Iron-based Prussian white(PW)materials have attracted considerable attention as promising cathodes for potassium-ion batteries(PIBs)due to their high capacity,easy preparation,and economic merits.However,the intrinsic...Iron-based Prussian white(PW)materials have attracted considerable attention as promising cathodes for potassium-ion batteries(PIBs)due to their high capacity,easy preparation,and economic merits.However,the intrinsic iron dissolution and uncontrollable cathode-electrolyte interface(CEI)formation in conventional organic electrolytes severely hinder their long-term cycling stability.Herein,we employ succinonitrile(SN),a bifunctional electrolyte additive,to suppress the iron dissolution and promote thin,uniform,and stable CEI formation of the PW cathode,thus improving its structural stability.Benefited from the coordination between the cyano groups in SN and iron atoms,this molecule can preferentially adsorb on the surface of PW to mitigate iron dissolution.SN also facilitates the decomposition of anions in potassium salt rather than organic solvents in electrolyte due to the attractive reaction between SN and anions.Consequently,the PW cathode with SN additive provides better electrochemical reversibility,showing capacity retention of 93.6%after 3000 cycles at 5C.In comparison,without SN,the capacity retention is only 87.4%after 1000 cycles under the same conditions.Moreover,the full cells of PW matched with commercial graphite(Gr)achieve stable cycling for 3500 cycles at a high rate of 20C,with an exceptional capacity decay of only 0.005%per cycle,surpassing the majority of recently reported results in literature.展开更多
Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,an...Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,and environmental friendliness.However,their practical application is significantly impeded by several serious issues that arise at the cathode-electrolyte interface,such as interface structure degradation including the uneven deposition of Li_(2)S,unstable cathode-electrolyte interphase(CEI)layer and intermediate polysulfide shuttle effect.Thus,an optimized cathode-electrolyte interface along with optimized electrodes is required for overall improvement.Herein,we comprehensively outline the challenges and corresponding strategies,including electrolyte optimization to create a dense CEI layer,regulating the Li_(2)S deposition pattern,and inhibiting the shuttle effect with regard to the solid-liquid-solid pathway,the transformation from solid-liquid-solid to solid-solid pathway,and solid-solid pathway at the cathode-electrolyte interface.In order to spur more perceptive research and hasten the widespread use of lithium-sulfur batteries,viewpoints on designing a stable interface with a deep comprehension are also put forth.展开更多
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
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
Lithium manganese oxide （LiMn2O4） is a principal cathode material for high power and high energy density electrochemical storage on account of its low cost, non-toxicity, and ease of preparation relative to other ca...Lithium manganese oxide （LiMn2O4） is a principal cathode material for high power and high energy density electrochemical storage on account of its low cost, non-toxicity, and ease of preparation relative to other cathode materials. However, there are well-documented problems with capacity fade of lithium ion batteries containing LiMn2O4. Experimental observations indicate that the manganese content of the electrolyte increases as an electrochemical cell containing LiMn2O4 ages, suggesting that active material loss by dissolution of divalent manganese from the LiMn2O4 surface is the primary reason for reduced cell life in LiMn2O4 batteries. To improve the retention of manganese in the active material, it is key to understand the reactions that occur at the cathode surface. Although a thin layer of electrolyte decomposition products is known to form at the cathode surface, the speciation and reaction mechanisms of Mn^2＋ in this interface layer are not yet well understood. To bridge this knowledge gap, reactive force field （ReaxFF） based molecular dynamics was applied to investigate the reactions occurring at the LiMn2O4 cathode surface and the mechanisms that lead to manganese dissolution. The ReaxFFMD simulations reveal that the cathode-electrolyte interface layer is composed of oxida- tion products of electrolyte solvent molecules including aldehydes, esters, alcohols, polycarbonates, and organic radicals. The oxidation reaction pathways for the electro- lyre solvent molecules involve the formation of surface hydroxyl species that react with exposed manganese atoms on the cathode surface. The presence of hydrogen fluoride （HF） induces formation of inorganic metal fluorides and surface hydroxyl species. Reaction products predicted by ReaxFF-based MD are in agreement with experimentally identified cathode-electrolyte interface compounds. An overall cathode-electrolyte interface reaction scheme is proposed based on the molecular simulation results.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
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
Safety and energy density are significant for lithium-ion batteries(LIBs),and the flammable organic elec-trolyte is one of the most critical causes of the safety problem of LIBs.Although LiNi0.8 Co 0.1 Mn 0.1 O 2(NCM8...Safety and energy density are significant for lithium-ion batteries(LIBs),and the flammable organic elec-trolyte is one of the most critical causes of the safety problem of LIBs.Although LiNi0.8 Co 0.1 Mn 0.1 O 2(NCM811)cathode with high capacity can improve the energy density,the interface stability between NCM811 cathode and electrolytes needs to be improved.Herein,we report a multifunctional additive,diethyl(2-(triethoxysilyl)ethyl)phosphonate(DETSP),which can suppress the flammability of the elec-trolyte and enhance the cycling stability of NCM811 cathode with a capacity retention of 89.9%after 400 cycles at 1 C,while that of the blank electrolyte is merely 61.3%.In addition,DETSP is compati-ble well with the graphite anode without impairing the electrochemical performances.Significantly,the performance and safety of NCM811/graphite full cells are also improved.Experimental and theoretical re-sults demonstrate that DETSP can scavenge acidic byproducts and is beneficial to form a stable cathode-electrolyte interface(CEI).Accordingly,DETSP can potentially be an effective solution to ameliorating the safety of the commercial electrolyte and improving the stability of high-voltage cathodes.展开更多
In recent years,due to the increasing demand for portable electronic devices,rechargeable solid-state battery technology has developed rapidly.Lithium-ion batteries are the systems of choice,offering high energy densi...In recent years,due to the increasing demand for portable electronic devices,rechargeable solid-state battery technology has developed rapidly.Lithium-ion batteries are the systems of choice,offering high energy density,flexible and lightweight design,and longer lifespan than comparable battery technologies.Therefore,a better understanding of the relationship between electrochemical mechanism and structural properties from theory and experiment will enable us to accelerate the development of high-performance and security batteries.This review discusses the interplay between theoretical calculation and experiment in the study of lithium ion battery materials.We introduce the application of theoretical calculation method in solid-state batteries through the combination of theory and experiment.We present the concept and assembly technology of solid-state batteries are reviewed.The basic parameters of solid-state electrolytes,especially sulfide-based solid-state electrolytes and their interface mechanisms with high-voltage cathode materials,are analyzed by theoretical methods.We present an overview on the scientific challenges,fundamental mechanisms,and design strategies for solid-state batteries,especially focusing on the issues of stability on solid-state electrolytes and the associated interfaces with both cathode and electrolyte.Owing to the theoretical models,we can not only reveal the unprecedented mechanism from the atomic scale,but also analyze the interface problems in the battery thoroughly,thus effectively designing more promising electrolyte and interface coating materials.It blazed a new trial for engineering an interphase with improved interfacial compatibility for a long-term cyclability.展开更多
Aqueous zinc-ion battery systems are attractive for next-generation energy storage devices,however,the unstable electrode electrolyte interphase,especially cathode electrolyte interphase(CEI),has induced rapid capacit...Aqueous zinc-ion battery systems are attractive for next-generation energy storage devices,however,the unstable electrode electrolyte interphase,especially cathode electrolyte interphase(CEI),has induced rapid capacity attenuation,insufficient cycle life,and severe safety issues.Evolving the researching of CEI formation,composition,dynamic structure,and reaction mechanisms would help in understanding the fundamental electrochemistry at CEI such as electron and ion transport processes,further strengthening the specific capacity,rate,and cycle performance of the cathode materials.In this review,we summarized the latest progress in understanding interfacial reaction mechanisms and ion dynamic behavior,emphasizing the impact of surface-specific adsorption and solvation behaviors on the interface's ultimate structure and chemical composition.Subsequently,the significant challenges that persist in CEI formation mechanisms,such as cathodic dissolution,by-product formation,electrostatic interactions,constrained electrochemical windows,oxygen evolution reaction,overpotentials,phase transitions,and additional factors,were discussed.These challenges are explored to identify triggers contributing to the depletion of active materials and alterations in the composition or state of the CEI.Ultimately,with a deep comprehension of interfacial behaviors,the review articulates innovative optimization strategies through a detailed categorization of approaches in electrolyte engineering,cathode engineering,and artificial CEI development.Furthermore,future challenges and development directions of CEI are presented.We hope to offer insights for constructing robust CEI films to achieve high performance aqueous zinc-ion batteries.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
In this work the surface of LiNi0.5Mn1.5O4(LMN)particles is modified by Mn3O4 coating through a simple wet grinding method,the electronic conductivity is significantly improved from 1.53×10^-7 S/cm to 3.15×1...In this work the surface of LiNi0.5Mn1.5O4(LMN)particles is modified by Mn3O4 coating through a simple wet grinding method,the electronic conductivity is significantly improved from 1.53×10^-7 S/cm to 3.15×10^-5 S/cm after 2.6 wt%Mn3O4 coating.The electrochemical test results indicate that Mn3O4 coating dramatically enhances both rate performance and cycling capability(at 55℃)of LNM.Among the samples,2.6 wt%Mn3O4-coated LNM not only exhibits excellent rate capability(a large capacity of 108 m Ah/g at 10 C rate)but also shows 78%capacity retention at 55 ℃ and 1 C rate after 100 cycles.展开更多
Layered lithium nickel-cobalt-manganese oxides(NCM)have been highlighted as advanced cathode materials for lithium-ion batteries(LIBs);however,their low interfacial stability must be overcome to ensure stable cycling ...Layered lithium nickel-cobalt-manganese oxides(NCM)have been highlighted as advanced cathode materials for lithium-ion batteries(LIBs);however,their low interfacial stability must be overcome to ensure stable cycling performance of the cell.In this work,we propose a one-step surface modification method that uses a task-specific precursor,N,N,N,N-tetraethylsulfamide(NTESA),to improve interfacial stability of Ni-rich NCM cathode materials.The unstable surface properties of Ni-rich NCM cathode material are improved by embedding an artificial cathode-electrolyte interphase(CEI)layer on the cathode surface by heat treatment of the Ni-rich NCM cathode material with an NTESA precursor at low temperature.Our material analyses indicate that this approach allows the formation of amine-and sulfone-functionalized CEI layers on the surface of Ni-rich NCM cathode material without changing the layered structure of the cathode material.NTESA-functionalized Ni-rich NCM cathode materials exhibit improved cycling retention after 100 cycles:for example,a cell cycled with a 3.0 NTESA-modified NCM811 cathode presents the highest retention ratio of 88.3%,whereas a cell cycled with a non-functionalized NCM811 cathode suffers from rapid fading of the cycling performance(68.4%).Our additional SEM,XPS,and EIS analyses indicate that electrolyte decomposition is suppressed during electrochemical cycling,thereby leading to smaller increases in the internal resistances.ICP-MS analyses of the cycled anodes also indicate that the NTESA-based artificial CEI layer inhibits the dissolution of transition metal components from the Ni-rich NCM cathode materials,thereby contributing to an improved overall electrochemical performance of the cell.展开更多
The amount of spent lithium-ion batteries (LIBs) is constantly increasing as their popularity grows. It is important todevelop a recycling method that cannot only convert large amounts of waste anode graphite into hig...The amount of spent lithium-ion batteries (LIBs) is constantly increasing as their popularity grows. It is important todevelop a recycling method that cannot only convert large amounts of waste anode graphite into high value-addedproducts but is also simple and environmentally friendly. In this work, spent graphite from an anode was transformed into a cathode for dual-ion batteries (DIBs) through a two-step treatment. This method enables the crystalstructure and morphology of spent graphite to recover from the adverse effects of long cycling and be restored to aregular layered structure with appropriate layer spacing for anion intercalation. In addition, pyrolysis of the solidelectrolyte interphase into an amorphous carbon layer prevents the electrode from degrading and improves itscycling performance. The recycled negative graphite has a high reversible capacity of 87 mAh g^(-1) at 200 mA g^(-1),and its rate performance when used as a cathode in DIBs is comparable to that of commercial graphite. This simplerecycling idea turns spent anode graphite into a cathode material with attractive potential and superior electrochemical performance, genuinely achieving sustainable energy use. It also provides a new method for recoveringexhausted batteries.展开更多
基金funding support from the Macao Science and Technology Development Fund(0013/2021/AMJ and 0082/2022/A2)support from the Multi-Year Research Grants(MYRG2022-00266-IAPME,and MYRG-GRG2023-00224-IAPME)provided by the Research&Development Office at the University of Macao+2 种基金the National Natural Science Foundation of China(52202328)the Shanghai Sailing Program(22YF1455500)the Shanghai Magnolia Talent Plan Pujiang Project(24PJD128)for their financial support。
文摘Iron-based Prussian white(PW)materials have attracted considerable attention as promising cathodes for potassium-ion batteries(PIBs)due to their high capacity,easy preparation,and economic merits.However,the intrinsic iron dissolution and uncontrollable cathode-electrolyte interface(CEI)formation in conventional organic electrolytes severely hinder their long-term cycling stability.Herein,we employ succinonitrile(SN),a bifunctional electrolyte additive,to suppress the iron dissolution and promote thin,uniform,and stable CEI formation of the PW cathode,thus improving its structural stability.Benefited from the coordination between the cyano groups in SN and iron atoms,this molecule can preferentially adsorb on the surface of PW to mitigate iron dissolution.SN also facilitates the decomposition of anions in potassium salt rather than organic solvents in electrolyte due to the attractive reaction between SN and anions.Consequently,the PW cathode with SN additive provides better electrochemical reversibility,showing capacity retention of 93.6%after 3000 cycles at 5C.In comparison,without SN,the capacity retention is only 87.4%after 1000 cycles under the same conditions.Moreover,the full cells of PW matched with commercial graphite(Gr)achieve stable cycling for 3500 cycles at a high rate of 20C,with an exceptional capacity decay of only 0.005%per cycle,surpassing the majority of recently reported results in literature.
基金supported by the National Natural Science Foundation of China(Grant Nos.52102302,22409161 and 52472249)the Young Talent Support Plan of Xi’an Jiaotong University(Grant No.DQ6J011)+4 种基金the Natural Science Foundation of Shaanxi Province(2023-JC-QN-0115)the China Postdoctoral Science Foundation(2022M712499)Beilin District Science and Technology Plan(GX2328)the support from Young Elite Scientists Sponsorship Program by Chinese Association for Science and Technologythe“High-Level Talent Introduction Plan”of Shaanxi Province and Siyuan Scholar of Xi’an Jiaotong University。
文摘Global interest in lithium-sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost,high gravimetric,volumetric energy densities,abundant resources,and environmental friendliness.However,their practical application is significantly impeded by several serious issues that arise at the cathode-electrolyte interface,such as interface structure degradation including the uneven deposition of Li_(2)S,unstable cathode-electrolyte interphase(CEI)layer and intermediate polysulfide shuttle effect.Thus,an optimized cathode-electrolyte interface along with optimized electrodes is required for overall improvement.Herein,we comprehensively outline the challenges and corresponding strategies,including electrolyte optimization to create a dense CEI layer,regulating the Li_(2)S deposition pattern,and inhibiting the shuttle effect with regard to the solid-liquid-solid pathway,the transformation from solid-liquid-solid to solid-solid pathway,and solid-solid pathway at the cathode-electrolyte interface.In order to spur more perceptive research and hasten the widespread use of lithium-sulfur batteries,viewpoints on designing a stable interface with a deep comprehension are also put forth.
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.
文摘Lithium manganese oxide （LiMn2O4） is a principal cathode material for high power and high energy density electrochemical storage on account of its low cost, non-toxicity, and ease of preparation relative to other cathode materials. However, there are well-documented problems with capacity fade of lithium ion batteries containing LiMn2O4. Experimental observations indicate that the manganese content of the electrolyte increases as an electrochemical cell containing LiMn2O4 ages, suggesting that active material loss by dissolution of divalent manganese from the LiMn2O4 surface is the primary reason for reduced cell life in LiMn2O4 batteries. To improve the retention of manganese in the active material, it is key to understand the reactions that occur at the cathode surface. Although a thin layer of electrolyte decomposition products is known to form at the cathode surface, the speciation and reaction mechanisms of Mn^2＋ in this interface layer are not yet well understood. To bridge this knowledge gap, reactive force field （ReaxFF） based molecular dynamics was applied to investigate the reactions occurring at the LiMn2O4 cathode surface and the mechanisms that lead to manganese dissolution. The ReaxFFMD simulations reveal that the cathode-electrolyte interface layer is composed of oxida- tion products of electrolyte solvent molecules including aldehydes, esters, alcohols, polycarbonates, and organic radicals. The oxidation reaction pathways for the electro- lyre solvent molecules involve the formation of surface hydroxyl species that react with exposed manganese atoms on the cathode surface. The presence of hydrogen fluoride （HF） induces formation of inorganic metal fluorides and surface hydroxyl species. Reaction products predicted by ReaxFF-based MD are in agreement with experimentally identified cathode-electrolyte interface compounds. An overall cathode-electrolyte interface reaction scheme is proposed based on the molecular simulation results.
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.
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(No.51773134)the Sichuan Science and Technology Program(No.2019YFH0112)+1 种基金the Fundamental Research Funds for the Central Universities,Institutional Research Fund from Sichuan University(No.2021SCUNL201)the 111 Project(No.B20001).
文摘Safety and energy density are significant for lithium-ion batteries(LIBs),and the flammable organic elec-trolyte is one of the most critical causes of the safety problem of LIBs.Although LiNi0.8 Co 0.1 Mn 0.1 O 2(NCM811)cathode with high capacity can improve the energy density,the interface stability between NCM811 cathode and electrolytes needs to be improved.Herein,we report a multifunctional additive,diethyl(2-(triethoxysilyl)ethyl)phosphonate(DETSP),which can suppress the flammability of the elec-trolyte and enhance the cycling stability of NCM811 cathode with a capacity retention of 89.9%after 400 cycles at 1 C,while that of the blank electrolyte is merely 61.3%.In addition,DETSP is compati-ble well with the graphite anode without impairing the electrochemical performances.Significantly,the performance and safety of NCM811/graphite full cells are also improved.Experimental and theoretical re-sults demonstrate that DETSP can scavenge acidic byproducts and is beneficial to form a stable cathode-electrolyte interface(CEI).Accordingly,DETSP can potentially be an effective solution to ameliorating the safety of the commercial electrolyte and improving the stability of high-voltage cathodes.
基金financial support from the National Natural Science Foundation of China(Nos.52171082 and 51001091)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.21IRTSTHN003)+2 种基金partially supported by the Provincial Scientific Research Program of Henan(No.182102310815)Nuclear Material Technology Innovation Fund for National Defense Technology Industry(No.ICNM-2021-YZ-02)the Science and Technology Project of Henan Province(No.232102241036).
文摘In recent years,due to the increasing demand for portable electronic devices,rechargeable solid-state battery technology has developed rapidly.Lithium-ion batteries are the systems of choice,offering high energy density,flexible and lightweight design,and longer lifespan than comparable battery technologies.Therefore,a better understanding of the relationship between electrochemical mechanism and structural properties from theory and experiment will enable us to accelerate the development of high-performance and security batteries.This review discusses the interplay between theoretical calculation and experiment in the study of lithium ion battery materials.We introduce the application of theoretical calculation method in solid-state batteries through the combination of theory and experiment.We present the concept and assembly technology of solid-state batteries are reviewed.The basic parameters of solid-state electrolytes,especially sulfide-based solid-state electrolytes and their interface mechanisms with high-voltage cathode materials,are analyzed by theoretical methods.We present an overview on the scientific challenges,fundamental mechanisms,and design strategies for solid-state batteries,especially focusing on the issues of stability on solid-state electrolytes and the associated interfaces with both cathode and electrolyte.Owing to the theoretical models,we can not only reveal the unprecedented mechanism from the atomic scale,but also analyze the interface problems in the battery thoroughly,thus effectively designing more promising electrolyte and interface coating materials.It blazed a new trial for engineering an interphase with improved interfacial compatibility for a long-term cyclability.
基金supported by the Fundamental Research Funds for the Central Universities,Natural Science Foundation of China(Nos.52202100 and U2004209)China Postdoctoral Science Foundation(No.314500)Postgraduate Research&Practice Innovation Program of Jiangsu Province(Nos.KYCX23_0451).
文摘Aqueous zinc-ion battery systems are attractive for next-generation energy storage devices,however,the unstable electrode electrolyte interphase,especially cathode electrolyte interphase(CEI),has induced rapid capacity attenuation,insufficient cycle life,and severe safety issues.Evolving the researching of CEI formation,composition,dynamic structure,and reaction mechanisms would help in understanding the fundamental electrochemistry at CEI such as electron and ion transport processes,further strengthening the specific capacity,rate,and cycle performance of the cathode materials.In this review,we summarized the latest progress in understanding interfacial reaction mechanisms and ion dynamic behavior,emphasizing the impact of surface-specific adsorption and solvation behaviors on the interface's ultimate structure and chemical composition.Subsequently,the significant challenges that persist in CEI formation mechanisms,such as cathodic dissolution,by-product formation,electrostatic interactions,constrained electrochemical windows,oxygen evolution reaction,overpotentials,phase transitions,and additional factors,were discussed.These challenges are explored to identify triggers contributing to the depletion of active materials and alterations in the composition or state of the CEI.Ultimately,with a deep comprehension of interfacial behaviors,the review articulates innovative optimization strategies through a detailed categorization of approaches in electrolyte engineering,cathode engineering,and artificial CEI development.Furthermore,future challenges and development directions of CEI are presented.We hope to offer insights for constructing robust CEI films to achieve high performance aqueous zinc-ion batteries.
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 National Key R&D Program of China(No.2018YFB0905400)the Fundamental Research Funds for the Central Universities(No.JZ2019HGBZ0140)+2 种基金the National Natural Science Foundation of China(No.U1630106No.51577175)China Postdoctoral Science Foundation(No.172731)。
文摘In this work the surface of LiNi0.5Mn1.5O4(LMN)particles is modified by Mn3O4 coating through a simple wet grinding method,the electronic conductivity is significantly improved from 1.53×10^-7 S/cm to 3.15×10^-5 S/cm after 2.6 wt%Mn3O4 coating.The electrochemical test results indicate that Mn3O4 coating dramatically enhances both rate performance and cycling capability(at 55℃)of LNM.Among the samples,2.6 wt%Mn3O4-coated LNM not only exhibits excellent rate capability(a large capacity of 108 m Ah/g at 10 C rate)but also shows 78%capacity retention at 55 ℃ and 1 C rate after 100 cycles.
基金financially supported by the National Research Foundation of Korea(NRF)(NRF-2019R1C1C1002249)the Technology Innovation Program(Nos.20010095 and 20011905)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)。
文摘Layered lithium nickel-cobalt-manganese oxides(NCM)have been highlighted as advanced cathode materials for lithium-ion batteries(LIBs);however,their low interfacial stability must be overcome to ensure stable cycling performance of the cell.In this work,we propose a one-step surface modification method that uses a task-specific precursor,N,N,N,N-tetraethylsulfamide(NTESA),to improve interfacial stability of Ni-rich NCM cathode materials.The unstable surface properties of Ni-rich NCM cathode material are improved by embedding an artificial cathode-electrolyte interphase(CEI)layer on the cathode surface by heat treatment of the Ni-rich NCM cathode material with an NTESA precursor at low temperature.Our material analyses indicate that this approach allows the formation of amine-and sulfone-functionalized CEI layers on the surface of Ni-rich NCM cathode material without changing the layered structure of the cathode material.NTESA-functionalized Ni-rich NCM cathode materials exhibit improved cycling retention after 100 cycles:for example,a cell cycled with a 3.0 NTESA-modified NCM811 cathode presents the highest retention ratio of 88.3%,whereas a cell cycled with a non-functionalized NCM811 cathode suffers from rapid fading of the cycling performance(68.4%).Our additional SEM,XPS,and EIS analyses indicate that electrolyte decomposition is suppressed during electrochemical cycling,thereby leading to smaller increases in the internal resistances.ICP-MS analyses of the cycled anodes also indicate that the NTESA-based artificial CEI layer inhibits the dissolution of transition metal components from the Ni-rich NCM cathode materials,thereby contributing to an improved overall electrochemical performance of the cell.
基金This work was financially supported by the National Natural Science Foundation of China(No.52173246 and 91963118)the 111 Project(No.B13013).
文摘The amount of spent lithium-ion batteries (LIBs) is constantly increasing as their popularity grows. It is important todevelop a recycling method that cannot only convert large amounts of waste anode graphite into high value-addedproducts but is also simple and environmentally friendly. In this work, spent graphite from an anode was transformed into a cathode for dual-ion batteries (DIBs) through a two-step treatment. This method enables the crystalstructure and morphology of spent graphite to recover from the adverse effects of long cycling and be restored to aregular layered structure with appropriate layer spacing for anion intercalation. In addition, pyrolysis of the solidelectrolyte interphase into an amorphous carbon layer prevents the electrode from degrading and improves itscycling performance. The recycled negative graphite has a high reversible capacity of 87 mAh g^(-1) at 200 mA g^(-1),and its rate performance when used as a cathode in DIBs is comparable to that of commercial graphite. This simplerecycling idea turns spent anode graphite into a cathode material with attractive potential and superior electrochemical performance, genuinely achieving sustainable energy use. It also provides a new method for recoveringexhausted batteries.
