Grain-boundary(GB) structures are commonly imaged as discrete atomic columns, yet the chemical modifications are gradual and extend into the adjacent lattices, notably the space charge, hence the two-dimensional defec...Grain-boundary(GB) structures are commonly imaged as discrete atomic columns, yet the chemical modifications are gradual and extend into the adjacent lattices, notably the space charge, hence the two-dimensional defects may also be treated as continuum changes to extended interfacial structure. This review presents a spatially-resolved analysis by electron energy-loss spectroscopy of the GB chemical structures in a series of SrTiO_3 bicrystals and a ceramic, using analytical electron microscopy of the pre-Cs-correction era. It has identified and separated a transient layer at the model Σ5 grain-boundaries(GBs) with characteristic chemical bonding, extending the continuum interfacial approach to redefine the GB chemical structure. This GB layer has evolved under segregation of iron dopant, starting from subtle changes in local bonds until a clear transition into a distinctive GB chemistry with substantially increased titanium concentration confined within the GB layer in 3-unit cells, heavily strained, and with less strontium. Similar segregated GB layer turns into a titania-based amorphous film in SrTiO_3 ceramic, hence reaching a more stable chemical structure in equilibrium with the intergranular Ti_2O_3 glass also. Space charge was not found by acceptor doping in both the strained Σ5 and amorphous GBs in SrTiO_3 owing to the native transient nature of the GB layer that facilitates the transitions induced by Fe segregation into novel chemical structures subject to local and global equilibria. These GB transitions may add a new dimension into the structure–property relationship of the electronic materials.展开更多
All-solid-state lithium batteries(ASSLBs)have advantages of safety and high energy density,and they are expected to become the next generation of energy storage devices.Sulfide-based solid-state electrolytes(SSEs)with...All-solid-state lithium batteries(ASSLBs)have advantages of safety and high energy density,and they are expected to become the next generation of energy storage devices.Sulfide-based solid-state electrolytes(SSEs)with high ionic conduc-tivity and low grain boundary resistance exhibit remarkable practical application.However,the space charge layer(SCL)eff ect and high interfacial resistance caused by a mismatch with the current commercial oxide cathodes restrict the develop-ment of sulfide SSEs and ASSLBs.This review summarizes the research progress on the SCL eff ect of sulfide SSEs and oxide cathodes,including the mechanism and direct evidence from high performance in-situ characterizations,as well as recent progress on the interfacial modification strategies to alleviate the SCL eff ect.This study provides future direction to stabilize the high performance sulfide-based solid electrolyte/oxide cathode interface for state-of-the-art ASSLBs and future all-SSE storage devices.展开更多
The development of lithium-ion solid electrolyte provides new ideas for solving the safety problems of secondary lithium-ion batteries(LIB) and, at the same time, the improvement of energy density. However, the conseq...The development of lithium-ion solid electrolyte provides new ideas for solving the safety problems of secondary lithium-ion batteries(LIB) and, at the same time, the improvement of energy density. However, the consequent solid-solid interfacial problems have become a typical bottleneck to the performance. It has been considered that the space charge layer(SCL) formed at the interface to balance the sharp electrochemical inherent difference of properties is one of the most important factors that affect the ion transportation along and across the interface. Its existence may hinder ion transportation and increase the interfacial impedance but may also help to provide a new percolation path for lithium ion and so to enhance the ion migration. However the mechanism of SPL formation and its regulation on ion transport is not very clear, so it has raised a lot of attention and interest from LIB researchers. The purpose of this article is to try to gain some knowledge of SCL and, at the same time to browse through the related research in recent years. Hopefully, it may help those interested in solid electrolyte development for all-solidstate lithium-ion batteries(ASSB) in the future.展开更多
Solid-state lithium metal batteries(SSLBs)contain various kinds of interfaces,among which the solid electrode|solid electrolyte(ED|SE)interface plays a decisive role in the battery's power density and cycling stab...Solid-state lithium metal batteries(SSLBs)contain various kinds of interfaces,among which the solid electrode|solid electrolyte(ED|SE)interface plays a decisive role in the battery's power density and cycling stability.However,it is still lack of comprehensive knowledge and understanding about various interfacial physical/chemical processes so far.Although tremendous efforts have been dedicated to investigate the origin of large interfacial resistance and sluggish charge(electron/ion)transfer process,many scientific and technological challenges still remain to be clarified.In this review,we detach and discuss the critical individual challenge,including charge transfer process,chemical and electrochemical instability,space charge layers,physical contact and mechanical instability.The fundamental concepts,individual effects on the charge transfer and potential solutions are summarized based on material's thermodynamics,electrode kinetics and mechanical effects.It is anticipated that future research should focus on quantitative analysis,modeling analysis and in-situ microstructure characterizations in order to obtain an efficient manipulation about the complex interfacial behaviors in all solid-state Li batteries.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.51532006)the Fund from Shanghai Municipal Science and Technology Commission(Grant No.16DZ2260600)+1 种基金the 111 Project of the Ministry of Educationthe Fund from the National Bureau of Foreign Experts(Project No.D16002)
文摘Grain-boundary(GB) structures are commonly imaged as discrete atomic columns, yet the chemical modifications are gradual and extend into the adjacent lattices, notably the space charge, hence the two-dimensional defects may also be treated as continuum changes to extended interfacial structure. This review presents a spatially-resolved analysis by electron energy-loss spectroscopy of the GB chemical structures in a series of SrTiO_3 bicrystals and a ceramic, using analytical electron microscopy of the pre-Cs-correction era. It has identified and separated a transient layer at the model Σ5 grain-boundaries(GBs) with characteristic chemical bonding, extending the continuum interfacial approach to redefine the GB chemical structure. This GB layer has evolved under segregation of iron dopant, starting from subtle changes in local bonds until a clear transition into a distinctive GB chemistry with substantially increased titanium concentration confined within the GB layer in 3-unit cells, heavily strained, and with less strontium. Similar segregated GB layer turns into a titania-based amorphous film in SrTiO_3 ceramic, hence reaching a more stable chemical structure in equilibrium with the intergranular Ti_2O_3 glass also. Space charge was not found by acceptor doping in both the strained Σ5 and amorphous GBs in SrTiO_3 owing to the native transient nature of the GB layer that facilitates the transitions induced by Fe segregation into novel chemical structures subject to local and global equilibria. These GB transitions may add a new dimension into the structure–property relationship of the electronic materials.
基金financially supported by National Natural Science Foundation of China(Nos.21575015,21203008,21975025,and 51772030)the Beijing Nature Science Foundation(No.2172051),the National Key Research and Develop-ment Program of China(No.2016YFB0100204)+1 种基金Beijing Outstand-ing Young Scientists Program(No.BJJWZYJH01201910007023)funded by State Key Laboratory for Modification of Chemi-cal Fibers and Polymer Materials,Donghua University.
文摘All-solid-state lithium batteries(ASSLBs)have advantages of safety and high energy density,and they are expected to become the next generation of energy storage devices.Sulfide-based solid-state electrolytes(SSEs)with high ionic conduc-tivity and low grain boundary resistance exhibit remarkable practical application.However,the space charge layer(SCL)eff ect and high interfacial resistance caused by a mismatch with the current commercial oxide cathodes restrict the develop-ment of sulfide SSEs and ASSLBs.This review summarizes the research progress on the SCL eff ect of sulfide SSEs and oxide cathodes,including the mechanism and direct evidence from high performance in-situ characterizations,as well as recent progress on the interfacial modification strategies to alleviate the SCL eff ect.This study provides future direction to stabilize the high performance sulfide-based solid electrolyte/oxide cathode interface for state-of-the-art ASSLBs and future all-SSE storage devices.
基金supported by the Special Guiding Program for Technology Innovation of Shaanxi Province (Grant No. 2022GF05-02)the National Natural Science Foundation of China (Grant No. 21971117)+7 种基金the Nankai University Central University Function Research Fund (Grant No.63186005)the Tianjin Rare Earth Key Laboratory of Materials and Application (Grant No. ZB19500202)the Open Fund of State Key Laboratory of Rare Earth Resources Utilization (Grant No. RERU2019001)the Project111 (Grant No. B18030)the Collaborative Innovation Project of BeijingTianjin-Hebei (Grant No. 19YFSLQY00030)the National Key R&D Program of China (Grant No. 2021YFA1202400)the Outstanding Youth of Tianjin Natural Science(Grant No. 20JCJQJC00130)the Key Project of Tianjin Natural Science Foundation (Grant No.20JCZDJC00650)
文摘The development of lithium-ion solid electrolyte provides new ideas for solving the safety problems of secondary lithium-ion batteries(LIB) and, at the same time, the improvement of energy density. However, the consequent solid-solid interfacial problems have become a typical bottleneck to the performance. It has been considered that the space charge layer(SCL) formed at the interface to balance the sharp electrochemical inherent difference of properties is one of the most important factors that affect the ion transportation along and across the interface. Its existence may hinder ion transportation and increase the interfacial impedance but may also help to provide a new percolation path for lithium ion and so to enhance the ion migration. However the mechanism of SPL formation and its regulation on ion transport is not very clear, so it has raised a lot of attention and interest from LIB researchers. The purpose of this article is to try to gain some knowledge of SCL and, at the same time to browse through the related research in recent years. Hopefully, it may help those interested in solid electrolyte development for all-solidstate lithium-ion batteries(ASSB) in the future.
基金financially supported by the National Key Research and Development Program of China(grant no.2018YFB0905400)the National Natural Science Foundation of China(21935009)。
文摘Solid-state lithium metal batteries(SSLBs)contain various kinds of interfaces,among which the solid electrode|solid electrolyte(ED|SE)interface plays a decisive role in the battery's power density and cycling stability.However,it is still lack of comprehensive knowledge and understanding about various interfacial physical/chemical processes so far.Although tremendous efforts have been dedicated to investigate the origin of large interfacial resistance and sluggish charge(electron/ion)transfer process,many scientific and technological challenges still remain to be clarified.In this review,we detach and discuss the critical individual challenge,including charge transfer process,chemical and electrochemical instability,space charge layers,physical contact and mechanical instability.The fundamental concepts,individual effects on the charge transfer and potential solutions are summarized based on material's thermodynamics,electrode kinetics and mechanical effects.It is anticipated that future research should focus on quantitative analysis,modeling analysis and in-situ microstructure characterizations in order to obtain an efficient manipulation about the complex interfacial behaviors in all solid-state Li batteries.
