A cone-shaped gadolinium doped ceria（Ce0.9Gd0.1O1.95,GDC） electrolyte cylinder with a thin wall was fabricated using slip cast-ing technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 c...A cone-shaped gadolinium doped ceria（Ce0.9Gd0.1O1.95,GDC） electrolyte cylinder with a thin wall was fabricated using slip cast-ing technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm,the length was 1.0 cm,and the thickness of the wall was 0.026 cm after sintering.Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process.A single solid oxide fuel cell（SOFC） was prepared with the cone-shaped electrolyte,NiO-GDC（70：30 wt.%） anode and Sm0.5Sr0.5CoO3（SSC） cathode.Its electrochemical performance（I-V curve） and electrochemical impedance spectroscopy（EIS） were studied with humidified hydrogen as the fuel and air as the oxidant.The maximum output power density was about 300 ？mW/cm2 at 700 oC.The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.展开更多
Slip casting and subsequent pressureless sintering(PLS)allow the preparation of complex-shaped and large-sized Ti3AlC2 components for many potential applications.The behaviors of the suspensions,green compacts,and sin...Slip casting and subsequent pressureless sintering(PLS)allow the preparation of complex-shaped and large-sized Ti3AlC2 components for many potential applications.The behaviors of the suspensions,green compacts,and sintered samples of Ti3AlC2 were studied in this paper.The optimized condition of 1 wt%of arabic gum as dispersant at pH=10 results in a Ti3AlC2 suspension for slip casting Ti3AlC2 green compacts without macro defects or cracks.The sintering temperature and Al4C3 embedding powder are found to dominate the properties of the sintered Ti3AlC2 samples.The Ti3AlC2 sample sintered at 1450℃for 1.5 h with Al4C3 embedding powder reaches the best properties,namely 95.3%relative density,hardness of 4.18 GPa,thermal conductivity of 29.11W·m-1·K-1,and electrical resistivity of 0.39μΩ·m.The findings in this work may pave the way for the application of MAX phases with large size and complex shape.展开更多
The conditions of ZnO-Al2O3 aqueous suspensions and slip casting were optimized to obtain dense green compacts and further to obtain high density ZnO-Al2O3 ceramic composites.The Zeta potential of raw powders was meas...The conditions of ZnO-Al2O3 aqueous suspensions and slip casting were optimized to obtain dense green compacts and further to obtain high density ZnO-Al2O3 ceramic composites.The Zeta potential of raw powders was measured.ZnO and Al2O3 powders have lower Zeta potential than-45 mV commonly at pH 8-10.3 with polyacrylic acid(PAA)added.The influence of pH and the mass fraction of the additives on the stability and fluidity of the suspensions added with PAA and polyethylene glycol(PEG) was investigated by experiments of viscosity and sedimentation.The suspensions have the lowest viscosity and the best stability at pH 9 with 0.2%PAA(mass fraction).The maximum density of green compacts is 66.6%of theoretical density(TD)with compacting and homogeneous green particles.An ultrahigh density sintered compact(>99.6%TD)could be obtained after pressureless sintering at 1 400℃for 2 h.展开更多
基金Project supported by the National "863" Program of China (2007AA05Z136)the National Natural Science Foundation of China (51172113)+1 种基金the Taishan Scholar Overseas Distinguished Professorship Program from the Shandong Province Government,the Shandong Natural Science Foundation for Distinguished Young Scholars (JQ201118)the Research Foundation for Talented Scholars of Qingdao University of Science and Technology (400-0022374)
文摘A cone-shaped gadolinium doped ceria（Ce0.9Gd0.1O1.95,GDC） electrolyte cylinder with a thin wall was fabricated using slip cast-ing technique.The diameter of the larger open end of the cone-shaped cylinder was 0.85 cm,the length was 1.0 cm,and the thickness of the wall was 0.026 cm after sintering.Both the electrolyte and electrode powders were fabricated by using a glycine-nitrate process.A single solid oxide fuel cell（SOFC） was prepared with the cone-shaped electrolyte,NiO-GDC（70：30 wt.%） anode and Sm0.5Sr0.5CoO3（SSC） cathode.Its electrochemical performance（I-V curve） and electrochemical impedance spectroscopy（EIS） were studied with humidified hydrogen as the fuel and air as the oxidant.The maximum output power density was about 300 ？mW/cm2 at 700 oC.The EIS results showed that the dominant loss of the SOFC was from the ohmic resistance of the electrolyte.
基金financially supported by National Natural Science Foundation of China (51731004, 51671054, 51501038)Natural Science Foundation of Jiangsu Province (BK20181285)“the Fundamental Research Funds for the Central Universities” in China (2242018K40108, 2242018K40109)
文摘Slip casting and subsequent pressureless sintering(PLS)allow the preparation of complex-shaped and large-sized Ti3AlC2 components for many potential applications.The behaviors of the suspensions,green compacts,and sintered samples of Ti3AlC2 were studied in this paper.The optimized condition of 1 wt%of arabic gum as dispersant at pH=10 results in a Ti3AlC2 suspension for slip casting Ti3AlC2 green compacts without macro defects or cracks.The sintering temperature and Al4C3 embedding powder are found to dominate the properties of the sintered Ti3AlC2 samples.The Ti3AlC2 sample sintered at 1450℃for 1.5 h with Al4C3 embedding powder reaches the best properties,namely 95.3%relative density,hardness of 4.18 GPa,thermal conductivity of 29.11W·m-1·K-1,and electrical resistivity of 0.39μΩ·m.The findings in this work may pave the way for the application of MAX phases with large size and complex shape.
基金Project(50477044)supported by the National Natural Science Foundation of China
文摘The conditions of ZnO-Al2O3 aqueous suspensions and slip casting were optimized to obtain dense green compacts and further to obtain high density ZnO-Al2O3 ceramic composites.The Zeta potential of raw powders was measured.ZnO and Al2O3 powders have lower Zeta potential than-45 mV commonly at pH 8-10.3 with polyacrylic acid(PAA)added.The influence of pH and the mass fraction of the additives on the stability and fluidity of the suspensions added with PAA and polyethylene glycol(PEG) was investigated by experiments of viscosity and sedimentation.The suspensions have the lowest viscosity and the best stability at pH 9 with 0.2%PAA(mass fraction).The maximum density of green compacts is 66.6%of theoretical density(TD)with compacting and homogeneous green particles.An ultrahigh density sintered compact(>99.6%TD)could be obtained after pressureless sintering at 1 400℃for 2 h.
