Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis metho...Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.展开更多
Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode...Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode materials with remarkable structural stability and high ionic conductivity are one of the most promising candidates for sodium storage electrodes.Nevertheless,the relatively low electronic conductivity of these materials makes them display poor electrochemical performance,significantly limiting their practical application.In recent years,the strategies of enhancing the inherent conductivity of NASICON-based cathode materials have been extensively studied through coating the active material with a conductive carbon layer,reducing the size of the cathode material,combining the cathode material with various carbon materials,and doping elements in the bulk phase.In this paper,we review the recent progress in the development of NASICON-based cathode materials for SIBs in terms of their synthesis,characterization,functional mechanisms,and performance validation/optimization.The advantages and disadvantages of such SIB cathode materials are analyzed,and the relationship between electrode structures and electrochemical performance as well as the strategies for enhancing their electrical conductivity and structural stability is highlighted.Some technical challenges of NASICON-based cathode materials with respect to SIB performance are analyzed,and several future research directions are also proposed for overcoming the challenges toward practical applications.展开更多
Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high c...Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high cost and relatively low energy density restrict their further practical application,which can be tailored by widening the operating voltages with earth-abundant elements such as Mn.Here,we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity.The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode(76.6%capacity retention over 5,000 cycles at 20 C)for SIBs,which exhibits high reversible capacity(113.1 mAh·g^−1 at 0.5 C)with relatively low volume change(7.6%).Importantly,its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated,and the full-cell configuration is demonstrated.This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.展开更多
Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state bat...Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state batteries,Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)represents a promising candidate as it features high chemical stability against air exposure and a high Na^(+)conductivity.NZSP pellets were usually calcined at a high temperature,and the high volatility of Na and P elements easily led to the formation of impurity phase.In this work,the effects of calcination temperature and stoichiometry on the phase purity and ionic conductivity of the NZSP electrolyte were studied.At an elevated sintering temperature,the NZSP electrolyte showed a high ionic conductivity owing to decreased porosity,and the highest ionic conductivity at 30℃was observed to be 2.75×10^(-5)S·cm^(-1)with an activation energy of 0.41 eV.For the stoichiometry,the introduction of 5 mol%excessive P results in formation of more Na_(3)PO_(4) and glass-like phase at the grain boundary,which caused the blurred grain boundary and reduced grain barrier,and effectively suppressed Na dendrite growth,then accounted for improved cycling performance of a Na‖Na symmetric cell.Our work provided insights on reasonable design and preparation of NZSP electrolyte towards practical realization of solid-state Na-metal batteries.展开更多
Sodium ion batteries (SIBs) are alternatives to lithium ion batteries (LIBs), and offer some significant benefits such as cost reduction and a lower environmental impact;however, to compete with LIBs, further research...Sodium ion batteries (SIBs) are alternatives to lithium ion batteries (LIBs), and offer some significant benefits such as cost reduction and a lower environmental impact;however, to compete with LIBs, further research is required to improve the performance of SIBs. In this study, an orthorhombic Na super ionic conductor structural Fe_(2)(MoO_(4))_(3) nanosheet with amorphous-crystalline core-shell alignment was synthesized using a facile low-temperature water-vapor-assisted solid-state reaction and applied as a cathode material for SIBs. The obtained material has a well-defined three-dimensional stacking structure, and exhibits a high specific capacity of 87.8 mAh·g^(−1) at a current density of 1 C = 91 mA·g^(−1) after 1,000 cycles, which is due to the considerable contribution of extra surface-related reaction such as the pseudo-capacitive process. This material shows significantly improved cycling and rated behavior as well as enhanced performance under high- and low-temperature conditions, as compared to the same materials prepared by the conventional high-temperature solid-state reaction. This enhancement is explained by the unique morphology in combination with the improved kinetics of the electrochemical reaction due to its lower charge transfer resistance and higher sodium ion conductivity.展开更多
基金Supported by the Major International Collaborative Project of the National Natural Science Foundation of China(No. 60574096)the Distinguished Young Scholars(No.60625301).
文摘Na superionic conductor（NASICON） nanoparticles were synthesized by a modified sol-gel method and sintered at a temperature range of 800--1000℃. The performance of the samples was characterized by the analysis methods of X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR）, and transmission electron microscopy（TEM） as well as conductivity measurement. Compared with those sintered at other temperatures, the NASICON material sintered at 900 ℃ had the best crystalline structure and higher conductivity.
基金the National Natural Science Foundation of China(Nos.51602193,21601122,21905169)the Belt and Road Initiatives International Cooperation Project(No.20640770300)+5 种基金the Shanghai“Chen Guang”Project(16CG63)the Shanghai Local Universities Capacity Building Project of Science and Technology Innovation Action Program(21010501700)the Shanghai Sailing Program(No.18YF1408600)the Fundamental Research Funds for the Central Universities(WD1817002)the EPSRC(EP/R023581/1,EP/P009050/1,EP/V027433/1)the Royal Society(RGS/R1/211080).
文摘Sodium-ion batteries(SIBs)have developed rapidly owing to the high natural abundance,wide distribution,and low cost of sodium.Among the various materials used in SIBs,sodium superion conductor(NASICON)-based electrode materials with remarkable structural stability and high ionic conductivity are one of the most promising candidates for sodium storage electrodes.Nevertheless,the relatively low electronic conductivity of these materials makes them display poor electrochemical performance,significantly limiting their practical application.In recent years,the strategies of enhancing the inherent conductivity of NASICON-based cathode materials have been extensively studied through coating the active material with a conductive carbon layer,reducing the size of the cathode material,combining the cathode material with various carbon materials,and doping elements in the bulk phase.In this paper,we review the recent progress in the development of NASICON-based cathode materials for SIBs in terms of their synthesis,characterization,functional mechanisms,and performance validation/optimization.The advantages and disadvantages of such SIB cathode materials are analyzed,and the relationship between electrode structures and electrochemical performance as well as the strategies for enhancing their electrical conductivity and structural stability is highlighted.Some technical challenges of NASICON-based cathode materials with respect to SIB performance are analyzed,and several future research directions are also proposed for overcoming the challenges toward practical applications.
基金supported by the National Natural Science Foundation of China(61071040)Leading Academic Discipline Project of Shanghai Municipal Education Commission,China(J50102)Research and Innovation Project of Shanghai Municipal Education Commission,China~~
基金This work was supported by the National Natural Science Foundation of China(Nos.51872334 and 51932011)the Innovation-Driven Project of Central South University(No.2020CX024).
文摘Sodium superionic conductor(NASICON)-type compounds have been regarded as promising cathodes for sodium-ion batteries(SIBs)due to their favorable ionic conductivity and robust structural stability.However,their high cost and relatively low energy density restrict their further practical application,which can be tailored by widening the operating voltages with earth-abundant elements such as Mn.Here,we propose a rational strategy of infusing Mn element in NASICON frameworks with sufficiently mobile sodium ions that enhances the redox voltage and ionic migration activity.The optimized structure of Na3.5Mn0.5V1.5(PO4)3/C is achieved and investigated systematically to be a durable cathode(76.6%capacity retention over 5,000 cycles at 20 C)for SIBs,which exhibits high reversible capacity(113.1 mAh·g^−1 at 0.5 C)with relatively low volume change(7.6%).Importantly,its high-areal-loading and temperature-resistant sodium ion storage properties are evaluated,and the full-cell configuration is demonstrated.This work indicates that this Na3.5Mn0.5V1.5(PO4)3/C composite could be a promising cathode candidate for SIBs.
基金financially supported by the National Natural Science Foundation of China(Nos.51902238 and 52172234)the Fundamental Research Funds for the Central Universities(Nos.2020IVA069,2020IVB043 and 2021IVA020B)
文摘Rechargeable batteries based on solid-state electrolytes are of great interest and importance for the next-generation energy storage due to their high energy output and improved safety.For building the solid-state batteries,Na_(3)Zr_(2)Si_(2)PO_(12)(NZSP)represents a promising candidate as it features high chemical stability against air exposure and a high Na^(+)conductivity.NZSP pellets were usually calcined at a high temperature,and the high volatility of Na and P elements easily led to the formation of impurity phase.In this work,the effects of calcination temperature and stoichiometry on the phase purity and ionic conductivity of the NZSP electrolyte were studied.At an elevated sintering temperature,the NZSP electrolyte showed a high ionic conductivity owing to decreased porosity,and the highest ionic conductivity at 30℃was observed to be 2.75×10^(-5)S·cm^(-1)with an activation energy of 0.41 eV.For the stoichiometry,the introduction of 5 mol%excessive P results in formation of more Na_(3)PO_(4) and glass-like phase at the grain boundary,which caused the blurred grain boundary and reduced grain barrier,and effectively suppressed Na dendrite growth,then accounted for improved cycling performance of a Na‖Na symmetric cell.Our work provided insights on reasonable design and preparation of NZSP electrolyte towards practical realization of solid-state Na-metal batteries.
基金This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (NRF-2017R1A2B3011967)This work was supported by the Engineering Research Center through National Research Foundation of Korea (NRF)funded by the Korean Government (MSIT) (NRF-2018R1A5A1025224).
文摘Sodium ion batteries (SIBs) are alternatives to lithium ion batteries (LIBs), and offer some significant benefits such as cost reduction and a lower environmental impact;however, to compete with LIBs, further research is required to improve the performance of SIBs. In this study, an orthorhombic Na super ionic conductor structural Fe_(2)(MoO_(4))_(3) nanosheet with amorphous-crystalline core-shell alignment was synthesized using a facile low-temperature water-vapor-assisted solid-state reaction and applied as a cathode material for SIBs. The obtained material has a well-defined three-dimensional stacking structure, and exhibits a high specific capacity of 87.8 mAh·g^(−1) at a current density of 1 C = 91 mA·g^(−1) after 1,000 cycles, which is due to the considerable contribution of extra surface-related reaction such as the pseudo-capacitive process. This material shows significantly improved cycling and rated behavior as well as enhanced performance under high- and low-temperature conditions, as compared to the same materials prepared by the conventional high-temperature solid-state reaction. This enhancement is explained by the unique morphology in combination with the improved kinetics of the electrochemical reaction due to its lower charge transfer resistance and higher sodium ion conductivity.
