Poly(ethylene oxide)(PEO)and Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)-based composite polymer electrolytes(CPEs)are considered one of the most promising solid electrolyte systems.However,agglomeration of LLZTO w...Poly(ethylene oxide)(PEO)and Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)-based composite polymer electrolytes(CPEs)are considered one of the most promising solid electrolyte systems.However,agglomeration of LLZTO within PEO and lack of Li^(+)channels result in poor electrochemical properties.Herein,a functional supramolecular combination(CD-TFSI)consisting of activeβ-cyclodextrin(CD)supramolecular with self-assembled LiTFSI salt is selected as an interface modifier to coat LLZTO fillers.Benefiting from vast H-bonds formed betweenβ-CD and PEO matrix and/or LLZTO,homogeneous dispersion and tight interface contact are obtained.Moreover,^(6)Li NMR spectra confirm a new Li^(+)transmission pathway from PEO matrix to LLZTO ceramic then to PEO matrix in the as-prepared PEO/LLZTO@CD-TFSI CPEs due to the typical cavity structure ofβ-CD.As a proof,the conductivity is increased from 5.3×10^(-4)S cm^(-1)to 8.7×10^(-4)S cm^(-1)at 60℃,the Li^(+)transference number is enhanced from 0.38 to 0.48,and the electrochemical stability window is extended to 5.1 V versus Li/Li^(+).Li‖LiFePO_(4)CR2032 coin full cells and pouch cells prove the practical application of the as-prepared PEO/LLZTO@CD-TFSI CPEs.This work offers a new strategy of interface modifying LLZTO fillers with functional supramolecular combination to optimize PEO/LLZTO CPEs for solid lithium batteries.展开更多
The inferior ionic conductivity of composite polymer electrolytes(CPEs)caused by grain boundary impedance is one of the critical issues.Adjustable ion transport channels at the molecular level can improve ionic conduc...The inferior ionic conductivity of composite polymer electrolytes(CPEs)caused by grain boundary impedance is one of the critical issues.Adjustable ion transport channels at the molecular level can improve ionic conductivity and lithium-ion transference number.Herein,UIO-66-NSO_(2)CF_(3)LiLi_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(UIOLiTF-LLZTO)ionic conductor derived from metal-organic frameworks(MOFs)was designed by a covalent grafted strategy of trifluoromethylsulfonyl(TF)group on UIOLiTF and a doping process of LLZTO,showing two new lithium-ion transfer channels driven by molecular coordinationdoping engineering.The first channel along UIOLiTF-UIOLiTF was constructed due to the existence of the TF group on UIOLiTF.The second channel along UIOLiTF-LLZTO was constructed due to the direct nanometer contact interface between the opened channel of UIOLiTF and LLZTO.Then TF group acts as“claws”to capture and transfer lithium-ion along the different channels,facilitating improving ionic conductivity and reducing grain boundary impedance.Benefiting from the molecular coordination-doping engineering,UIOLiTF-LLZTO exhibits high ionic conductivity of 9.86×10^(-4)S cm^(-1),a large lithium-ion transference number of 0.79,and a wide electrochemical window of 5.35 V.Meanwhile,all-solid-state Li|UIOLiTF-LLZTO|LiFePO4 batteries show a high specific capacity of 164.5 mAh g^(-1)and 155.6 mAh g^(-1)at 0.2 C and 0.5 C,respectively.Therefore,UIOLiTF-LLZTO demonstrates the way towards the development of MOFs-based CPEs for all-solid-state lithium batteries with high performance.展开更多
High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface...High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle performance.Herein,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis method.As an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal cracking.Moreover,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 cathode.As a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C.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
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
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
基金the financial support of the National Natural Science Foundation of China(Nos.21773167,51972220)the National Key Research and Development Program of China(No.2021YFE0107200)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.20KJA480003)the Key R&D Project funded by Department of Science and Technology of Jiangsu Province(No.BE2020003)
文摘Poly(ethylene oxide)(PEO)and Li_(6.75)La_(3)Zr_(1.75)Ta_(0.25)O_(12)(LLZTO)-based composite polymer electrolytes(CPEs)are considered one of the most promising solid electrolyte systems.However,agglomeration of LLZTO within PEO and lack of Li^(+)channels result in poor electrochemical properties.Herein,a functional supramolecular combination(CD-TFSI)consisting of activeβ-cyclodextrin(CD)supramolecular with self-assembled LiTFSI salt is selected as an interface modifier to coat LLZTO fillers.Benefiting from vast H-bonds formed betweenβ-CD and PEO matrix and/or LLZTO,homogeneous dispersion and tight interface contact are obtained.Moreover,^(6)Li NMR spectra confirm a new Li^(+)transmission pathway from PEO matrix to LLZTO ceramic then to PEO matrix in the as-prepared PEO/LLZTO@CD-TFSI CPEs due to the typical cavity structure ofβ-CD.As a proof,the conductivity is increased from 5.3×10^(-4)S cm^(-1)to 8.7×10^(-4)S cm^(-1)at 60℃,the Li^(+)transference number is enhanced from 0.38 to 0.48,and the electrochemical stability window is extended to 5.1 V versus Li/Li^(+).Li‖LiFePO_(4)CR2032 coin full cells and pouch cells prove the practical application of the as-prepared PEO/LLZTO@CD-TFSI CPEs.This work offers a new strategy of interface modifying LLZTO fillers with functional supramolecular combination to optimize PEO/LLZTO CPEs for solid lithium batteries.
基金the National Natural Science Foundation of China(No.52002227)Postdoctoral Research Foundation of China(2022M721971)+1 种基金National Natural Science Foundation of China(No.51872173)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents,and Key Laboratory of Photochemical Conversion and Optoelectronic Materials,TIPC,CAS.
文摘The inferior ionic conductivity of composite polymer electrolytes(CPEs)caused by grain boundary impedance is one of the critical issues.Adjustable ion transport channels at the molecular level can improve ionic conductivity and lithium-ion transference number.Herein,UIO-66-NSO_(2)CF_(3)LiLi_(6.4)La_(3)Zr_(1.4)Ta_(0.6)O_(12)(UIOLiTF-LLZTO)ionic conductor derived from metal-organic frameworks(MOFs)was designed by a covalent grafted strategy of trifluoromethylsulfonyl(TF)group on UIOLiTF and a doping process of LLZTO,showing two new lithium-ion transfer channels driven by molecular coordinationdoping engineering.The first channel along UIOLiTF-UIOLiTF was constructed due to the existence of the TF group on UIOLiTF.The second channel along UIOLiTF-LLZTO was constructed due to the direct nanometer contact interface between the opened channel of UIOLiTF and LLZTO.Then TF group acts as“claws”to capture and transfer lithium-ion along the different channels,facilitating improving ionic conductivity and reducing grain boundary impedance.Benefiting from the molecular coordination-doping engineering,UIOLiTF-LLZTO exhibits high ionic conductivity of 9.86×10^(-4)S cm^(-1),a large lithium-ion transference number of 0.79,and a wide electrochemical window of 5.35 V.Meanwhile,all-solid-state Li|UIOLiTF-LLZTO|LiFePO4 batteries show a high specific capacity of 164.5 mAh g^(-1)and 155.6 mAh g^(-1)at 0.2 C and 0.5 C,respectively.Therefore,UIOLiTF-LLZTO demonstrates the way towards the development of MOFs-based CPEs for all-solid-state lithium batteries with high performance.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2503900)the National Natural Science Foundation of China(Grant No.52372203)+1 种基金the National Natural Science Foundation of China(Grant No.52202259)the Shandong Province Natural Science Foundation(ZR2022QE093).
文摘High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle performance.Herein,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis method.As an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal cracking.Moreover,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 cathode.As a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C.
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.
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.
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.
