Coral Microstructure of Graded CGO/
LSCF Oxygen Electrode by Electrostatic
Spray Deposition for Energy (IT-SOFC,
SOEC)
~
J. Sar
1,3
, F. Charlot
2
, A. Almeida
3
, L. Dessemond
1
, E. Djurado
1
*
1
Laboratoire d’Eletrochimie et de Physico-Chimie des Matériaux et des Interfaces – LEPMI, UMR 5279 CNRS, Grenoble INP, Université
de Savoie, Université Joseph Fourier, 1130 Rue de la Piscine, B. P. 75, 38402 St. Martin d’Hères, France
2
Consortium des Moyens Technologiques Communs – CMTC, Grenoble INP, 1260 Rue de la Piscine, B. P. 75, 38402 St. Martin
d’Hères, France
3
Dep. Eng. Quimica, Instituto Superior Tecnico, Av. Rovisco Pais, Torre Sul, 1049-001 Lisboa, Portugal
Received June 25, 2013; accepted February 26, 2014; published online
1 Introduction
The increasing world’s energy consumption demands to cre-
ate an advanced technology for diversified energy supply and
reduce pollution. High-temperature solid oxide cells (SOCs) can
be reversibly operated as electrolyzer cells (SOECs) for water
splitting or syngas production [1] and as fuel cells (SOFCs).
SOCs are used to produce energy created directly from electro-
chemical processes between oxygen and fuel, which can be
hydrogen, hydrocarbons, or ethanol, named solid oxide fuel
cells (SOFCs). The global researches on SOFCs focus on improv-
ing the cells properties by lowering operating temperatures
from above 900 °C to below 700 °C in so called intermediate
temperature SOFCs (IT-SOFCs).
Intermediate temperatures help to increase overall lifetime
and reduce operation and fabrication costs. However, electro-
lyte ohmic losses and electrode polarizations of the cell are
increased. Consequently, new materials have to be provided
to follow investigation at lower temperatures. In general,
materials for SOFCs are La
1–x
Sr
x
MnO
3–x
(LSM) as an oxygen
electrode, yttria-stabilized zirconia (YSZ = 8 mol.%
Y
2
O
3
-doped ZrO
2
) as an electrolyte and cermet composition
of Ni/YSZ as a hydrogen electrode. In IT-SOFC, alternative
materials to LSM electronic conductors are mixed ionic and
electronic conductors (MIEC) such as La
0.6
Sr
0.4
Co
0.2
Fe
0.8
O
3–d
(LSCF). Perovskite LSCF presents high electrical conductivity
Abstract
The goal of this work was to fabricate a composite based on
Ce
0.9
Gd
0.1
O
1.95
(CGO) and La
0.6
Sr
0.4
Co
0.2
Fe
0.8
O
3–d
(LSCF) as
a porous and thin oxygen electrode film adherent to
(ZrO
2
)
0.92
(Y
2
O
3
)
0.08
(YSZ) substrate by electrostatic spray
deposition in order to improve durability in solid oxide fuel
cells operating at intermediate temperature (IT-SOFC) and
solid oxide electrolyzer cells. A simultaneous gradient in
composition and in porosity of CGO/LSCF coatings has
been successfully obtained by choosing proper deposition
parameters and physicochemical properties of the precursor
solution. Detailed microstructural characterization was
made by SEM and completed with 3D focused ion beam-
scanning electron beam (FIB-SEM) tomography. The graded
composition rich in CGO close to YSZ and rich in LSCF at
the electrode surface has been investigated by energy disper-
sive X-ray spectroscopy through line profile of coral micro-
structure. Only cubic CGO and cubic LSCF perovskite were
detected by XRD in deposited coatings after heat treatment
at 900 °C for 2 h.
Keywords: CGO, Electrostatic Spray Deposition, FIB-SEM
Tomography, Graded Composition, LSCF, SOEC, SOFC
–
~
Paper presented at the “Fundamentals & Developments of Fuel
Cells Conference 2013 (FDFC2013)”, April 16–18, 2013,
Karlsruhe, Germany.
–
[
*
] Corresponding author, elisabeth.djurado@lepmi.grenoble-inp.fr
FUEL CELLS 00, 0000, No. 0, 1–7 © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1
ORIGINAL RESEARCH PAPER
DOI: 10.1002/fuce.201300146