Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified W...Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.展开更多
The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising propert...The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising properties of ethylene oxide-based electrolytes,their typical clamp-like coordination geometry leads to crowd solvation sheath and overly strong interactions between Li^(+)and electrolytes,rendering difficult dissociation of Li+and unfavorable solid electrolyte interface(SEI).Herein,we explore weakly solvating characteristics of polyacetal electrolytes owing to their alternately changing intervals between–O–coordinating sites in the main chain.Such structural asymmetry leads to unique distorted helical solvation sheath,and can effectively reduce Li^(+)-electrolyte binding and tune Li^(+)desolvation kinetics in the insitu formed polymer electrolytes,yielding anion-derived SEI and dendrite-free Li electrodeposition.Combining with photoinitiated cationic ring-opening polymerization,polyacetal electrolytes can be instantly formed within 5 min at the surface of electrode,with high segmental chain motion and well adapted interfaces.Such in-situ polyacetal electrolytes enabled more than 1300-h of stable lithium electrodeposition and prolonged cyclability over 200 cycles in solid-state batteries at ambient temperatures,demonstrating the vital role of molecular structure in changing solvating behavior and Li deposition stability for high-performance electrolytes.展开更多
Lithium(Li)batteries are major players in the power source market of electric vehicles and portable electronic devices.Electrolytes are critical to determining the performance of Li batteries.Conventional electrolytes...Lithium(Li)batteries are major players in the power source market of electric vehicles and portable electronic devices.Electrolytes are critical to determining the performance of Li batteries.Conventional electrolytes fall behind the ever-growing demands for fast-charging,wide-temperature operation,and safety properties of Li batteries.Despite the great success of(localized)high-concentration electrolytes,they still suffer from disadvantages,such as low ionic conductivity and high cost.Weakly solvating electrolytes(WSEs),also known as low-solvating electrolytes,offer another solution to these challenges,and they have attracted intensive research interests in recent years.This contribution reviews the working mechanisms,design principles,and recent advances in the development of WSEs.A summary and perspective regarding future research directions in this field is also provided.The insights will benefit academic and industrial communities in the design of safe and high-performance next-generation Li batteries.展开更多
Development of advanced high-voltage electrolytes is key to achieving high-energy-density lithium metal batteries(LMBs).Weakly solvating electrolytes(WSE)can produce unique anion-driven interphasial chemistry via alte...Development of advanced high-voltage electrolytes is key to achieving high-energy-density lithium metal batteries(LMBs).Weakly solvating electrolytes(WSE)can produce unique anion-driven interphasial chemistry via altering the solvating power of the solvent,but it is difficult to dissolve the majority of Li salts and fail to cycle at a cut-off voltage above 4.5 V.Herein,we present a new-type WSE that is regulated by the anion rather than the solvent,and the first realize stable cycling of dimethoxyethane(DME)at 4.6 V without the use of the“solvent-in-salt”strategy.The relationships between the degree of dissociation of salts,the solvation structure of electrolytes,and the electrochemical performance of LMBs were systematically investigated.We found that LiBF_(4),which has the lowest degree of dissociation,can construct an anion-rich inner solvation shell,resulting in anion-derived anode/cathode interphases.Thanks to such unusual solvation structure and interphasial chemistry,the Li-LiCoO_(2)full cell with LiBF_(4)-based WSE could deliver excellent rate performance(115 mAh g^(-1)at 10 C)and outstanding cycling stability even under practical conditions,including high loading(10.7 mg cm^(-2)),thin Li(50μm),and limited electrolyte(1.2μL mg^(-1)).展开更多
Advanced electrolyte engineering is an important strategy for developing high-efficacy lithium(Li)metal batteries(LMBs).Unfortunately,the current electrolytes limit the scope for creating batteries that perform well o...Advanced electrolyte engineering is an important strategy for developing high-efficacy lithium(Li)metal batteries(LMBs).Unfortunately,the current electrolytes limit the scope for creating batteries that perform well over temperature ranges.Here,we present a new electrolyte design that uses fluorosulfonyl carboxylate as a non-solvating solvent to form difluoroxalate borate(DFOB-)anion-rich solvation sheath,to realize high-performance working of temperature-tolerant LMBs.With this optimized electrolyte,favorable SEI and CEI chemistries on Li metal anode and nickel-rich cathode are achieved,respectively,leading to fast Li^(+)transfer kinetics,dendrite-free Li deposition and suppressed electrolyte deterioration.Therefore,Li||LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2)batteries with a thin Li foil(50μm)show a long-term cycling lifespan over 400 cycles at 1C and a superior capacity retention of 90%after 200 cycles at 0.5C under 25℃.Moreover,this electrolyte extends the operating temperature from-10 to 30℃and significantly improve the capacity retention and Coulombic efficiency of batteries are improved at high temperature(60℃).Fluorosulfonyl carboxylates thus have considerable potential for use in high-performance and allweather LMBs,which broadens the new exploring of electrolyte design.展开更多
Ether electrolytes for potassium-ion batteries exhibit a broader electrochemical window and greater applicability,yet most of them are high-concentration electrolytes with elevated cost.In this study,we propose the us...Ether electrolytes for potassium-ion batteries exhibit a broader electrochemical window and greater applicability,yet most of them are high-concentration electrolytes with elevated cost.In this study,we propose the use of a weakly solvating cyclic ether electrolyte with tetrahydropyran(THP)as the solvent.This approach induces the formation of a thin and dense inorganic-rich solid electrolyte interphase(SEI)film,which is accompanied by a decrease in the activation energy of electrode interfacial reactions due to the weak ligand binding of THP with K^(+).Density functional theory(DFT)simulations also corroborate the hypothesis that K^(+)has a lower binding energy with THP.During potassium storage process,the phenomenon of solvent co-intercalation of graphite does not occur,which greatly reduces the destruction of the graphite structure and enables a superior electrochemical performance and enhanced cycling stability at a lower concentration(2 M).At a current density of 0.2 C(55.8 mA·g^(-1)),the battery can be stably cycled for 800 cycles(approximately 8 months)with a specific capacity of 171.8 mAh·g^(-1).This study provides a new ether-based electrolyte for potassium ion batteries and effectively reduces the electrolyte cost,which is expected to inspire further development of energy storage batteries.展开更多
Practical high-voltage lithium metal batteries hold promise for high energy density applications,but face stability challenges in electrolytes for both 4 V-class cathodes and lithium anode.To address this,we delve int...Practical high-voltage lithium metal batteries hold promise for high energy density applications,but face stability challenges in electrolytes for both 4 V-class cathodes and lithium anode.To address this,we delve into the positive impacts of two crucial moieties in electrolyte chemistry:fluorine atom(-F)and cyano group(-CN)on the electrochemical performance of polyether electrolytes and lithium metal batteries.Cyano-bearing polyether electrolytes possess strong solvation,accelerating Li^(+)desolvation with minimal SEI impact.Fluorinated polyether electrolytes possess weak solvation,and stabilize the lithium anode via preferential decomposition of F-segment,exhibiting nearly 6000-h stable cycling of lithium symmetric cell.Furthermore,the electron-withdrawing prop-erties of-F and-CN groups significantly bolster the high-voltage tolerance of copolymer electrolyte,extending its operational range up to 5 V.This advance-ment enables the development of 4 V-class lithium metal batteries compatible with various cathodes,including 4.45 V LiCoO_(2),4.5 V LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),and 4.2 V LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2).These findings provide insights into design prin-ciples centered around polymer components for high-performance polymer electrolytes.展开更多
Lithium-sulfur(Li-S)batteries hold great promise to be the next-generation candidate for high-energy-density secondary batteries but in the prerequisite of using low electrolyte-to-sulfur(E/S)ratios.Highly solvating e...Lithium-sulfur(Li-S)batteries hold great promise to be the next-generation candidate for high-energy-density secondary batteries but in the prerequisite of using low electrolyte-to-sulfur(E/S)ratios.Highly solvating electrolytes(HSEs)and sparingly solvating electrolytes(SSEs),with opposite nature towards the dissolution of polysulfides,have recently emerged as two effective solutions to decrease the E/S ratio and increase the overall practical energy density of Li-S batteries.HSEs featuring with high polysulfide solvation ability have the potential to reduce the E/S ratio by dissolving more polysulfides with less electrolyte,while SSEs alter the sulfur reaction pathway from a dissolution-precipitation mechanism to a quasi-solid mechanism,thereby independent on the use of electrolyte amount.Both HSEs and SSEs show respective effectiveness in lean-electrolyte Li-S batteries,but encounter different challenges to bring Li-S batteries into practical application.This review aims to present a comparative discussion on their unique features and basic electrochemical reaction mechanisms in practical lean-electrolyte Li-S batteries.Emphasis is focused on the current technical challenges and possible solutions for their future development.展开更多
Li^(+) solvation structures have a decisive influence on the electrode/electrolyte interfacial properties and battery performances.Reduced salt concentration may result in an organic rich solid electrolyte interface(S...Li^(+) solvation structures have a decisive influence on the electrode/electrolyte interfacial properties and battery performances.Reduced salt concentration may result in an organic rich solid electrolyte interface(SEI)and catastrophic cycle stability,which makes low concentration electrolytes(LCEs)rather challenging.Solvents with low solvating power bring in new chances to LCEs due to the weak salt-solvent interactions.Herein,an LCE with only 0.25 mol L^(-1) salt is prepared with fluoroethylene carbonate(FEC)and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)).Molecular dynamics simulations and experiments prove that the low solvating power solvent FEC not only renders reduced desolvation energy to Li^(+) and improves the battery kinetics,but also promotes the formation of a LiF-rich SEI that hinders the electrolyte consumption.Li||Cu cell using the LCE shows a high coulombic efficiency of 99.20%,and LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)||Li cell also exhibits satisfying capacity retention of 89.93%in 200 cycles,which demonstrates the great potential of solvating power regulation in LCEs development.展开更多
Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacl...Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacles beyond the issue of ionic conductivity.This investigation unveils a novel formulation that constructs an anion-rich solvation sheath within strong solvents,effectively addressing all three of these challenges to bolster low-temperature performance.The developed electrolyte,characterized by an enhanced concentration of contact ion pairs(CIPs)and aggregates(AGGs),facilitates the formation of an inorganic-rich interphase layer on the anode and cathode particles.This promotes de-solvation at low temperatures and stabilizes the electrode-electrolyte interphase.Full cells composed of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)and graphite,when equipped with this electrolyte,showcase remarkable cycle stability and capacity retention,with 93.3% retention after 500 cycles at room temperature(RT)and 95.5%after 120 cycles at -20℃.This study validates the utility of the anion-rich solvation sheath in strong solvents as a strategy for the development of low-temperature electrolytes.展开更多
Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium me...Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium metal batteries(MMBs).Nevertheless,the large charge-radius ratio of Mg^(2+)induces the strong interactions of Mg^(2+)with solvent molecules of electrolyte and anionic framework of cathode,resulting in a notable voltage polarization and structural deterioration during cycling process.Herein,an in-situ multi-scale structural engineering is proposed to activate the interlayer-expanded V_(2)O_(5)cathode(pillared by tetrabutylammonium cation)via adding hexadecyltrimethylammonium bromide(CTAB)additive into electrolyte.During cycling,the in-situ incorporation of CTA^(+)not only enhances the electrostatic shielding effect and Mg species migration,but also stabilizes the interlayer spacing.Besides,CTA^(+)is prone to be adsorbed on cathode surface and induces the loss-free pulverization and amorphization of electroactive grains,leading to the pronounced effect of intercalation pseudocapacitance.CTAB additive also enables to scissor the Mg^(2+)solvation sheath and tailor the insertion mode of Mg species,further endowing V_(2)O_(5)cathode with fast reaction kinetics.Based on these merits,the corresponding V2O5‖Mg full cells exhibit the remarkable rate performance with capacities as high as 317.6,274.4,201.1,and 132.7 mAh g^(-1)at the high current densities of 0.1,0.2,0.5,and 1 A g^(-1),respectively.Moreover,after 1000 cycles,the capacity is still preserved to be 90,4 mAh g^(-1)at 1 A g^(-1)with an average coulombic efficiency of~100%.Our strategy of synergetic modulations of cathode host and electrolyte solvation structures provides new guidance for the development of high-rate,large-capacity,and long-life MMBs.展开更多
The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions durin...The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions during cycling.Electrolyte additive modification is considered one of the most effective and simplest methods for solving the aforementioned problems.Herein,the pyridine derivatives(PD)including 2,4-dihydroxypyridine(2,4-DHP),2,3-dihydroxypyridine(2,3-DHP),and 2-hydroxypyrdine(2-DHP),were em-ployed as novel electrolyte additives in ZnSO_(4)electrolyte.Both density functional theory calculation and experimental findings demonstrated that the incorporation of PD additives into the electrolyte effectively modulates the solvation structure of hydrated Zn ions,thereby suppressing side reactions in AZIBs.Ad-ditionally,the adsorption of PD molecules on the zinc anode surface contributed to uniform Zn deposi-tion and dendrite growth inhibition.Consequently,a 2,4-DHP-modified Zn/Zn symmetrical cell achieved an extremely long cyclic stability up to 5650 h at 1 mA cm^(-2).Furthermore,the Zn/NH_(4)V_(4)O_(10)full cell with 2,4-DHP-containing electrolyte exhibited an outstanding initial capacity of 204 mAh g^(-1),with a no-table capacity retention of 79%after 1000 cycles at 5 A g^(-1).Hence,this study expands the selection of electrolyte additives for AZIBs,and the working mechanism of PD additives provides new insights for electrolyte modification enabling highly reversible zinc anode.展开更多
The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design c...The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.展开更多
Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challe...Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling.To address these issues,a new eutectic electrolyte based on Zn(ClO_(4))_(2)·6H_(2)O-N-methylacetamide(ZN)is proposed in this work.Compared with aqueous electrolyte,the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn^(2+),effectively suppressing zinc dendrite growth and side reactions.As a result,the Zn//NH4 V4 O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g^(-1).Therefore,this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn^(2+)solvation structure on the cycle stability,contributing to the exploration of novel electrolytes for high-performance AZIBs.展开更多
Lithium-ion batteries(LIBs)are an electrochemical energy storage technology that has been widely used for portable electrical devices,electric vehicles,and grid storage,etc.To satisfy the demand for user convenience e...Lithium-ion batteries(LIBs)are an electrochemical energy storage technology that has been widely used for portable electrical devices,electric vehicles,and grid storage,etc.To satisfy the demand for user convenience especially for electric vehicles,the development of a fast-charging technology for LIBs has become a critical focus.In commercial LIBs,the slow kinetics of Li+intercalation into the graphite anode from the electrolyte solution is known as the main restriction for fast-charging.We summarize the recent advances in obtaining fast-charging graphite-based anodes,mainly involving modifications of the electrolyte solution and graphite anode.Specifically,strategies for increasing the ionic conductivity and regulating the Li+solvation/desolvation state in the electrolyte solution,as well as optimizing the fabrication and the intrinsic activity of graphite-based anodes are discussed in detail.This review considers practical ways to obtain fast Li+intercalation kinetics into a graphite anode from the electrolyte as well as analysing progress in the commercialization of fast-charging LIBs.展开更多
LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully ...LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully revealed.Herein,we systematically studied the evolution of solvation structures with increasing LiNO_(3) concentration in both carbonate and ether electrolytes.The results from molecular dynamics simulations unveil that the Li^(+)solvation structure is less affected in carbonate electrolytes,while in ether electrolytes,there is a significant decrease of solvent molecules in Li^(+)coordination,and a larger average size of Li^(+)solvation structure emerges as LiNO_(3) concentration increases.Notably,the formation of large ion aggregates with size of several nanometers(nano-clusters),is observed in ether-based electrolytes at conventional Li^(+)concentration(1 M)with higher NO_(3)^(-) ratio,which is further proved by infrared spectroscopy and small-angle X-ray scattering experiments.The nano-clusters with abundant anions are endowed with a narrow energy gap of molecular orbitals,contributing to the formation of an inorganic rich electrode/electrolyte interphase that enhances the reversibility of lithium stripping/plating with Coulombic efficiency up to 99.71%.The discovery of nano-clusters elucidates the underlying mechanism linking ions/solvent aggregation states of electrolytes to interfacial stability in advanced battery systems.展开更多
Continuous-flow upgrading of pentaerythritol synthesis technology via base-catalyzed aldol and Cannizzaro reactions of formaldehyde and acetaldehyde faces the challenge of effectively controlling the critical side rea...Continuous-flow upgrading of pentaerythritol synthesis technology via base-catalyzed aldol and Cannizzaro reactions of formaldehyde and acetaldehyde faces the challenge of effectively controlling the critical side reaction of hydroxymethyl acetaldehyde(HA)to the acrolein intermediate.Here,we first identified the forms of industrial formaldehyde as methane diol that easily converts to the alkaline formaldehyde under alkaline(NaOH)environment.The carbonyl group of alkaline formaldehyde induces deprotonation of acetaldehyde instead of the recognized base-hydroxyl group-induced deprotonation,and it needs to overcome only 18.31 kcal·mol^(-1)(1 kcal=4.186 kJ)energy barrier to form key intermediates of HA.The sodium solvation cage formed by NaOH hexa-coordinated formaldehyde effectively inhibits the alkalinity,thus contributing to a high energy barrier(46.21 kcal·mol^(-1))to unwanted acrolein formation.In addition,the solvation cage gradually opens to increase the alkalinity with the consumption of formaldehyde,thus facilitating the subsequent Cannizzaro reaction(to overcome 11.77 kcal·mol^(-1)).In comparison,strong alkalinity promotes the formation of acrolein(36.65 kcal·mol^(-1))to initiate the acetal side reaction,while weak alkalinity reduces the possibility of the Cannizzaro reaction(to overcome 20.44 kcal·mol^(-1)).This theoretically reveals the importance of the segmented feeding of weak and strong bases to successively control the aldol reaction and Cannizzaro reaction,and the combination of Na_(2)CO_(3) or HCOONa with NaOH improves the pentaerythritol yield by 7%to 13%compared to that of NaOH alone(70%yield)within 1 min at a throughput of 155.7 ml·min^(-1).展开更多
Solvated zinc ions are prone to undergo desolvation at the electrode/electrolyte interfaces,and unstable H_(2)O molecules within the solvated sheaths tend to trigger hydrogen evolution reaction(HER),further accelerati...Solvated zinc ions are prone to undergo desolvation at the electrode/electrolyte interfaces,and unstable H_(2)O molecules within the solvated sheaths tend to trigger hydrogen evolution reaction(HER),further accelerating interfaces decay.Herein,we propose for the first time a novel strategy to enhance the interfacial stabilities by insitu dynamic reconstruction of weakly solvated Zn2þduring the desolvation processes at heterointerfaces.Theoretical calculations indicate that,due to built-in electric field effects(BEFs),the plating/stripping mechanism shifts from[Zn(H_(2)O)_(6)]_(2)þto[Zn(H_(2)O)_(5)(SO_(4))^(2-)]_(2)þwithout additional electrolyte additives,reducing the solvation ability of H_(2)O,enhancing the competitive coordination of SO_(4)^(2-),essentially eliminating the undesirable side effects of anodes.Hence,symmetric cells can operate stably for 3000 h(51.7-times increase in cycle life),and the full cells can operate stably for 5000 cycles(51.5-times increase in cycle life).This study provides valuable insights into the critical design of weakly solvated Zn^(2+) þand desolvation processes at heterointerfaces.展开更多
The electrospray thruster supplied by ionic liquid is a promising micro-propulsion thruster with small size and precise thrust, which can emit both cations and anions to achieve self-neutralization. In order to furthe...The electrospray thruster supplied by ionic liquid is a promising micro-propulsion thruster with small size and precise thrust, which can emit both cations and anions to achieve self-neutralization. In order to further investigate the effect of ion solvation energy on the evaporation of cations and anions from ionic liquid under the action of a uniform electric field, this paper establishes a transient Electrohydrodynamic (EHD) model for free ionic liquid droplets undergoing ion evaporation. The dynamic processes of droplet deformation and ion evaporation are simulated. And the study further focuses on the influence of different ion solvation energies for cations on the droplet morphology and the ion evaporation characteristics at the positively charged end and negatively charged end of the droplet. The results indicate that, when the ion solvation energy for cations is higher than that of anions, it will cause the ion evaporation at the positively charged end of the droplet to lag behind the ion evaporation at the negatively charged end. And the higher the ion solvation energy for the cations, the longer the evaporation lag time at the positively charged end of the droplet, which will lead to a higher peak of surface charge density that can be reached, resulting in a larger evaporation current and sharper droplet stretching deformation. Additionally, the peak surface charge density of the positively charged end of the droplet is linearly related to the ion solvation energy for cations, while the peak surface charge density of the negatively charged end remains almost unchanged and is not significantly affected by the ion solvation energy for cations.展开更多
Electrolytes are crucial components in electrochemical energy storage devices,sparking considerable research interest.However,the significance of anions in the electrolytes is often underestimated.In fact,the anions h...Electrolytes are crucial components in electrochemical energy storage devices,sparking considerable research interest.However,the significance of anions in the electrolytes is often underestimated.In fact,the anions have significant impacts on the performance and stability of lithium batteries.Therefore,comprehensively understanding anion chemistry in electrolytes is of crucial importance.Herein,indepth comprehension of anion chemistry and its positive effects on the interface,solvation structure of Li-ions,as well as the electrochemical performance of the batteries have been emphasized and summarized.This review aims to present a full scope of anion chemistry and furnish systematic cognition for the rational design of advanced electrolytes for better lithium batteries with high energy density,lifespan,and safety.Furthermore,insightful analysis and perspectives based on the current research are proposed.We hope that this review sheds light on new perspectives on understanding anion chemistry in electrolytes.展开更多
基金supported by Hengyang City,Hunan Province Science and Technology Innovation Project(No.202250045319)the National Natural Science Foundation of China(Nos.11375084,21808125)the Scientific Research Planning Project of Jilin Provincial Education Department(No.JJKH20241249KJ)。
文摘Weakly solvating electrolyte(WSE)demonstrates superior compatibility with lithium(Li)metal batteries(LMBs).However,its application in fast-charging high-voltage LMBs is challenging.Here,we propose a diluent modified WSE for fast-charging high-voltage LMBs,which is formed by adding diluent of 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether(TTE)into the tetrahydropyran(THP)based WSE.A relatively loose solvation structure is formed due to the formation of weak hydrogen bond between TTE and THP,which accelerates the de-solvation kinetics of Li~+.Besides,more anions are involved in solvation structure in the presence of TTE,yielding inorganic-rich interphases with improved stability.Li(30μm)||Li Ni_(0.5)Co_(0.2)Mn_(0.3)O_(2)(4.1 mAh/cm^(2))batteries with the TTE modified WSE retain over 64%capacity retention after 175 cycles under high rate of 3 C and high-voltage of 4.5 V,much better than that with pure THP based WSE.This work points out that the combination of diluent with weakly solvating solvent is a promising approach to develop high performance electrolytes for fast-charging high-voltage LMBs.
基金financially supported by National Natural Science Foundation of China(52003231,22065037)Yunnan Fundamental Research Projects(202201AW070015)。
文摘The host structure of polymers significantly influences ion transport and interfacial stability of electrolytes,dictating battery cycle life and safety for solid-state lithium metal batteries.Despite promising properties of ethylene oxide-based electrolytes,their typical clamp-like coordination geometry leads to crowd solvation sheath and overly strong interactions between Li^(+)and electrolytes,rendering difficult dissociation of Li+and unfavorable solid electrolyte interface(SEI).Herein,we explore weakly solvating characteristics of polyacetal electrolytes owing to their alternately changing intervals between–O–coordinating sites in the main chain.Such structural asymmetry leads to unique distorted helical solvation sheath,and can effectively reduce Li^(+)-electrolyte binding and tune Li^(+)desolvation kinetics in the insitu formed polymer electrolytes,yielding anion-derived SEI and dendrite-free Li electrodeposition.Combining with photoinitiated cationic ring-opening polymerization,polyacetal electrolytes can be instantly formed within 5 min at the surface of electrode,with high segmental chain motion and well adapted interfaces.Such in-situ polyacetal electrolytes enabled more than 1300-h of stable lithium electrodeposition and prolonged cyclability over 200 cycles in solid-state batteries at ambient temperatures,demonstrating the vital role of molecular structure in changing solvating behavior and Li deposition stability for high-performance electrolytes.
基金supported by the Hong Kong Polytechnic University(No.CDBJ)Z.Wang thanks the funding support from the Centrally Funded Postdoctoral Fellowship Scheme of the Hong Kong Polytechnic University(No.1-YXAU).
文摘Lithium(Li)batteries are major players in the power source market of electric vehicles and portable electronic devices.Electrolytes are critical to determining the performance of Li batteries.Conventional electrolytes fall behind the ever-growing demands for fast-charging,wide-temperature operation,and safety properties of Li batteries.Despite the great success of(localized)high-concentration electrolytes,they still suffer from disadvantages,such as low ionic conductivity and high cost.Weakly solvating electrolytes(WSEs),also known as low-solvating electrolytes,offer another solution to these challenges,and they have attracted intensive research interests in recent years.This contribution reviews the working mechanisms,design principles,and recent advances in the development of WSEs.A summary and perspective regarding future research directions in this field is also provided.The insights will benefit academic and industrial communities in the design of safe and high-performance next-generation Li batteries.
基金supported by the Key Program for International S&T Cooperation Projects of China(No.2017YFE0124300)National Natural Science Foundation of China(Nos.51971002,52171205 and 52171197)+1 种基金Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0393)Anhui Provincial Natural Science Foundation for Excellent Youth Scholars(No.2108085Y16).
文摘Development of advanced high-voltage electrolytes is key to achieving high-energy-density lithium metal batteries(LMBs).Weakly solvating electrolytes(WSE)can produce unique anion-driven interphasial chemistry via altering the solvating power of the solvent,but it is difficult to dissolve the majority of Li salts and fail to cycle at a cut-off voltage above 4.5 V.Herein,we present a new-type WSE that is regulated by the anion rather than the solvent,and the first realize stable cycling of dimethoxyethane(DME)at 4.6 V without the use of the“solvent-in-salt”strategy.The relationships between the degree of dissociation of salts,the solvation structure of electrolytes,and the electrochemical performance of LMBs were systematically investigated.We found that LiBF_(4),which has the lowest degree of dissociation,can construct an anion-rich inner solvation shell,resulting in anion-derived anode/cathode interphases.Thanks to such unusual solvation structure and interphasial chemistry,the Li-LiCoO_(2)full cell with LiBF_(4)-based WSE could deliver excellent rate performance(115 mAh g^(-1)at 10 C)and outstanding cycling stability even under practical conditions,including high loading(10.7 mg cm^(-2)),thin Li(50μm),and limited electrolyte(1.2μL mg^(-1)).
基金the support from the Key-Area Research and Development Program of Guangdong Province (2020B090919003)the Yunnan Major Scientific and Technological Projects (202202AG050003)+4 种基金the Natural Science Foundation of China (22202078, 51904135,52162030)the Department of Education of Guangdong Province(2020KQNCX082)the Applied Basic Research Foundation of Yunnan Province (202103AA080019)the National Key R&D Program of China (2018YFB01040)the support of the supported by the Testing Technology Center of Materials and Devices of Tsinghua Shenzhen International Graduate School (SIGS)
文摘Advanced electrolyte engineering is an important strategy for developing high-efficacy lithium(Li)metal batteries(LMBs).Unfortunately,the current electrolytes limit the scope for creating batteries that perform well over temperature ranges.Here,we present a new electrolyte design that uses fluorosulfonyl carboxylate as a non-solvating solvent to form difluoroxalate borate(DFOB-)anion-rich solvation sheath,to realize high-performance working of temperature-tolerant LMBs.With this optimized electrolyte,favorable SEI and CEI chemistries on Li metal anode and nickel-rich cathode are achieved,respectively,leading to fast Li^(+)transfer kinetics,dendrite-free Li deposition and suppressed electrolyte deterioration.Therefore,Li||LiNi_(0.80)Co_(0.15)Al_(0.05)O_(2)batteries with a thin Li foil(50μm)show a long-term cycling lifespan over 400 cycles at 1C and a superior capacity retention of 90%after 200 cycles at 0.5C under 25℃.Moreover,this electrolyte extends the operating temperature from-10 to 30℃and significantly improve the capacity retention and Coulombic efficiency of batteries are improved at high temperature(60℃).Fluorosulfonyl carboxylates thus have considerable potential for use in high-performance and allweather LMBs,which broadens the new exploring of electrolyte design.
基金financial support from the National Key Research and Development Program of China(No.2022YFB2404300)the National Natural Science Foundation of China(Nos.22409153 and 52101269).
文摘Ether electrolytes for potassium-ion batteries exhibit a broader electrochemical window and greater applicability,yet most of them are high-concentration electrolytes with elevated cost.In this study,we propose the use of a weakly solvating cyclic ether electrolyte with tetrahydropyran(THP)as the solvent.This approach induces the formation of a thin and dense inorganic-rich solid electrolyte interphase(SEI)film,which is accompanied by a decrease in the activation energy of electrode interfacial reactions due to the weak ligand binding of THP with K^(+).Density functional theory(DFT)simulations also corroborate the hypothesis that K^(+)has a lower binding energy with THP.During potassium storage process,the phenomenon of solvent co-intercalation of graphite does not occur,which greatly reduces the destruction of the graphite structure and enables a superior electrochemical performance and enhanced cycling stability at a lower concentration(2 M).At a current density of 0.2 C(55.8 mA·g^(-1)),the battery can be stably cycled for 800 cycles(approximately 8 months)with a specific capacity of 171.8 mAh·g^(-1).This study provides a new ether-based electrolyte for potassium ion batteries and effectively reduces the electrolyte cost,which is expected to inspire further development of energy storage batteries.
基金National Key Research and Development Program,Grant/Award Number:2019YFA0705701National Natural Science Foundation of China,Grant/Award Numbers:22179149,22075329,22008267,51573215,21978332+1 种基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2021A0505030022Research and Development Project of Henan Academy of Sciences China,Grant/Award Number:232018002。
文摘Practical high-voltage lithium metal batteries hold promise for high energy density applications,but face stability challenges in electrolytes for both 4 V-class cathodes and lithium anode.To address this,we delve into the positive impacts of two crucial moieties in electrolyte chemistry:fluorine atom(-F)and cyano group(-CN)on the electrochemical performance of polyether electrolytes and lithium metal batteries.Cyano-bearing polyether electrolytes possess strong solvation,accelerating Li^(+)desolvation with minimal SEI impact.Fluorinated polyether electrolytes possess weak solvation,and stabilize the lithium anode via preferential decomposition of F-segment,exhibiting nearly 6000-h stable cycling of lithium symmetric cell.Furthermore,the electron-withdrawing prop-erties of-F and-CN groups significantly bolster the high-voltage tolerance of copolymer electrolyte,extending its operational range up to 5 V.This advance-ment enables the development of 4 V-class lithium metal batteries compatible with various cathodes,including 4.45 V LiCoO_(2),4.5 V LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2),and 4.2 V LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2).These findings provide insights into design prin-ciples centered around polymer components for high-performance polymer electrolytes.
基金The authors acknowledge the support from the National Natural Science Foundation of China(Nos.U2002213 and 51972219)the Science and Technology Development Fund Macao SAR(No.0077/2021/A2),the Collaborative Innovation Center of Suzhou Nano Science and Technology,the 111 Project,and the Joint International Research Laboratory of Carbon-based Functional Materials and Devices.
文摘Lithium-sulfur(Li-S)batteries hold great promise to be the next-generation candidate for high-energy-density secondary batteries but in the prerequisite of using low electrolyte-to-sulfur(E/S)ratios.Highly solvating electrolytes(HSEs)and sparingly solvating electrolytes(SSEs),with opposite nature towards the dissolution of polysulfides,have recently emerged as two effective solutions to decrease the E/S ratio and increase the overall practical energy density of Li-S batteries.HSEs featuring with high polysulfide solvation ability have the potential to reduce the E/S ratio by dissolving more polysulfides with less electrolyte,while SSEs alter the sulfur reaction pathway from a dissolution-precipitation mechanism to a quasi-solid mechanism,thereby independent on the use of electrolyte amount.Both HSEs and SSEs show respective effectiveness in lean-electrolyte Li-S batteries,but encounter different challenges to bring Li-S batteries into practical application.This review aims to present a comparative discussion on their unique features and basic electrochemical reaction mechanisms in practical lean-electrolyte Li-S batteries.Emphasis is focused on the current technical challenges and possible solutions for their future development.
基金supported by the National Key Research and Development Program of China(2019YFA0705603)the National Natural Science Foundation of China(22078341)+1 种基金the Natural Science Foundation of Hebei Province(B2020103028)financial support from York University。
文摘Li^(+) solvation structures have a decisive influence on the electrode/electrolyte interfacial properties and battery performances.Reduced salt concentration may result in an organic rich solid electrolyte interface(SEI)and catastrophic cycle stability,which makes low concentration electrolytes(LCEs)rather challenging.Solvents with low solvating power bring in new chances to LCEs due to the weak salt-solvent interactions.Herein,an LCE with only 0.25 mol L^(-1) salt is prepared with fluoroethylene carbonate(FEC)and 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether(D_(2)).Molecular dynamics simulations and experiments prove that the low solvating power solvent FEC not only renders reduced desolvation energy to Li^(+) and improves the battery kinetics,but also promotes the formation of a LiF-rich SEI that hinders the electrolyte consumption.Li||Cu cell using the LCE shows a high coulombic efficiency of 99.20%,and LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)||Li cell also exhibits satisfying capacity retention of 89.93%in 200 cycles,which demonstrates the great potential of solvating power regulation in LCEs development.
基金the National Natural Science Foundation of China(No.22279070[L.Wang]and U21A20170[X.He])the Ministry of Science and Technology of China(No.2019YFA0705703[L.Wang])。
文摘Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacles beyond the issue of ionic conductivity.This investigation unveils a novel formulation that constructs an anion-rich solvation sheath within strong solvents,effectively addressing all three of these challenges to bolster low-temperature performance.The developed electrolyte,characterized by an enhanced concentration of contact ion pairs(CIPs)and aggregates(AGGs),facilitates the formation of an inorganic-rich interphase layer on the anode and cathode particles.This promotes de-solvation at low temperatures and stabilizes the electrode-electrolyte interphase.Full cells composed of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)and graphite,when equipped with this electrolyte,showcase remarkable cycle stability and capacity retention,with 93.3% retention after 500 cycles at room temperature(RT)and 95.5%after 120 cycles at -20℃.This study validates the utility of the anion-rich solvation sheath in strong solvents as a strategy for the development of low-temperature electrolytes.
基金supported by the National Natural Science Foundation of China(52372249)support by the Program of Shanghai Academic Research Leader(21XD1424400)。
文摘Vanadium pentoxide(V_(2)O_(5))displays the characteristics of high theoretical specific capacity,high operating voltage,and adjustable layered structure,possessing the considerable potential as cathode in magnesium metal batteries(MMBs).Nevertheless,the large charge-radius ratio of Mg^(2+)induces the strong interactions of Mg^(2+)with solvent molecules of electrolyte and anionic framework of cathode,resulting in a notable voltage polarization and structural deterioration during cycling process.Herein,an in-situ multi-scale structural engineering is proposed to activate the interlayer-expanded V_(2)O_(5)cathode(pillared by tetrabutylammonium cation)via adding hexadecyltrimethylammonium bromide(CTAB)additive into electrolyte.During cycling,the in-situ incorporation of CTA^(+)not only enhances the electrostatic shielding effect and Mg species migration,but also stabilizes the interlayer spacing.Besides,CTA^(+)is prone to be adsorbed on cathode surface and induces the loss-free pulverization and amorphization of electroactive grains,leading to the pronounced effect of intercalation pseudocapacitance.CTAB additive also enables to scissor the Mg^(2+)solvation sheath and tailor the insertion mode of Mg species,further endowing V_(2)O_(5)cathode with fast reaction kinetics.Based on these merits,the corresponding V2O5‖Mg full cells exhibit the remarkable rate performance with capacities as high as 317.6,274.4,201.1,and 132.7 mAh g^(-1)at the high current densities of 0.1,0.2,0.5,and 1 A g^(-1),respectively.Moreover,after 1000 cycles,the capacity is still preserved to be 90,4 mAh g^(-1)at 1 A g^(-1)with an average coulombic efficiency of~100%.Our strategy of synergetic modulations of cathode host and electrolyte solvation structures provides new guidance for the development of high-rate,large-capacity,and long-life MMBs.
基金supported by the Key Science and Technol-ogy Program of Henan Province(No.232102241020)the Ph.D.Research Startup Foundation of Henan University of Science and Technology(No.400613480015)+1 种基金the Postdoctoral Research Startup Foundation of Henan University of Science and Technology(No.400613554001)the Natural Science Foundation of Henan Province(242300420021).
文摘The poor reversibility and stability of Zn anodes greatly restrict the practical application of aqueous Zn-ion batteries(AZIBs),resulting from the uncontrollable dendrite growth and H_(2)O-induced side reactions during cycling.Electrolyte additive modification is considered one of the most effective and simplest methods for solving the aforementioned problems.Herein,the pyridine derivatives(PD)including 2,4-dihydroxypyridine(2,4-DHP),2,3-dihydroxypyridine(2,3-DHP),and 2-hydroxypyrdine(2-DHP),were em-ployed as novel electrolyte additives in ZnSO_(4)electrolyte.Both density functional theory calculation and experimental findings demonstrated that the incorporation of PD additives into the electrolyte effectively modulates the solvation structure of hydrated Zn ions,thereby suppressing side reactions in AZIBs.Ad-ditionally,the adsorption of PD molecules on the zinc anode surface contributed to uniform Zn deposi-tion and dendrite growth inhibition.Consequently,a 2,4-DHP-modified Zn/Zn symmetrical cell achieved an extremely long cyclic stability up to 5650 h at 1 mA cm^(-2).Furthermore,the Zn/NH_(4)V_(4)O_(10)full cell with 2,4-DHP-containing electrolyte exhibited an outstanding initial capacity of 204 mAh g^(-1),with a no-table capacity retention of 79%after 1000 cycles at 5 A g^(-1).Hence,this study expands the selection of electrolyte additives for AZIBs,and the working mechanism of PD additives provides new insights for electrolyte modification enabling highly reversible zinc anode.
基金supported by the National Natural Science Foundation of China(Nos.22208221,22178221)the Natural Science Foundation of Guangdong Province(Nos.2024A1515011078,2024A1515011507)+1 种基金the Shenzhen Science and Technology Program(Nos.JCYJ20220818095805012,JCYJ20230808105109019)the Start-up Research Funding of Shenzhen University(No.868-000001032522).
文摘The deterioration of aqueous zinc-ion batteries(AZIBs)is confronted with challenges such as unregulated Zn^(2+)diffusion,dendrite growth and severe decay in battery performance under harsh environments.Here,a design concept of eutectic electrolyte is presented by mixing long chain polymer molecules,polyethylene glycol dimethyl ether(PEGDME),with H_(2)O based on zinc trifluoromethyl sulfonate(Zn(OTf)2),to reconstruct the Zn^(2+)solvated structure and in situ modified the adsorption layer on Zn electrode surface.Molecular dynamics simulations(MD),density functional theory(DFT)calculations were combined with experiment to prove that the long-chain polymer-PEGDME could effectively reduce side reactions,change the solvation structure of the electrolyte and priority absorbed on Zn(002),achieving a stable dendrite-free Zn anode.Due to the comprehensive regulation of solvation structure and zinc deposition by PEGDME,it can stably cycle for over 3200 h at room temperature at 0.5 mA/cm^(2)and 0.5 mAh/cm^(2).Even at high-temperature environments of 60℃,it can steadily work for more than 800 cycles(1600 h).Improved cyclic stability and rate performance of aqueous Zn‖VO_(2)batteries in modified electrolyte were also achieved at both room and high temperatures.Beyond that,the demonstration of stable and high-capacity Zn‖VO_(2)pouch cells also implies its practical application.
基金supported by the Natural Science Foundation of Henan Province(No.242300420021)the Major Science and Technology Projects of Henan Province(No.221100230200)+4 种基金the Open Fund of State Key Laboratory of Advanced Refractories(No.SKLAR202210)the Key Science and Technology Program of Henan Province(No.232102241020)the Undergraduate Innovation and Entrepreneurship Training Program of Henan Province(No.S202310464012)the Ph.D.Research Startup Foundation of Henan University of Science and Technology(No.400613480015)the Postdoctoral Research Startup Foundation of Henan University of Science and Technology(No.400613554001).
文摘Aqueous Zn-ion batteries(AZIBs)have been regarded as promising alternatives to Li-ion batteries due to their advantages,such as low cost,high safety,and environmental friendliness.However,AZIBs face significant challenges in limited stability and lifetime owing to zinc dendrite growth and serious side reactions caused by water molecules in the aqueous electrolyte during cycling.To address these issues,a new eutectic electrolyte based on Zn(ClO_(4))_(2)·6H_(2)O-N-methylacetamide(ZN)is proposed in this work.Compared with aqueous electrolyte,the ZN eutectic electrolyte containing organic N-methylacetamide could regulate the solvated structure of Zn^(2+),effectively suppressing zinc dendrite growth and side reactions.As a result,the Zn//NH4 V4 O10 full cell with the eutectic ZN-1-3 electrolyte demonstrates significantly enhanced cycling stability after 1000 cycles at 1 A g^(-1).Therefore,this study not only presents a new eutectic electrolyte for zinc-ion batteries but also provides a deep understanding of the influence of Zn^(2+)solvation structure on the cycle stability,contributing to the exploration of novel electrolytes for high-performance AZIBs.
文摘Lithium-ion batteries(LIBs)are an electrochemical energy storage technology that has been widely used for portable electrical devices,electric vehicles,and grid storage,etc.To satisfy the demand for user convenience especially for electric vehicles,the development of a fast-charging technology for LIBs has become a critical focus.In commercial LIBs,the slow kinetics of Li+intercalation into the graphite anode from the electrolyte solution is known as the main restriction for fast-charging.We summarize the recent advances in obtaining fast-charging graphite-based anodes,mainly involving modifications of the electrolyte solution and graphite anode.Specifically,strategies for increasing the ionic conductivity and regulating the Li+solvation/desolvation state in the electrolyte solution,as well as optimizing the fabrication and the intrinsic activity of graphite-based anodes are discussed in detail.This review considers practical ways to obtain fast Li+intercalation kinetics into a graphite anode from the electrolyte as well as analysing progress in the commercialization of fast-charging LIBs.
基金supported by the National Natural Science Foundation of China(No.22372083,52201259)the National Key R&D Program of China(2021YFB2500300)+2 种基金the Fundamental Research Funds for the Central Universities:Nankai University(63241607)the Natural Science Foundation of Tianjin(No.22JCZDJC00380)the Young Elite Scientist Sponsorship Program by CAST.
文摘LiNO_(3) is known to significantly enhance the reversibility of lithium metal batteries;however,the modification of solvation structures in various solvents and its further impact on the interface have not been fully revealed.Herein,we systematically studied the evolution of solvation structures with increasing LiNO_(3) concentration in both carbonate and ether electrolytes.The results from molecular dynamics simulations unveil that the Li^(+)solvation structure is less affected in carbonate electrolytes,while in ether electrolytes,there is a significant decrease of solvent molecules in Li^(+)coordination,and a larger average size of Li^(+)solvation structure emerges as LiNO_(3) concentration increases.Notably,the formation of large ion aggregates with size of several nanometers(nano-clusters),is observed in ether-based electrolytes at conventional Li^(+)concentration(1 M)with higher NO_(3)^(-) ratio,which is further proved by infrared spectroscopy and small-angle X-ray scattering experiments.The nano-clusters with abundant anions are endowed with a narrow energy gap of molecular orbitals,contributing to the formation of an inorganic rich electrode/electrolyte interphase that enhances the reversibility of lithium stripping/plating with Coulombic efficiency up to 99.71%.The discovery of nano-clusters elucidates the underlying mechanism linking ions/solvent aggregation states of electrolytes to interfacial stability in advanced battery systems.
基金funded by the National Natural Science Foundation of China(22478632)Key Scientific and Technological Project of Henan Province(242102321032).
文摘Continuous-flow upgrading of pentaerythritol synthesis technology via base-catalyzed aldol and Cannizzaro reactions of formaldehyde and acetaldehyde faces the challenge of effectively controlling the critical side reaction of hydroxymethyl acetaldehyde(HA)to the acrolein intermediate.Here,we first identified the forms of industrial formaldehyde as methane diol that easily converts to the alkaline formaldehyde under alkaline(NaOH)environment.The carbonyl group of alkaline formaldehyde induces deprotonation of acetaldehyde instead of the recognized base-hydroxyl group-induced deprotonation,and it needs to overcome only 18.31 kcal·mol^(-1)(1 kcal=4.186 kJ)energy barrier to form key intermediates of HA.The sodium solvation cage formed by NaOH hexa-coordinated formaldehyde effectively inhibits the alkalinity,thus contributing to a high energy barrier(46.21 kcal·mol^(-1))to unwanted acrolein formation.In addition,the solvation cage gradually opens to increase the alkalinity with the consumption of formaldehyde,thus facilitating the subsequent Cannizzaro reaction(to overcome 11.77 kcal·mol^(-1)).In comparison,strong alkalinity promotes the formation of acrolein(36.65 kcal·mol^(-1))to initiate the acetal side reaction,while weak alkalinity reduces the possibility of the Cannizzaro reaction(to overcome 20.44 kcal·mol^(-1)).This theoretically reveals the importance of the segmented feeding of weak and strong bases to successively control the aldol reaction and Cannizzaro reaction,and the combination of Na_(2)CO_(3) or HCOONa with NaOH improves the pentaerythritol yield by 7%to 13%compared to that of NaOH alone(70%yield)within 1 min at a throughput of 155.7 ml·min^(-1).
基金financially supported by the National Natural Science Foundation of China(51977097).
文摘Solvated zinc ions are prone to undergo desolvation at the electrode/electrolyte interfaces,and unstable H_(2)O molecules within the solvated sheaths tend to trigger hydrogen evolution reaction(HER),further accelerating interfaces decay.Herein,we propose for the first time a novel strategy to enhance the interfacial stabilities by insitu dynamic reconstruction of weakly solvated Zn2þduring the desolvation processes at heterointerfaces.Theoretical calculations indicate that,due to built-in electric field effects(BEFs),the plating/stripping mechanism shifts from[Zn(H_(2)O)_(6)]_(2)þto[Zn(H_(2)O)_(5)(SO_(4))^(2-)]_(2)þwithout additional electrolyte additives,reducing the solvation ability of H_(2)O,enhancing the competitive coordination of SO_(4)^(2-),essentially eliminating the undesirable side effects of anodes.Hence,symmetric cells can operate stably for 3000 h(51.7-times increase in cycle life),and the full cells can operate stably for 5000 cycles(51.5-times increase in cycle life).This study provides valuable insights into the critical design of weakly solvated Zn^(2+) þand desolvation processes at heterointerfaces.
基金supported by the National Key R&D Program of China(No.2020YFC2201100)the National Natural Science Foundation of China(Nos.12175032,12102082,12275044,12402327,12405290 and 12211530449)+4 种基金the Joint Program of the Science and Technology Program of Liaoning,China(No.2023JH2/101700285)the Fundamental Research Funds for the Central Universities of China(Nos.DUT22RC(3)078,DUT23RC(3)040 and DUT24ZD106)the S&T Program of Hebei,China(No.246Z2301G)the S&T Innovation Program of Hebei,China(Nos.SJMYF2022X18 and SJMYF2022X06)the Beijing Engineering Research Center of Efficient and Green Aerospace Propulsion Technology and Advanced Space Propulsion Laboratory of BICE,China(No.LabASP-2023-07).
文摘The electrospray thruster supplied by ionic liquid is a promising micro-propulsion thruster with small size and precise thrust, which can emit both cations and anions to achieve self-neutralization. In order to further investigate the effect of ion solvation energy on the evaporation of cations and anions from ionic liquid under the action of a uniform electric field, this paper establishes a transient Electrohydrodynamic (EHD) model for free ionic liquid droplets undergoing ion evaporation. The dynamic processes of droplet deformation and ion evaporation are simulated. And the study further focuses on the influence of different ion solvation energies for cations on the droplet morphology and the ion evaporation characteristics at the positively charged end and negatively charged end of the droplet. The results indicate that, when the ion solvation energy for cations is higher than that of anions, it will cause the ion evaporation at the positively charged end of the droplet to lag behind the ion evaporation at the negatively charged end. And the higher the ion solvation energy for the cations, the longer the evaporation lag time at the positively charged end of the droplet, which will lead to a higher peak of surface charge density that can be reached, resulting in a larger evaporation current and sharper droplet stretching deformation. Additionally, the peak surface charge density of the positively charged end of the droplet is linearly related to the ion solvation energy for cations, while the peak surface charge density of the negatively charged end remains almost unchanged and is not significantly affected by the ion solvation energy for cations.
基金supported by National Key Research and Development Program of China(2022YFB2402200)the China Postdoctoral Science Foundation(grant nos.2023T160591)the Joint Fund of the Technical R&D Program of Henan Province(grant nos.232301420044).
文摘Electrolytes are crucial components in electrochemical energy storage devices,sparking considerable research interest.However,the significance of anions in the electrolytes is often underestimated.In fact,the anions have significant impacts on the performance and stability of lithium batteries.Therefore,comprehensively understanding anion chemistry in electrolytes is of crucial importance.Herein,indepth comprehension of anion chemistry and its positive effects on the interface,solvation structure of Li-ions,as well as the electrochemical performance of the batteries have been emphasized and summarized.This review aims to present a full scope of anion chemistry and furnish systematic cognition for the rational design of advanced electrolytes for better lithium batteries with high energy density,lifespan,and safety.Furthermore,insightful analysis and perspectives based on the current research are proposed.We hope that this review sheds light on new perspectives on understanding anion chemistry in electrolytes.
