Garnet-type oxide solid electrolytes are the critical materials for all-solid-state lithium ion batteries.Nanoscale spectroscopic analysis on solid electrolytes plays a key role in bridging the gap between microstruct...Garnet-type oxide solid electrolytes are the critical materials for all-solid-state lithium ion batteries.Nanoscale spectroscopic analysis on solid electrolytes plays a key role in bridging the gap between microstructure and properties.In this work,Auger electron spectroscopy(AES),which can directly detect lithium element and distinguish its valence state,was applied to characterize the garnet-type Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6O12)(LLZTO).Different spectroscopy parameters were evaluated and optimal acquisition conditions were provided.Electron induced precipitation of lithium metal from LLZTO was observed.By exploring the influence factors of precipitation and combining transmission electron microscopy(TEM)and focused ion beam(FIB)experiments,the underlying mechanism of the phenomenon was revealed and previous controversy was resolved.The analysis method was also extended to other types of solid electrolytes,and this work provides a reference for future in-depth research on the structure-property relationship of solid electrolytes using AES.展开更多
Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ioni...Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ionic conductivity and slow Li+transference.Herein,based on the“binary electrolytes”of poly(vinylidene fluoride-chlorotrifluoroethylene)(P(VDF-CTFE))and lithium salt(LiTFSI),a kind of eutectogel hybrid electrolytes(EHEs)with high Li+transference number was developed via tuning the spontaneous coupling of charge and vacated space generated by Li-cation diffusion utilizing the Li6.4La3Zr1.4Ta0.6O12(LLZTO)dopant.LLZTO doping promotes the dissociation of lithium salt,increases Li+carrier density,and boosts ion jumping and the coordination/decoupling reactions of Li+.As a result,the optimized EHEs-10%possess a high Li-transference number of 0.86 and a high Li+conductivity of 3.2×10–4 S·cm–1 at room temperature.Moreover,the prepared EHEs-10%composite solid electrolyte presents excellent lithiumphilic and compatibility,and can be tested stably for 1,200 h at 0.3 mA·cm–2 with assembled lithium symmetric batteries.Likewise,the EHEs-10%films match well with high-loading LiFePO4 and LiCoO2 cathodes(>10 mg·cm–2)and exhibit remarkable interface stability.Particularly,the LiFePO4//EHEs-10%//Li and LiCoO2//EHEs-10%//Li cells deliver high rate performance of 118 mAh·g–1 at 1 C and 93.7 mAh·g–1 at 2 C with coulombic efficiency of 99.3%and 98.1%,respectively.This work provides an in-depth understanding and new insights into our design for polymer electrolytes with fast Li+diffusion.展开更多
The aggregation of inorganic particles with high mass ratio will form a heterogeneous electric field in the solid polymer electrolytes(SPEs),which is difficult to be compatible with lithium anode,leading to inadequate...The aggregation of inorganic particles with high mass ratio will form a heterogeneous electric field in the solid polymer electrolytes(SPEs),which is difficult to be compatible with lithium anode,leading to inadequate ionic conductivity.Herein,a facile spray drying method is adopted to increase the mass ratio of inorganic particles and solve the aggregation problems of fillers simultaneously.The polyvinylidene fluoride(PVDF)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)covers the surface of each Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)granules during the nebulization process,then forming flat solid electrolytes via layer-by-layer deposition.Characterized by the atomic force microscope,the obtained solid electrolytes achieve a homogenous dispersion of Young’s modulus and surface electric field.As a result,the as-prepared SPEs present high tensile strength of 7.1 MPa,high ionic conductivity of 1.86×10^(−4)S·cm^(−1)at room temperature,and wide electrochemical window up to 5.0 V,demonstrating increased mechanical strength and uniform lithium-ion migration channels for SPEs.Thanks to the as-prepared SPEs,the lithiumsymmetrical cells show a highly stable Li plating/stripping cycling for over 1,000 h at 0.1 mA·cm^(−2).The corresponding Li/LCoO_(2)batteries also present good rate capability and excellent cyclic performance with capacity retention of 80%after 100 cycles at room temperature.展开更多
NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定...NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。展开更多
Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and in...Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for SSLMBs.To overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the CSE.The synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room temperature.Furthermore,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode interface.The synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V vs.Li/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.展开更多
Satisfactory ionic conductivity,excellent mechanical stability,and high-temperature resistance are the prerequisites for the safe application of solid polymer electrolytes(SPEs)in all-solid-state lithium metal batteri...Satisfactory ionic conductivity,excellent mechanical stability,and high-temperature resistance are the prerequisites for the safe application of solid polymer electrolytes(SPEs)in all-solid-state lithium metal batteries(ASSLMBs).In this study,a novel poly(m-phenylene isophthalamide)(PMIA)-core/poly(ethylene oxide)(PEO)-shell nanofiber membrane and the functional Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)ceramic nanopar-ticle are simultaneously introduced into the PEO-based SPEs to prepare composite polymer electrolytes(CPEs).The core PMIA layer of composite nanofibers can greatly improve the mechanical strength and thermal stability of the CPEs,while the shell PEO layer can provide the 3D continuous transport channels for lithium ions.In addition,the introduction of functional LLZTO nanoparticle not only reduces the crys-tallinity of PEO,but also promotes the dissociation of lithium salts and releases more Li^(+)ions through its interaction with the Lewis acid-base of anions,thereby overall improving the transport of lithium ions.Consequently,the optimized CPEs present high ionic conductivity of 1.38×10^(−4)S/cm at 30℃,signifi-cantly improved mechanical strength(8.5 MPa),remarkable thermal stability(without obvious shrinkage at 150℃),and conspicuous Li dendrites blocking ability(>1800 h).The CPEs also both have good com-patibility and cyclic stability with LiFePO_(4)(>2000 cycles)and high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)(>500 cycles)cathodes.In addition,even at low temperature(40℃),the assembled LiFePO4/CPEs/Li bat-tery still can cycle stably.The novel design can provide an effective way to exploit high-performance solid-state electrolytes.展开更多
Garnet-type solid-state batteries(SSBs)are considered to be one of the most promising candidates to realize next-generation lithium metal batteries with high energy density and safety.However,the dendrite-induced shor...Garnet-type solid-state batteries(SSBs)are considered to be one of the most promising candidates to realize next-generation lithium metal batteries with high energy density and safety.However,the dendrite-induced short-circuit and the poor interfacial contact impeded the practical application.Herein,interface engineering to achieve low interfacial resistance without high temperature calcination was developed,which Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)was simply coated with complex hydride(Li_(4)(BH_(4))_(3)I(3L1L))in various mass ratios n(Li_(4)(BH_(4))_(3)I)-(100−n)LLZTO(10≤n≤40).The interfacial conductivity increases by more than three orders of magnitude from 8.29×10^(−6)S·cm^(−1)to 1.10×10^(−2)S·cm^(−1).Symmetric Li cells exhibit a high critical current density(CCD)of 4.0 mA·cm^(−2) and an excellent cycling stability for 200 h at 4.0 mA·cm^(−2).SSBs with polymeric sulfur-polyacrylonitrile(SPAN)cathode achieve a high discharge capacity of 1149 mAh·g^(−1) with a capacity retention of 91%after 100 cycles(0.2 C).This attempt guides a simple yet efficient strategy for obtaining a stable Li/LLZTO interface,which would promote the development of solid-state batteries.展开更多
Despite the high energy density of lithium metal batteries(LMBs),their application in rechargeable batteries is still hampered due to insufficient safety.Here,we present a novel flame-retardant solid-state electrolyte...Despite the high energy density of lithium metal batteries(LMBs),their application in rechargeable batteries is still hampered due to insufficient safety.Here,we present a novel flame-retardant solid-state electrolyte based on polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)with nano SiO_(2)aerogel as an inert filler but Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)as an auxiliary component to enhance the ion conductivity.The introduction of SiO_(2)aerogels imparts the polymer electrolyte with exceptional thermal stability and flame retardancy.Simultaneously,the interaction between hydroxyl groups of SiO_(2)particles and PVDF-HFP creates a strong cross-linking structure,enhancing the mechanical strength and stability of the electrolyte.Furthermore,the presence of SiO_(2)aerogel and LLZTO facilitates the dissociation of lithium salts through Lewis acid-base interactions,resulting in a high ionic conductivity of 1.01×10^(−3)S·cm^(−1)and a wide electrochemical window of~5.0 V at room temperature for the prepared electrolytes.Remarkably,the assembled Li|Li cell demonstrates the excellent resistance to lithium dendrite and runs stablly for over 1500 h at a current density of 0.25 mA·cm^(−2).Thus,we prepare a pouch cell with high safety,which can work normally after short-circuiting under the external folding and cutting.展开更多
基金supported by the Shanghai Science and Technology Plan(No.21DZ2260400)the startup funding from ShanghaiTech University.The electron microscopy characterization was supported by the Center for High-resolution Electron Microscopy(CћEM)at ShanghaiTech University。
文摘Garnet-type oxide solid electrolytes are the critical materials for all-solid-state lithium ion batteries.Nanoscale spectroscopic analysis on solid electrolytes plays a key role in bridging the gap between microstructure and properties.In this work,Auger electron spectroscopy(AES),which can directly detect lithium element and distinguish its valence state,was applied to characterize the garnet-type Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6O12)(LLZTO).Different spectroscopy parameters were evaluated and optimal acquisition conditions were provided.Electron induced precipitation of lithium metal from LLZTO was observed.By exploring the influence factors of precipitation and combining transmission electron microscopy(TEM)and focused ion beam(FIB)experiments,the underlying mechanism of the phenomenon was revealed and previous controversy was resolved.The analysis method was also extended to other types of solid electrolytes,and this work provides a reference for future in-depth research on the structure-property relationship of solid electrolytes using AES.
基金This work was supported by the International Cooperation Projects of Sichuan Provincial Department of Science and Technology(No.2021YFH0126)Quzhou Science and Technology Bureau Project(No.2021D006)+2 种基金the Fundamental Research Funds for the Central Universities(No.A030202063008029)The China Postdoctoral Science Foundation(Nos.2021T140433,2020M683408)the Natural Science Foundation of Shaanxi Province(No.2021JQ-538).
文摘Polymer-based solid electrolytes have been extensively studied for solid-state lithium metal batteries to achieve high energy density and reliable security.But,its practical application is severely limited by low ionic conductivity and slow Li+transference.Herein,based on the“binary electrolytes”of poly(vinylidene fluoride-chlorotrifluoroethylene)(P(VDF-CTFE))and lithium salt(LiTFSI),a kind of eutectogel hybrid electrolytes(EHEs)with high Li+transference number was developed via tuning the spontaneous coupling of charge and vacated space generated by Li-cation diffusion utilizing the Li6.4La3Zr1.4Ta0.6O12(LLZTO)dopant.LLZTO doping promotes the dissociation of lithium salt,increases Li+carrier density,and boosts ion jumping and the coordination/decoupling reactions of Li+.As a result,the optimized EHEs-10%possess a high Li-transference number of 0.86 and a high Li+conductivity of 3.2×10–4 S·cm–1 at room temperature.Moreover,the prepared EHEs-10%composite solid electrolyte presents excellent lithiumphilic and compatibility,and can be tested stably for 1,200 h at 0.3 mA·cm–2 with assembled lithium symmetric batteries.Likewise,the EHEs-10%films match well with high-loading LiFePO4 and LiCoO2 cathodes(>10 mg·cm–2)and exhibit remarkable interface stability.Particularly,the LiFePO4//EHEs-10%//Li and LiCoO2//EHEs-10%//Li cells deliver high rate performance of 118 mAh·g–1 at 1 C and 93.7 mAh·g–1 at 2 C with coulombic efficiency of 99.3%and 98.1%,respectively.This work provides an in-depth understanding and new insights into our design for polymer electrolytes with fast Li+diffusion.
基金the financial support from the National Natural Science Foundation of China(No.21805147).
文摘The aggregation of inorganic particles with high mass ratio will form a heterogeneous electric field in the solid polymer electrolytes(SPEs),which is difficult to be compatible with lithium anode,leading to inadequate ionic conductivity.Herein,a facile spray drying method is adopted to increase the mass ratio of inorganic particles and solve the aggregation problems of fillers simultaneously.The polyvinylidene fluoride(PVDF)with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)covers the surface of each Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)granules during the nebulization process,then forming flat solid electrolytes via layer-by-layer deposition.Characterized by the atomic force microscope,the obtained solid electrolytes achieve a homogenous dispersion of Young’s modulus and surface electric field.As a result,the as-prepared SPEs present high tensile strength of 7.1 MPa,high ionic conductivity of 1.86×10^(−4)S·cm^(−1)at room temperature,and wide electrochemical window up to 5.0 V,demonstrating increased mechanical strength and uniform lithium-ion migration channels for SPEs.Thanks to the as-prepared SPEs,the lithiumsymmetrical cells show a highly stable Li plating/stripping cycling for over 1,000 h at 0.1 mA·cm^(−2).The corresponding Li/LCoO_(2)batteries also present good rate capability and excellent cyclic performance with capacity retention of 80%after 100 cycles at room temperature.
文摘NASICON型快离子导体Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)(LATP)具有较高的离子电导率、较宽的电化学窗口及良好的水和空气稳定性,但其界面接触性能差。石榴石型Li_(7)La_(3)Zr_(2)O_(12)(LLZO)锂离子电导率高、电化学窗口较宽且热稳定性好,但其立方相结构不稳定,影响其实际应用。采用溶液浇筑法,制备纯PVDF-LiTFSI电解质膜和以PVDF为基、3种不同质量比的Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)的固态电解质膜,并探讨纯PVDF-LiTFSI电解质膜和3种不同质量比的活性无机电解质填料对复合固态电解质离子电导率的影响。结果表明,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时,电解质膜的XRD图谱的衍射峰比纯PVDF-LiTFSI下降更为明显,电化学窗口为3.9 V左右,表现出更好的稳定性。在不同温度下分别测量其离子电导率发现,Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1时的电解质膜均高于纯PVDF-LiTFSI电解质膜和Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为2∶1和3∶1时的电解质膜。将其装配成电池后发现,0.1C下电池首次充放电比容量分别为90 m A·h/g和87 m A·h/g。以0.5C的电流循环25圈,放电比容量从57 mA·h/g衰减至51mA·h/g,容量保持率为99.7%。所以,以PVDF为基、Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)和Li_(1+x)Al_(x)Ti_(2-x)(PO_(4))_(3)质量比为1∶1的固态电解质膜有优良的倍率性能和循环稳定性能。
基金supported by the National Research Foundation of Korea (NRF) grant funded by the MSIT,Korea (No. 2018R1A5A1025224 and No. 2019R1A2C1084020)this research received funding support from a grant from the Korea Planning&Evaluation Institute of Industrial Technology (KEIT),funded by the MOTIE of Korea (No. 10077287)。
文摘Composite solid electrolytes(CSEs)have emerged as promising candidates for safe and high-energy–density solid-state lithium metal batteries(SSLMBs).However,concurrently achieving exceptional ionic conductivity and interface compatibility between the electrolyte and electrode presents a significant challenge in the development of high-performance CSEs for SSLMBs.To overcome these challenges,we present a method involving the in-situ polymerization of a monomer within a self-supported porous Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZT)to produce the CSE.The synergy of the continuous conductive LLZT network,well-organized polymer,and their interface can enhance the ionic conductivity of the CSE at room temperature.Furthermore,the in-situ polymerization process can also con-struct the integration and compatibility of the solid electrolyte–solid electrode interface.The synthesized CSE exhibited a high ionic conductivity of 1.117 mS cm^(-1),a significant lithium transference number of 0.627,and exhibited electrochemical stability up to 5.06 V vs.Li/Li+at 30℃.Moreover,the Li|CSE|LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cell delivered a discharge capacity of 105.1 mAh g^(-1) after 400 cycles at 0.5 C and 30℃,corresponding to a capacity retention of 61%.This methodology could be extended to a variety of ceramic,polymer electrolytes,or battery systems,thereby offering a viable strategy to improve the electrochemical properties of CSEs for high-energy–density SSLMBs.
基金supported by the National Natural Science Foundation of China (Nos.52203066,51973157,61904123)the Tianjin Natural Science Foundation (No.18JCQNJC02900)+3 种基金National Innovation and Entrepreneurship Training Program for College students (No.202310058007)Tianjin Municipal College Students’ Innovation and Entrepreneurship Training Program (No.202310058088)Science & Technology Development Fund of Tianjin Education Commission for Higher Education (No.2018KJ196)State Key Laboratory of Membrane and Membrane Separation,Tiangong University
文摘Satisfactory ionic conductivity,excellent mechanical stability,and high-temperature resistance are the prerequisites for the safe application of solid polymer electrolytes(SPEs)in all-solid-state lithium metal batteries(ASSLMBs).In this study,a novel poly(m-phenylene isophthalamide)(PMIA)-core/poly(ethylene oxide)(PEO)-shell nanofiber membrane and the functional Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)ceramic nanopar-ticle are simultaneously introduced into the PEO-based SPEs to prepare composite polymer electrolytes(CPEs).The core PMIA layer of composite nanofibers can greatly improve the mechanical strength and thermal stability of the CPEs,while the shell PEO layer can provide the 3D continuous transport channels for lithium ions.In addition,the introduction of functional LLZTO nanoparticle not only reduces the crys-tallinity of PEO,but also promotes the dissociation of lithium salts and releases more Li^(+)ions through its interaction with the Lewis acid-base of anions,thereby overall improving the transport of lithium ions.Consequently,the optimized CPEs present high ionic conductivity of 1.38×10^(−4)S/cm at 30℃,signifi-cantly improved mechanical strength(8.5 MPa),remarkable thermal stability(without obvious shrinkage at 150℃),and conspicuous Li dendrites blocking ability(>1800 h).The CPEs also both have good com-patibility and cyclic stability with LiFePO_(4)(>2000 cycles)and high-voltage LiNi_(0.8)Mn_(0.1)Co_(0.1)O_(2)(NMC811)(>500 cycles)cathodes.In addition,even at low temperature(40℃),the assembled LiFePO4/CPEs/Li bat-tery still can cycle stably.The novel design can provide an effective way to exploit high-performance solid-state electrolytes.
基金This study was financially supported by the National Natural Science Foundation of China(Nos.52171180,51802154,and 51971065)the National Science Fund for Distinguished Young Scholars(No.51625102)+3 种基金the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-07-E00028)the Fundamental Research Funds for the Central Universities(No.NG2022005)the Open Fund for Graduate Innovation Base in Nanjing University of Aeronautics and Astronautics(No.xcxjh20210612)partially supported by the Fundamental Research Funds for the Central Universities,NS2021043.
文摘Garnet-type solid-state batteries(SSBs)are considered to be one of the most promising candidates to realize next-generation lithium metal batteries with high energy density and safety.However,the dendrite-induced short-circuit and the poor interfacial contact impeded the practical application.Herein,interface engineering to achieve low interfacial resistance without high temperature calcination was developed,which Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)was simply coated with complex hydride(Li_(4)(BH_(4))_(3)I(3L1L))in various mass ratios n(Li_(4)(BH_(4))_(3)I)-(100−n)LLZTO(10≤n≤40).The interfacial conductivity increases by more than three orders of magnitude from 8.29×10^(−6)S·cm^(−1)to 1.10×10^(−2)S·cm^(−1).Symmetric Li cells exhibit a high critical current density(CCD)of 4.0 mA·cm^(−2) and an excellent cycling stability for 200 h at 4.0 mA·cm^(−2).SSBs with polymeric sulfur-polyacrylonitrile(SPAN)cathode achieve a high discharge capacity of 1149 mAh·g^(−1) with a capacity retention of 91%after 100 cycles(0.2 C).This attempt guides a simple yet efficient strategy for obtaining a stable Li/LLZTO interface,which would promote the development of solid-state batteries.
基金the National Key Research and Development Program Intergovernmental International Science and Technology Innovation Cooperation(No.2022YFE0109400)Leading Edge Technology of Jiangsu Province(Nos.BK20202008 and BK20220009)Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Despite the high energy density of lithium metal batteries(LMBs),their application in rechargeable batteries is still hampered due to insufficient safety.Here,we present a novel flame-retardant solid-state electrolyte based on polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)with nano SiO_(2)aerogel as an inert filler but Li_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(LLZTO)as an auxiliary component to enhance the ion conductivity.The introduction of SiO_(2)aerogels imparts the polymer electrolyte with exceptional thermal stability and flame retardancy.Simultaneously,the interaction between hydroxyl groups of SiO_(2)particles and PVDF-HFP creates a strong cross-linking structure,enhancing the mechanical strength and stability of the electrolyte.Furthermore,the presence of SiO_(2)aerogel and LLZTO facilitates the dissociation of lithium salts through Lewis acid-base interactions,resulting in a high ionic conductivity of 1.01×10^(−3)S·cm^(−1)and a wide electrochemical window of~5.0 V at room temperature for the prepared electrolytes.Remarkably,the assembled Li|Li cell demonstrates the excellent resistance to lithium dendrite and runs stablly for over 1500 h at a current density of 0.25 mA·cm^(−2).Thus,we prepare a pouch cell with high safety,which can work normally after short-circuiting under the external folding and cutting.
