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 13.007A. 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
Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and high-safety.However,the inevitable volatilization of lithium compounds during si...Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and high-safety.However,the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state electrolytes.Herein,the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte(Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZT))through the reversible manipulating of Li_(2)O atmosphere.Li_(2)ZrO_(3)is used as mother powder additive,which reacts with Li_(2)O in sintering atmosphere and forms Li_(6)Zr_(2)O_(7).Li_(2)ZrO_(3)/Li_(6)Zr_(2)O_(7)buffer pair manipulates the sintering Li_(2)O atmosphere,which is vital for LLZT,within the Li_(2)O partial pressure range corresponding to Li_(2)ZrO_(3)and Li_(6)Zr_(2)O_(7).Furthermore,the reversibility mechanism of buffer pair for Li_(2)O absorption and release is revealed.The obtained LLZT exhibits a relative density of over 96%and an ionic conductivity exceeding 7×10^(−4)S·cm^(−1)with no abnormal grain growth.The symmetric cell demonstrates an excellent lithium dendrite suppressing ability(stable cycling at a current density of 0.3 mA·cm^(−2)for over 1000 h).Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process,which reduces the dependence of LLZT on the Li_(2)O atmosphere,making it conducive to large-scale preparation of electrolyte ceramics.展开更多
All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,th...All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of ASSBs.This review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission mechanism.Meanwhile,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable performance.Furthermore,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO electrolytes.Following the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.展开更多
This paper describes the solid-state production of a unique yellowish-grey microwave dielectric ceramic,Ca_(3)Fe_(2)Ge_(3)O_(12)(CFG).Rietveld refinement demonstrated that CFG corresponds to a cubic system(space group...This paper describes the solid-state production of a unique yellowish-grey microwave dielectric ceramic,Ca_(3)Fe_(2)Ge_(3)O_(12)(CFG).Rietveld refinement demonstrated that CFG corresponds to a cubic system(space group 230:Ia 3 d).The relative density of the ceramic initially increased and then decreased with the sintering temperature,reaching a maximum of 96.92%at 1330℃.According to scanning electron mi-croscopy and energy-dispersive spectroscopy results,the CFG ceramic grains are spherical and consistent in size;furthermore,they have distinct grain boundaries and a uniform distribution of the four con-stituent elements.The CFG ceramic has a superior crystal structure and a high crystallinity,according to transmission electron microscopy.Raman spectroscopy revealed that the Q×f value of the ceramic and the full width at half maximum of the Raman peak are negatively correlated.The ceramic possesses the best overall dielectric characteristics after sintering at 1330℃for 4 h:ε_(r)=10.31,Q×f=82636 GHz,andτ_(f)=-45.66×10^(-6)℃^(-1),showing that it is a promising candidate for use in mobile devices.展开更多
Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stabil...Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stability.To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity,a series of TaeCe co-doping cubic Li_(6.4)La_(3)Zr_(1.4-x)Ta_(0.6)Ce_(x)O_(12)(LLZTCO,x=,0.02,0.04,0.06,0.08,0.10,0.20,0.30)electrolytes were successfully synthesized through conventional solid-phase method.The Ta^(5+)doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase.The Ce^(4+)with a larger ionic radius is introduced into the lattice to widen the Lit migration bottleneck size,which significantly increased the ionic conductivity to 1.05×10^(-3)S/cm.It also shows excellent stability to lithium metal by the optimization of Lit transport channel.Li||LLZTCO||Li symmetric cells can cycle stably for more than 6000 h at a current density of 0.1 mA/cm^(2)without any surface modifications.The commercialization potential of LLZTCO samples in all solid-state lithium batteries(ASSLBs)is confirmed by the prepared LiFePO_(4)||LLZTCO||Li cells with a capacity retention rate of 98%after 100 cycles at 0.5C.This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.展开更多
All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal ...All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state batteries.In order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid electrolytes.In this perspective,we review several methods reported to grow single crystals of garnet-type electrolytes.Pros and cons of different growth methods are discussed.Furthermore,we introduce some case studies on electrochemical properties of garnet-type single crystals.In addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.展开更多
Solid polymer electrolytes(SPEs), such as polyethylene oxide(PEO), are characteristic of good flexibility and excellent processability, but they suffer from low ionic conductivity and small Li+transference number at a...Solid polymer electrolytes(SPEs), such as polyethylene oxide(PEO), are characteristic of good flexibility and excellent processability, but they suffer from low ionic conductivity and small Li+transference number at ambient temperature. Inorganic solid electrolytes(ISEs), garnet-type Li7La3Zr2O12 and its derivatives(LLZO-based) in particular, possess high ionic conductivity at room temperature, wide electrochemical stability window, large Li+transference number as well as good stability against Li metal anode.Nevertheless, lithium dendrites growth, interfacial contact issue and brittle nature of LLZO-based ceramic electrolytes prevent their practical applications. In response to these shortcomings, LLZO-based/polymer solid composite electrolytes(SCEs), taking complementary advantages of two kinds of electrolytes, and thus simultaneously improving the electrode wettability, ionic conductivity and mechanical strength, have been made to develop high-performance SCEs in recent years. Herein, the intrinsic properties and research progress of LLZO-based/polymer SCEs, including LLZO-based/PEO SCEs(LLZO-based/PEO SCEs with uniform dispersion of LLZO-based fillers and LLZO-based/PEO layered SCEs) and LLZO-based/novel polymers SCEs, are summarized. Besides, comprehensive updates on their applications in solid-state batteries are also presented. Finally, challenges and perspectives of LLZO-based/polymer SCEs for advanced allsolid-state lithium batteries(ASSLBs) are suggested. This review paper aims to provide systematic research progress of LLZO-based/polymer SCEs, to allow for more efficient and target-oriented research on improving LLZO-based/polymer SCEs.展开更多
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 13.007A. 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 Research and Development Program of China(No.2022YFB3807700)the National Natural Science Foundation of China(Nos.U20A20248 and U1930208)+1 种基金the Key-Area Research and Development Program of Guangdong Province(No.2020B090919001)the Shanghai Engineering Research Center of Inorganic Energy Materials and Electric Power Sources(No.18DZ2280800).
文摘Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and high-safety.However,the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state electrolytes.Herein,the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte(Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZT))through the reversible manipulating of Li_(2)O atmosphere.Li_(2)ZrO_(3)is used as mother powder additive,which reacts with Li_(2)O in sintering atmosphere and forms Li_(6)Zr_(2)O_(7).Li_(2)ZrO_(3)/Li_(6)Zr_(2)O_(7)buffer pair manipulates the sintering Li_(2)O atmosphere,which is vital for LLZT,within the Li_(2)O partial pressure range corresponding to Li_(2)ZrO_(3)and Li_(6)Zr_(2)O_(7).Furthermore,the reversibility mechanism of buffer pair for Li_(2)O absorption and release is revealed.The obtained LLZT exhibits a relative density of over 96%and an ionic conductivity exceeding 7×10^(−4)S·cm^(−1)with no abnormal grain growth.The symmetric cell demonstrates an excellent lithium dendrite suppressing ability(stable cycling at a current density of 0.3 mA·cm^(−2)for over 1000 h).Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process,which reduces the dependence of LLZT on the Li_(2)O atmosphere,making it conducive to large-scale preparation of electrolyte ceramics.
基金financially supported by the National Natural Science Foundation of China (Nos. 22025507 and 21931012)the Key Research Program of Frontier Sciences, CAS (No. ZDBS-LY-SLH020)Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202010)。
文摘All-solid-state batteries(ASSBs) hold great promise for next-generation energy storage technologies owing to their advantage in different aspects such as energy density,safety,and wide temperature tolerance.However,the use of solid-state electrolytes(SSEs) instead of liquid ones meanwhile brings serious concerns related to the point-to-point contact between SSEs and electrodes,which is known to result in high interface resistance and inhomogeneous distribution of charges during the Li^(+)plating/stripping process,eventually leading to a premature failure of ASSBs.This review focuses on the garnet-type SSEs in the formula of Li_(7)La_(3)Zr_(2)O_(12)(LLZO),and discusses the structure-performance relationship of this ceramic electrolyte in detail to achieve a clear understanding of its Li^(+)transmission mechanism.Meanwhile,the challenges of cubic phase LLZO(c-LLZO) for their application in solidstate batteries(SSBs) are demonstrated by the Li/LLZO interface,which features the importance of Li metal wettability and dendrite suppression for sustainable performance.Furthermore,this review summarizes the recent research strategies to combat these contact issues at the Li/LLZO interface,highlighting the essential role played by surface modification of LLZO electrolytes.Following the obtained insights,perspectives for future research on LLZO to accelerate its potential development of SSBs in commercialized applications are also provided.
基金supported by Natural Science Foundation of China(Grant Nos.61761015,11664008)Natural Science Foundation of Guangxi(Grant No 2018GXNSFFA050001)the High Level Innovation Team and Outstanding Scholar Program of Guangxi Institutes.
文摘This paper describes the solid-state production of a unique yellowish-grey microwave dielectric ceramic,Ca_(3)Fe_(2)Ge_(3)O_(12)(CFG).Rietveld refinement demonstrated that CFG corresponds to a cubic system(space group 230:Ia 3 d).The relative density of the ceramic initially increased and then decreased with the sintering temperature,reaching a maximum of 96.92%at 1330℃.According to scanning electron mi-croscopy and energy-dispersive spectroscopy results,the CFG ceramic grains are spherical and consistent in size;furthermore,they have distinct grain boundaries and a uniform distribution of the four con-stituent elements.The CFG ceramic has a superior crystal structure and a high crystallinity,according to transmission electron microscopy.Raman spectroscopy revealed that the Q×f value of the ceramic and the full width at half maximum of the Raman peak are negatively correlated.The ceramic possesses the best overall dielectric characteristics after sintering at 1330℃for 4 h:ε_(r)=10.31,Q×f=82636 GHz,andτ_(f)=-45.66×10^(-6)℃^(-1),showing that it is a promising candidate for use in mobile devices.
基金the National Natural Science Foundation of China(Grant No.52102123)Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC2008,and Grant No.2023NSFSC0442)the China Postdoctoral Science Foundation(2022M710619).
文摘Garnet-type Li_(7)La_(3)Zr_(2)O_(12)(LLZO)is one of the most promising solid-state electrolytes(SSEs).However,the application of LLZO is limited by structural instability,low ionic conductivity,and poor lithium stability.To obtain a garnet-type solid electrolyte with a stable structure and high ionic conductivity,a series of TaeCe co-doping cubic Li_(6.4)La_(3)Zr_(1.4-x)Ta_(0.6)Ce_(x)O_(12)(LLZTCO,x=,0.02,0.04,0.06,0.08,0.10,0.20,0.30)electrolytes were successfully synthesized through conventional solid-phase method.The Ta^(5+)doping can introduce more lithium vacancies and effectively maintain the stability of the cubic phase.The Ce^(4+)with a larger ionic radius is introduced into the lattice to widen the Lit migration bottleneck size,which significantly increased the ionic conductivity to 1.05×10^(-3)S/cm.It also shows excellent stability to lithium metal by the optimization of Lit transport channel.Li||LLZTCO||Li symmetric cells can cycle stably for more than 6000 h at a current density of 0.1 mA/cm^(2)without any surface modifications.The commercialization potential of LLZTCO samples in all solid-state lithium batteries(ASSLBs)is confirmed by the prepared LiFePO_(4)||LLZTCO||Li cells with a capacity retention rate of 98%after 100 cycles at 0.5C.This new co-doping method presents a practical solution for the realization of high-performance ASSLBs.
基金This work was supported by the start-up funds from the University of California,Riverside.The authors thank Dr.Yutao Li from the University of Texas at Austin for helpful discussion.
文摘All-solid-state batteries have attracted much attention due to their improved safety and higher energy density as compared to the conventional batteries.Owing to the excellent chemical stability against lithium metal and relatively high ionic conductivity at room-temperature,garnet-type fast lithium ion conductors with three-dimensional lithium ion transport channels are promising solid electrolytes for all-solid-state batteries.In order to better understand the intrinsic lithium-ion transport mechanisms and prevent lithium dendrite formation,it is desired to investigate single-crystal solid electrolytes.In this perspective,we review several methods reported to grow single crystals of garnet-type electrolytes.Pros and cons of different growth methods are discussed.Furthermore,we introduce some case studies on electrochemical properties of garnet-type single crystals.In addition,we provide some perspectives about potential research directions of single-crystal solid electrolytes for all-solid-state batteries.
基金the National Natural Science Foundation of China(Grant No.21875071)the National Natural Science Foundation of China-Hong Kong Research Grant Council(NSFC-RGC)Joint Research Scheme(Grant No.21661162002 and N_HKUST601/16)the Guangzhou Scientific and Technological Planning Project(Grant No.201704030061)。
文摘Solid polymer electrolytes(SPEs), such as polyethylene oxide(PEO), are characteristic of good flexibility and excellent processability, but they suffer from low ionic conductivity and small Li+transference number at ambient temperature. Inorganic solid electrolytes(ISEs), garnet-type Li7La3Zr2O12 and its derivatives(LLZO-based) in particular, possess high ionic conductivity at room temperature, wide electrochemical stability window, large Li+transference number as well as good stability against Li metal anode.Nevertheless, lithium dendrites growth, interfacial contact issue and brittle nature of LLZO-based ceramic electrolytes prevent their practical applications. In response to these shortcomings, LLZO-based/polymer solid composite electrolytes(SCEs), taking complementary advantages of two kinds of electrolytes, and thus simultaneously improving the electrode wettability, ionic conductivity and mechanical strength, have been made to develop high-performance SCEs in recent years. Herein, the intrinsic properties and research progress of LLZO-based/polymer SCEs, including LLZO-based/PEO SCEs(LLZO-based/PEO SCEs with uniform dispersion of LLZO-based fillers and LLZO-based/PEO layered SCEs) and LLZO-based/novel polymers SCEs, are summarized. Besides, comprehensive updates on their applications in solid-state batteries are also presented. Finally, challenges and perspectives of LLZO-based/polymer SCEs for advanced allsolid-state lithium batteries(ASSLBs) are suggested. This review paper aims to provide systematic research progress of LLZO-based/polymer SCEs, to allow for more efficient and target-oriented research on improving LLZO-based/polymer SCEs.
