed Li_(2)S_(2)/Li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate Li_(2)S_(2)/Li_(2)S via solution pathways.Such bi-phasic mediation of the sulfur species benefits reduction kinetics of LiPS conversion,especially for the massive Li_(2)S_(2)/Li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely buried.This strategy endows the Li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.展开更多
Lithium-sulfur(Li-S) batteries are promising for high energy-storage applications but suffer from sluggish conversion reaction kinetics and substantial lithium sulfide(Li_(2)S) oxidation barrier,especially under high ...Lithium-sulfur(Li-S) batteries are promising for high energy-storage applications but suffer from sluggish conversion reaction kinetics and substantial lithium sulfide(Li_(2)S) oxidation barrier,especially under high sulfur loadings.Here,we report a Li cation-doped tungsten oxide(Li_(x)WO_(x)) electrocatalyst that efficiently accelerates the S■HLi_(2)S interconversion kinetics.The incorporation of Li dopants into WO_(x) cationic vacancies enables bidirectional electrocatalytic activity for both polysulfide reduction and Li_(2)S oxidation,along with enhanced Li^(+) diffusion.In conjunction with theoretical calculations,it is discovered that the improved electrocatalytic activity originates from the Li dopant-induced geometric and electronic structural optimization of the Li_(x)WO_(x),which promotes the anchoring of sulfur species at favourable adsorption sites while facilitating the charge transfer kinetics.Consequently,Li-S cells with the Li_(x)WO_(x) bidirectional electrocatalyst show stable cycling performance and high sulfur utilization under high sulfur loadings.Our approach provides insights into cation engineering as an effective electrocatalyst design strategy for advancing high-performance Li-S batteries.展开更多
In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery performance.The effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,...In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery performance.The effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,DN[ClO_(4)]^(-)=8.4,DN[SO_(3)CF_(3)]^(-)=16.9,and DN[NO_(3)]^(-)=21.1)on the patterns of lithium-sulfur batteries and lithium metal electrode performances with sulfola ne-based electrolytes is investigated.An increase in DN of lithium salt anions leads to an increase in the depth and rate of electrochemical reduction of sulfur and long-chain lithium polysulfides and to a decrease in those for medium-and short-chain lithium polysulfides.DN of lithium salt anions has weak effect on the discharge capacity of lithium-sulfur batteries and the Coulomb efficiency during cycling,with the exception of LiSO_(3)CF_(3)and LiNO_(3).An increase in DN of lithium salt anions leads to an increase in the cycling duration of lithium metal anodes and to a decrease in the presence of lithium polysulfides.In sulfolane solutions of LiNO_(3)and LiSO_(3)CF_(3),lithium polysulfides do not affect the cycling duration of lithium metal anodes.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
Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously em...Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy 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
The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.Ho...The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.However, the practical LSBs are impeded by the well-known "shuttle effect" combined with other technical drawbacks. The "shuttle effect" causes rapid capacity decay, severe self-discharging and low active material utilization. The polysulfide(PS) which has lone pair electrons in each sulfur atom is considered as Lewis base and shows strong affinity to various polar, Lewis acid and catenation interactive materials but very weakly interacts with the non-polar conductive carbons. The "shuttle effect" occurs due to the diffusion of high order PS from the cathode to the anode and then low-order PS back to the cathode. The PS is polar and, due to a lone pair of electrons associated with the sulfur atom, is considered a Lewis base. As such, the PS shows a strong affinity with various polar and Lewis acid materials. In addition, a more novel trapping can be performance through a catenation reaction. For LSBs to compete with the state-of-the-art lithium ion batteries(LIBs), the LSB areal capacity need to be ~6 m Ah cm-2(which is proportional to sulfur loading). To achieve this target the PS shuttling needs to mitigate, which can be achieved through using functional materials. This review addresses the aforementioned phenomena by considering the PS phase interacts with the various functional materials and how this impacts areal capacity and cycling stability of LSBs.展开更多
Inhibiting the “shuttle effect” of soluble polysulfides and improving reaction kinetics are the key factors necessary for further exploration of high-performance Li-S batteries. Herein, an effective interface engine...Inhibiting the “shuttle effect” of soluble polysulfides and improving reaction kinetics are the key factors necessary for further exploration of high-performance Li-S batteries. Herein, an effective interface engineering strategy is reported, wherein nitriding of an Ni-based precursor is controlled to enhance Li-S cell regulation. The resulting in-situ formed NiO-Ni_(3)N heterostructure interface not only has a stronger polysulfide adsorption effect than that of monomeric NiO or Ni_(3)N but also has a faster Li ion diffusion ability than a simple physical mixture. More importantly, this approach couples the respective advantages of NiO and Ni_(3)N to reduce polarization and facilitate electron transfer during polysulfide reactions and synergistically catalyze polysulfide conversion. In addition, ultrafine nanoparticles are thought to effectively improve the use of additive materials. In summary, Li-S batteries based on this NiO-Ni_(3)N heterostructure have the features of long cycle stability, rapid charging-discharging, and good performance under high sulfur loading.展开更多
基金supported by the National Natural Science Foundation of China(22075091)the Natural Science Foundation of Hubei Province(Grant No.2021CFA066)。
文摘Li-S batteries are regarded as one of the most promising candidates for next-generation battery systems with high energy density and low cost.However,the dissolution-precipitation reaction mechanism of the sulfur(S)cathode enhances the kinetics of the redox processes of the insulating sulfu r,which also arouses the notorious shuttle effect,leading to serious loss of S species and corrosion of Li anode.To get a balance between the shuttle restraining and the kinetic property,a combined strategy of electrolyte regulation and cathode modification is proposed via introducing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoroprpyl ether(HFE)instead of 1,2-dimethoxyethane(DME),and SeS_(7)instead of S_8.The introduction of HFE tunes the solvation structure of the LiTFSI and the dissolution of intermediate polysulfides with Se doping(LiPSSes),and optimize the interface stability of the Li anode simultaneously.The minor Se substitution compensates the decrease in kinetic due to the decreased solubility of LiPSs.In this way,the Li-SeS_(7)batteries deliver a reversible capacity of 1062 and 1037 mAh g^(-1)with 2.0 and 5.5 mg SeS_(7)cm^(-2)loading condition,respectively.Besides,an electrolyte-electrode loading model is established to explain the relationship between the optimal electrolyte and cathode loading.It makes more sense to guide the electrolyte design for practical Li-S batteries.
基金the financial support from the Australian Research Council (ARC) through Future Fellowship (FT210100298)DECRA Fellowship (DE230101068)+2 种基金Discovery Project (DP230100198 and DP210102215)Linkage Projects (LP220100088 and LP180100722)partially supported by AIIM FOR GOLD Grant (2017, 2018)
文摘Metal sulfides are a class of promising anode materials for sodium-ion batteries(SIBs)owing to their high theoretical specific capacity.Nevertheless,the reactant products(polysulfides)could dissolve into electrolyte,shuttle across separator,and react with sodium anode,leading to severe capacity loss and safety concerns.Herein,for the first time,gallium(Ga)-based liquid metal(LM)alloy is incorporated with MoS_(2)nanosheets to work as an anode in SIBs.The electron-rich,ultrahigh electrical conductivity,and self-healing properties of LM endow the heterostructured MoS_(2)-LM with highly improved conductivity and electrode integrity.Moreover,LM is demonstrated to have excellent capability for the adsorption of polysulfides(e.g.,Na_(2)S,Na_(2)S_(6),and S_(8))and subsequent catalytic conversion of Na_(2)S.Consequently,the MoS_(2)-LM electrode exhibits superior ion diffusion kinetics and long cycling performance in SIBs and even in lithium/potassium-ion battery(LIB/PIB)systems,far better than those electrodes with conventional binders(polyvinylidene difluoride(PVDF)and sodium carboxymethyl cellulose(CMC)).This work provides a unique material design concept based on Ga-based liquid metal alloy for metal sulfide anodes in rechargeable battery systems and beyond.
基金supported in part by the Institute for Advanced Study of Central South University and the High Performance Computing Center of Central South Universitythe funding from Guangdong Natural Science Funds(No.2023A0505050107)。
文摘Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.
基金financially supported by the National Natural Science Foundation of China(No.22372103)Guangdong Basic and Applied Basic Research Foundation,China(2021A1515010241,2024A1515010032)the Shenzhen Science and Technology Foundation,China(JCYJ20220531103216037)。
文摘Although lithium-sulfur batteries(LSBs)exhibit high theoretical energy density,their practical application is hindered by poor conductivity of the sulfur cathode,the shuttle effect,and the irreversible deposition of Li_(2)S.To address these issues,a novel composite,using electrospinning technology,consisting of Fe_(3)Se_(4)and porous nitrogen-doped carbon nanofibers was designed for the interlayer of LSBs.The porous carbon nanofiber structure facilitates the transport of ions and electrons,while the Fe_(3)Se_(4)material adsorbs lithium polysulfides(LiPSs)and accelerates its catalytic conversion process.Furthermore,the Fe_(3)Se_(4)material interacts with soluble LiPSs to generate a new polysulfide intermediate,Li_(x)FeS_(y)complex,which changes the electrochemical reaction pathway and facilitates the three-dimensional deposition of Li_(2)S,enhancing the reversibility of LSBs.The designed LSB demonstrates a high specific capacity of1529.6 mA h g^(-1)in the first cycle at 0.2 C.The rate performance is also excellent,maintaining an ultra-high specific capacity of 779.7 mA h g^(-1)at a high rate of 8 C.This investigation explores the mechanism of the interaction between the interlayer and LiPSs,and provides a new strategy to regulate the reaction kinetics and Li_(2)S deposition in LSBs.
基金supported by the National Natural Science Foundation of China(Grant Nos.22075064,21673065)。
文摘Metal sulfides are promising anode materials for sodium ion batteries(SIBs)due to their high theoretical specific capacity and abundant source.Nevertheless,significant challenges,including large volume change,sluggish Na^(+)transport kinetics and polysulfides intermediates,have greatly affect their long cycle stability.Unfortunately,the majority of current studies only focus on the first two aspects,but lack of sufficient attention and insights into the effect of polysulfides intermediates.Here,a porous of CoS_(x)(P-CoS_(x))electrode material is fabricated as an example to investigate the influence of polysulfides on its cycling performance.The results show that polysulfides cause a slight loss of reversible capacity during the battery cycling,while the failure of the battery is due to its significant fluctuations in reversible capacity after extensive cycles.Detailed analyses demonstrate that the intense fluctuation in capacity originates from the faster growth of dendrites caused by the reaction of sodium polysulfides with sodium foil and/or the reaction of elemental sulfur with sodium foil to penetrate the separator,resulting in a local short circuit.To suppress these undesirable side reaction,N,S co-doped porous carbon tubes(N,S-PC)rich in C–S and C–N bonds have been added to adsorb polysulfides and alleviate their reaction with sodium foil.As a result,the capacity of the P-CoS_(x) electrode with N,S-PC(P-CoS_(x)/N,S-PC)remains stable without significant fluctuations for 1000 cycles,which is much better than that of the pure P-CoS_(x) electrode(intense fluctuation in capacity after 320 cycles).Our work offers insights into the crucial influence of polysulfides on the cycle performance of the P-CoS_(x) anode and provides a feasible strategy to prolong the cycle life of metal sulfide anode for SIBs.
基金supported by the National Natural Science Funds,China(No.21676198)the Program of Introducing Talents of Discipline to Universities,China(No.B06006)。
文摘High-energy-density lithium-sulfur batteries has attracted substantial attention as competitive candidates for large-scale energy storage technologies.Still,the adverse“shuttle effect”and sluggish sulfur conversion reaction kinetics immensely obstruct their commercial viability.Herein,a two-dimensional metallic 1T phase WS_(2)(1T-WS_(2))nanosheets modified functional separator is developed to improve the electrochemical performance.Meanwhile,the semiconducting bulk-WS_(2) crystals,and 2H phase WS_(2)(2H-WS_(2))nanosheets with more basal-plane Svacancy defects are also prepared to probe the contributions of the crystal structure(phase),S-vacancy defects,and edges to the Li–S batteries performance experimentally and theoretically.In merits of the synergistic effect of high ion and electron conductivity,enhanced binding ability to lithium polysulfides(LiPSs),and sufficient electrocatalytic active sites,the 1T-WS_(2) shows highly efficient electrocatalysis of LiPSs conversion and further improves Li–S battery performance.As expected,thus-fabricated cells with 1T-WS_(2) nanosheets present superior cycle stability that maintain capacity decline of 0.039%per cycle after 1000 cycles at 1.0 C.The strategy presented here offers a viable approach to reveal the critical factors for LiPSs catalytic conversion,which is beneficial to developing advanced Li–S batteries with enhanced properties.
基金the National Natural Science Foundation of China(51773134)the Program for the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(51721091)+2 种基金the Sichuan Province Science and Technology Project(2019YFH0112)the Sichuan Province Youth Science and Technology Innovation Team(2017TD0006)the Fundamental Research Funds for the Central Universities(2017SCU04A14 and YJ201821)。
文摘Lithium-sulfur(Li-S) batteries as extremely promising high-density energy storage devices have attracted extensive concern. However, practical applications of Li-S batteries are severely restricted by not only intrinsic polysulfides shuttle resulting from their concentration gradient diffusion and sluggish conversion kinetics but also serious safety issue caused by thermolabile and combustible polymer separators.Herein, it is presented for the first time that a robust and multifunctional separator with urchin-like Co-doped Fe OOH microspheres and multiwalled carbon nanotubes(MWCNTs) as an interlayer simultaneously achieves to suppress polysulfides shuttle as well as improves thermotolerance and nonflammability of commercial PP separator. Accordingly, Li-S batteries with modified separator exhibit remarkable performance in a wide range temperatures of-25–100 ℃. Typically, under 25 ℃, ultrahigh initial capacities of 1441 and 827.29 m A h g-1 at 1 C and 2 C are delivered, and remained capacities of 936 and 663.18 mA h g-1 can be obtained after 500 cycles, respectively. At 0.1 C, the S utilization can reach up to 97%. Significantly, at 1 C, the batteries also deliver an excellent performance with remained capacities of high to862.3, 608.4 and 420.6 m A h g-1 after 100, 300 and 450 cycles under 75, 0 and-25 ℃, respectively. This work provides a new insight for developing stable and safe high-performance Li-S batteries.
基金The authors appreciate support from the National Key Research and Development Program of China(No.2018YFE0124500)the Young Elite Scientists Sponsorship Program by Tianjin(TJSQNTJ-2020-11)the National Natural Science Foundation of China(Nos.51932005,U1710109).
文摘Lithium-Sulfur (Li-S) batteries with high theoretical energy density are promising energy storage systems in the next decades, while the lithium polysulfides (LiPSs) shuttling caused by the sluggish sulfur redox reaction severely lowers the practical performance. The use of interlayer between the cathode and separator has been widely investigated to physically or chemically block the LiPSs, while the introduction of catalytic materials is a more effective strategy to accelerate the conversion of LiPSs. MXene with rich surface chemistry has shown its potential for facilitating the catalytic conversion, however, the aggregation of MXene sheets usually leads to the loss of the catalytic active sites. Herein, we report a diatomite/MXene (DE/MX) hybrid material as the bifunctional interlayer for improving the adsorption/conversion of LiPSs in Li-S batteries. The diatomite with porous structure and rich silica-hydroxyl functional groups could trap LiPSs effectively, while prevent the aggregation of MXene. The DE/MX based interlayer showed bifunctions of enhancing the chemical adsorption and promoting the conversion of LiPSs. The Li-S batteries with the DE/MX interlayer delivered an improved cycling stability with a low capacity decay of 0.059% per cycle over 1000 cycles at 1.0 C. Moreover, stable 200 cycles can be realized with a high sulfur loading electrode up to 6.0 mg cm^(−2). This work provides an effective strategy to construct bifunctional interlayers for hindering the shuttling of LiPSs and boosting the practical application of Li-S batteries.
基金sponsored by the National Natural Science Foundation of China(22178244 and 21978193)the Natural Science Foundation of Shanxi Province(202103021224039 and201901D211064)。
文摘Room-temperature sodium-sulfur(RT Na-S)batteries hold great promise for large-scale energy storage applications owing to the high energy density and earth-abundance of Na and S.However,the dissolution and migration of sodium polysulfides,uncontrollable Na dendrite growth,and the lack of studies on Na electrodeposition kinetics have hindered the development of these batteries.Herein,we reveal the mechanism of sodium polysulfides on the Na plating/stripping kinetics using a three-electrode system.First,the kinetic behavior deviates from the commonly supposed Butler-Volmer model,which is well described by the Marcus model.In addition,the specific adsorption of polysulfides on the sodium electrode surface is a key factor influencing the kinetics.Higher-order polysulfides(S_(8)^(2-)and S_(6)^(2-))exhibit distinct specific adsorption behaviors because of their high adsorption energies compared to lower-order polysulfides(S_(4)^(2-)and S_(2)^(2-)).The electrostatic effect caused by specific adsorption can accelerate the kinetics,whereas the blocking effect can slow the kinetics.Thus,this competitive relationship enables low concentrations of high-order polysulfides to stimulate kinetics.This implies that a weak shuttle effect is beneficial for obtaining a stable Na deposition in RT Na-S batteries.An in-depth understanding of the Na electrodeposition kinetics provides beneficial clues for future metal sodium/electrolyte interface designs.
基金the support from the National Science Foundation of China(22179071,51772169,51802261,52072217)the Major Technological Innovation Project of Hubei Science and Technology Department(2019AAA164)supported by the Research Project of Education Department of Hubei Province(D20191202)。
文摘WS_(2)with layered graphite-like structure as anode for sodium ion batteries has high specific capacity.However,the poor cycling performance and rate capability of WS_(2)caused by the low electronic conductivity and structure changes during cycles inhibit its practical application.Herein,metallic phase(1T)W_(x)Mo_(1−x)S2(x=1,0.9,0.8 and 0.6)with high electronic conductivity and expanded interlayer spacing of 0.95 nm was directly prepared via a simple hydrothermal method.Specially,1T W_(0.9)Mo_(0.1)S_(2)as anode for sodium ion batteries displays high capacities of 411 mAh g^(-1)at 0.1 A g^(-1)after 180 cycles and 262 mAh g^(-1)at 1 A g^(-1)after 280 cycles and excellent rate capability(245 mAh g^(-1)at 5 A g^(-1)).The full cell based on Na_(3)V_(2)(PO_(4))_(2)O_(2)F/C cathode and 1T W_(0.9)Mo_(0.1)S_(2)anode also exhibits high capacity and good cycling performance.The irreversible electrochemical reaction of 1T W_(0.9)Mo_(0.1)S_(2)with Na ions during first few cycles results in the main products of W-Mo alloy and S.The strong adsorption of W-Mo alloy with polysulfides can effectively suppress the dissolution and shuttle effect of polysulfides,which ensures the excellent cycling performance of 1T W_(0.9)Mo_(0.1)S_(2).
基金supported by the Fundamental Research Funds for Central Universities(SCUT No.2019ZD22)Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06N569)。
文摘The slow redox dynamics and dissolution of polysulfides in lithium-sulfur(Li-S)batteries result in poor rate performance and rapid decay of battery capacity,thus limiting their practical application.Ferroelectric barium titanate(BT)nanoparticles have been reported to effectively improve the electrochemical performance of Li-S batteries due to the inherent self-polarization and high adsorption capacity of the BT nanoparticles towards polysulfides.Here in this paper,BT nanoparticles,behave as highly efficient electrocatalyst and demonstrate much higher redox dynamics towards the conversion reaction of polysulfides and Li2S than TiO2,as shown by both electrochemical measurements and density functional theory calculation.The coupling of the sulfur host of the hollow and graphitic carbon flakes(HGCF)and the BT nanoparticles(HGCF/S-BT)enable excellent electrochemical performance of Li-S batteries,delivering a0.047%capacity decay per cycle in 1000 cycles at 1 C,788 mAh g^-1 at 2 C and a reversible capacity of613 mAh g^-1 after 300 cycles at a current density of 0.5 C at a S loading of 3.4 mg cm^-2.HGCF/S-BT also shows great promise for practical application in flexible devices as demonstrated on the soft-packaged Li-S batteries.
基金support from the “Joint International Laboratory on Environmental and Energy Frontier Materials”“Innovation Research Team of High-Level Local Universities in Shanghai”support from the National Natural Science Foundation of China (22209103)
文摘Lithium–sulfur(Li–S)batteries are supposed to be one of the most potential next-generation batteries owing to their high theoretical capacity and low cost.Nevertheless,the shuttle effect of firm multi-step two-electron reaction between sulfur and lithium in liquid electrolyte makes the capacity much smaller than the theoretical value.Many methods were proposed for inhibiting the shuttle effect of polysulfide,improving corresponding redox kinetics and enhancing the integral performance of Li–S batteries.Here,we will comprehensively and systematically summarize the strategies for inhibiting the shuttle effect from all components of Li–S batteries.First,the electrochemical principles/mechanism and origin of the shuttle effect are described in detail.Moreover,the efficient strategies,including boosting the sulfur conversion rate of sulfur,confining sulfur or lithium polysulfides(LPS)within cathode host,confining LPS in the shield layer,and preventing LPS from contacting the anode,will be discussed to suppress the shuttle effect.Then,recent advances in inhibition of shuttle effect in cathode,electrolyte,separator,and anode with the aforementioned strategies have been summarized to direct the further design of efficient materials for Li–S batteries.Finally,we present prospects for inhibition of the LPS shuttle and potential development directions in Li–S batteries.
基金supported by the National Natural Science Foundation of China(22379121)Shenzhen Foundation Research Program(JCYJ20220530112812028)+1 种基金Fundamental Research Funds for the Central Universities(G2022KY0606)Zhejiang Province Key Laboratory of Flexible Electronics Open Fund(2023FE005)。
文摘Expediting redox kinetics of sulfur species on conductive scaffolds with limited charge accessible surface is considered as an imperative approach to realize energy-dense and power-intensive lithium-sulfur(Li-S)batteries.In this work,the concept of concurrent hetero-/homo-geneous electrocatalysts is proposed to simultaneously mediate liquid-solid conversion of lithium polysulfides(LiPSs)and solid lithium disulfide/sulfide(Li_(2)S_(2)/Li_(2)S)propagation,the latter of which suffers from sluggish reduction kinetics due to buried conductive scaffold surface by extensive deposition of Li_(2)S_(2)/Li_(2)S.The selected model material to verify this concept is a two-in-one catalyst:carbon nanotube(CNT)scaffold supported iron-cobalt(Fe-Co)alloy nanoparticles and partially carbonized selenium(C-Se)component.The Fe-Co alloy serves as a heterogeneous electrocatalyst to seed Li_(2)S_(2)/Li_(2)S through sulphifilic active sites,while the C-Se sustainably releases soluble lithium polyselenides and functions as a homogeneous electrocatalyst to propagate Li_(2)S_(2)/Li_(2)S via solution pathways.Such bi-phasic mediation of the sulfur species benefits reduction kinetics of LiPS conversion,especially for the massive Li_(2)S_(2)/Li_(2)S growth scenario by affording an additional solution directed route in case of conductive surface being largely buried.This strategy endows the Li-S batteries with improved cycling stability(836 mA h g^(-1)after 180 cycles),rate capability(547 mA h g^(-1)at 4 C)and high sulfur loading superiority(2.96 mA h cm^(-2)at 2.4 mg cm^(-2)).This work hopes to enlighten the employment of bi-phasic electrocatalysts to dictate liquid-solid transformation of intermediates for conversion chemistry batteries.
基金financially Australian Research Council (DE210101157 and FT190100058)。
文摘Lithium-sulfur(Li-S) batteries are promising for high energy-storage applications but suffer from sluggish conversion reaction kinetics and substantial lithium sulfide(Li_(2)S) oxidation barrier,especially under high sulfur loadings.Here,we report a Li cation-doped tungsten oxide(Li_(x)WO_(x)) electrocatalyst that efficiently accelerates the S■HLi_(2)S interconversion kinetics.The incorporation of Li dopants into WO_(x) cationic vacancies enables bidirectional electrocatalytic activity for both polysulfide reduction and Li_(2)S oxidation,along with enhanced Li^(+) diffusion.In conjunction with theoretical calculations,it is discovered that the improved electrocatalytic activity originates from the Li dopant-induced geometric and electronic structural optimization of the Li_(x)WO_(x),which promotes the anchoring of sulfur species at favourable adsorption sites while facilitating the charge transfer kinetics.Consequently,Li-S cells with the Li_(x)WO_(x) bidirectional electrocatalyst show stable cycling performance and high sulfur utilization under high sulfur loadings.Our approach provides insights into cation engineering as an effective electrocatalyst design strategy for advancing high-performance Li-S batteries.
基金supported by the Russian Science Foundation as part of joint project of RSF-NSFC no.21-43-00006“Polysulfide IonSolvent Complexes and Their Electrochemical Behavior in Lithium-Sulfur Batteries”with the National Natural Science Foundation of China(22061132002)。
文摘In lithium-sulfur batteries,cell design,specifically electrolyte design,has a key impact on the battery performance.The effect of lithium salt anion donor number(DN)(DN[PF_(6)]^(-)=2.5,DN[N(SO_(2)CF_(3))_(2)]^(-)=5.4,DN[ClO_(4)]^(-)=8.4,DN[SO_(3)CF_(3)]^(-)=16.9,and DN[NO_(3)]^(-)=21.1)on the patterns of lithium-sulfur batteries and lithium metal electrode performances with sulfola ne-based electrolytes is investigated.An increase in DN of lithium salt anions leads to an increase in the depth and rate of electrochemical reduction of sulfur and long-chain lithium polysulfides and to a decrease in those for medium-and short-chain lithium polysulfides.DN of lithium salt anions has weak effect on the discharge capacity of lithium-sulfur batteries and the Coulomb efficiency during cycling,with the exception of LiSO_(3)CF_(3)and LiNO_(3).An increase in DN of lithium salt anions leads to an increase in the cycling duration of lithium metal anodes and to a decrease in the presence of lithium polysulfides.In sulfolane solutions of LiNO_(3)and LiSO_(3)CF_(3),lithium polysulfides do not affect the cycling duration of lithium metal anodes.
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(21805162 and 21671096)National Key Research and Development Program(2018YFB0104300)+3 种基金Key Program of the Natural Science Foundation of China(51732005)Guangdong Provincial Key Laboratory of Energy Materials for Electric Power(2018B030322001)Shenzhen Key Laboratory of Solid State Batteries(No.ZDSYS201802081843465)Research Support for Postdoctoral Scholars coming to Shenzhen(K19407556)。
文摘Lithium-sulfur(Li-S)batteries possess overwhelming energy density of 2654 Wh kg-1,and are considered as the next-generation battery technology for energy demanding applications.Flooded electrolytes are ubiquitously employed in cells to ensure sufficient redox kinetics and preclude the interference of the electrolyte depletion due to side reactions with the lithium metal anode.This strategy is capable of enabling long-lasting,high-capacity and excellent-rate battery performances,but it mask the requirements of practical Li-S batteries,where high-sulfur-loading/content and lean electrolyte are prerequisite to realize the energy-dense Li-S batteries.Sparingly and highly solvating electrolytes have emerged as effective yet simple approaches to decrease the electrolyte/sulfur ratio through altering sulfur species and exerting new reaction pathways.Sparingly solvating electrolytes are characterized by few free solvents to solvate lithium polysulfides,rendering a quasi-solid sulfur conversion and decoupling the reaction mechanisms from electrolyte quantity used in cells;while highly solvating electrolytes adopt highdonicity or high-permittivity solvents and take their advantages of strong solvation ability toward polysulfide intermediates,thereby favoring the polysulfide formation and stabilizing unique radicals,which subsequently accelerate redox kinetics.Both solvation chemistry approaches have their respective features to allow the operation of cells under electrolyte-starved conditions.This Review discusses their unique features and basic physicochemical properties in the working Li-S batteries,presents remaining technical and scientific issues and provides future directions for the electrolyte chemistry to attain highenergy 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.
文摘The lithium sulfur batteries(LSBs) are considered as one of the promising next generation energy storage devices due to the high theoretical specific capacity of sulfur(1675 m Ah g-1), naturally available, low cost.However, the practical LSBs are impeded by the well-known "shuttle effect" combined with other technical drawbacks. The "shuttle effect" causes rapid capacity decay, severe self-discharging and low active material utilization. The polysulfide(PS) which has lone pair electrons in each sulfur atom is considered as Lewis base and shows strong affinity to various polar, Lewis acid and catenation interactive materials but very weakly interacts with the non-polar conductive carbons. The "shuttle effect" occurs due to the diffusion of high order PS from the cathode to the anode and then low-order PS back to the cathode. The PS is polar and, due to a lone pair of electrons associated with the sulfur atom, is considered a Lewis base. As such, the PS shows a strong affinity with various polar and Lewis acid materials. In addition, a more novel trapping can be performance through a catenation reaction. For LSBs to compete with the state-of-the-art lithium ion batteries(LIBs), the LSB areal capacity need to be ~6 m Ah cm-2(which is proportional to sulfur loading). To achieve this target the PS shuttling needs to mitigate, which can be achieved through using functional materials. This review addresses the aforementioned phenomena by considering the PS phase interacts with the various functional materials and how this impacts areal capacity and cycling stability of LSBs.
基金financial support of the Youth Project of the Provincial Natural Science Foundation of Anhui(No. 2008085QE267)the Doctoral Research Initiation Foundation of Anhui Normal University (No. 751973)+2 种基金the National Natural Science Foundation of China (No. 51972162)the Fundamental Research Funds for the Central Universities (No. 0213-14380196)the Science and Technology Project of Nanchang (No. 2017-SJSYS-008)。
文摘Inhibiting the “shuttle effect” of soluble polysulfides and improving reaction kinetics are the key factors necessary for further exploration of high-performance Li-S batteries. Herein, an effective interface engineering strategy is reported, wherein nitriding of an Ni-based precursor is controlled to enhance Li-S cell regulation. The resulting in-situ formed NiO-Ni_(3)N heterostructure interface not only has a stronger polysulfide adsorption effect than that of monomeric NiO or Ni_(3)N but also has a faster Li ion diffusion ability than a simple physical mixture. More importantly, this approach couples the respective advantages of NiO and Ni_(3)N to reduce polarization and facilitate electron transfer during polysulfide reactions and synergistically catalyze polysulfide conversion. In addition, ultrafine nanoparticles are thought to effectively improve the use of additive materials. In summary, Li-S batteries based on this NiO-Ni_(3)N heterostructure have the features of long cycle stability, rapid charging-discharging, and good performance under high sulfur loading.
