The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specro...The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3 can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3-, and the Cr-spinel solidsolution [CaCr2O4] precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3 grew epitaxially.展开更多
A series of 20Li_(2)O-30V_(2)O_(5)-(50-x)SiO_(2)-xB_(2)O_(3)(mol.%)(x=10,20,30,40)glasses were prepared by the traditional melt-quenching synthesis.The amorphous nature of the glasses was determined by XRD,DSC and TEM...A series of 20Li_(2)O-30V_(2)O_(5)-(50-x)SiO_(2)-xB_(2)O_(3)(mol.%)(x=10,20,30,40)glasses were prepared by the traditional melt-quenching synthesis.The amorphous nature of the glasses was determined by XRD,DSC and TEM investigations.FTIR measurement revealed the functional group of obtained glasses.And EDS results confirmed the presence and uniform distribution of elements in the glasses.20Li_(2)O-30V_(2)O_(5)-40SiO_(2)-10B_(2)O_(3)(LVSB10)sample with the highest V^(4+) ratio exhibited the best cycling capacity.In order to further improve cycling stability of LVSB10 sample,ball milling was employed to reduce the particle size.The ball milled LVSB10 sample(LVSB10-b)showed an improved first discharge capacity,cycling stability and rate capacity.EIS measurements showed that ball milling can effectively decrease charge transfer impedance and facilitate Li^(+) ion diffusion.This work provides a new way to explore a new type of cathode materials for lithium ion batteries.展开更多
The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with B...The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.展开更多
文摘The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3 can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3-, and the Cr-spinel solidsolution [CaCr2O4] precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3 grew epitaxially.
基金financially supported by Shenzhen Basic Research Project Funds(JCYJ20170817161127616).
文摘A series of 20Li_(2)O-30V_(2)O_(5)-(50-x)SiO_(2)-xB_(2)O_(3)(mol.%)(x=10,20,30,40)glasses were prepared by the traditional melt-quenching synthesis.The amorphous nature of the glasses was determined by XRD,DSC and TEM investigations.FTIR measurement revealed the functional group of obtained glasses.And EDS results confirmed the presence and uniform distribution of elements in the glasses.20Li_(2)O-30V_(2)O_(5)-40SiO_(2)-10B_(2)O_(3)(LVSB10)sample with the highest V^(4+) ratio exhibited the best cycling capacity.In order to further improve cycling stability of LVSB10 sample,ball milling was employed to reduce the particle size.The ball milled LVSB10 sample(LVSB10-b)showed an improved first discharge capacity,cycling stability and rate capacity.EIS measurements showed that ball milling can effectively decrease charge transfer impedance and facilitate Li^(+) ion diffusion.This work provides a new way to explore a new type of cathode materials for lithium ion batteries.
基金Funded by the National Natural Science Foundation of China(No.52472012)Opening Project of State Silica-Based Materials Laboratory of Anhui Province(No.2022KF11)the Research and Development of Glass Powder for Laser Sealing and Its Sealing Technology(No.K24556)。
文摘The low-melting glass of Bi2O_(3)-B2O_(3)-SiO_(2)(BiBSi)system was used for the first time for laser sealing of vacuum glazing.Under the condition of constant boron content,how the structure and properties vary with Bi/Si ratio in low-melting glass was investigated.In addition,the relationships between laser power,low-melting glass solder with different Bi/Si ratios and laser sealing shear strength were revealed.The results show that a decrease in the Bi/Si ratio can cause a contraction of the glass network of the low-melting glass,leading to an increase of its characteristic temperature and a decrease of its coefficient of thermal expansion.During laser sealing,the copper ions in the low-melting glass play an endothermic role.A change in the Bi/Si ratio will affect the valence state transition of the copper ions in the low-melting glass.The absorbance of the low-melting glass does not follow the expected correlation with the Bi/Si ratio,but shows a linear correlation with the content of divalent copper ions.The greater the concentration of divalent copper ions,the greater the absorbance of the low-melting glass,and the lower the laser power required for laser sealing.The shear strength of the low melting glass solder after laser sealing was tested,and it was found that the maximum shear strength of Z1 glass sample was the highest up to 2.67 MPa.
