scholarly journals Samples of Ba1−xSrxCe0.9Y0.1O3−δ, 0 < x < 0.1, with Improved Chemical Stability in CO2-H2 Gas-Involving Atmospheres as Potential Electrolytes for a Proton Ceramic Fuel Cell

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1874
Author(s):  
Magdalena Dudek ◽  
Bartłomiej Lis ◽  
Radosław Lach ◽  
Salius Daugėla ◽  
Tomas Šalkus ◽  
...  

Comparative studies were performed on variations in the ABO3 perovskite structure, chemical stability in a CO2-H2 gas atmosphere, and electrical conductivity measurements in air, hydrogen, and humidity-involving gas atmospheres of monophase orthorhombic Ba1−xSrxCe0.9Y0.1O3−δ samples, where 0 < x < 0.1. The substitution of strontium with barium resulting in Ba1−xSrxCe0.9Y0.1O3−δ led to an increase in the specific free volume and global instability index when compared to BaCe0.9Y0.1O3−δ. Reductions in the tolerance factor and cell volume were found with increases in the value of x in Ba1−xSrxCe0.9Y0.1O3−δ. Based on the thermogravimetric studies performed for Ba1−xSrxCe0.9Y0.1O3−δ, where 0 < x < 0.1, it was found that modified samples of this type exhibited superior chemical resistance in a CO2 gas atmosphere when compared to BaCe0.9Y0.1O3−δ. The application of broadband impedance spectroscopy enabled the determination of the bulk and grain boundary conductivity of Ba1−xSrxCe0.9Y0.1O3−δ samples within the temperature range 25–730 °C. It was found that Ba0.98Sr0.02Ce0.9Y0.1O3−δ exhibited a slightly higher grain interior and grain boundary conductivity when compared to BaCe0.9Y0.1O3−δ. The Ba0.95Sr0.05Ce0.9Y0.1O3−δ sample also exhibited improved electrical conductivity in hydrogen gas atmospheres or atmospheres involving humidity. The greater chemical resistance of Ba1−xSrxCe0.9Y0.1O3−δ, where x = 0.02 or 0.05, in a CO2 gas atmosphere is desirable for application in proton ceramic fuel cells supplied by rich hydrogen processing gases.

2018 ◽  
Vol 20 (22) ◽  
pp. 14997-15001 ◽  
Author(s):  
Ho-Il Ji ◽  
Hyoungchul Kim ◽  
Hae-Weon Lee ◽  
Byung-Kook Kim ◽  
Ji-Won Son ◽  
...  

Theoretical open-circuit voltage and electrical conductivity of BZY20 at 500 °C under O2 and H2O chemical potential gradients in a range of interest for protonic ceramic fuel cells are investigated.


Solid Earth ◽  
2015 ◽  
Vol 6 (3) ◽  
pp. 1037-1043 ◽  
Author(s):  
K. S. Hui ◽  
H. Zhang ◽  
H. P. Li ◽  
L. D. Dai ◽  
H. Y. Hu ◽  
...  

Abstract. In this study, the electrical conductivity of quartz andesite was measured in situ under conditions of 0.5–2.0 GPa and 723–973 K using a YJ-3000t multi-anvil press and a Solartron-1260 Impedance/Gain-Phase Analyzer. Experimental results indicate that grain interior transport controls the higher frequencies (102–106 Hz), whereas the grain boundary process dominates the lower frequencies (10−1–102 Hz). For a given pressure and temperature range, the relationship between Log σ and T−1 follows the Arrhenius relation. As temperature increased, both the grain boundary and grain interior conductivities of quartz andesite increased; however, with increasing pressure, both the grain boundary and grain interior conductivities of the sample decreased. By the virtue of the dependence of grain boundary conductivity on pressure, the activation enthalpy and the activation volume were calculated to be 0.87–0.92 eV and 0.56 ± 0.52 cm3 mol−1, respectively. The small polaron conduction mechanism for grain interior process and the ion conduction mechanism for grain boundary process are also discussed.


2013 ◽  
Vol 32 (6) ◽  
pp. 551-556 ◽  
Author(s):  
Bülent Aktaş

AbstractThe effect of the addition of a small amount of CuO on the microstructure, hardness, fracture toughness and electrical conductivity properties of 8YSZ were investigated using 8 mol% yttria-stabilized cubic zirconia (8YSZ). The addition of 1 wt% CuO to 8YSZ powders were doped using a colloidal process. Undoped and CuO doped 8YSZ specimens were pressureless sintered at 1400 °C for 10 h. The grain size measurement results showed that the presence of CuO as a intergranular second phase at the grain boundaries of the 8YSZ gave rise to a decrease in the grain size. The fracture toughness values for undoped and 1 wt% CuO-doped 8YSZ specimens were obtained as 1.79 and 2.20 MPa.m1/2, respectively. The decrease in the grain size of the 8YSZ with CuO addition caused an increase in the fracture toughness. The electrical conductivity of the undoped and 1 wt% CuO-doped 8YSZ specimens was measured using a frequency response analyzer in the frequency range of 100 mHz–13 MHz and at the temperature range of 300–800 °C. The electrical conductivity results showed that there was a decrease in the grain interior, and specific grain boundary conductivity, with the addition of a small amount of CuO to 8YSZ. The presence of a second phase layer with high resistance at the grain boundaries of the 8YSZ caused a decrease in the specific grain boundary conductivity.


2021 ◽  
Author(s):  
Tao Li ◽  
Xuefeng Chang ◽  
Lifang Mei ◽  
Xiayun Shu ◽  
Jidong Ma ◽  
...  

Ti3C2Tx is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti3C2Tx has problems such as collapse of the layered structure and low...


2021 ◽  
Vol 506 ◽  
pp. 230134
Author(s):  
Tomohiro Kuroha ◽  
Yoshiki Niina ◽  
Mizuki Shudo ◽  
Go Sakai ◽  
Naoki Matsunaga ◽  
...  

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 968
Author(s):  
Fumitada Iguchi ◽  
Keisuke Hinata

The elastic properties of 0, 10, 15, and 20 mol% yttrium-doped barium zirconate (BZY0, BZY10, BZY15, and BZY20) at the operating temperatures of protonic ceramic fuel cells were evaluated. The proposed measurement method for low sinterability materials could accurately determine the sonic velocities of small-pellet-type samples, and the elastic properties were determined based on these velocities. The Young’s modulus of BZY10, BZY15, and BZY20 was 224, 218, and 209 GPa at 20 °C, respectively, and the values decreased as the yttrium concentration increased. At high temperatures (>20 °C), as the temperature increased, the Young’s and shear moduli decreased, whereas the bulk modulus and Poisson’s ratio increased. The Young’s and shear moduli varied nonlinearly with the temperature: The values decreased rapidly from 100 to 300 °C and gradually at temperatures beyond 400 °C. The Young’s modulus of BZY10, BZY15, and BZY20 was 137, 159, and 122 GPa at 500 °C, respectively, 30–40% smaller than the values at 20 °C. The influence of the temperature was larger than that of the change in the yttrium concentration.


2004 ◽  
Vol 108 (21) ◽  
pp. 4567-4569 ◽  
Author(s):  
Hironori Nakajima ◽  
Toshiyuki Nohira ◽  
Yasuhiko Ito

Sign in / Sign up

Export Citation Format

Share Document