β-β″-Al2O3precursor powder was successfully prepared by a solid-phase sintering method with Li2CO3, Na2CO3 （as the sources of Li20 and Na20, respectively） and β″-Al2O3 powder as the raw materials. The precursor...β-β″-Al2O3precursor powder was successfully prepared by a solid-phase sintering method with Li2CO3, Na2CO3 （as the sources of Li20 and Na20, respectively） and β″-Al2O3 powder as the raw materials. The precursor was characterized by X-ray diffraction （XRD） and scan- ning electron microscope （SEM）. The results indicate that the amount of Na20 in the raw materials has a great effect on the formation of β″-Al2O3 in the β-β″-Al2O3 precursor. When Na20 content is 10 wt%, the content of β″-Al2O3 phase reaches the maximum value of 86.24 wt% in the precursor. The β-β″-Al2O3 ceramic was prepared from β-β″-Al2O3 precursor powder by isostatic pressing and burying sintering process. The conductive property of the β-β″-Al2O3 ceramic was examined by electrochemical impedance spectroscopy （EIS） method, and the density was measured by the Archimedes method. The results reveal that when 10 wt% Na20 was added, the sample exhibits the best performance with the lowest resistivity of 4.51.cm and the highest density of 3.25 g.cm 3. A solid electrolyte battery of PtlSnQ, Na2SnO3113 β-β″-Al2O3 Na CrO2, Cr2lO3 Pt was assembled by the β-β″-Al2O3 electrolyte tube to measure the open potential of the resulting battery, and the formation free energy of sodium stannate was calculated In the temperature range of 1273-773 K, the relationship between formation free energy of sodiumstannate and temperature was generated as follows：△GNa2SnO3 0=-1040.83＋0.2221T±7.54.展开更多
A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2, CO2| Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell lI: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt. (Na,K-β/β...A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2, CO2| Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell lI: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt. (Na,K-β/β'-AI2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region of phase equilibrium for Na, K-β/β'-AI2O3 material. The relationship between CO2 sensor voltage response and phase equilibrium of solid electrolyte Na, K-β/β-AI2O3 is discussed in this paper.展开更多
A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in te...A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in temperature range of 912—1223 K:E=652.1— 0.2092 T+2.3(mV).Using this equation and cited free energies of formation of NaCrO_2, Cr_2O_3 and SnO_2,the molar free energy of formation of Na_2 SnO_3 may be calculated by ΔG°=-1050+0.2544 T±5.4(kJ mol^(-1)).展开更多
基金financially supported by the National Natural Science Foundation of China (No.51234009)
文摘β-β″-Al2O3precursor powder was successfully prepared by a solid-phase sintering method with Li2CO3, Na2CO3 （as the sources of Li20 and Na20, respectively） and β″-Al2O3 powder as the raw materials. The precursor was characterized by X-ray diffraction （XRD） and scan- ning electron microscope （SEM）. The results indicate that the amount of Na20 in the raw materials has a great effect on the formation of β″-Al2O3 in the β-β″-Al2O3 precursor. When Na20 content is 10 wt%, the content of β″-Al2O3 phase reaches the maximum value of 86.24 wt% in the precursor. The β-β″-Al2O3 ceramic was prepared from β-β″-Al2O3 precursor powder by isostatic pressing and burying sintering process. The conductive property of the β-β″-Al2O3 ceramic was examined by electrochemical impedance spectroscopy （EIS） method, and the density was measured by the Archimedes method. The results reveal that when 10 wt% Na20 was added, the sample exhibits the best performance with the lowest resistivity of 4.51.cm and the highest density of 3.25 g.cm 3. A solid electrolyte battery of PtlSnQ, Na2SnO3113 β-β″-Al2O3 Na CrO2, Cr2lO3 Pt was assembled by the β-β″-Al2O3 electrolyte tube to measure the open potential of the resulting battery, and the formation free energy of sodium stannate was calculated In the temperature range of 1273-773 K, the relationship between formation free energy of sodiumstannate and temperature was generated as follows：△GNa2SnO3 0=-1040.83＋0.2221T±7.54.
文摘A type of CO2 sensor based on oxygen concentration cell was designed as following: Cell I: Pt | Au, O2, CO2| Na2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt or Cell lI: Pt|Au, O2, CO2|K2CO3(Au)|NKBA(Au)|YSZ|O2, CO2|Pt. (Na,K-β/β'-AI2O3 is named by NKBA). The sensor signal is consistent with the Nernstian slope within the region of phase equilibrium for Na, K-β/β'-AI2O3 material. The relationship between CO2 sensor voltage response and phase equilibrium of solid electrolyte Na, K-β/β-AI2O3 is discussed in this paper.
文摘A β”/β-Al_2O_3 solid electrolyte was prepared and used in a Na conentration galvanic cell: (-)O_2(in Ar),SnO_2,Na_2SnO_3|β"/β-Al_2O_3]NaCrO_2,Cr_2O_3,O_2(in Ar)(+).The emf measurements were carried out in temperature range of 912—1223 K:E=652.1— 0.2092 T+2.3(mV).Using this equation and cited free energies of formation of NaCrO_2, Cr_2O_3 and SnO_2,the molar free energy of formation of Na_2 SnO_3 may be calculated by ΔG°=-1050+0.2544 T±5.4(kJ mol^(-1)).
