Surface enhanced performance of La0.6Sr0.4Co0.2Fe0.8O3-δ cathodes by infiltration Pr-Ni-Mn-O progress

Overview of Approaches to Increase the Electrochemical Activity of Conventional Perovskite Air Electrodes

“…The effective approach to increase the electrochemical activity of the conventional perovskite electrodes by increasing the TPB is related to the preparation of decorated electrodes by the infiltration (also called impregnation) method, where the porous cathode is filled with various additives [148,163,304,323,340,382,403,[434][435][436][437][438] as well as decorating the electrode surface with nanocatalysts [141,154,315,387,405,416,426,439] and nanocoatings [303,308,341,342], which significantly improve the electrode surface diffusion and exchange with the gas phase.…”

Review of SOFC Cathode Performance Enhancement by Surface Modifications: Recent Advances and Future Directions

“…The PBCC impregnated with BaO also maintains a very stable performance of 0.022 Ω cm 2 at 750 °C for 140 h. A durability test was also conducted at the same temperature and in direct contact with Cr for 110 h. The R p increasing rates of BaO-infiltrated PBCC and the original PBCC were 0.09 and 0.55% h –1 , respectively. Shi et al used a multistep infiltration process to coat the porous LSCF cathode with Pr-Ni-Mn oxide (PNM5) films, which greatly increased the ORR activity of the cathode and reduced the polarization resistance by half compared to the baseline LSCF. The thin layer of nanoparticles consisting of MnO, NiO, and Pr 6 O 11 has a large gas–solid interface reaction area and more TPB, which is an important reason for reduction of the R p value.…”

Downward Band Bending as an Efficient Strategy to Accelerate Oxygen Exchange Kinetics in Mixed Conducting Oxides─Studies on Different Oriented LSCF Thin Films

“…8 Subsequently, various methods have been applied to enhance the oxygen surface exchange reaction kinetics, including optimizing oxide compositions, 11 reducing particle sizes to nano ones, 12 and/or composing multiphase MIECs based on their respective advantages in the catalytic activities toward oxygen reduction or oxygen-transporting properties. 13 T h i s c o n t e n t i s Although lots of achievements have been made, the underlying mechanisms to improve oxygen surface exchange kinetics are still unclear and wait for further exploration, especially for those MIECs with composition evolution, such as La 1−x Sr x CoO 3−δ (LSC), 13,14 La 1−x Sr x Co 0.2 Fe 0.8 O 3−δ (LSCF), 15,16 SrTi 1−x Fe x O 3 , 17 and other Sr-containing oxides. 18,19 Previous investigations suggested that Sr-enriched species could be automatically generated on the surface of these Sr-containing oxides due to the existence of surface oxygen vacancies, 13 the strain induced by the lattice mismatch with substrates, 20 and/or cation size mismatch 21 and could be kinetically accelerated by annealing temperature, 22 applied voltage, 18 and atmospheric CO 2 due to the formation of SrCO 3 (a secondary phase).…”

“…Although lots of achievements have been made, the underlying mechanisms to improve oxygen surface exchange kinetics are still unclear and wait for further exploration, especially for those MIECs with composition evolution, such as La 1– x Sr x CoO 3−δ (LSC), , La 1– x Sr x Co 0.2 Fe 0.8 O 3−δ (LSCF), , SrTi 1– x Fe x O 3 , and other Sr-containing oxides. , Previous investigations suggested that Sr-enriched species could be automatically generated on the surface of these Sr-containing oxides due to the existence of surface oxygen vacancies, the strain induced by the lattice mismatch with substrates, and/or cation size mismatch and could be kinetically accelerated by annealing temperature, applied voltage, and atmospheric CO 2 due to the formation of SrCO 3 (a secondary phase) . The segregated Sr-enriched layers, which are insulating and electrochemically inactive, are generally believed to have a detrimental effect on the oxygen surface exchange reaction kinetics of MIECs for the reduced active surface. , For example, Pan et al investigated the electrode performance of LSCF before and after diluted nitric acid etching and suggested that the degradation of the LSCF electrode should root in the surface segregation of Sr-based species, which retards the oxygen surface adsorption/desorption, surface dissociation/association, and surface diffusion kinetics .…”