High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based ...High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based electrolytes,particularly at extreme temperatures.In this study,we develop a stable electrolyte incorporating lithium difluorophosphate(LiDFP)as an additive to enhance the electrochemical performance of DIBs over a wide temperature range.LiDFP preferentially decomposes to form a rapid anion-transporting,mechanically robust CEI layer on graphite,which provides better protection by suppressing graphite's volume expansion,preventing electrolyte oxidative decomposition,and enhancing reaction kinetics.As a result,Li||graphite half cells using LiDFP electrolyte exhibit outstanding rate performance(90.8% capacity retention at 30 C)and excellent cycle stability(82.2% capacity retention after 5000 cycles)at room temperature.Moreover,graphite||graphite full cells with LiDFP electrolyte demonstrate stable discharge capacity across a temperature range of-20 to 40℃,expanding the potential applications of LiDFP.This work establishes a novel strategy for optimizing the interphase through electrolyte design,paving the way for all-climate DIBs with improved performance and stability.展开更多
Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers f...Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers from the notorious structural degradation and interfacial side reactions with electrolytes and thus incurs premature failure,especially at high charge cut-off voltages(≥4.4 V).For this,various structural and interphase regulation strategies(such as coating modification,element doping,and electrolyte engineering)are developed to enhance the cycling survivability of Ni-rich cathodes.Among them,electrolyte engineering by changing solvation structure and introducing additives has been considered an efficient method for constructing robust cathode-electrolyte interphases(CEI),inhibiting the formation of harmful species(such as HF and H_(2)O)or restraining the dissolution of transition metal ions.However,there is still an absence of systematic guidelines for selecting and designing competitive electrolyte systems for Ni-rich layered cathodes.In this review,we comprehensively summarize the recent research progress on electrolyte engineering for Ni-rich layered cathodes according to their working mechanisms.Moreover,we propose future perspectives of improving the electrolyte performance,which will provide new insights for designing novel electrolytes toward high-performance Ni-rich layered cathodes.展开更多
Lithium-rich manganese-based oxides(LRMOs;xLi_(2)MnO_(3)(1−x)LiMO_(2);M=transition metal,0<x<1)with excellent specific capacity(>300 mAh/g)and high operating voltage(≥4.8V)are the preferred cathode materials...Lithium-rich manganese-based oxides(LRMOs;xLi_(2)MnO_(3)(1−x)LiMO_(2);M=transition metal,0<x<1)with excellent specific capacity(>300 mAh/g)and high operating voltage(≥4.8V)are the preferred cathode materials for high-specific-energy lithium metal batteries(LMBs)[1].However,LRMOs face a series of serious problems such as irreversible lattice oxygen loss,transition metal(TM)migration,phase transfer,and interfacial side reactions at high voltages,resulting in rapid decay of capacity and voltage[2,3].In situ generating well-functional CEI through electrolyte engineering can effectively address these challenges[4].展开更多
As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(etheny...As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.展开更多
Dual-ion battery(DIB) composed of graphite cathode and lithium anode is regarded as an advanced secondary battery because of the low cost, high working voltage and environmental friendliness. However,DIB operated at h...Dual-ion battery(DIB) composed of graphite cathode and lithium anode is regarded as an advanced secondary battery because of the low cost, high working voltage and environmental friendliness. However,DIB operated at high potential(usually ≥ 4.5 V versus Li+/Li) is confronted with severe challenges including electrolyte decomposition on cathode interface, and structural deterioration of graphite accompanying with anions de-/intercalation, hinder its cyclic life. To address those drawbacks and preserve the DIB virtues, a feasible and scalable surface modification is achieved for the commercial graphite cathode of mesocarbon microbead. In/ex-situ studies reveal that, such an interfacial engineering facilitates and reconstructs the formation of chemically stable cathode electrolyte interphase with better flexibility alleviating the decomposition of electrolyte, regulating the anions de-/intercalation behavior in graphite with the retainment of structural integrity and without exerting considerable influence on kinetics of anions diffusion. As a result, the modified mesocarbon microbead exhibits a much-extended cycle life with high capacity retention of 82.3% even after 1000 cycles. This study demonstrates that the interface modification of electrode and coating skeleton play important roles on DIB performance improvement, providing the feasible basis for practical application of DIB owing to the green and scalable coating procedures.展开更多
The thermal stability window of current commercial carbonate-based electrolytes is no longer sufficient to meet the ever-increasing cathode working voltage requirements of high energy density lithium-ion batteries.It ...The thermal stability window of current commercial carbonate-based electrolytes is no longer sufficient to meet the ever-increasing cathode working voltage requirements of high energy density lithium-ion batteries.It is crucial to construct a robust cathode-electrolyte interphase(CEI)for high-voltage cathode electrodes to separate the electrolytes from the active cathode materials and thereby suppress the side reactions.Herein,this review presents a brief historic evolution of the mechanism of CEI formation and compositions,the state-of-art characterizations and modeling associated with CEI,and how to construct robust CEI from a practical electrolyte design perspective.The focus on electrolyte design is categorized into three parts:CEI-forming additives,anti-oxidation solvents,and lithium salts.Moreover,practical considerations for electrolyte design applications are proposed.This review will shed light on the future electrolyte design which enables aggressive high-voltage cathodes.展开更多
Ni-rich lithium nickel–cobalt-manganese oxides(NCM) are considered the most promising cathode materials for lithium-ion batteries(LIBs);however, relatively poor cycling performance is a bottleneck preventing their wi...Ni-rich lithium nickel–cobalt-manganese oxides(NCM) are considered the most promising cathode materials for lithium-ion batteries(LIBs);however, relatively poor cycling performance is a bottleneck preventing their widespread use in energy systems. In this work, we propose the use of a dually functionalized surface modifier, calcium sulfate(CaSO_(4), CSO), in an efficient one step method to increase the cycling performance of Ni-rich NCM cathode materials. Thermal treatment of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathode materials with a CSO precursor allows the formation of an artificial Ca-and SO_(x)-functionalized cathode–electrolyte interphase(CEI) layer on the surface of Ni-rich NCM cathode materials. The CEI layer then inhibits electrolyte decomposition at the interface between the Ni-rich NCM cathode and the electrolyte. Successful formation of the CSO-modified CEI layer is confirmed by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy analyses, and the process does not affect the bulk structure of the Ni-rich NCM cathode material. During cycling, the CSO-modified CEI layer remarkably decreases electrolyte decomposition upon cycling at both room temperature and 45 ℃, leading to a substantial increase in cycling retention of the cells. A cell cycled with a 0.1 CSO-modified(modified with 0.1% CSO)NCM811 cathode exhibits a specific capacity retention of90.0%, while the cell cycled with non-modified NCM811 cathode suffers from continuous fading of cycling retention(74.0%) after 100 cycles. SEM, electrochemical impedance spectroscopy(EIS), X-ray photoelectron spectroscopy(XPS), and inductively coupled plasma mass spectrometry(ICP-MS) results of the recovered electrodes demonstrate that undesired surface reactions such as electrolyte decomposition and metal dissolution are well controlled in the cell because of the artificial CSO-modified CEI layer present on the surface of Ni-rich NCM811 cathodes.展开更多
B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)t...B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)to facilitate the rapid Li+migration.Nevertheless,its wide-temperature application has been limited by the instability of B-derived CEI layer at high temperature.Herein,dual electrolyte additives,consisting of lithium tetraborate(Li_(2)TB)and 2,4-difluorobiphenyl(FBP),are proposed to boost the widetemperature performances of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM)cathode.Theoretical calculation and electrochemical performances analyses indicate that Li_(2)TB and FBP undergo successive decomposition to form a unique dual-layer CEI.FBP acts as a synergistic filming additive to Li_(2)TB,enhancing the hightemperature performance of NCM cathode while preserving the excellent low-temperature cycle stability and the superior rate capability conferred by Li_(2)TB additive.Therefore,the capacity retention of NCM‖Li cells using optimal FBP-Li_(2)TB dual electrolyte additives increases to 100%after 200 cycles at-10℃,99%after 200 cycles at 25℃,and 83%after 100 cycles at 55℃,respectively,much superior to that of base electrolyte(63%/69%/45%).More surprisingly,galvanostatic c ha rge/discharge experiments at different temperatures reveal that NCM‖Li cells using FBP-Li_(2)TB additives can operate at temperatures ranging from-40℃to 60℃.This synergistic interphase modification utilizing dual electrolyte additives to construct a unique dual-layer CEI adaptive to a wide temperature range,provides valuable insights to the practical applications of NCM cathodes for all-climate batteries.展开更多
Ethers are promising electrolyte solvents for secondary Li metal batteries because of their excellent reduction stability.However,their oxidation stability has been mostly relying on the high concentration approach,an...Ethers are promising electrolyte solvents for secondary Li metal batteries because of their excellent reduction stability.However,their oxidation stability has been mostly relying on the high concentration approach,and limited progress has been made on building effective interphase to protect the cathode from the corrosion of the electrolyte.In this work,we construct a semi-crystalline interfacial layer on the surface of Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)cathode that can achieve improved electrochemical stability in the highly corrosive chemical environment formed by the decomposition of ether molecules.Different from traditional brittle crystalline interphases,the optimized semi-crystalline layer with low modulus and high ionic conductivity can effectively relieve electrode strain and maintain the integrity of the interface layer.Due to this design,the continuous oxidation decomposition of ether-based electrolytes could be significantly suppressed and the battery shows outstanding cycling stability(84%capacity retention after 300 cycles).This article provides a solution to address the oxidation instability issue of ether-based electrolytes.展开更多
Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is regarded as the promising cathode for lithium-ion batteries(LIBs).However,the challenges such as safety issues and poor cycling performance have seriously hindered...Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is regarded as the promising cathode for lithium-ion batteries(LIBs).However,the challenges such as safety issues and poor cycling performance have seriously hindered its commercial applications.In order to overcome these difficulties,there has been extensive research and development of electrolyte modifications for high-energy-density LIBs with Ni-rich cathodes.Herein,this review introduces the research progress based on solvent additives,salt type additives and other electrolytes for LIBs with NCM811cathode materials and discusses how they control the interface stability.In particular,some recommendations for further modification of enhancing electrolyte stability and improving NCM811 electrochemical properties are summarized and proposed,which put forward new design rules for the screening and customizing ideal electrolyte additives for high performance NCM811 cathode-based LIBs.展开更多
In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2...In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA))have been arousing great interests to improve the energy density of LIBs.However,these Nirich cathodes always suffer from rapid capacity degradation induced by unstable cathode-electrolyte interphase(CEI)layer and destruction of bulk crystal structure.Therefore,varied electrode/electrolyte interface engineering strategies(such as electrolyte formulation,material coating or doping)have been developed for Ni-rich cathodes protection.Among them,developing electrolyte functional additives has been proven to be a simple,effective,and economic method to improve the cycling stability of Nirich cathodes.This is achieved by removing unfavorable species(such as HF,H_(2)O)or constructing a stable and protective CEI layer against unfavorable reactive species(such as HF,H_(2)O).Herein,this review mainly introduces the varied classes of electrolyte functional additives and their working mechanism for interfacial engineering of Ni-rich cathodes.Especially,key favorable species for stabilizing CEI layer are summarized.More importantly,we put forward perspectives for screening and customizing ideal functional additives for high performance Ni-rich cathodes based LIBs.展开更多
Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the...Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.展开更多
The battery energy density can be improved by raising the operating voltage,however,which may lead to rapid capacity decay due to the continuous electrolyte decomposition and the thickening of electrode electrolyte in...The battery energy density can be improved by raising the operating voltage,however,which may lead to rapid capacity decay due to the continuous electrolyte decomposition and the thickening of electrode electrolyte interphases.To address these challenges,we proposed tripropyl phosphate(TPP)as an additive-regulating Li~+solvation structure to construct a stable Li F–rich electrode carbonate-based electrolyte interphases for sustaining 4.6 V Li||LiCoO_(2)batteries.This optimized interphases could help reduce the resistance and achieve better rate performance and cycling stability.As expected,the Li||LiCoO_(2)battery retained 79.4%capacity after 100 cycles at 0.5 C,while the Li||Li symmetric cell also kept a stable plating/stripping process over 450 h at the current density of 1.0 mA/cm^(2)with a deposited amount of0.5 mAh/cm^(2).展开更多
The growing need for higher energy density in rechargeable batteries necessitates the exploration of cathode materials with enhanced specific energy for lithium-ion batteries.Due to their exceptional cost-effectivenes...The growing need for higher energy density in rechargeable batteries necessitates the exploration of cathode materials with enhanced specific energy for lithium-ion batteries.Due to their exceptional cost-effectiveness and specific capacity,lithium-rich manganese-based cathode materials(LRMs)obtain in-creasing attention in the pursuit of enhancing energy density and reducing costs.The implementation has faced obstacles in various applications due to substantial capacity and voltage degradation,insufficient safety performance,and restricted rate capability during cycling.These issues arise from the migration of transition metal,the release of oxygen,and structural transformation.In this review,we provide an integrated survey of the structure,lithium storage mechanism,challenges,and origins of LRMs,as well as recent advancements in various coating strategies.Particularly,the significance of optimizing the design of the cathode electrolyte interphase was emphasized to enhance electrode performance.Furthermore,future perspective was also addressed alongside in-situ measurements,advanced synthesis techniques,and the application of machine learning to overcome encountered challenges in LRMs.展开更多
Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/...Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/cathode electrolyte interphase(SEI/CEI) with electrolytes [2]. However, both Li anode and transition metal oxide cathode have high interfacial reactivity at extreme voltages, which highly needs compatible electrolytes.Recently, localized high-concentration electrolytes (LHCEs) have promisingly stabilized the dual electrodes of high-voltage LMBs[3].展开更多
Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits t...Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.展开更多
Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cath...Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.展开更多
The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited b...The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited by compatibility issues between high-energy-density cathode materials,such as Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF),and high-voltage electrolytes.Addressing the challenges,H-NaODFB(comprising 93.91%NaODFB and 5.85%NaBF_(4))electrolyte significantly improves the electrochemical performance and stability of NVPF cathodes,Na/NVPF half-cells using H-NaODFB electrolyte retained 92.4%capacity after 900cycles,while Na/Na symmetric cells demonstrated a cycle life exceeding 600 h at 0.5 mA cm^(-2).The superior performance is attributed to improved Na^(+)(de)intercalation reversibility,lower interfacial impedance(619.8 vs.10,650.0Ω),and faster reaction kinetics compared to NaODFB alone.Advanced time of flight-secondary ion mass spectrometry(TOF-SIMS),X-ray photoelectron spectroscopy(XPS)and aberration corrected transmission electron microscope(AC-TEM),combined with first-principles calculations,revealed that NaBF_(4)in the H-NaODFB electrolyte plays a critical role in forming a stable cathode electrolyte interphase(CEI).The CEI consists of an initial inorganic and organic layer,followed by a fluoroborate layer,and finally a stable organic-inorganic polymeric layer,enhancing electrode stability and preventing over-oxidation.These findings provide valuable insights for designing high-performance electrolytes for SIBs.展开更多
Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy densit...Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy density.However,their practical application is hindered by dissolution in electrolytes,structural degradation,and sluggish lithium-ion transport.In this study,we introduce fluoroethylene carbonate(FEC)as an electrolyte additive to engineer a protective cathode–electrolyte interphase(CEI)layer,effectively mitigating cathode pulverization and enhancing battery stability of the organic cathode material,dilithium salt of 2,5-dihydroxy-1,4-benzoquinone(Li_(2)DHBQ).Electrochemical,morphological,and compositional analyses,including cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS),confirm that an optimal 1%FEC concentration forms a uniform CEI layer,significantly improving structural integrity and reducing interfacial resistance.Consequently,the battery with 1%FEC retains 185 mAh·g^(−1) after 200 cycles at 500 mA·g^(−1),with a capacity decay rate of just 0.049%per cycle,compared to 81 mAh·g^(−1) and 0.302%per cycle for the FEC-free battery.Additionally,the 1%FEC battery exhibits a capacitive charge storage contribution of up to 93.7%,resulting in excellent rate performance.These findings underscore the crucial role of CEI engineering in stabilizing organic cathodes,offering a practical approach to achieving high-rate and long-cycle LIBs.展开更多
Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-pot...Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-potential cathodes failing to apply in full cells.Herein,vinylene carbonate(VC)as an additive into NaCF_(3) SO_(3)-Diglyme(DGM)could make sodium-ion full cells applicable without preactivation of cathode and anode.The assembled FeS@C||Na3 V2(PO_(4))_(3)@C full cell with this electrolyte exhibits long term cycling stability and high capacity retention.The deduced reason is additive VC,whose HOMO level value is close to that of DGM,not only change the solvent sheath structure of Na^(+),but also is synergistically oxidized with DGM to form integrity and consecutive cathode electrolyte interphase on Na3 V2(PO_(4))_(3)@C cathode,which could effectively improve the oxidative stability of electrolyte and prevent the electrolyte decomposition.This work displays a new way to optimize the sodium-ion full cell seasily with bright practical application potential.展开更多
基金the financial support received from the National Natural Science Foundation of China(22378426,22138013)the Natural Science Foundation of Shandong Province(ZR2022MB088)the Taishan Scholar Project(ts201712020)。
文摘High-voltage dual-ion batteries(DIBs)face significant challenges,including graphite cathode degradation,cathode-electrolyte interphase(CEI)instability,and the thermodynamic instability of conventional carbonate-based electrolytes,particularly at extreme temperatures.In this study,we develop a stable electrolyte incorporating lithium difluorophosphate(LiDFP)as an additive to enhance the electrochemical performance of DIBs over a wide temperature range.LiDFP preferentially decomposes to form a rapid anion-transporting,mechanically robust CEI layer on graphite,which provides better protection by suppressing graphite's volume expansion,preventing electrolyte oxidative decomposition,and enhancing reaction kinetics.As a result,Li||graphite half cells using LiDFP electrolyte exhibit outstanding rate performance(90.8% capacity retention at 30 C)and excellent cycle stability(82.2% capacity retention after 5000 cycles)at room temperature.Moreover,graphite||graphite full cells with LiDFP electrolyte demonstrate stable discharge capacity across a temperature range of-20 to 40℃,expanding the potential applications of LiDFP.This work establishes a novel strategy for optimizing the interphase through electrolyte design,paving the way for all-climate DIBs with improved performance and stability.
基金supported by the National Key Research and Development Program of China(2021YFF0500600)National Natural Science Foundation of China(Nos.U2001220,52203298 and 523B2022)+2 种基金National Science Fund for Distinguished Young Scholars(No.52325206)Shenzhen Technical Plan Project(Nos.RCJC20200714114436091,JCYJ20220530143012027,JCYJ20220818101003008 and JCYJ20220818101003007)Tsinghua Shenzhen International Graduate School-Shenzhen Pengrui Young Faculty Program of Shenzhen Pengrui Foundation(No.SZPR2023006).
文摘Nickel(Ni)-rich layered oxides have drawn great attention as cathode for lithium batteries due to their high capacity,high working voltage and competitive cost.Unfortunately,the operation of Ni-rich cathodes suffers from the notorious structural degradation and interfacial side reactions with electrolytes and thus incurs premature failure,especially at high charge cut-off voltages(≥4.4 V).For this,various structural and interphase regulation strategies(such as coating modification,element doping,and electrolyte engineering)are developed to enhance the cycling survivability of Ni-rich cathodes.Among them,electrolyte engineering by changing solvation structure and introducing additives has been considered an efficient method for constructing robust cathode-electrolyte interphases(CEI),inhibiting the formation of harmful species(such as HF and H_(2)O)or restraining the dissolution of transition metal ions.However,there is still an absence of systematic guidelines for selecting and designing competitive electrolyte systems for Ni-rich layered cathodes.In this review,we comprehensively summarize the recent research progress on electrolyte engineering for Ni-rich layered cathodes according to their working mechanisms.Moreover,we propose future perspectives of improving the electrolyte performance,which will provide new insights for designing novel electrolytes toward high-performance Ni-rich layered cathodes.
文摘Lithium-rich manganese-based oxides(LRMOs;xLi_(2)MnO_(3)(1−x)LiMO_(2);M=transition metal,0<x<1)with excellent specific capacity(>300 mAh/g)and high operating voltage(≥4.8V)are the preferred cathode materials for high-specific-energy lithium metal batteries(LMBs)[1].However,LRMOs face a series of serious problems such as irreversible lattice oxygen loss,transition metal(TM)migration,phase transfer,and interfacial side reactions at high voltages,resulting in rapid decay of capacity and voltage[2,3].In situ generating well-functional CEI through electrolyte engineering can effectively address these challenges[4].
基金financially supported by the Scientific Research Innovation Project of Graduate School of South China Normal University (No. 2024KYLX081)。
文摘As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.
基金the financial support from the National Natural Science Foundation of China(91963118)the Fundamental Research Funds for the Central Universities(2412019ZD010)。
文摘Dual-ion battery(DIB) composed of graphite cathode and lithium anode is regarded as an advanced secondary battery because of the low cost, high working voltage and environmental friendliness. However,DIB operated at high potential(usually ≥ 4.5 V versus Li+/Li) is confronted with severe challenges including electrolyte decomposition on cathode interface, and structural deterioration of graphite accompanying with anions de-/intercalation, hinder its cyclic life. To address those drawbacks and preserve the DIB virtues, a feasible and scalable surface modification is achieved for the commercial graphite cathode of mesocarbon microbead. In/ex-situ studies reveal that, such an interfacial engineering facilitates and reconstructs the formation of chemically stable cathode electrolyte interphase with better flexibility alleviating the decomposition of electrolyte, regulating the anions de-/intercalation behavior in graphite with the retainment of structural integrity and without exerting considerable influence on kinetics of anions diffusion. As a result, the modified mesocarbon microbead exhibits a much-extended cycle life with high capacity retention of 82.3% even after 1000 cycles. This study demonstrates that the interface modification of electrode and coating skeleton play important roles on DIB performance improvement, providing the feasible basis for practical application of DIB owing to the green and scalable coating procedures.
基金Open access funding provided by Shanghai Jiao Tong University
文摘The thermal stability window of current commercial carbonate-based electrolytes is no longer sufficient to meet the ever-increasing cathode working voltage requirements of high energy density lithium-ion batteries.It is crucial to construct a robust cathode-electrolyte interphase(CEI)for high-voltage cathode electrodes to separate the electrolytes from the active cathode materials and thereby suppress the side reactions.Herein,this review presents a brief historic evolution of the mechanism of CEI formation and compositions,the state-of-art characterizations and modeling associated with CEI,and how to construct robust CEI from a practical electrolyte design perspective.The focus on electrolyte design is categorized into three parts:CEI-forming additives,anti-oxidation solvents,and lithium salts.Moreover,practical considerations for electrolyte design applications are proposed.This review will shed light on the future electrolyte design which enables aggressive high-voltage cathodes.
基金financially supported by the National Research Foundation of Korea(NRF)(Nos.NRF2019R1C1C1002249 and NRF-2017R1A6A1A06015181)the Technology Innovation Program(Nos.20010095 and 20011905)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Ni-rich lithium nickel–cobalt-manganese oxides(NCM) are considered the most promising cathode materials for lithium-ion batteries(LIBs);however, relatively poor cycling performance is a bottleneck preventing their widespread use in energy systems. In this work, we propose the use of a dually functionalized surface modifier, calcium sulfate(CaSO_(4), CSO), in an efficient one step method to increase the cycling performance of Ni-rich NCM cathode materials. Thermal treatment of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811) cathode materials with a CSO precursor allows the formation of an artificial Ca-and SO_(x)-functionalized cathode–electrolyte interphase(CEI) layer on the surface of Ni-rich NCM cathode materials. The CEI layer then inhibits electrolyte decomposition at the interface between the Ni-rich NCM cathode and the electrolyte. Successful formation of the CSO-modified CEI layer is confirmed by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy analyses, and the process does not affect the bulk structure of the Ni-rich NCM cathode material. During cycling, the CSO-modified CEI layer remarkably decreases electrolyte decomposition upon cycling at both room temperature and 45 ℃, leading to a substantial increase in cycling retention of the cells. A cell cycled with a 0.1 CSO-modified(modified with 0.1% CSO)NCM811 cathode exhibits a specific capacity retention of90.0%, while the cell cycled with non-modified NCM811 cathode suffers from continuous fading of cycling retention(74.0%) after 100 cycles. SEM, electrochemical impedance spectroscopy(EIS), X-ray photoelectron spectroscopy(XPS), and inductively coupled plasma mass spectrometry(ICP-MS) results of the recovered electrodes demonstrate that undesired surface reactions such as electrolyte decomposition and metal dissolution are well controlled in the cell because of the artificial CSO-modified CEI layer present on the surface of Ni-rich NCM811 cathodes.
基金supported by the National Natural Science Foundation of China(No.21972049)。
文摘B-containing electrolyte additives are widely used to enhance the cycle performance at low temperature and the rate capability of lithium-ion batteries by constructing an efficient cathode electrolyte interphase(CEI)to facilitate the rapid Li+migration.Nevertheless,its wide-temperature application has been limited by the instability of B-derived CEI layer at high temperature.Herein,dual electrolyte additives,consisting of lithium tetraborate(Li_(2)TB)and 2,4-difluorobiphenyl(FBP),are proposed to boost the widetemperature performances of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM)cathode.Theoretical calculation and electrochemical performances analyses indicate that Li_(2)TB and FBP undergo successive decomposition to form a unique dual-layer CEI.FBP acts as a synergistic filming additive to Li_(2)TB,enhancing the hightemperature performance of NCM cathode while preserving the excellent low-temperature cycle stability and the superior rate capability conferred by Li_(2)TB additive.Therefore,the capacity retention of NCM‖Li cells using optimal FBP-Li_(2)TB dual electrolyte additives increases to 100%after 200 cycles at-10℃,99%after 200 cycles at 25℃,and 83%after 100 cycles at 55℃,respectively,much superior to that of base electrolyte(63%/69%/45%).More surprisingly,galvanostatic c ha rge/discharge experiments at different temperatures reveal that NCM‖Li cells using FBP-Li_(2)TB additives can operate at temperatures ranging from-40℃to 60℃.This synergistic interphase modification utilizing dual electrolyte additives to construct a unique dual-layer CEI adaptive to a wide temperature range,provides valuable insights to the practical applications of NCM cathodes for all-climate batteries.
基金supported by the National Natural Science Foundation of China(22179124,21905265)the Fundamental Research Funds for the Central Universities(WK3430000007)。
文摘Ethers are promising electrolyte solvents for secondary Li metal batteries because of their excellent reduction stability.However,their oxidation stability has been mostly relying on the high concentration approach,and limited progress has been made on building effective interphase to protect the cathode from the corrosion of the electrolyte.In this work,we construct a semi-crystalline interfacial layer on the surface of Li(Ni_(0.8)Co_(0.1)Mn_(0.1))O_(2)cathode that can achieve improved electrochemical stability in the highly corrosive chemical environment formed by the decomposition of ether molecules.Different from traditional brittle crystalline interphases,the optimized semi-crystalline layer with low modulus and high ionic conductivity can effectively relieve electrode strain and maintain the integrity of the interface layer.Due to this design,the continuous oxidation decomposition of ether-based electrolytes could be significantly suppressed and the battery shows outstanding cycling stability(84%capacity retention after 300 cycles).This article provides a solution to address the oxidation instability issue of ether-based electrolytes.
基金financially supported by the National Natural Science Foundation of China(Nos.51971090,U21A20311)。
文摘Nickel-rich LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)is regarded as the promising cathode for lithium-ion batteries(LIBs).However,the challenges such as safety issues and poor cycling performance have seriously hindered its commercial applications.In order to overcome these difficulties,there has been extensive research and development of electrolyte modifications for high-energy-density LIBs with Ni-rich cathodes.Herein,this review introduces the research progress based on solvent additives,salt type additives and other electrolytes for LIBs with NCM811cathode materials and discusses how they control the interface stability.In particular,some recommendations for further modification of enhancing electrolyte stability and improving NCM811 electrochemical properties are summarized and proposed,which put forward new design rules for the screening and customizing ideal electrolyte additives for high performance NCM811 cathode-based LIBs.
基金supported by the National Key R&D Program of China(Grant No.2017YFE0127600)the National Natural Science Foundation of China(Grant No.U1706229、21901248)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA22010600)the National Natural Science Foundation for Distinguished Young Scholars of China(No.51625204)the Taishan Scholars of Shandong Province(ts201511063)。
文摘In advantages of their high capacity and high operating voltage,the nickel(Ni)-rich layered transition metal oxide cathode materials(LiNi_(x)Co_(y)Mn_(z)O_(2)(NCMxyz,x+y+z=1,x≥0.5)and LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA))have been arousing great interests to improve the energy density of LIBs.However,these Nirich cathodes always suffer from rapid capacity degradation induced by unstable cathode-electrolyte interphase(CEI)layer and destruction of bulk crystal structure.Therefore,varied electrode/electrolyte interface engineering strategies(such as electrolyte formulation,material coating or doping)have been developed for Ni-rich cathodes protection.Among them,developing electrolyte functional additives has been proven to be a simple,effective,and economic method to improve the cycling stability of Nirich cathodes.This is achieved by removing unfavorable species(such as HF,H_(2)O)or constructing a stable and protective CEI layer against unfavorable reactive species(such as HF,H_(2)O).Herein,this review mainly introduces the varied classes of electrolyte functional additives and their working mechanism for interfacial engineering of Ni-rich cathodes.Especially,key favorable species for stabilizing CEI layer are summarized.More importantly,we put forward perspectives for screening and customizing ideal functional additives for high performance Ni-rich cathodes based LIBs.
基金the financial supports from the KeyArea Research and Development Program of Guangdong Province (2020B090919001)the National Natural Science Foundation of China (22078144)the Guangdong Natural Science Foundation for Basic and Applied Basic Research (2021A1515010138 and 2023A1515010686)。
文摘Li metal batteries using high-voltage layered oxides cathodes are of particular interest due to their high energy density.However,they suffer from short lifespan and extreme safety concerns,which are attributed to the degradation of layered oxides and the decomposition of electrolyte at high voltage,as well as the high reactivity of metallic Li.The key is the development of stable electrolytes against both highvoltage cathodes and Li with the formation of robust interphase films on the surfaces.Herein,we report a highly fluorinated ether,1,1,1-trifluoro-2-[(2,2,2-trifluoroethoxy)methoxy]ethane(TTME),as a cosolvent,which not only functions as a diluent forming a localized high concentration electrolyte(LHCE),but also participates in the construction of the inner solvation structure.The TTME-based electrolyte is stable itself at high voltage and induces the formation of a unique double-layer solid electrolyte interphase(SEI)film,which is embodied as one layer rich in crystalline structural components for enhanced mechanical strength and another amorphous layer with a higher concentration of organic components for enhanced flexibility.The Li||Cu cells display a noticeably high Coulombic efficiency of 99.28%after 300 cycles and Li symmetric cells maintain stable cycling more than 3200 h at 0.5 mA/cm^(2) and 1.0m Ah/cm^(2).In addition,lithium metal cells using LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) and Li CoO_(2) cathodes(both loadings~3.0 m Ah/cm^(2))realize capacity retentions of>85%over 240 cycles with a charge cut-off voltage of 4.4 V and 90%for 170 cycles with a charge cut-off voltage of 4.5 V,respectively.This study offers a bifunctional ether-based electrolyte solvent beneficial for high-voltage Li metal batteries.
基金supported by the National Natural Science Foundation of China(No.U21A20311)the Distinguished Scientist Fellowship Program(DSFP)at King Saud University,Riyadh,Saudi Arabia。
文摘The battery energy density can be improved by raising the operating voltage,however,which may lead to rapid capacity decay due to the continuous electrolyte decomposition and the thickening of electrode electrolyte interphases.To address these challenges,we proposed tripropyl phosphate(TPP)as an additive-regulating Li~+solvation structure to construct a stable Li F–rich electrode carbonate-based electrolyte interphases for sustaining 4.6 V Li||LiCoO_(2)batteries.This optimized interphases could help reduce the resistance and achieve better rate performance and cycling stability.As expected,the Li||LiCoO_(2)battery retained 79.4%capacity after 100 cycles at 0.5 C,while the Li||Li symmetric cell also kept a stable plating/stripping process over 450 h at the current density of 1.0 mA/cm^(2)with a deposited amount of0.5 mAh/cm^(2).
基金the support from the National Natural Science Foun-dation of China(Grant No.U21A20311)the Distinguished Scientist Fellowship Program(DSFP)at King Saud University,Riyadh,Saudi Arabia.
文摘The growing need for higher energy density in rechargeable batteries necessitates the exploration of cathode materials with enhanced specific energy for lithium-ion batteries.Due to their exceptional cost-effectiveness and specific capacity,lithium-rich manganese-based cathode materials(LRMs)obtain in-creasing attention in the pursuit of enhancing energy density and reducing costs.The implementation has faced obstacles in various applications due to substantial capacity and voltage degradation,insufficient safety performance,and restricted rate capability during cycling.These issues arise from the migration of transition metal,the release of oxygen,and structural transformation.In this review,we provide an integrated survey of the structure,lithium storage mechanism,challenges,and origins of LRMs,as well as recent advancements in various coating strategies.Particularly,the significance of optimizing the design of the cathode electrolyte interphase was emphasized to enhance electrode performance.Furthermore,future perspective was also addressed alongside in-situ measurements,advanced synthesis techniques,and the application of machine learning to overcome encountered challenges in LRMs.
文摘Lithium metal batteries (LMBs) show great potential in delivering high energy density (>500 Wh/kg) with cycling [1]. The cycling life of LMBs is mainly improved by regulating the composition and structure of solid/cathode electrolyte interphase(SEI/CEI) with electrolytes [2]. However, both Li anode and transition metal oxide cathode have high interfacial reactivity at extreme voltages, which highly needs compatible electrolytes.Recently, localized high-concentration electrolytes (LHCEs) have promisingly stabilized the dual electrodes of high-voltage LMBs[3].
基金supported by the Natural Science Foundation of China(No.22109079)the Natural Science Foundation of China(No.21973008)+2 种基金the Natural Science Foundation of China(No.22179010)the National Key R&D Program of China(No.2021YFB2400200)Taishan Scholars of Shandong Province(No.tsqnz20231212)。
文摘Polyethylene oxide(PEO)-based solid polymer electrolytes are considered as promising material for solidstate sodium metallic batteries(SSMBs).However,their poor interfacial stability with high-voltage cathode limits their application in high-energy–density solid-state batteries.Herein,a uniform,sulfur-containing inorganic–organic composite cathode–electrolyte interphase layer was in situ formed by the addition of sodium polyvinyl sulfonate(NaPVS).The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(3)(NVP)|PEOsodium hexauorophosphate(NaPF6)|Na battery shows a higher initial capacity of 111.2 mAh.g^(-1)and an ultra-high capacity retention of 90.5%after 300 cycles.The 5 wt%NaPVS-Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF)|PEO-NaPF_(6)|Na battery with the high cutoff voltage of 4.2 V showed a specific discharge capacity of 88.9 mAh.g^(-1)at 0.5C for 100 cycles with a capacity retention of 79%,which is much better than that of the pristine-NVPF(PR-NVPF)|PEO-NaPF_(6)|Na battery(33.2%).The addition of NaPVS not only enhances the diffusion kinetics at the interface but also improves the rate performance and stability of the battery,thus bolstering its viability for high-energy applications.In situ phase tracking further elucidates that NaPVS effectively mitigates self-discharge induced by the oxidative decomposition of PEO at high temperature.This work proposes a general strategy to maintain the structural stability of the cathode–electrolyte interface in PEO-based high-performance SSMBs.
基金supported by the National Natural Science Foundation of China(Nos.51931006,U22A20118).
文摘Spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)cathode draws significant attention in the field of energy storage due to its unique voltage plateau.To further enhance the long-term electrochemical stability of LNMO,the LNMO cathode covered with an ultrathin ZrO_(2)layer was prepared through atomic layer deposition(ALD).It is found that the LNMO cathode deposited with 20 layers of ZrO_(2)(LNMOZ20)exhibits the best electrochemical performance,achieving a high discharge capacity of 117.1 mA·h/g,with a capacity retention of 87.4%after 600 cycles at a current density of 1C.Furthermore,even at higher current densities of 5C and 10C,the LNMOZ20 electrode still demonstrates excellent stability with discharge capacities reaching 111.7 and 103.6 mA·h/g,and capacity retentions maintaining at 81.0%and 101.4%after 2000 cycles,respectively.This study highlights that the incorporation of an ultrathin ZrO_(2)layer by ALD is an effective strategy for enhancing the long-term cycling stability of LNMO cathodes.
基金financially supported by the Cultivation and Construction of Ten National Science and Technology Innovation Platforms in Qinghai Province(2024-ZJ-J03)Xining Major Science and Technology Innovation Platform Capacity Building Project(2024-Z1)+1 种基金funding from Young Scholars of Western China,Chinese Academy of Sciences(E110HX0501)Qinghai Province Youth Science and Technology Talent Support Project(2022QHSKXRCTJ06)。
文摘The global shift towards low-carbon energy storage has increased interest in sodium-ion batteries(SIBs)as a safer,cost-effective alternative to lithium-ion batteries.However,the commercial viability has been limited by compatibility issues between high-energy-density cathode materials,such as Na_(3)V_(2)(PO_(4))_(2)F_(3)(NVPF),and high-voltage electrolytes.Addressing the challenges,H-NaODFB(comprising 93.91%NaODFB and 5.85%NaBF_(4))electrolyte significantly improves the electrochemical performance and stability of NVPF cathodes,Na/NVPF half-cells using H-NaODFB electrolyte retained 92.4%capacity after 900cycles,while Na/Na symmetric cells demonstrated a cycle life exceeding 600 h at 0.5 mA cm^(-2).The superior performance is attributed to improved Na^(+)(de)intercalation reversibility,lower interfacial impedance(619.8 vs.10,650.0Ω),and faster reaction kinetics compared to NaODFB alone.Advanced time of flight-secondary ion mass spectrometry(TOF-SIMS),X-ray photoelectron spectroscopy(XPS)and aberration corrected transmission electron microscope(AC-TEM),combined with first-principles calculations,revealed that NaBF_(4)in the H-NaODFB electrolyte plays a critical role in forming a stable cathode electrolyte interphase(CEI).The CEI consists of an initial inorganic and organic layer,followed by a fluoroborate layer,and finally a stable organic-inorganic polymeric layer,enhancing electrode stability and preventing over-oxidation.These findings provide valuable insights for designing high-performance electrolytes for SIBs.
基金supported by the Natural Sciences and Engineering Research Council of Canada(NSERC)through the Discovery Grants(No.RGPIN-2022-03835)Alliance Grants(No.ALLRP 581429-23)the Mitacs Accelerate Fellowship(No.IT35432).
文摘Organic cathode materials present a promising alternative for the inorganic counterparts in conventional lithiumion batteries(LIBs)due to lower cost,reduced environmental impact,renewability,and enhanced energy density.However,their practical application is hindered by dissolution in electrolytes,structural degradation,and sluggish lithium-ion transport.In this study,we introduce fluoroethylene carbonate(FEC)as an electrolyte additive to engineer a protective cathode–electrolyte interphase(CEI)layer,effectively mitigating cathode pulverization and enhancing battery stability of the organic cathode material,dilithium salt of 2,5-dihydroxy-1,4-benzoquinone(Li_(2)DHBQ).Electrochemical,morphological,and compositional analyses,including cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS),confirm that an optimal 1%FEC concentration forms a uniform CEI layer,significantly improving structural integrity and reducing interfacial resistance.Consequently,the battery with 1%FEC retains 185 mAh·g^(−1) after 200 cycles at 500 mA·g^(−1),with a capacity decay rate of just 0.049%per cycle,compared to 81 mAh·g^(−1) and 0.302%per cycle for the FEC-free battery.Additionally,the 1%FEC battery exhibits a capacitive charge storage contribution of up to 93.7%,resulting in excellent rate performance.These findings underscore the crucial role of CEI engineering in stabilizing organic cathodes,offering a practical approach to achieving high-rate and long-cycle LIBs.
基金supported by the National Natural Science Foundation of China(Nos.U1804129,21771164,21671205,U1804126)Zhongyuan Youth Talent Support Program of Henan ProvinceZhengzhou University Youth Innovation Program。
文摘Application of sodium-ion batteries is suppressed due to the lack of appropriate electrolytes matching cathode and anode simultaneously.Ether-based electrolytes,preference of anode materials,cannot match with high-potential cathodes failing to apply in full cells.Herein,vinylene carbonate(VC)as an additive into NaCF_(3) SO_(3)-Diglyme(DGM)could make sodium-ion full cells applicable without preactivation of cathode and anode.The assembled FeS@C||Na3 V2(PO_(4))_(3)@C full cell with this electrolyte exhibits long term cycling stability and high capacity retention.The deduced reason is additive VC,whose HOMO level value is close to that of DGM,not only change the solvent sheath structure of Na^(+),but also is synergistically oxidized with DGM to form integrity and consecutive cathode electrolyte interphase on Na3 V2(PO_(4))_(3)@C cathode,which could effectively improve the oxidative stability of electrolyte and prevent the electrolyte decomposition.This work displays a new way to optimize the sodium-ion full cell seasily with bright practical application potential.
