Preparation and Characterization of (La_0.8Sr_0.2)_0.95MnO_3−δ (LSM) Thin Films and LSM/LSCF Interface for Solid Oxide Fuel Cells

Abstract

Uniform, dense, and conformal coatings of (La,Sr)MnO 3Àd (LSM) have been successfully deposited on a silicon wafer and a dense (La,Sr)(Co,Fe)O 3Àd (LSCF) substrate using a stable LSM sol consisting of metal acetate and nitrate precursors dissolved in a mixed organic solvent of 2-methoxyethanol and acetic acid with enhanced wettability. The processing conditions are optimized for precise control of composition, morphology, microstructure, and thickness of the LSM films to examine the microstructure and chemical stability of an LSM film as a catalytic coating for an LSCF cathode. The thicknesses of the LSM films are controlled within the range of 5-60 nm by spincoating of LSM sol with different concentrations. The LSM films grow epitaxially on the LSCF substrate grains after annealing at 800°C for 1 h due to their structural similarity. The LSM coatings show good stability on LSCF substrates and may suppress strontium oxide segregation on LSCF surface during annealing at 850°C for 900 h, implying that LSMcoated LSCF surfaces have better structural and chemical stability under typical fuel cell operating conditions.

Advances in Cathode Materials for Solid Oxide Fuel Cells: Complex Oxides without Alkaline Earth Metal Elements

“…[ 235 ] Third, the similar structure between the LNF materials and the LSCF cathode backbone allows for facile formation of a conformal coating of them on an LSCF surface, which has the potential to offer much stronger tolerance than those reported through discrete particle deposition. [ 458,464 ] …”

Solid Oxide Fuel Cells

“…The thin . b Current density of two test cells with and without infiltration as a function of time at a constant voltage of 0.7 V and approximate cathodic overpotential of -0.12 V. c Cell voltages and power densities as a function of current density for full cells with and without infiltration of LSM after long-term testing [92] LSM film formation on LSCF surface and stability of LSM/LSCF were carefully discussed by Choi et al [95]. In the SDC infiltrated LSCF cathode, Nie et al [94] found that the microstructures and performances of SDC infiltrated LSCF cathodes depend sensitively on the amount of SDC introduced and the microstructure of the SDC coatings.…”

Enhanced density of sol–gel derived La0.8S0.2MnO3 thin film with an electric field assisted deposition

“…Recently, a continuous (La 0.8 Sr 0.2 ) 0.95 MnO 3 À d coating has been prepared by Choi et al via a sol-gel process [11], in which relevant acetate along with acetic acid and 2-methoxyethanol was used as precursor and solvent, respectively. However, such a water-free-based solution infiltration method seems to have some drawbacks which would not be preferred in SOFC industry techniques.…”