Silicon is considered one of the most promising candidates for incorporation into carbon-based anodes in lithium-ion batteries(LIBs)due to its high specific capacity.However,the significant volume changes during charg...Silicon is considered one of the most promising candidates for incorporation into carbon-based anodes in lithium-ion batteries(LIBs)due to its high specific capacity.However,the significant volume changes during charge and discharge cycles lead to repeated reconstruction of the solid electrolyte interface(SEI)film and continuous loss of active lithium.Pre-lithiation method is regarded as a highly attractive approach for effectively compensating for active lithium loss during the charge and discharge cycles of LIBs.Constructing a stable SEI film is particularly crucial in the pre-lithiation process.In this study,we developed a direct contact pre-lithiation(DC-Pr)method to create a temperature-tailored robust SEI film interface on silicon-carbon(Si@C)electrodes.By investigating the morphology,structure,and composition of the SEI formed on Si@C electrodes at different pre-lithiation temperatures(50,25,0,and-25℃),we demonstrated that controlling the lithiation temperature to regulate the migration rate of lithium ions within the Si@C electrode yields a lithiated Si@C anode(25-Pr-Si@C)at 25℃ with a continuous,uniform SEI film(~3.65 nm)enriched with Li_(2)O-LiF,which exhibits synergistic effects.Importantly,the initial Coulombic efficiency(ICE)of 25-Pr-Si@C significantly improved from 85.4% in the unlithiated Si@C electrode(Blank-Si@C)to 106.1%.Additionally,the full cell configuration using a high areal loading of lithiated Si@C(~5.5 mA h cm^(-2))as the anode and NCM811 as the cathode(NCM811||25-Pr-Si@C)demonstrated superior cycling performance,maintaining 69.4% of capacity retention and achieving a Coulombic efficiency of over 99.7% after 150 cycles(0.5 C).Therefore,this simple and efficient experimental design provides a high-performance,controllable,and scalable pre-lithiation method for LIBs,paving the way for the commercialization of LIBs utilizing pre-lithiation techniques.展开更多
Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)...Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)-based batteries have attracted much attention in developing new energy storage devices.In Zn battery system,the battery performance is significantly affected by the solid electrolyte interface(SEI),which is controlled by electrode and electrolyte,and attracts dendrite growth,electrochemical stability window range,metallic Zn anode corrosion and passivation,and electrolyte mutations.Therefore,the design of SEI is decisive for the overall performance of Zn battery systems.This paper summarizes the formation mechanism,the types and characteristics,and the characterization techniques associated with SEI.Meanwhile,we analyze the influence of SEI on battery performance,and put forward the design strategies of SEI.Finally,the future research of SEI in Zn battery system is prospected to seize the nature of SEI,improve the battery performance and promote the large-scale application.展开更多
Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this ...Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this paper,homotype heterojunctions are designed on HC to induce the generation of stable solid electrolyte interfaces,which can effectively increase the ICE of HC from 64.7%to 81.1%.The results show that using a simple surface engineering strategy to construct a homotypic amorphous Al_(2)O_(3) layer on the HC could shield the active sites,and further inhibit electrolyte decomposition and side effects occurrence.Particularly,due to the suppression of continuous decomposition of NaPF 6 in ester-based electrolytes,the accumulation of NaF could be reduced,leading to the formation of thinner and denser solid electrolyte interface films and a decrease in the interface resistance.The HC anode can not only improve the ICE but elevate its sodium storage performance based on this homotype heterojunction composed of HC and Al_(2)O_(3).The optimized HC anode exhibits an outstanding reversible capacity of 321.5mAhg^(−1) at 50mAg^(−1).The cycling stability is also improved effectively,and the capacity retention rate is 86.9%after 2000 cycles at 1Ag^(−1) while that of the untreated HC is only 52.6%.More importantly,the improved sodium storage behaviors are explained by electrochemical kinetic analysis.展开更多
Transition metal selenides have been widely studied as anode materials of sodium ion batteries(SIBs),however,the investigation of solid-electrolyte-interface(SEI)on these materials,which is critical to the electrochem...Transition metal selenides have been widely studied as anode materials of sodium ion batteries(SIBs),however,the investigation of solid-electrolyte-interface(SEI)on these materials,which is critical to the electrochemical performance of SIBs,remains at its infancy.Here in this paper,ZnSe@C nanoparticles were prepared from ZIF-8 and the SEI layers on these electrodes with and without reduced graphene oxide(rGO)layers were examined in details by X-ray photoelectron spectroscopies at varied charged/discharged states.It is observed that fast and complicated electrolyte decomposition reactions on ZnSe@C leads to quite thick SEI film and intercalation of solvated sodium ions through such thick SEI film results in slow ion diffusion kinetics and unstable electrode structure.However,the presence of rGO could efficiently suppress the decomposition of electrolyte,thus thin and stable SEI film was formed.ZnSe@C electrodes wrapped by rGO demonstrates enhanced interfacial charge transfer kinetics and high electrochemical performance,a capacity retention of 96.4%,after 1000 cycles at 5 A/g.This study might offer a simple avenue for the designing high performance anode materials through manipulation of SEI film.展开更多
Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its deve...Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its development. Recently, several feasible electrolytes have been developed. Nevertheless, as a pivotal part, the solid electrolyte interface(SEI) formed on CMA has not been paid enough attention to. In this review, based on the passivation mechanism of CMA, the favorable composition of SEI is emphasized with the corresponding electrolytes. It is considered that boron-containing and organic–inorganic hybrid SEI might be preferred. By comparing electrolytes and SEI on CMA with lithium and magnesium metal anodes, the root causes of CMA passivation are further elaborated, enlightening rational design rules of suitable SEI. Furthermore, some noteworthy details when assembling secondary calcium metal batteries(CMBs) are put forward. It is expected that deeper understanding of SEI on CMA will promote the development of CMBs.展开更多
Aqueous zinc metal batteries(ZMBs)are promising for grid-scale energy storage,but their practical application is hindered by limited cycling life and inferior low-temperature performance,primarily due to Zn dendrite g...Aqueous zinc metal batteries(ZMBs)are promising for grid-scale energy storage,but their practical application is hindered by limited cycling life and inferior low-temperature performance,primarily due to Zn dendrite growth and parasitic reactions at the electrolyte-electrode interface.To address these challenges,we develop a new and cheap hydrated eutectic electrolyte(HEE)composed of ZnCl_(2),choline chloride(ChCl),and H_(2)O,which can fundamentally tune desirable interface chemistries for dendrite-free and low-temperature ZMBs.The optimized HEE with a solvation structure of ZnCl_(3)(ChCl)(H_(2)O)_(2) shows a high co nductivity of 15.98 mS cm^(-1)and excellent freeze resistance below-40℃.It has been found that hydrogen bonding between ChCl and H_(2)O effectively reduces water activity,while preferential adsorption of ChCl molecules at the inner Helmholtz plane promotes the formation of a protective solid electrolyte interphase(SEI)on Zn metal anodes,which greatly suppresses the dendrites and side reactions.Therefore,the HEE endows the as-fabricated Zn//Zn symmetric cells and Zn//polyaniline full batteries with superior electrochemical performance at-40℃,such as a long cycling life of 870 h at 1 mA cm^(-2)and 1 mAh cm^(-2)and a high capacity of 75 mAh g^(-1)at 0.3 A g^(-1).The HEE reported here may pave a new way to construct high-performance ZMBs for specific low-temperature application scenarios.展开更多
Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effecti...Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effective capacity and threatens large-scale safe performance.With significant advantages over ethylene carbonate(EC)electrolytes,fluorinated electrolytes can more effectively suppress internal gas evolution,thereby improving battery safety and cycling stability.To reveal the mechanism behind gas formation in lithium-ion batteries,our study investigated the transport behavior and interfacial products of fluorinated electrolytes under various operation conditions,including electrode material and electrolyte composition.Innovatively,we applied the reaction network integrator ReacNetGenerator to the analysis of the solid electrolyte interface(SEI)in lithium batteries,providing more molecular fingerprint information from the perspective of specific products.Using reactive molecular dynamics(MD)simulations with the ReaxFF force field and EChemDID,complemented by density functional theory(DFT)calculations,our results demonstrate that fluorinated electrolytes can effectively suppress the decomposition of LiPF_(6) to produce toxic gases PFs and PF_3.DFT analysis further reveals that highly fluorinated solvents(e.g.,FEMC)enhance the anti-reduction stability of PF_(6)~-through synergistic regulation of molecular orbital energy levels,thermodynamic electron affinity,charge transfer,and electrostatic potential distribution,thereby mitigating LiPF_(6) decomposition.Additionally,fluorinated electrolytes generate significantly more LiF components than non-fluorinated ones to promote the formation of a stable and durable solid electrolyte interface(SEI).Experimental validations via XPS and GC-MS confirm reduced CO_(2) generation and LiF-enriched SEI formation,aligning with simulation and DFT data.The findings provide valuable insights for the design of advanced electrolytes aimed at ensuring large-scale,safe energy storage solutions.展开更多
Silicon(Si),a promising high-capacity anode material for lithium-ion batteries,suffers from severe volume changes upon cycling,leading to rapid capacity fading.This study mitigates the capacity fading issue by introdu...Silicon(Si),a promising high-capacity anode material for lithium-ion batteries,suffers from severe volume changes upon cycling,leading to rapid capacity fading.This study mitigates the capacity fading issue by introducing a surface SiNx layer on micron Si,which is in-situ converted into a LixSiNy-based artificial solid electrolyte interphase(SEI).This artificial SEI not only effectively restricts SEI growth to the outmost surface,but also induces a self-optimized structural evolution of the inner Si from micron particles to nanoporous network within 20 cycles.This self-optimized nanoprous Si network exhibits low volume expansion and enhanced reaction kinetics.Consequently,the Si@SiNx/TiN demonstrates a high capacity,stable cycling,and good fast-charging capability.展开更多
electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which ar...electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which are highly dependent on the thickness. Thus, understanding the formation mechanism and the SEI thickness is of prime interest. First, we apply dimensional analysis to obtain an explicit relation between the thickness and the number density in this study. Then the SEI thickness in the initial charge-discharge cycle is analyzed and estimated for the first time using the Cahn-Hilliard phase-field model. In addition, the SEI thickness by molecular dynamics simulation validates the theoretical results. It has been shown that the established model and the simulation in this paper estimate the SEI thickness concisely within order-of-magnitude of nanometers. Our results may help in evaluating the performance of SEI and assist the future design of Li-ion battery.展开更多
Metal-carbon dioxide(CO_(2))batteries hold great promise for reducing greenhouse gas emissions and are regarded as one of the most promising energy storage techniques due to their efficiency advantages in CO_(2)recove...Metal-carbon dioxide(CO_(2))batteries hold great promise for reducing greenhouse gas emissions and are regarded as one of the most promising energy storage techniques due to their efficiency advantages in CO_(2)recovery and conversion.Moreover,rechargeable nonaqueous metal-CO_(2)batteries have attracted much attention due to their high theoretical energy density.However,the stability issues of the electrode-electrolyte interfaces of nonaqueous metal-CO_(2)(lithium(Li)/sodium(Na)/potassium(K)-CO_(2))batteries have been troubling its development,and a large number of related research in the field of electrolytes have conducted in recent years.This review retraces the short but rapid research history of nonaqueous metal-CO_(2)batteries with a detailed electrochemical mechanism analysis.Then it focuses on the basic characteristics and design principles of electrolytes,summarizes the latest achievements of various types of electrolytes in a timely manner and deeply analyzes the construction strategies of stable electrode-electrolyte interfaces for metal-CO_(2)batteries.Finally,the key issues related to electrolytes and interface engineering are fully discussed and several potential directions for future research are proposed.This review enriches a comprehensive understanding of electrolytes and interface engineering toward the practical applications of next-generation metal-CO_(2)batteries.展开更多
The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid elect...The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.展开更多
Silicon is considered one of the most promising anode materials owing to its high theoretical energy density,however,the volume expansion/contraction during electrochemical lithiation/delithiation cycles leads to inst...Silicon is considered one of the most promising anode materials owing to its high theoretical energy density,however,the volume expansion/contraction during electrochemical lithiation/delithiation cycles leads to instability of the solid electrolyte interphase(SEI),which ultimately results in capacity degradation.Herein,the local stress and deformation evolution status of an SEI layer on an anode particle are investigated through a quantitative electrochemical-mechanical model.The impacts of structural uniformity,mechanical strength,and operating conditions on the stability of the SEI layer are investigated in detail.The simulation results demonstrate that when the silicon particle radius decreases from 800 nm to 600 and 400 nm,the failure time increases by 29%and 65%,respectively,of the original failure time;When the structural defect depth ratio is reduced from 0.6 to 0.4 and 0.2,the failure time increases by 72%and 132%,respectively;For the discharge rate,the condition at 0.1 C has 34%and 139%longer time to failure than that at 0.2 C and 0.3 C,respectively.This work provides insight into the rational design of stable SEI layers and sheds light on possible methods for constructing silicon-based lithium-ion batteries with longer cycling lives.展开更多
The reversibility and stability of aqueous Zn metal batteries(AZMBs)are largely limited by Zn dendrites and interfacial parasitic reactions.Herein,we propose a parallel modulation strategy to boost the reversibility o...The reversibility and stability of aqueous Zn metal batteries(AZMBs)are largely limited by Zn dendrites and interfacial parasitic reactions.Herein,we propose a parallel modulation strategy to boost the reversibility of the Zn anode by introducing N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate(TCFH)as an additive in the electrolyte.TCFH is composed of PF6-and TN+with opposite charges.PF6-can spontaneously induce the in-situ generation of ZnF_(2)solid electrolyte interface(SEI)on the anode,which can improve the transport kinetics of Zn^(2+)at the interface,thus promoting the rapid and uniform deposition of Zn as well as inhibiting the growth of dendrites.In addition,TN+is enriched at the anode surface during Zn deposition through the anchoring effect,which brings a reconfiguration of the ion/molecule distribution.The anchored-TN+reduces the concentrations of H_(2)O and SO_(4)^(2-),sufficiently restraining the parasitic reaction.Thanks to the dual-phase interface engineering constructed of PF6-and TN+in parallel,the symmetric cell with the proposed electrolyte survives long cycling stability over750 h at 20 mA cm^(-2),10 mAh cm^(-2).This study offers a distinct viewpoint to the multidimensional optimization of Zn anodes for high-performance AZMBs.展开更多
Considering the growing pre-lithiation demand for high-performance Si-based anodes and consequent additional costs caused by the strict pre-lithiation environment,developing effective and environmentally stable pre-li...Considering the growing pre-lithiation demand for high-performance Si-based anodes and consequent additional costs caused by the strict pre-lithiation environment,developing effective and environmentally stable pre-lithiation additives is a challenging research hotspot.Herein,interfacial engineered multifunctional Li_(13)Si_(4)@perfluoropolyether(PFPE)/LiF micro/nanoparticles are proposed as anode pre-lithiation additives,successfully constructed with the hybrid interface on the surface of Li_(13)Si_(4)through PFPE-induced nucleophilic substitution.The synthesized multifunctional Li_(13)Si_(4)@PFPE/LiF realizes the integration of active Li compensation,long-term chemical structural stability in air,and solid electrolyte interface(SEI)optimization.In particular,the Li_(13)Si_(4)@PFPE/LiF with a high pre-lithiation capacity(1102.4 mAh g^(-1))is employed in the pre-lithiation Si-based anode,which exhibits a superior initial Coulombic efficiency of 102.6%.Additionally,in situ X-ray diffraction/Raman,density functional theory calculation,and finite element analysis jointly illustrate that PFPE-predominant hybrid interface with modulated abundant highly electronegative F atoms distribution reduces the water adsorption energy and oxidation kinetics of Li_(13)Si_(4)@PFPE/LiF,which delivers a high pre-lithiation capacity retention of 84.39%after exposure to extremely moist air(60%relative humidity).Intriguingly,a LiF-rich mechanically stable bilayer SEI is constructed on anodes through a pre-lithiation-driven regulation for the behavior of electrolyte decomposition.Benefitting from pre-lithiation via multifunctional Li_(13)Si_(4)@PFPE/LiF,the full cell and pouch cell assembled with pre-lithiated anodes operate with long-time stability of 86.5%capacity retention over 200 cycles and superior energy density of 549.9 Wh kg^(-1),respectively.The universal multifunctional pre-lithiation additives provide enlightenment on promoting large-scale applications of pre-lithiation on commercial high-energy-density and long-cycle-life lithium-ion batteries.展开更多
With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretica...With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretical capacity and low redox potential.However,the commercial application of LMAs is impeded by the uncontrolled growth of lithium dendrites.Such dendrite growth may result in internal short circuits,detrimental side reactions,and the formation of dead lithium.Therefore,the growth of lithium metal must be controlled.This article summarizes our recent efforts in inhibiting such dendrite growth,decreasing the detrimental side reactions,and elongating the LMA lifespan by optimizing the electrolyte structure and by designing appropriate current collectors.After identifying that the unstable solid electrolyte inter-face(SEI)film is responsible for the potential dropping in carbonate electrolytes,we developed LiPF_(6)-LiNO_(3) dual-salt electrolyte and lithium bis(fluorosulfonyl)imide(LiFSI)-carbonate electrolyte to stabilize the SEI film of LMAs.In addition,we achieved controlled lithium depos-ition by designing the structure and material of the current collectors,including selective lithium deposition in porous current collectors,lithio-philic metal guided lithium deposition,and iron carbide induced underpotential lithium deposition in nano-cavities.The limitations of the cur-rent strategies and prospects for future research are also presented.展开更多
Aluminum-ion batteries(AIBs)with Al metal anode are attracting increasing research interest on account of their high safety,low cost,large volumetric energy density(≈8046 mA h cm−3),and environmental friendliness.Spe...Aluminum-ion batteries(AIBs)with Al metal anode are attracting increasing research interest on account of their high safety,low cost,large volumetric energy density(≈8046 mA h cm−3),and environmental friendliness.Specifically,the reversible Al electrostripping/deposition is achieved with the rapid development of room temperature ionic liquids,and rapid progress has been made in fabricating high-performance and durable AIBs during the past decade.This review provides an integrated comprehension of the evolution of AIBs and highlights the development of various non-aqueous and aqueous electrolytes including high-temperature molten salts,room temperature ionic liquids,and gel–polymer electrolytes.The critical issues on the interplay of electrolytes are outlined in terms of the voltage window span,the effective ion species during charge storage(Al 3+or Al x Cl?y)and their underlying charge transfer(e.g.,interfacial transfer and diffusion),and the solid electrolyte interface formation and its role.Following the critical insight,future perspectives on how to practically design feasible AIBs are given.展开更多
Hydrous electrolytes with high electrochemical potentials were obtained by hydrating water molecules into solutes to form high Li:water molar ratio electrolytes(HMRE).Solid polyethylene glycol(PEG) were e mployed to e...Hydrous electrolytes with high electrochemical potentials were obtained by hydrating water molecules into solutes to form high Li:water molar ratio electrolytes(HMRE).Solid polyethylene glycol(PEG) were e mployed to enha nce the molar ratio of Li^(+) to water in the electrolytes while reducing the consumption of Li-salt.The obtained mole ratio of Li^(+) to wa ter molecules in the hydrous electrolytes was greater than 1:1;however,the mass fraction of Li-salt was reduced to 61%(approximately 5.5 mol/kg,based on water and PEG).Compared with that of water-in-salt electrolytes,the mass fraction of Li-salt could be remarkably reduced by adding solid PEG.The electrochemical stability of the electrolytes improved considerably because of the strong hydration of Li^(+) by the water molecules.A beneficial passivation effect,arising from the decomposition of the electrolyte,at a wide potential window was observed.展开更多
Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the p...Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the possible maximum apparent current density that a given ASSLSC system can endure and how to reveal this potential still require study.Herein,a capacity perturbation strategy aiming to better measure the possible maximum j_(Ac)^(a)is proposed for the first time.With garnet-based plane-surface structure ASSLSCs as an exemplification,the j_(Ac)^(a)is quite small when the capacity is dramatically large.Under a perturbed capacity of 0.001 mA h cm^(-2),the j_(Ac)^(a)is determined to be as high as 2.35 mA cm^(-2)at room temperature.This investigation demonstrates that the capacity perturbation strategy is a feasible strategy for measuring the possible maximum j_(Ac)^(a)of Li/solid electrolyte interface,and hopefully provides good references to explore the critical current density of other types of electrochemical systems.展开更多
N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (...N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (PS) were added to the electrolyte system respectively as additives to improve the property of solid electrolyte interface and cyclic performance. The results of cyclic voltammetry showed that homogenous and compact solid electrolyte interface film formed on graphite electrode which was detected by observing the morphology of cycled graphite anode. Charging and discharging performance of LiFePO4/Li half cell was tested in the electrolyte with or without additives. The initial specific discharging capacities were increased to 129.4 and 123.0 mA·h/g by the addition of VC and PS, respectively, compared with that of additive-free electrolyte. The discharging retentions were 88.9% and 84.6% in electrolyte containing VC and PS after 10 cycles.展开更多
Silicon(Si)is a promising anode material for rechargeable batteries due to its high theoretical capacity and abundance,but its practical application is hindered by the continuous growth of porous solid-electrolyte int...Silicon(Si)is a promising anode material for rechargeable batteries due to its high theoretical capacity and abundance,but its practical application is hindered by the continuous growth of porous solid-electrolyte interphase(SEI),leading to capacity fade.Herein,a LiF-Pie structured SEI is proposed,with LiF nanodomains encapsulated in the inner layer of the organic cross-linking silane matrix.A series of advanced techniques such as cryogenic electron microscopy,time-of-flight secondary ion mass spectrometry,and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry have provided detailed insights into the formation mechanism,nanostructure,and chemical composition of the interface.With such SEI,the capacity retention of LiCoO_(2)||Si is significantly improved from 49.6%to 88.9%after 300 cycles at 100 mA g^(-1).These findings provide a desirable interfacial design principle with enhanced(electro)chemical and mechanical stability,which are crucial for sustaining Si anode functionality,thereby significantly advancing the reliability and practical application of Si-based anodes.展开更多
基金the financial support from the Shanghai Oriental Talent Program(QNDS2024007)On-Campus Scene Verification Project of Tongji University(kh0170020242359)+4 种基金Shanghai Research Institute of China Shenhua Coal-to-Liquids Chemical Co.,Ltd.the National Natural Science Foundation of China(52307249)National Science Foundation of Shanghai Province(23ZR1465900)Fundamental Research Funds for the Central Universities at Tongji University(PA2022000668,22120220426)Nanchang Automotive Institute of Intelligence&New Energy of Tongji University(TPDTC202211-02)。
文摘Silicon is considered one of the most promising candidates for incorporation into carbon-based anodes in lithium-ion batteries(LIBs)due to its high specific capacity.However,the significant volume changes during charge and discharge cycles lead to repeated reconstruction of the solid electrolyte interface(SEI)film and continuous loss of active lithium.Pre-lithiation method is regarded as a highly attractive approach for effectively compensating for active lithium loss during the charge and discharge cycles of LIBs.Constructing a stable SEI film is particularly crucial in the pre-lithiation process.In this study,we developed a direct contact pre-lithiation(DC-Pr)method to create a temperature-tailored robust SEI film interface on silicon-carbon(Si@C)electrodes.By investigating the morphology,structure,and composition of the SEI formed on Si@C electrodes at different pre-lithiation temperatures(50,25,0,and-25℃),we demonstrated that controlling the lithiation temperature to regulate the migration rate of lithium ions within the Si@C electrode yields a lithiated Si@C anode(25-Pr-Si@C)at 25℃ with a continuous,uniform SEI film(~3.65 nm)enriched with Li_(2)O-LiF,which exhibits synergistic effects.Importantly,the initial Coulombic efficiency(ICE)of 25-Pr-Si@C significantly improved from 85.4% in the unlithiated Si@C electrode(Blank-Si@C)to 106.1%.Additionally,the full cell configuration using a high areal loading of lithiated Si@C(~5.5 mA h cm^(-2))as the anode and NCM811 as the cathode(NCM811||25-Pr-Si@C)demonstrated superior cycling performance,maintaining 69.4% of capacity retention and achieving a Coulombic efficiency of over 99.7% after 150 cycles(0.5 C).Therefore,this simple and efficient experimental design provides a high-performance,controllable,and scalable pre-lithiation method for LIBs,paving the way for the commercialization of LIBs utilizing pre-lithiation techniques.
基金This research was supported by the Fundamental Research Funds for the Central Universities(0515022GH0202253 and 0515022SH0201253).
文摘Due to its high theoretical capacity(820 mAh g^(−1)),low standard electrode potential(−0.76 V vs.SHE),excellent stability in aqueous solutions,low cost,environmental friendliness and intrinsically high safety,zinc(Zn)-based batteries have attracted much attention in developing new energy storage devices.In Zn battery system,the battery performance is significantly affected by the solid electrolyte interface(SEI),which is controlled by electrode and electrolyte,and attracts dendrite growth,electrochemical stability window range,metallic Zn anode corrosion and passivation,and electrolyte mutations.Therefore,the design of SEI is decisive for the overall performance of Zn battery systems.This paper summarizes the formation mechanism,the types and characteristics,and the characterization techniques associated with SEI.Meanwhile,we analyze the influence of SEI on battery performance,and put forward the design strategies of SEI.Finally,the future research of SEI in Zn battery system is prospected to seize the nature of SEI,improve the battery performance and promote the large-scale application.
基金supported by the National Natural Science Foundation of China(grant nos.21975026 and 22005033)the National Postdoctoral Program of China(no.BX20180037)+1 种基金China Postdoctoral Science Foundation(no.2018M640077)the Beijing Institute of Technology Research Fund Program for Young Scholars(no.XSQD-202108005).
文摘Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this paper,homotype heterojunctions are designed on HC to induce the generation of stable solid electrolyte interfaces,which can effectively increase the ICE of HC from 64.7%to 81.1%.The results show that using a simple surface engineering strategy to construct a homotypic amorphous Al_(2)O_(3) layer on the HC could shield the active sites,and further inhibit electrolyte decomposition and side effects occurrence.Particularly,due to the suppression of continuous decomposition of NaPF 6 in ester-based electrolytes,the accumulation of NaF could be reduced,leading to the formation of thinner and denser solid electrolyte interface films and a decrease in the interface resistance.The HC anode can not only improve the ICE but elevate its sodium storage performance based on this homotype heterojunction composed of HC and Al_(2)O_(3).The optimized HC anode exhibits an outstanding reversible capacity of 321.5mAhg^(−1) at 50mAg^(−1).The cycling stability is also improved effectively,and the capacity retention rate is 86.9%after 2000 cycles at 1Ag^(−1) while that of the untreated HC is only 52.6%.More importantly,the improved sodium storage behaviors are explained by electrochemical kinetic analysis.
基金supported by the Fundamental Research Funds for Central Universities(SCUT Grant No.2019ZD22)the Guangdong Innovative and Entrepreneurial Research Team Program(No.2016ZT06N569)。
文摘Transition metal selenides have been widely studied as anode materials of sodium ion batteries(SIBs),however,the investigation of solid-electrolyte-interface(SEI)on these materials,which is critical to the electrochemical performance of SIBs,remains at its infancy.Here in this paper,ZnSe@C nanoparticles were prepared from ZIF-8 and the SEI layers on these electrodes with and without reduced graphene oxide(rGO)layers were examined in details by X-ray photoelectron spectroscopies at varied charged/discharged states.It is observed that fast and complicated electrolyte decomposition reactions on ZnSe@C leads to quite thick SEI film and intercalation of solvated sodium ions through such thick SEI film results in slow ion diffusion kinetics and unstable electrode structure.However,the presence of rGO could efficiently suppress the decomposition of electrolyte,thus thin and stable SEI film was formed.ZnSe@C electrodes wrapped by rGO demonstrates enhanced interfacial charge transfer kinetics and high electrochemical performance,a capacity retention of 96.4%,after 1000 cycles at 5 A/g.This study might offer a simple avenue for the designing high performance anode materials through manipulation of SEI film.
基金supported by the National Natural Science Foundation of China(51872196)the Natural Science Foundation of Tianjin,China(17JCJQJC44100)。
文摘Owing to its low potential, crustal abundances and environmental friendliness, calcium metal anode(CMA) is emerging as a powerful contender in post-lithium era. However, the passivation of CMA fatally hinders its development. Recently, several feasible electrolytes have been developed. Nevertheless, as a pivotal part, the solid electrolyte interface(SEI) formed on CMA has not been paid enough attention to. In this review, based on the passivation mechanism of CMA, the favorable composition of SEI is emphasized with the corresponding electrolytes. It is considered that boron-containing and organic–inorganic hybrid SEI might be preferred. By comparing electrolytes and SEI on CMA with lithium and magnesium metal anodes, the root causes of CMA passivation are further elaborated, enlightening rational design rules of suitable SEI. Furthermore, some noteworthy details when assembling secondary calcium metal batteries(CMBs) are put forward. It is expected that deeper understanding of SEI on CMA will promote the development of CMBs.
基金supported by the National Natural Science Foundation of China(22479022,52174276)the Central Guidance for Local Science and Technology Development Foundation(Youth Science Program Type A of Liaoning Province,2025JH6/101100007)+1 种基金the Liaoning Revitalization Talents Program(XLYC2007129)the Fundamental Research Funds for the Central Universities(N25QNR011)。
文摘Aqueous zinc metal batteries(ZMBs)are promising for grid-scale energy storage,but their practical application is hindered by limited cycling life and inferior low-temperature performance,primarily due to Zn dendrite growth and parasitic reactions at the electrolyte-electrode interface.To address these challenges,we develop a new and cheap hydrated eutectic electrolyte(HEE)composed of ZnCl_(2),choline chloride(ChCl),and H_(2)O,which can fundamentally tune desirable interface chemistries for dendrite-free and low-temperature ZMBs.The optimized HEE with a solvation structure of ZnCl_(3)(ChCl)(H_(2)O)_(2) shows a high co nductivity of 15.98 mS cm^(-1)and excellent freeze resistance below-40℃.It has been found that hydrogen bonding between ChCl and H_(2)O effectively reduces water activity,while preferential adsorption of ChCl molecules at the inner Helmholtz plane promotes the formation of a protective solid electrolyte interphase(SEI)on Zn metal anodes,which greatly suppresses the dendrites and side reactions.Therefore,the HEE endows the as-fabricated Zn//Zn symmetric cells and Zn//polyaniline full batteries with superior electrochemical performance at-40℃,such as a long cycling life of 870 h at 1 mA cm^(-2)and 1 mAh cm^(-2)and a high capacity of 75 mAh g^(-1)at 0.3 A g^(-1).The HEE reported here may pave a new way to construct high-performance ZMBs for specific low-temperature application scenarios.
基金funding support from the National Natural Science Foundation of China(Grant No.52302302)the National Key R&D Program of China(Grant No.2022YFE0208000)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Special Funds of Tongji University for“Sino-German Cooperation 2.0 Strategy”。
文摘Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effective capacity and threatens large-scale safe performance.With significant advantages over ethylene carbonate(EC)electrolytes,fluorinated electrolytes can more effectively suppress internal gas evolution,thereby improving battery safety and cycling stability.To reveal the mechanism behind gas formation in lithium-ion batteries,our study investigated the transport behavior and interfacial products of fluorinated electrolytes under various operation conditions,including electrode material and electrolyte composition.Innovatively,we applied the reaction network integrator ReacNetGenerator to the analysis of the solid electrolyte interface(SEI)in lithium batteries,providing more molecular fingerprint information from the perspective of specific products.Using reactive molecular dynamics(MD)simulations with the ReaxFF force field and EChemDID,complemented by density functional theory(DFT)calculations,our results demonstrate that fluorinated electrolytes can effectively suppress the decomposition of LiPF_(6) to produce toxic gases PFs and PF_3.DFT analysis further reveals that highly fluorinated solvents(e.g.,FEMC)enhance the anti-reduction stability of PF_(6)~-through synergistic regulation of molecular orbital energy levels,thermodynamic electron affinity,charge transfer,and electrostatic potential distribution,thereby mitigating LiPF_(6) decomposition.Additionally,fluorinated electrolytes generate significantly more LiF components than non-fluorinated ones to promote the formation of a stable and durable solid electrolyte interface(SEI).Experimental validations via XPS and GC-MS confirm reduced CO_(2) generation and LiF-enriched SEI formation,aligning with simulation and DFT data.The findings provide valuable insights for the design of advanced electrolytes aimed at ensuring large-scale,safe energy storage solutions.
基金supported by the National Key Research and Development Program of China(2022YFB3803501)the Key Research and Development Program of Hubei Province(2021BAA176)+1 种基金the Hainan Provincial Natural Science Foundation of China(522CXTD516)the Science and Technology special fund of Hainan Province(ZDYF2025GXJS008)。
文摘Silicon(Si),a promising high-capacity anode material for lithium-ion batteries,suffers from severe volume changes upon cycling,leading to rapid capacity fading.This study mitigates the capacity fading issue by introducing a surface SiNx layer on micron Si,which is in-situ converted into a LixSiNy-based artificial solid electrolyte interphase(SEI).This artificial SEI not only effectively restricts SEI growth to the outmost surface,but also induces a self-optimized structural evolution of the inner Si from micron particles to nanoporous network within 20 cycles.This self-optimized nanoprous Si network exhibits low volume expansion and enhanced reaction kinetics.Consequently,the Si@SiNx/TiN demonstrates a high capacity,stable cycling,and good fast-charging capability.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11372313, U1562105, and 11611130019)the Chinese Academy of Sciences (CAS) through CAS Interdisciplinary Innovation Team Project, the CAS Key Research Program of Frontier Sciences (Grant No. QYZDJ-SSW-JSC019)the CAS Strategic Priority Research Program (Grant No. XDB22040401)
文摘electrolyte. The properties of lithium-ion (Li-ion) battery, such as cycle life, irreversible capacity loss, self-discharge rate, electrode corrosion and safety are usually ascribed to the quality of the SEI, which are highly dependent on the thickness. Thus, understanding the formation mechanism and the SEI thickness is of prime interest. First, we apply dimensional analysis to obtain an explicit relation between the thickness and the number density in this study. Then the SEI thickness in the initial charge-discharge cycle is analyzed and estimated for the first time using the Cahn-Hilliard phase-field model. In addition, the SEI thickness by molecular dynamics simulation validates the theoretical results. It has been shown that the established model and the simulation in this paper estimate the SEI thickness concisely within order-of-magnitude of nanometers. Our results may help in evaluating the performance of SEI and assist the future design of Li-ion battery.
基金supports from the Beijing Laboratory of New Energy Storage Technology, North China Electric Power Universitythe Program of the National Energy Storage Industry-Education Platformthe Interdisciplinary Innovation Program of North China Electric Power University (No. XM2212315)
文摘Metal-carbon dioxide(CO_(2))batteries hold great promise for reducing greenhouse gas emissions and are regarded as one of the most promising energy storage techniques due to their efficiency advantages in CO_(2)recovery and conversion.Moreover,rechargeable nonaqueous metal-CO_(2)batteries have attracted much attention due to their high theoretical energy density.However,the stability issues of the electrode-electrolyte interfaces of nonaqueous metal-CO_(2)(lithium(Li)/sodium(Na)/potassium(K)-CO_(2))batteries have been troubling its development,and a large number of related research in the field of electrolytes have conducted in recent years.This review retraces the short but rapid research history of nonaqueous metal-CO_(2)batteries with a detailed electrochemical mechanism analysis.Then it focuses on the basic characteristics and design principles of electrolytes,summarizes the latest achievements of various types of electrolytes in a timely manner and deeply analyzes the construction strategies of stable electrode-electrolyte interfaces for metal-CO_(2)batteries.Finally,the key issues related to electrolytes and interface engineering are fully discussed and several potential directions for future research are proposed.This review enriches a comprehensive understanding of electrolytes and interface engineering toward the practical applications of next-generation metal-CO_(2)batteries.
基金supported by the National Natural Science Foundation of China (51773134)the Sichuan Science and Technology Program (2019YFH0112)+2 种基金the Fundamental Research Funds for the Central UniversitiesInstitutional Research Fund from Sichuan University (2021SCUNL201)the 111 Project (B20001)。
文摘The rapid development and widespread application of lithium-ion batteries(LIBs) have increased demand for high-safety and high-performance LIBs. Accordingly, various additives have been used in commercial liquid electrolytes to severally adjust the solvation structure of lithium ions, control the components of solid electrolyte interphase, or reduce flammability. While it is highly desirable to develop low-cost multifunctional electrolyte additives integrally that address both safety and performance on LIBs, significant challenges remain. Herein, a novel phosphorus-containing organic small molecule, bis(2-methoxyethyl) methylphosphonate(BMOP), was rationally designed to serve as a fluorine-free and multifunctional additive in commercial electrolytes. This novel electrolyte additive is low-toxicity,high-efficiency, low-cost, and electrode-compatible, which shows the significant improvement to both electrochemical performance and fire safety for LIBs through regulating the electrolyte solvation structure, constructing the stable electrode-electrolyte interphase, and suppressing the electrolyte combustion. This work provides a new avenue for developing safer and high-performance LIBs.
基金the funding support from National Key R&D Program of China(2023YFB2408100)Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(YSBR-098)+2 种基金National Innovative Talents Program(GG2090007001)CAS Program(KJ2090130001)USTC Startup Program(KY2090000044).
文摘Silicon is considered one of the most promising anode materials owing to its high theoretical energy density,however,the volume expansion/contraction during electrochemical lithiation/delithiation cycles leads to instability of the solid electrolyte interphase(SEI),which ultimately results in capacity degradation.Herein,the local stress and deformation evolution status of an SEI layer on an anode particle are investigated through a quantitative electrochemical-mechanical model.The impacts of structural uniformity,mechanical strength,and operating conditions on the stability of the SEI layer are investigated in detail.The simulation results demonstrate that when the silicon particle radius decreases from 800 nm to 600 and 400 nm,the failure time increases by 29%and 65%,respectively,of the original failure time;When the structural defect depth ratio is reduced from 0.6 to 0.4 and 0.2,the failure time increases by 72%and 132%,respectively;For the discharge rate,the condition at 0.1 C has 34%and 139%longer time to failure than that at 0.2 C and 0.3 C,respectively.This work provides insight into the rational design of stable SEI layers and sheds light on possible methods for constructing silicon-based lithium-ion batteries with longer cycling lives.
基金financially supported by the National Natural Science Foundation of China(52172159)the Postdoctoral Fellowship Program of CPSF(GZB20230631).
文摘The reversibility and stability of aqueous Zn metal batteries(AZMBs)are largely limited by Zn dendrites and interfacial parasitic reactions.Herein,we propose a parallel modulation strategy to boost the reversibility of the Zn anode by introducing N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate(TCFH)as an additive in the electrolyte.TCFH is composed of PF6-and TN+with opposite charges.PF6-can spontaneously induce the in-situ generation of ZnF_(2)solid electrolyte interface(SEI)on the anode,which can improve the transport kinetics of Zn^(2+)at the interface,thus promoting the rapid and uniform deposition of Zn as well as inhibiting the growth of dendrites.In addition,TN+is enriched at the anode surface during Zn deposition through the anchoring effect,which brings a reconfiguration of the ion/molecule distribution.The anchored-TN+reduces the concentrations of H_(2)O and SO_(4)^(2-),sufficiently restraining the parasitic reaction.Thanks to the dual-phase interface engineering constructed of PF6-and TN+in parallel,the symmetric cell with the proposed electrolyte survives long cycling stability over750 h at 20 mA cm^(-2),10 mAh cm^(-2).This study offers a distinct viewpoint to the multidimensional optimization of Zn anodes for high-performance AZMBs.
基金Huaiyu Shao acknowledges the Shenzhen-Hong Kong-Macao Science and Technology Plan Project(Category C)(Grant No.SGDX20220530111004028)the Macao Science and Technology Development Fund(FDCT)for funding(FDCT No.0013/2024/RIB1,FDCT-MOST joint project No.0026/2022/AMJ and No.006/2022/ALC of the Macao Centre for Research and Development in Advanced Materials[2022–2024])+2 种基金the Multi-Year Research Grant(MYRG)from University of Macao(project No.MYRG-GRG2023-00140-IAPME-UMDF and No.MYRG-GRG2024-00206-IAPME)Natural Science Foundation of Guangdong Province(Grant No.2023A1515010765)Science and Technology Program of Guangdong Province of China(Grant No.2023A0505030001)。
文摘Considering the growing pre-lithiation demand for high-performance Si-based anodes and consequent additional costs caused by the strict pre-lithiation environment,developing effective and environmentally stable pre-lithiation additives is a challenging research hotspot.Herein,interfacial engineered multifunctional Li_(13)Si_(4)@perfluoropolyether(PFPE)/LiF micro/nanoparticles are proposed as anode pre-lithiation additives,successfully constructed with the hybrid interface on the surface of Li_(13)Si_(4)through PFPE-induced nucleophilic substitution.The synthesized multifunctional Li_(13)Si_(4)@PFPE/LiF realizes the integration of active Li compensation,long-term chemical structural stability in air,and solid electrolyte interface(SEI)optimization.In particular,the Li_(13)Si_(4)@PFPE/LiF with a high pre-lithiation capacity(1102.4 mAh g^(-1))is employed in the pre-lithiation Si-based anode,which exhibits a superior initial Coulombic efficiency of 102.6%.Additionally,in situ X-ray diffraction/Raman,density functional theory calculation,and finite element analysis jointly illustrate that PFPE-predominant hybrid interface with modulated abundant highly electronegative F atoms distribution reduces the water adsorption energy and oxidation kinetics of Li_(13)Si_(4)@PFPE/LiF,which delivers a high pre-lithiation capacity retention of 84.39%after exposure to extremely moist air(60%relative humidity).Intriguingly,a LiF-rich mechanically stable bilayer SEI is constructed on anodes through a pre-lithiation-driven regulation for the behavior of electrolyte decomposition.Benefitting from pre-lithiation via multifunctional Li_(13)Si_(4)@PFPE/LiF,the full cell and pouch cell assembled with pre-lithiated anodes operate with long-time stability of 86.5%capacity retention over 200 cycles and superior energy density of 549.9 Wh kg^(-1),respectively.The universal multifunctional pre-lithiation additives provide enlightenment on promoting large-scale applications of pre-lithiation on commercial high-energy-density and long-cycle-life lithium-ion batteries.
基金financially supported by the National Natural Science Foundation of China(No.21773301)。
文摘With the increasing demand for high energy-density batteries for portable electronics and large-scale energy storage systems,the lithium metal anode(LMA)has received tremendous attention because of its high theoretical capacity and low redox potential.However,the commercial application of LMAs is impeded by the uncontrolled growth of lithium dendrites.Such dendrite growth may result in internal short circuits,detrimental side reactions,and the formation of dead lithium.Therefore,the growth of lithium metal must be controlled.This article summarizes our recent efforts in inhibiting such dendrite growth,decreasing the detrimental side reactions,and elongating the LMA lifespan by optimizing the electrolyte structure and by designing appropriate current collectors.After identifying that the unstable solid electrolyte inter-face(SEI)film is responsible for the potential dropping in carbonate electrolytes,we developed LiPF_(6)-LiNO_(3) dual-salt electrolyte and lithium bis(fluorosulfonyl)imide(LiFSI)-carbonate electrolyte to stabilize the SEI film of LMAs.In addition,we achieved controlled lithium depos-ition by designing the structure and material of the current collectors,including selective lithium deposition in porous current collectors,lithio-philic metal guided lithium deposition,and iron carbide induced underpotential lithium deposition in nano-cavities.The limitations of the cur-rent strategies and prospects for future research are also presented.
基金D.M.and D.Y.contributed equally to this work.This research was financially supported by the National Natural Science Foundation of China(No.51772094).
文摘Aluminum-ion batteries(AIBs)with Al metal anode are attracting increasing research interest on account of their high safety,low cost,large volumetric energy density(≈8046 mA h cm−3),and environmental friendliness.Specifically,the reversible Al electrostripping/deposition is achieved with the rapid development of room temperature ionic liquids,and rapid progress has been made in fabricating high-performance and durable AIBs during the past decade.This review provides an integrated comprehension of the evolution of AIBs and highlights the development of various non-aqueous and aqueous electrolytes including high-temperature molten salts,room temperature ionic liquids,and gel–polymer electrolytes.The critical issues on the interplay of electrolytes are outlined in terms of the voltage window span,the effective ion species during charge storage(Al 3+or Al x Cl?y)and their underlying charge transfer(e.g.,interfacial transfer and diffusion),and the solid electrolyte interface formation and its role.Following the critical insight,future perspectives on how to practically design feasible AIBs are given.
基金supported by the National Natural Science Foundation of China (No.11975043)the Natural Science Foundation of Shandong Province (No.ZR2017LEM011)。
文摘Hydrous electrolytes with high electrochemical potentials were obtained by hydrating water molecules into solutes to form high Li:water molar ratio electrolytes(HMRE).Solid polyethylene glycol(PEG) were e mployed to enha nce the molar ratio of Li^(+) to water in the electrolytes while reducing the consumption of Li-salt.The obtained mole ratio of Li^(+) to wa ter molecules in the hydrous electrolytes was greater than 1:1;however,the mass fraction of Li-salt was reduced to 61%(approximately 5.5 mol/kg,based on water and PEG).Compared with that of water-in-salt electrolytes,the mass fraction of Li-salt could be remarkably reduced by adding solid PEG.The electrochemical stability of the electrolytes improved considerably because of the strong hydration of Li^(+) by the water molecules.A beneficial passivation effect,arising from the decomposition of the electrolyte,at a wide potential window was observed.
基金the financial support from the Natural Science Foundation for Distinguished Young Scholars of Hunan Province(2020JJ2047)the science and technology innovation Program of Hunan Province(2022RC3048)+2 种基金the Program of Huxiang Young Talents(2019RS2002)the Innovation-Driven Project of Central South University(2020CX027)the Fundamental Research Funds for the Central Universities of Central South University(2021zzts0125)。
文摘Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal batteries.Nevertheless,how much the possible maximum apparent current density that a given ASSLSC system can endure and how to reveal this potential still require study.Herein,a capacity perturbation strategy aiming to better measure the possible maximum j_(Ac)^(a)is proposed for the first time.With garnet-based plane-surface structure ASSLSCs as an exemplification,the j_(Ac)^(a)is quite small when the capacity is dramatically large.Under a perturbed capacity of 0.001 mA h cm^(-2),the j_(Ac)^(a)is determined to be as high as 2.35 mA cm^(-2)at room temperature.This investigation demonstrates that the capacity perturbation strategy is a feasible strategy for measuring the possible maximum j_(Ac)^(a)of Li/solid electrolyte interface,and hopefully provides good references to explore the critical current density of other types of electrochemical systems.
基金Supported by National Natural Science Foundation of China (No.20976174)Open-end Fund of National Key Laboratory of Multiphase Complex Systems (No.MPCS-2011-D-06)
文摘N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide was synthesized for the application in ionic liquid based electrolytes in lithium ion battery, 10% vinylene carbonate (VC) and 10% 1,3-propane sultone (PS) were added to the electrolyte system respectively as additives to improve the property of solid electrolyte interface and cyclic performance. The results of cyclic voltammetry showed that homogenous and compact solid electrolyte interface film formed on graphite electrode which was detected by observing the morphology of cycled graphite anode. Charging and discharging performance of LiFePO4/Li half cell was tested in the electrolyte with or without additives. The initial specific discharging capacities were increased to 129.4 and 123.0 mA·h/g by the addition of VC and PS, respectively, compared with that of additive-free electrolyte. The discharging retentions were 88.9% and 84.6% in electrolyte containing VC and PS after 10 cycles.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB2502200)the National Natural Science Foundation of China(NSFC nos.52172257 and 22409211)+2 种基金the China Postdoctoral Science Foundation(No.2023M743739)the Postdoctoral Fellowship Program of CPSF(No.GZC20232939)CAS Youth Interdisciplinary Team。
文摘Silicon(Si)is a promising anode material for rechargeable batteries due to its high theoretical capacity and abundance,but its practical application is hindered by the continuous growth of porous solid-electrolyte interphase(SEI),leading to capacity fade.Herein,a LiF-Pie structured SEI is proposed,with LiF nanodomains encapsulated in the inner layer of the organic cross-linking silane matrix.A series of advanced techniques such as cryogenic electron microscopy,time-of-flight secondary ion mass spectrometry,and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry have provided detailed insights into the formation mechanism,nanostructure,and chemical composition of the interface.With such SEI,the capacity retention of LiCoO_(2)||Si is significantly improved from 49.6%to 88.9%after 300 cycles at 100 mA g^(-1).These findings provide a desirable interfacial design principle with enhanced(electro)chemical and mechanical stability,which are crucial for sustaining Si anode functionality,thereby significantly advancing the reliability and practical application of Si-based anodes.
