The effects of different doping amounts of BaO on the structure and oxidation behavior of UO 2 were investigated by a series of methods. The results indicated that the solid solutions (U 1- y Ba y )O 2- y was formed after sintering. With the increase of y value, the lattice parameters of (U 1- y Ba y )O 2- y and oxygen vacancies increased, OOT and MRT gradually rose and O/(U + M) final decreased. The oxidation products were characterized by XRD, SEM and XPS. As y value increased, the average valence state of uranium decreased, the oxidation became incomplete and the average activation energy of (U 1- y Ba y )O 2- y increased from 89.50 to 125.15 kJ/mol. Graphical
BaO is dispersed in UO 2 matrix and formed oxygen vacancies. The delayed UO 2 oxidation is more obvious with more BaO doping. And the difference of U valence state is found from the oxidation products at 550 ℃.
Wang Xintao,Zhong Jianyi,Li Zhanggui,Xiang Jiali,Hou Bingxue,Tan Zanxiong,Liu Lisha,Wang Cheng Cheng
The development of high-performance and chromium-tolerant stable hierarchical cathodes is crucial for practical applications of solid oxide fuel cells (SOFCs). This work presents a synergistic strategy to manufacture hierarchical cathodes, focusing on optimizing microstructural and electrochemical properties. By integrating advanced fabrication techniques, including nanostructuring and surface engineering, we achieved a significant enhancement in high entropy double perovskite cathode. The electrochemical activities and chromium tolerance of BaO impregnated on (La 0.2 Pr 0.2 Sm 0.2 Gd 0.2 Nd 0.2 )Ba 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5 (LPSGNBSCF) high-entropy double perovskite cathodes in SOFCs were investigated in this study. Here, an optimum coated amount of BaO-LPSGNBSCF-0.15 mol/L electrode exhibited smaller electrode polarization resistance ( R p ) of 0.22 Ω cm 2 than pure LPSGNBSCF electrode with R p of 0.5 Ω cm 2 operating at 800 °C in the presence of Cr 2 O 3 for 100 h. The synergistic catalyst coating of BaO-LPSGNBSCF-0.15 M could lead to less Cr deposition and SrCrO 4 formation on LPSGNBSCF after exposure to Cr 2 O 3 . Moreover, the cell delivered the maximum power density of 985.9 mW/cm 2 at 800 °C, higher than 803.1 mW/cm 2 of bare LPSGNBSCF single cell and showed good stability with 100 h in short-term test. This work elucidated a rational design of efficient and durable high-entropy-based chromium tolerant cathode for SOFCs.
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