By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders...By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders were dispersed with the terpineol as the dispersant through different methods such as ball milling and high-shear dispersing. Coagulation factor （CF） was used to mark the degree of agglomeration on the nano-scale GDC in this work. The effect of agglomeration on the densification behavior at different sintering temperatures was investigated. The studies indicated that agglomeration retarded the densification at the sintering stage. The powders with better dispersion exhibited a higher sintered density at the same temperature. After effective dispersion treatment, GDC could be fully densified at the sintering temperature of 1300 ℃. The densification temperature was significantly lower than those reported previously. The high sintering kinetics of the ceramics was obtained based on the agglomeration control.展开更多
A kind of novel ceria electrolyte was examined.Various trivalent oxides were added as co-dopants to Ce 0.8Gd 0.2O 1.9,and their effects on the conductivity of ceria electrolyte were discussed.It has been foun...A kind of novel ceria electrolyte was examined.Various trivalent oxides were added as co-dopants to Ce 0.8Gd 0.2O 1.9,and their effects on the conductivity of ceria electrolyte were discussed.It has been found that the co-dopant of trivalent oxides of Sm,Nd,La and Y improves the ionic conductivity notably.Furthermore,the fine original powders,co-dopant and higher sintering temperature may hasten the sintering.展开更多
Ceria-based electrolytes have been widely researched in intermediate-temperature solid oxide fuel cell （SOFC）, which might be operated at 500-600℃. Sintering behavior with lithium oxide as sintering additive and el...Ceria-based electrolytes have been widely researched in intermediate-temperature solid oxide fuel cell （SOFC）, which might be operated at 500-600℃. Sintering behavior with lithium oxide as sintering additive and electrical conductivity of gadolinia doped ceria （GdonCe0.902-σ, GDC10） electrolyte was studied in this paper by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical impedance spectroscopy （EIS）. As the results,, the fully dense GDC10 electrolytes are obtained at a low temperature of 800℃ with 2.5 mol% Li20 as sintering additive （called 5LiGDCS00）. During sintering process, lithium oxides adsorbed by around GDC10 surface help to sinter at 800~C and are kept at the grain boundary of GDC10 in the end. The fine grains of 100-400 nm and high electrical conductivity of 0.014 S/cm at 600~C in 5LiGDC800 were achieved, which contributed to the lower sintering temperature and enhanced grain boundary conductivity, respectively. Lithium, staying at grain boundary, reduces the depletion of oxygen vacancies in the space charge layers and increases the oxygen vacancy concentration in the grain boundary, which leads to improve the total electrical conductivity of 5LiGDC800.展开更多
基金Project supported by the Key Research Programof the National Natural Science Foundation (90610035)
文摘By synthesizing reactive powders via a self-sustaining combustion synthesis, the glycine-nitrate process, the gadolinium-doped celia （GDC） with the chemical formula Ce0.8Gd0.2O1.9 was prepared. The resultant powders were dispersed with the terpineol as the dispersant through different methods such as ball milling and high-shear dispersing. Coagulation factor （CF） was used to mark the degree of agglomeration on the nano-scale GDC in this work. The effect of agglomeration on the densification behavior at different sintering temperatures was investigated. The studies indicated that agglomeration retarded the densification at the sintering stage. The powders with better dispersion exhibited a higher sintered density at the same temperature. After effective dispersion treatment, GDC could be fully densified at the sintering temperature of 1300 ℃. The densification temperature was significantly lower than those reported previously. The high sintering kinetics of the ceramics was obtained based on the agglomeration control.
文摘A kind of novel ceria electrolyte was examined.Various trivalent oxides were added as co-dopants to Ce 0.8Gd 0.2O 1.9,and their effects on the conductivity of ceria electrolyte were discussed.It has been found that the co-dopant of trivalent oxides of Sm,Nd,La and Y improves the ionic conductivity notably.Furthermore,the fine original powders,co-dopant and higher sintering temperature may hasten the sintering.
基金supported by the National Natural Science Foundation of China (Grant No. 50730004)the Ministry of Science and Technology of the People’s Republic of China (No. 2009DFA6136)
文摘Ceria-based electrolytes have been widely researched in intermediate-temperature solid oxide fuel cell （SOFC）, which might be operated at 500-600℃. Sintering behavior with lithium oxide as sintering additive and electrical conductivity of gadolinia doped ceria （GdonCe0.902-σ, GDC10） electrolyte was studied in this paper by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical impedance spectroscopy （EIS）. As the results,, the fully dense GDC10 electrolytes are obtained at a low temperature of 800℃ with 2.5 mol% Li20 as sintering additive （called 5LiGDCS00）. During sintering process, lithium oxides adsorbed by around GDC10 surface help to sinter at 800~C and are kept at the grain boundary of GDC10 in the end. The fine grains of 100-400 nm and high electrical conductivity of 0.014 S/cm at 600~C in 5LiGDC800 were achieved, which contributed to the lower sintering temperature and enhanced grain boundary conductivity, respectively. Lithium, staying at grain boundary, reduces the depletion of oxygen vacancies in the space charge layers and increases the oxygen vacancy concentration in the grain boundary, which leads to improve the total electrical conductivity of 5LiGDC800.
基金supported by the National Basic Research Program of China (973 Program 2010CB732302+5 种基金 2012CB215500)the National High Technology Research and Development Program of China (863 Program 2011AA050704)the National Natural Science Foundation of China (21376238 21306189 51101146)~~
