Attempted preparation of La _0.5Ba _0.5MnO _{3− δ} leading to an in-situ formation of manganate nanocomposites as a cathode for proton-conducting solid oxide fuel cells

Abstract

A La0.5Ba0.5MnO3-δ oxide was prepared using the sol-gel technique. Instead of a pure phase, La0.5Ba0.5MnO3-δ was discovered to be a combination of La0.7Ba0.3MnO3-δ and BaMnO3. The in-situ production of La0.7Ba0.3MnO3-δ+BaMnO3 nanocomposites enhanced oxygen vacancy formation compared to single-phase La0.7Ba0.3MnO3-δ-or BaMnO3, providing potential benefits as a cathode for fuel cells. Subsequently, La0.7Ba0.3MnO3-δ-+BaMnO3 nanocomposites were utilized as the cathode for proton-conducting solid oxide fuel cells (H-SOFCs), which significantly improved cell performance. At 700 o C, an H-SOFC with a La0.7Ba0.3MnO3-δ+ BaMnO3 nanocomposite cathode achieved the highest power density yet recorded for H-SOFCs with manganate cathodes: 1504 mW cm -2 . This performance was much greater than the single-phase La0.7Ba0.3MnO3-δ or BaMnO3 cathode cells. In addition, the cell demonstrated excellent working stability. First-principles calculations indicated that the La0.7Ba0.3MnO3-δ/BaMnO3 interface was crucial for the enhanced cathode performance.The oxygen reduction reaction (ORR) free energy barrier was significantly lower at the La0.7Ba0.3MnO3-δ/BaMnO3 interface than at the La0.7Ba0.3MnO3-δ or BaMnO3 surfaces, which explained the origins of the high performance and gave a guide for the construction of novel cathodes for H-SOFCs.

Ameliorating La0.5Sr1.5MnO4 with Ni-doping to enhance cathode electrocatalysis for proton-conducting solid oxide fuel cells

“…The slightly higher BEs for all oxygen species in LSMN are correlative with the intricate B-site environment after Ni-incorporation, which connect with oxygens directly. Anyhow, the highly oxidative oxygen species (O − /O 2 2− ) are closely related to the surface oxygen vacancies 34–36 and the calculated relative concentration of O − /O 2 2− species increased from 8.2% for LSMO to 16.5% for LSMN, which indicates that B-site Ni substitution could increase the surface oxygen vacancy concentration, thus promoting the adsorption and activation of oxygen at the active site and facilitating the ORR process. 34,35…”

Revealing the detrimental CO2 reduction effect of La0.6Sr0.4FeO3-δ-derived heterostructure in solid oxide electrolysis cells

“…Compare with fresh samples the powders calcined at 1300°C just exhibited slightly different crystallinity and had no effect on the conductivity test. 41 The electrical conductivity of LSF and LSF8 samples in an oxidizing atmosphere and reducing atmosphere both reveal a transition from semiconductor-like to metal-like behavior 42 , 43 , 44 ( Figures 2 C and S7 ), i.e., the electrical conductivity first increases with increasing temperature until it reaches a maximum, then decreases with temperature subsequently. In addition, the electrical conductivity of RP-LSF is almost negligible compared to LSF.…”

Manipulating Nb-doped SrFeO 3− δ with excellent performance for proton-conducting solid oxide fuel cells

“…A vacuum layer of 15 Å was added to avoid interactions with other slabs. Additional details of the calculations can be found in prior studies [29,30].…”