Nanocrystalline cathode functional layer for SOFC

Abstract

Recently, it was shown that thin functional layers introduced between an electrolyte and cathode might improve cathode performance. However, the mechanism of this improvement still needs analysis. In this paper, a thin (~140 nm), spin-coated perovskite layer (La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ) was placed between a cathode (La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ) and an electrolyte (Ce 0.8 Gd 0.2 O 2-δ) and the effects of this investigated. The microstructure of this layer was varied in order to determine its impact on the electrical and electrochemical properties. It has been shown that a mesoporous, nanocrystalline layer increases the active area for oxygen reduction and charge transfer through the cathode/electrolyte interface, which improves performance. Moreover, the stability of the cathode from thermal stresses is increased. In contrast, the coarsening of the grain and the layer densification has a reduced impact on the cathode performance.

Analysis of Thermal Stress in a Solid Oxide Fuel Cell Due to the Sulfur Poisoning Interface of the Electrolyte and Cathode

“…The delamination and cracks, in turn, affect the electrochemical performance. 45 The results are in good accordance with the previous experimental results, i.e., the sulfur poisoning deactivates the active cathode and causes deterioration in the microstructure. 9,10,13,20 It also offers a deep understanding of SO 2 poisoning of the LSM cathode and helps to optimize the material composition and morphology to avoid potential mechanical failure and catalytic deactivation.…”

“…Nevertheless, stress variations contribute to the delamination of ICE and the crack of the active cathode. The delamination and cracks, in turn, affect the electrochemical performance …”

Improvement of Oxygen Electrode Performance of Intermediate Temperature Solid Oxide Cells by Spray Pyrolysis Deposited Active Layers

“…Chrzan et al. [ 21,22 ] investigate different perovskite layers such as La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 , LaNi 0.6 Fe 0.4 O 3 (LNF), and SrTi 0.65 Fe 0.35 O 3 produced by spin‐coating method. Molin et al.…”

“…Modification of the oxygen electrode interface was also developed in our research group. Chrzan et al [21,22] investigate different perovskite layers such as La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 , LaNi 0.6 Fe 0.4 O 3 (LNF), Intermediate temperature solid oxide fuel cells oxygen electrodes are modified by active interfacial layers. Spray pyrolysis is used to produce thin (≈500 nm) layers of mixed ionic and electronic conductors: Sm 0.5 Sr 0.5 CoO 3−δ (SSC), La 0.6 Sr 0.4 CoO 3−δ (LSC), La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3−δ (LSCF), and Pr 6 O 11 (PrO x ) on the electrode-electrolyte interface.…”

Fabrication of improved La0.8Sr0.2MnO3 cathode layer for solid oxide fuel cells using economical coating methods

“…Dip coating is a simple, cost, and time saving technique that can be utilized on a variety of complicated shapes . Spraying and brush painting are other beneficial and effective processes which are used for producing porous and also dense ceramic layers . These methods were used and studied individually by a number of investigators for coating several cathodes on the substrates of SOFCs.…”