Dataset Information

A Promising Proton Conducting Electrolyte BaZr1-xHoxO3-? (0.05 ? x ? 0.20) Ceramics for Intermediate Temperature Solid Oxide Fuel Cells.

ABSTRACT: In this study, the Ho-substituted BaZrO3 electrolyte ceramics (BaZr1-xHoxO3-?, 0.05 ? x ? 0.20) were synthesized through a low-cost flash pyrolysis process followed by conventional sintering. The effects of Ho-substitution in BaZrO3 studied in terms of the structural phase relationship, microstructure and electrical conductivity to substantiate augmented total electrical conductivity for intermediate temperature solid oxide fuel cells (IT-SOFCs). The Rietveld refined X-ray diffraction (XRD) patterns revealed that pure phase with [Formula: see text] space group symmetry of cubic crystal system as originated in all samples sintered at 1600?°C for 8?h. The Raman spectroscopic investigations also approved that Ho incorporation in BaZrO3 ceramics. Field Emission Scanning Microscopic (FESEM) study informed a mixture of fine and coarse grains in the fracture surface of Ho-substituted BaZrO3 sintered samples. The relative density and average grain size of samples were observed to decrease as per the addition of Ho-substitution in BaZrO3 ceramics. The electrical conductivity study was accomplished by Electrical Impedance Spectroscopy (EIS) under 3% humidified O2 atmosphere from 300 to 800?°C. Furthermore, the total electrical conductivity of BaZr0.8Ho0.2O3-? ceramic was found to be 5.8?×?10-3 S-cm-1 at 600?°C under 3% humidified atmosphere, which may be a promising electrolyte for IT-SOFCs.

SUBMITTER: Saini DS

PROVIDER: S-EPMC7044191 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

A Promising Proton Conducting Electrolyte BaZr1-xHoxO3-δ (0.05 ≤ x ≤ 0.20) Ceramics for Intermediate Temperature Solid Oxide Fuel Cells.

Saini Deepash S DS Ghosh Avijit A Tripathy Shuvendu S Kumar Aparabal A Sharma Sanjeev K SK Kumar Nawnit N Majumdar Shubhankar S Bhattacharya Debasis D

Scientific reports 20200226 1

In this study, the Ho-substituted BaZrO3 electrolyte ceramics (BaZr1-xHoxO3-δ, 0.05 ≤ x ≤ 0.20) were synthesized through a low-cost flash pyrolysis process followed by conventional sintering. The effects of Ho-substitution in BaZrO3 studied in terms of the structural phase relationship, microstructure and electrical conductivity to substantiate augmented total electrical conductivity for intermediate temperature solid oxide fuel cells (IT-SO ...[more]

PMID: 32103038

Similar Datasets

Project description:Exploring mechanisms for sluggish cathode reactions is of great importance for solid oxide fuel cells (SOFCs), which will benefit the development of suitable cathode materials and then accelerate cathode reaction rates. Moreover, possible reaction mechanisms for one cathode should be different when operating in oxygen ion conducting SOFCs (O-SOFC) and in proton conducting SOFCs (P-SOFCs), and therefore, they lead to different reaction rates. In this work, a Ruddlesden-Popper (R-P) oxide, Sr3Fe2O7 (SFO), was selected as a promising cathode for both O-SOFCs and P-SOFCs. Using the first-principles approach, a microscopic understanding of the O2 reactions over this cathode surface was investigated operating in both cells. Compared with La0.5Sr0.5Co0.25Fe0.75O3 (LSCF), the low formation energies of oxygen vacancies and low migration energy barriers for oxygen ions in SFO make oxygen conduction more preferable which is essential for cathode reactions in O-SOFCs. Nevertheless, a large energy barrier (2.28 eV) is predicted for oxygen dissociation reaction over the SFO (001) surface, while there is a zero barrier over the LSCF (001) surface. This result clearly indicates that SFO shows a weaker activity toward the oxygen reduction, which may be due to the low surface energies and the specific R-P structure. Interestingly, in P-SOFCs, the presence of protons on the SFO (001) surface can largely depress the energy barriers to around 1.46-1.58 eV. Moreover, surface protons benefit the oxygen adsorption and dissociation over the SFO (001) surface. This result together with the extremely low formation energies and migration energy barriers for protons seem to suggest that SFO could work more effectively in P-SOFCs than in O-SOFCs. It's also suggested that too many protons at the SFO surface will lead to high energy barriers for the water formation process, and thus that over-ranging steam concentrations in the testing atmosphere may have a negative effect on cell performances. Our study firstly and clearly presents the different energy barriers for one cathode performing in both O- and P-SOFCs according to their different working mechanisms. The results will be helpful to find the constraints for using cathodes toward oxygen reduction reactions, and to develop effective oxide cathode materials for SOFCs.

Dataset Information

A Promising Proton Conducting Electrolyte BaZr1-xHoxO3-? (0.05 ? x ? 0.20) Ceramics for Intermediate Temperature Solid Oxide Fuel Cells.

Publications

A Promising Proton Conducting Electrolyte BaZr<sub>1-x</sub>Ho<sub>x</sub>O<sub>3-δ</sub> (0.05 ≤ x ≤ 0.20) Ceramics for Intermediate Temperature Solid Oxide Fuel Cells.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets