Various solid electrolytes,such as sulfides(10^-3-10^-2 S cm^-1)and oxides(10^-4–10^-3 S cm^-1)are explored and developed to solve the safety problems in commercial Li-ion batteries using liquid flammable electrolyte...Various solid electrolytes,such as sulfides(10^-3-10^-2 S cm^-1)and oxides(10^-4–10^-3 S cm^-1)are explored and developed to solve the safety problems in commercial Li-ion batteries using liquid flammable electrolytes.Metallic Li anode is required for pursuing high power density(>300 Wh kg^-1)for solid-state batteries[1,2].展开更多
The synthesis and transport properties of the Li6La3BiSnO1212 solid electrolyte by a solid-state reaction were reported. The condition to synthesize the Li6La3BiSnO1212 is 785 °C for 36 h in air. The refined latt...The synthesis and transport properties of the Li6La3BiSnO1212 solid electrolyte by a solid-state reaction were reported. The condition to synthesize the Li6La3BiSnO1212 is 785 °C for 36 h in air. The refined lattice constant of Li6La3 BiSnO1212 is 13.007 ?. Qualitative phase analysis by X-ray powder diffraction patterns combined with the Rietveld method reveals garnet type compounds as major phases. The Li-ion conductivity of the prepared Li6La3BiSnO12 is 0.85×10-4 S/cm at 22 °C, which is comparable with that of the Li5La3Bi2O12. The Li6La3BiSnO1212 compounds are chemically stable against Li CoO2 which is widely used as cathode material up to 700 °C but not against the Li Mn2O4 if the temperature is higher than 550 °C. The Li6La3 BiSnO1212 exhibits higher chemical stability than Li5La3Bi2O12, which is due to Sn substitution for Bi.展开更多
Cubic phase Li7La3Zr2O12(LLZO),a member of the Li–Garnet family,is a promising solid electrolyte and has been widely studied in recent years.However,LLZO samples prepared via conventional ambient air sintering report...Cubic phase Li7La3Zr2O12(LLZO),a member of the Li–Garnet family,is a promising solid electrolyte and has been widely studied in recent years.However,LLZO samples prepared via conventional ambient air sintering reported in the published literature often contain large grains with lower than desired(<94%)relative density.In this study,a non-contact method of co-firing with mother powder method is proposed to prepare high-quality Ta-doped LLZO–MgO composite ceramics.By sintering at 1150℃for 5 h,the ceramics can reach relative density of 98.2%,conductivity of 5.17×10^-4 S cm^-1 at 25℃and fracture strength of 150 MPa.The sintered samples have uniform fine-grained microstructure and high critical current densities of 0.75–0.95 mA cm-2 at room temperature in Li–Li symmetry cell with Au modification.In addition,systematic sintering experiments and characterizations are conducted to explore the function of MgO in inhibiting the Ta-LLZO grain growth and its existing form inside the composite ceramics.展开更多
石榴石固体电解质由于其高的离子电导率,对锂金属稳定等优点成为了下一代高性能锂电池的重要研究方向之一。但锂金属负极界面浸润性与锂枝晶问题限制了其应用。本文通过简单的液相沉积结合高温烧结的方法,在石榴石固体电解质片表面构建...石榴石固体电解质由于其高的离子电导率,对锂金属稳定等优点成为了下一代高性能锂电池的重要研究方向之一。但锂金属负极界面浸润性与锂枝晶问题限制了其应用。本文通过简单的液相沉积结合高温烧结的方法,在石榴石固体电解质片表面构建了一层稳定的硼酸三锂(Li_(3)BO_(3))修饰层。研究表明,Li_(3)BO_(3)修饰层可以有效改善石榴石固体电解质与锂金属负极界面接触,促进锂的均匀沉积/溶出,从而抑制锂枝晶生长,提高界面稳定性。Li_(3)BO_(3)修饰后石榴石电解质片与锂金属之间紧密结合,Li/石榴石界面阻抗由修饰前的1780Ω·cm2降低至58Ω·cm^(2)。得益于界面接触的改善,Li_(3)BO_(3)修饰后的LLZTO电解质组装的对称电池可以在0.1 m·cm^(-2)的电流密度下稳定工作超过700 h。而未修饰的对称电池在0.05 m A·cm^(-2)的电流密度下短时间工作即出现微短路现象。展开更多
Rechargeable Li metal batteries using Li metal anodes have attracted worldwide interest because of their high energy density. The critical barriers limiting their commercial application include uncontrolled dendritic ...Rechargeable Li metal batteries using Li metal anodes have attracted worldwide interest because of their high energy density. The critical barriers limiting their commercial application include uncontrolled dendritic Li growth and the unstable Li-electrolyte interface. Considerable efforts have been directed towards solving these problems, e.g., modifying the electrolyte, creating artificial interfacial layers for the Li metal, and constructing three-dimensional structures for the Li metal. However, stabilizing the Li metal interface remains challenging because of the highly reactive nature of the Li metal. In this study, we utilize a Li-ion conducting hybrid film comprising a garnet-type ion conductor and a poly（ethylene oxide）-based polymer electrolyte as a protective layer to stabilize the Li-electrolyte interface and mitigate the growth of Li dendrites. The hybrid ion-conducting layer can block Li dendrites from proliferating and accommodate Li volume expansion because of its robust mechanical properties. Moreover, the ion-conducting layer allows Li deposition only underneath it, rather than on the surface, functioning as a permanent protective layer to ensure the stability of the Li metal over a long cycling life. The dendrite-inhibiting effect of the ion-conducting protective layer is visually evidenced by in situ microscopy using planar batteries. The protective Li metal anode exhibits excellent cycling stability and low voltage hysteresis （-15 mV at 0.2 mA-cm-2） for a cycle life as long as 1,000 h. It also shows a high Coulombic efficiency （-99.5%） in a full cell against a LiFePO4 cathode, exhibiting promise for application in Li metal batteries. Our results imply that the ion-conducting protective layer markedly improves the metal anode, yielding safe, long-life, and high-energy-density batteries.展开更多
Rechargeable lithium-oxygen （Li-O2） batteries have received intensive research interest due to its ultrahigh energy density, while its cycle stability is still hindered by the high reactivity of the Li anode with ox...Rechargeable lithium-oxygen （Li-O2） batteries have received intensive research interest due to its ultrahigh energy density, while its cycle stability is still hindered by the high reactivity of the Li anode with oxygen and moisture. To alleviate the corrosion of the metallic lithium anodes for achieving a stable Li-O2 battery, and as a proof-of-concept experiment, a distinctive hybrid electrolyte system with an organic/ceramic/organic electrolyte （OCOE） architecture is designed. Importantl~ the cycle number of Li-O2 batteries with OCOE is significantly improved compared with batteries with an organic electrolyte （OE）. This might be attributed to the effective suppression of the lithium anode corrosion caused by the OE degradation and the crossover of oxygen from the cathode. We consider that our facile, low-cost, and highly effective lithium protection strategy presents a new avenue to address the daunting corrosion problem of lithium metal anodes in Li-O2 batteries. In addition, the proposed strategy can be easily extended to other metal-O2 battery systems, such as Na-O2 batteries.展开更多
基金financially supported by Ganfeng Lithium Co., Ltd.
文摘Various solid electrolytes,such as sulfides(10^-3-10^-2 S cm^-1)and oxides(10^-4–10^-3 S cm^-1)are explored and developed to solve the safety problems in commercial Li-ion batteries using liquid flammable electrolytes.Metallic Li anode is required for pursuing high power density(>300 Wh kg^-1)for solid-state batteries[1,2].
基金Project(51372278)supported by the National Natural Science Foundation of ChinaProject(2010RS4015)supported by the Natural Science Foundation of Hunan Province,China+1 种基金Project(2014ejing004)supported by the Hunan Intellectual Property Bureau,ChinaProject(CSUZC2014020)supported by the Open-End Fund for the Valuable and Precision Instruments of Central South University,China
文摘The synthesis and transport properties of the Li6La3BiSnO1212 solid electrolyte by a solid-state reaction were reported. The condition to synthesize the Li6La3BiSnO1212 is 785 °C for 36 h in air. The refined lattice constant of Li6La3 BiSnO1212 is 13.007 ?. Qualitative phase analysis by X-ray powder diffraction patterns combined with the Rietveld method reveals garnet type compounds as major phases. The Li-ion conductivity of the prepared Li6La3BiSnO12 is 0.85×10-4 S/cm at 22 °C, which is comparable with that of the Li5La3Bi2O12. The Li6La3BiSnO1212 compounds are chemically stable against Li CoO2 which is widely used as cathode material up to 700 °C but not against the Li Mn2O4 if the temperature is higher than 550 °C. The Li6La3 BiSnO1212 exhibits higher chemical stability than Li5La3Bi2O12, which is due to Sn substitution for Bi.
基金financially supported by the National Key R&D Program of China under Grant No.2018YFB0905400,Corning Incorporatedthe National Natural Science Foundation of China under Grant No.51772315,No.51432010
文摘Cubic phase Li7La3Zr2O12(LLZO),a member of the Li–Garnet family,is a promising solid electrolyte and has been widely studied in recent years.However,LLZO samples prepared via conventional ambient air sintering reported in the published literature often contain large grains with lower than desired(<94%)relative density.In this study,a non-contact method of co-firing with mother powder method is proposed to prepare high-quality Ta-doped LLZO–MgO composite ceramics.By sintering at 1150℃for 5 h,the ceramics can reach relative density of 98.2%,conductivity of 5.17×10^-4 S cm^-1 at 25℃and fracture strength of 150 MPa.The sintered samples have uniform fine-grained microstructure and high critical current densities of 0.75–0.95 mA cm-2 at room temperature in Li–Li symmetry cell with Au modification.In addition,systematic sintering experiments and characterizations are conducted to explore the function of MgO in inhibiting the Ta-LLZO grain growth and its existing form inside the composite ceramics.
文摘石榴石固体电解质由于其高的离子电导率,对锂金属稳定等优点成为了下一代高性能锂电池的重要研究方向之一。但锂金属负极界面浸润性与锂枝晶问题限制了其应用。本文通过简单的液相沉积结合高温烧结的方法,在石榴石固体电解质片表面构建了一层稳定的硼酸三锂(Li_(3)BO_(3))修饰层。研究表明,Li_(3)BO_(3)修饰层可以有效改善石榴石固体电解质与锂金属负极界面接触,促进锂的均匀沉积/溶出,从而抑制锂枝晶生长,提高界面稳定性。Li_(3)BO_(3)修饰后石榴石电解质片与锂金属之间紧密结合,Li/石榴石界面阻抗由修饰前的1780Ω·cm2降低至58Ω·cm^(2)。得益于界面接触的改善,Li_(3)BO_(3)修饰后的LLZTO电解质组装的对称电池可以在0.1 m·cm^(-2)的电流密度下稳定工作超过700 h。而未修饰的对称电池在0.05 m A·cm^(-2)的电流密度下短时间工作即出现微短路现象。
文摘Rechargeable Li metal batteries using Li metal anodes have attracted worldwide interest because of their high energy density. The critical barriers limiting their commercial application include uncontrolled dendritic Li growth and the unstable Li-electrolyte interface. Considerable efforts have been directed towards solving these problems, e.g., modifying the electrolyte, creating artificial interfacial layers for the Li metal, and constructing three-dimensional structures for the Li metal. However, stabilizing the Li metal interface remains challenging because of the highly reactive nature of the Li metal. In this study, we utilize a Li-ion conducting hybrid film comprising a garnet-type ion conductor and a poly（ethylene oxide）-based polymer electrolyte as a protective layer to stabilize the Li-electrolyte interface and mitigate the growth of Li dendrites. The hybrid ion-conducting layer can block Li dendrites from proliferating and accommodate Li volume expansion because of its robust mechanical properties. Moreover, the ion-conducting layer allows Li deposition only underneath it, rather than on the surface, functioning as a permanent protective layer to ensure the stability of the Li metal over a long cycling life. The dendrite-inhibiting effect of the ion-conducting protective layer is visually evidenced by in situ microscopy using planar batteries. The protective Li metal anode exhibits excellent cycling stability and low voltage hysteresis （-15 mV at 0.2 mA-cm-2） for a cycle life as long as 1,000 h. It also shows a high Coulombic efficiency （-99.5%） in a full cell against a LiFePO4 cathode, exhibiting promise for application in Li metal batteries. Our results imply that the ion-conducting protective layer markedly improves the metal anode, yielding safe, long-life, and high-energy-density batteries.
文摘Rechargeable lithium-oxygen （Li-O2） batteries have received intensive research interest due to its ultrahigh energy density, while its cycle stability is still hindered by the high reactivity of the Li anode with oxygen and moisture. To alleviate the corrosion of the metallic lithium anodes for achieving a stable Li-O2 battery, and as a proof-of-concept experiment, a distinctive hybrid electrolyte system with an organic/ceramic/organic electrolyte （OCOE） architecture is designed. Importantl~ the cycle number of Li-O2 batteries with OCOE is significantly improved compared with batteries with an organic electrolyte （OE）. This might be attributed to the effective suppression of the lithium anode corrosion caused by the OE degradation and the crossover of oxygen from the cathode. We consider that our facile, low-cost, and highly effective lithium protection strategy presents a new avenue to address the daunting corrosion problem of lithium metal anodes in Li-O2 batteries. In addition, the proposed strategy can be easily extended to other metal-O2 battery systems, such as Na-O2 batteries.
