Crystallization kinetics of metastable B-quartz solid solution as a desirable phase for the production of trans- parent lithium aluminosilicate （LAS） glass ceramics was investigated in the presence of Y203. Accordin...Crystallization kinetics of metastable B-quartz solid solution as a desirable phase for the production of trans- parent lithium aluminosilicate （LAS） glass ceramics was investigated in the presence of Y203. Accordingly, differential thermal analysis scans were performed thoroughly to study the mechanism of crystallization kinetics. The aim of this investigation is to discover the complicated mechanism of crystallization process in the presence of co-additives and ac- cordingly find a way for increasing the transparency of glass ceramics. It is shown that the bulk （3D） growth is intensively increased by the enhancement of Y203. Then again, reducing nucleation and increasing growth mechanisms were recog- nized for the LAS system in the presence of Y2O3. Results of the investigation illustrate that when co-additives are added to glasses, it is necessary to nucleate the optical component separately before the growth process.展开更多
The crystallinity of lithium aluminosilicate(LAS) glass after crystallization were studied at different temperatures by X-ray diffractometry and the crystallinity of the standard glass ceramic with known crystal and g...The crystallinity of lithium aluminosilicate(LAS) glass after crystallization were studied at different temperatures by X-ray diffractometry and the crystallinity of the standard glass ceramic with known crystal and glass phases was examined. The crystallization mechanism of LAS glass was analyzed by the crystallinity, with a formula relating the crystallinity (X) and temperature (T). The results show that the calculated crystallinity of LAS glass by XRD increases with the crystallization temperature, in the range of 40%?50%, which is close to the calculated ones of standard samples with spodumene quartz ratio of 40%?70%. The activation energy of LAS glass is different within different temperature ranges; nEc is 125.44 kJ/mol at 710?810 ℃ and nEc is 17.42 kJ/mol at 810?980 ℃, which indicates different crystallization mechanisms. It has been proved that the required energy for crystallization of glass in the lower temperature range includes the interfacial energy between glass and crystalline phase and the free energy difference of atoms in structures of glass and crystal, and in the higher temperature ranges only the interfacial energy between glass and crystalline phase is considered.展开更多
The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)cer...The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)ceramics.The effect of LDGC on the sintering,mechanical,and translucent properties of Y-TZP ceramics was investigated in the present study.The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100℃,which was much lower than the sintering temperature for pure Y-TZP.When sintered at 1100℃,the Y-TZP with 1 wt%LDGC reached a relative density of 95.45%,and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa-m12.Moreover,its translucency was also improved.While,the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia,which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains.The escaped yttrium atoms diffused into the intergranular glass phase.The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.展开更多
The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries(ASSLBs).Because of their advantages in safety,wor...The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries(ASSLBs).Because of their advantages in safety,working temperature,high energy density,and packaging,ASSLBs can develop an ideal energy storage system for modern electric vehicles(EVs).A solid electrolyte(SE)model must have an economical synthesis approach,exhibit electrochemical and chemical stability,high ionic conductivity,and low interfacial resistance.Owing to its highest conductivity of 17 mS·cm^(-1),and deformability,the sulfide-based Li_(7)P_(3)S_(11) solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs.Herein,we present a current glimpse of the progress of synthetic procedures,structural aspects,and ionic conductivity improvement strategies.Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques.The chemical stability of Li_(7)P_(3)S_(11) could be enhanced via oxide doping,and hard and soft acid/base(HSAB)concepts are also discussed.The issues to be undertaken for designing the ideal solid electrolytes,interfacial challenges,and high energy density have been discoursed.This review aims to provide a bird’s eye view of the recent development of Li_(7)P_(3)S_(11)-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density allsolid-state lithium batteries.展开更多
The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric com...The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric composition Li2O·2SiO2 (LS2). A group of samples was processed at 2.5 GPa, 4 GPa and 7.7 GPa at room temperature and a second group was crystallized under high pressure and high temperature. Large shifts of the binding energy toward higher energies were observed in the X-ray photoelectron spectroscopy spectra for samples of the first group after densification at 2.5 and 4 GPa. For samples processed at 7.7 Gpa, the major component of the binding energy for the Si 2p environment remained practically unchanged compared to the pristine sample but new components, with smaller intensities, appeared in the spectra, indicating the existence of distinct Q-species induced by high pressure. This behavior may be related to changes in the number of bridged and non-bridged oxygen atoms in the glass structure. The results for the second group of samples, crystallized under high pressure, showed evidences of three binding energies for the O atoms, one of them related to non-bridged and two of them to bridged O atoms.展开更多
文摘Crystallization kinetics of metastable B-quartz solid solution as a desirable phase for the production of trans- parent lithium aluminosilicate （LAS） glass ceramics was investigated in the presence of Y203. Accordingly, differential thermal analysis scans were performed thoroughly to study the mechanism of crystallization kinetics. The aim of this investigation is to discover the complicated mechanism of crystallization process in the presence of co-additives and ac- cordingly find a way for increasing the transparency of glass ceramics. It is shown that the bulk （3D） growth is intensively increased by the enhancement of Y203. Then again, reducing nucleation and increasing growth mechanisms were recog- nized for the LAS system in the presence of Y2O3. Results of the investigation illustrate that when co-additives are added to glasses, it is necessary to nucleate the optical component separately before the growth process.
基金Project(2003C11030) supported by the High Science & Technique Brainstorm of Zhejiang Province, China
文摘The crystallinity of lithium aluminosilicate(LAS) glass after crystallization were studied at different temperatures by X-ray diffractometry and the crystallinity of the standard glass ceramic with known crystal and glass phases was examined. The crystallization mechanism of LAS glass was analyzed by the crystallinity, with a formula relating the crystallinity (X) and temperature (T). The results show that the calculated crystallinity of LAS glass by XRD increases with the crystallization temperature, in the range of 40%?50%, which is close to the calculated ones of standard samples with spodumene quartz ratio of 40%?70%. The activation energy of LAS glass is different within different temperature ranges; nEc is 125.44 kJ/mol at 710?810 ℃ and nEc is 17.42 kJ/mol at 810?980 ℃, which indicates different crystallization mechanisms. It has been proved that the required energy for crystallization of glass in the lower temperature range includes the interfacial energy between glass and crystalline phase and the free energy difference of atoms in structures of glass and crystal, and in the higher temperature ranges only the interfacial energy between glass and crystalline phase is considered.
基金supported by the Shanghai Committee of Science and Technology,China(No.17441904100).
文摘The novel dental ceramics can be fabricated at lower temperatures when sol-gel derived lithium disilicate glass ceramics(LDGC)was used as an additive for yttria stabilized tetragonal zirconia polycrystalline(Y-TZP)ceramics.The effect of LDGC on the sintering,mechanical,and translucent properties of Y-TZP ceramics was investigated in the present study.The results showed that the LDGC additive effectively improved the densification of Y-TZP at 1100℃,which was much lower than the sintering temperature for pure Y-TZP.When sintered at 1100℃,the Y-TZP with 1 wt%LDGC reached a relative density of 95.45%,and prossessed a flexural strength of 482.4 MPa and a fracture toughness of 5.94 MPa-m12.Moreover,its translucency was also improved.While,the addition of LDGC could result in an escape of yttrium atoms from the grain lattice of zirconia,which induced the tetragonal-monoclinic transformation of zirconia and abnormal growth of monoclinic grains.The escaped yttrium atoms diffused into the intergranular glass phase.The results indicated that the novel Y-TZP-LDGC ceramics has a great potential to be used for all-ceramic restorations.
基金the National Natural Science Foundation of China(51772030,21203008,21975025)the Natural Science Foundation of Beijing(2172051)+1 种基金Beijing Outstanding Young Scientists Program(BJJWZYJH01201910007023)the State Key Laboratory funding by the project for Modification of Chemical Fibers and Polymer Materials,Donghou University.
文摘The development of an inorganic electrochemical stable solid-state electrolyte is essentially responsible for future state-of-the-art all-solid-state lithium batteries(ASSLBs).Because of their advantages in safety,working temperature,high energy density,and packaging,ASSLBs can develop an ideal energy storage system for modern electric vehicles(EVs).A solid electrolyte(SE)model must have an economical synthesis approach,exhibit electrochemical and chemical stability,high ionic conductivity,and low interfacial resistance.Owing to its highest conductivity of 17 mS·cm^(-1),and deformability,the sulfide-based Li_(7)P_(3)S_(11) solid electrolyte is a promising contender for the high-performance bulk type of ASSLBs.Herein,we present a current glimpse of the progress of synthetic procedures,structural aspects,and ionic conductivity improvement strategies.Structural elucidation and mechanistic approaches have been extensively discussed by using various characterization techniques.The chemical stability of Li_(7)P_(3)S_(11) could be enhanced via oxide doping,and hard and soft acid/base(HSAB)concepts are also discussed.The issues to be undertaken for designing the ideal solid electrolytes,interfacial challenges,and high energy density have been discoursed.This review aims to provide a bird’s eye view of the recent development of Li_(7)P_(3)S_(11)-based solid-state electrolyte applications and explore the strategies for designing new solid electrolytes with a target-oriented approach to enhance the efficiency of high energy density allsolid-state lithium batteries.
文摘The aim of this work was to investigate by X-ray photoelectron spectroscopy the effect of high pressure on the chemical environments of Si 2p, O 1s and Li 1s in lithium disilicate glass ceramic with stoichiometric composition Li2O·2SiO2 (LS2). A group of samples was processed at 2.5 GPa, 4 GPa and 7.7 GPa at room temperature and a second group was crystallized under high pressure and high temperature. Large shifts of the binding energy toward higher energies were observed in the X-ray photoelectron spectroscopy spectra for samples of the first group after densification at 2.5 and 4 GPa. For samples processed at 7.7 Gpa, the major component of the binding energy for the Si 2p environment remained practically unchanged compared to the pristine sample but new components, with smaller intensities, appeared in the spectra, indicating the existence of distinct Q-species induced by high pressure. This behavior may be related to changes in the number of bridged and non-bridged oxygen atoms in the glass structure. The results for the second group of samples, crystallized under high pressure, showed evidences of three binding energies for the O atoms, one of them related to non-bridged and two of them to bridged O atoms.
