Synthesis and Characterization of Cobalt Doped with Yttria-Stabilized Zirconia Electrolytes

2017 ◽  
Vol 888 ◽  
pp. 151-156 ◽  
Author(s):  
Johar Banjuraizah ◽  
Tinesha Selvaraj ◽  
Zainal Arifin Ahmad
Keyword(s):  
Crystal Structure ◽  
Ionic Conductivity ◽  
Operating Temperature ◽  
Yttria Stabilized Zirconia ◽  
Synthesis And Characterization ◽  
Stabilized Zirconia ◽  
Co Doping ◽  
Higher Temperature ◽  
Sintering Behaviour

Effect of Cobalt doped 8YSZ on the ionic conductivity. SOFCs mostly operate at higher temperature. By substitute with dopants, it can reduce the operating temperature and costs. In this experiment, cobalt (1, 2 and 3 mol%) mixed with 8YSZ and sintered at 1550 °C, hold for two hours. Crystal structure, microstructure, sintering behaviour and ionic conductivity at 300 °C were investigated. XRD demonstrates three phases (cubic, monoclinic and tetragonal) were obtained. It was confirmed that small additions of Co-doping promotes densification, grain growth and ionic conductivity compared to pure 8YSZ. YSZZn obtained the highest ionic conductivity1.36 x 10-5 Ω− 1 cm-1 at 300 °C.

Synthesis and Characterization of Zirconia-Alumina Ceramics Doped Niobium Oxide

2017 ◽  
Vol 888 ◽  
pp. 103-107
Author(s):  
Johar Banjuraizah ◽  
Zaimi Zul@Azhar ◽  
Zainal Arifin Ahmad
Keyword(s):  
Mechanical Properties ◽  
Niobium Oxide ◽  
Yttria Stabilized Zirconia ◽  
Synthesis And Characterization ◽  
Alumina Ceramics ◽  
Stabilized Zirconia ◽  
Oxide Addition ◽  
Positive Effect

Pure 8 mol% yttria stabilized zirconia (YSZ) and alumina with 1:4 to form ZTA sample and niobium oxide (Nb2O5) as dopant was added to the ZTA system. The samples were sintered at 1650 °C for 2h. The effect of niobium oxide addition as dopant in the ZTA ceramics sample were investigated. It is found that addition of niobium oxide up to 5wt.% had a positive effect on the microstructure and hardness of the ZTA ceramics sample which improve the mechanical properties of the ceramics samples.

Characterizations of Synthetic 8mol% YSZ with Comparison to 3mol %YSZ for HT-SOFC

2020 ◽  
Vol 38 (4A) ◽  
pp. 491-500
Author(s):  
Abeer F. Al-Attar ◽  
Saad B. H. Farid ◽  
Fadhil A. Hashim
Keyword(s):  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Structural Information ◽  
Impedance Analysis ◽  
High Energy ◽  
Yttria Stabilized Zirconia ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Powder Morphology ◽  
X Ray

In this work, Yttria (Y2O3) was successfully doped into tetragonal 3mol% yttria stabilized Zirconia (3YSZ) by high energy-mechanical milling to synthesize 8mol% yttria stabilized Zirconia (8YSZ) used as an electrolyte for high temperature solid oxide fuel cells (HT-SOFC). This work aims to evaluate the densification and ionic conductivity of the sintered electrolytes at 1650°C. The bulk density was measured according to ASTM C373-17. The powder morphology and the microstructure of the sintered electrolytes were analyzed via Field Emission Scanning Electron Microscopy (FESEM). The chemical analysis was obtained with Energy-dispersive X-ray spectroscopy (EDS). Also, X-ray diffraction (XRD) was used to obtain structural information of the starting materials and the sintered electrolytes. The ionic conductivity was obtained through electrochemical impedance spectroscopy (EIS) in the air as a function of temperatures at a frequency range of 100(mHz)-100(kHz). It is found that the 3YSZ has a higher density than the 8YSZ. The impedance analysis showed that the ionic conductivity of the prepared 8YSZ at 800°C is0.906 (S.cm) and it was 0.214(S.cm) of the 3YSZ. Besides, 8YSZ has a lower activation energy 0.774(eV) than that of the 3YSZ 0.901(eV). Thus, the prepared 8YSZ can be nominated as an electrolyte for the HT-SOFC.

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