- Email: [email protected]
Hysteresis in SOFC cathode reaction
Fuel Cell Partnership and its efforts to promote fuel cell technology and showcase a hydrogen infrastructure. Stuart Energy recently moved to a new facility near Toronto airport, which will serve as the company’s principal office, operations, research and development, sales and marketing, system manufacturing and engineering centre. The move represents a major step towards a dedicated production line and manufacturing processes for both its energy and industrial products, and will allow the company to install n e w R & D l a b o r a t o r i e s a l o n g s i d e Iargercapacity product development and production facilities. Thanks to a successful initial public offering (PO) in October 2000, Stuart Energy is well financed to carry out its vision to provide hydrogen fuel from water, anywhere, anytime for everybody. with Hong Kong-based Cheung Kong Moving towards a Infrastructure, set up last summer, and is hydrogen infrastructure working to establish a distributed hydrogen T h e c o m p a n y h a s e s t a b l i s h e d a s t r o n g infrastructure in Asia. In addition, Stuart Asian partnership through its joint venture Energy is actively involved in the California
Research Trends
For more information, contact: Stuart Energy Systems Corporation, 5101 Orbitor Drive, Mississauga, Ontario L4W 4V1, Canada. Tel: +I 905 282 7700, Fax: +l 905 282 7701, Email: [email protected], h~~:~~w~.stua~energy.com
LSGM with the three oxides was Coz03 > NiO >
layer. Thin, dense layers without cracks were
Fe,O,, and La-containing oxides were detected in these binary powder mixtures after firing. The
prepared through adjusting shrinkage and the shrinkage rate of the deposited zirconia layer on
Sintering temperature of LSM-YSZ composite cathodes
Fe,03-LSGM anode, mixed with 40 ~01% LSGM powder and sintered at 115O”C, had the highest
the presintered porous substrate. A method for
initial performance compared with NiO- LSGM
direct control of the layer thickness during electrophoretic deposition was developed. An
The correlation between sintering temperature,
and Co203- LSGM anodes, and so is a possible
SOFC ap~Ii~tion with porous anode substrates
microstructure and performance of composite electrodes comprising lanthanum strontium
anode starting material for LSGM-based SOFCs. X. Zhang, S. Ohara, H. Okawa, R. Marie,
and thin zirconia electrolytes was used to
manganate (LSM) and YSZ with a current
T. Fukui: Solid State Ionics 139(1/2) 145-152
J. Will, M.K.M. Hruschka, L. Gubler, L.J.
collector of LSM has been studied at 1000°C in air. The microstructure was less dense and
(2 January 2001).
Gauckler: 1. of American Ceramic SOL. 84(2) 328-332 (February 2001).
contained smaller grains as the sintering temperature was reduced from 1300 to 1150°C. This increased the active triple-phase boundary line between electrode, electrolyte and gas phase, leading to reduced polarization resistance with decreasing
sintering
temperature. When
measuring at a reference temperature of 850°C the lowest polarization resistance was found for
Hysteresis in SOFC cathode reaction The oxygen electrode reaction at the PtlYSZ interface was investigated at 1000°C on Pt point electrodes on YSZ and YSZ point contacts on Pt. Linear potential sweeps showed a pronounced nonlinear current/voltage relation and inductive hysteresis, in particular at low sweep rates (- 1
sintering temperatures of 950-1000°C. M.J. Jorgensen, S. Primdahl, C . B a g g e r ,
pV/s). Inductive behaviour at low frequency was attributed to current-induced activation and
M. Mogensen: S&d State Ionics 139(1/Z) l-l 1
subsequent deactivation at equilibrium.
(2 January 2001).
T. Jacobsen, 8. Zachau-Christiansen, L. Bay, M. Juhl Jorgensen: I&ctrochimica Acta 46(7)
Interactions of LSGM electrolyte with different anode materials This study investigated the interactions of an Srand Mg-doped lanthanum gallate (LSGM with composition La,,,Sr,,,Ga,,,M~,zO~) electrolyte with Fe,O,, Co,O, and NiO as the anode starting materials. The order of reactivity of the
Fuel Cells Bulletin No. 35
1019-1024 (15 January2001).
Ele~rophoretic deposition of zirconia on porous anodic substrates
demonstrate the method’s potential.
Graphite nanofibre fuel cell electrode The potential of graphite nanofibre (GNF)supported Pt catalysts as an electrode for fuel cell applications was investigated using electrochemical oxidation of methanol at 40°C as a probe reaction. Catalysts consisting of 5 wt% Pt supported on ‘platelet’ and ‘ribbon’ type GNFs, which expose mainly edge sites to the reactants, exhibited activities comparable to 25 wt% Pt on Vulcan carbon. The GNF-supported metal particles were significantly less susceptible to CO poisoning than traditional catalysts. This improvement is linked to the metal particles adopting specific crystallographic orientations
Thin (<20 pm) zirconia layers were prepared on
when dispersed on the highly tailored GNF structures. C.A. Bessel, K. Laubernds, N.M. Rodriguez,
porous substrates using electrophoretic deposition, with a cosintering step of substrate and
R.T.K. Baker: j of Physical Chemistry B 105(6) 1115-l 118 (February 2001).
0
Research Trends
For more information, contact: Stuart Energy Systems Corporation, 5101 Orbitor Drive, Mississauga, Ontario L4W 4V1, Canada. Tel: +I 905 282 7700, Fax: +l 905 282 7701, Email: [email protected], h~~:~~w~.stua~energy.com
LSGM with the three oxides was Coz03 > NiO >
layer. Thin, dense layers without cracks were
Fe,O,, and La-containing oxides were detected in these binary powder mixtures after firing. The
prepared through adjusting shrinkage and the shrinkage rate of the deposited zirconia layer on
Sintering temperature of LSM-YSZ composite cathodes
Fe,03-LSGM anode, mixed with 40 ~01% LSGM powder and sintered at 115O”C, had the highest
the presintered porous substrate. A method for
initial performance compared with NiO- LSGM
direct control of the layer thickness during electrophoretic deposition was developed. An
The correlation between sintering temperature,
and Co203- LSGM anodes, and so is a possible
SOFC ap~Ii~tion with porous anode substrates
microstructure and performance of composite electrodes comprising lanthanum strontium
anode starting material for LSGM-based SOFCs. X. Zhang, S. Ohara, H. Okawa, R. Marie,
and thin zirconia electrolytes was used to
manganate (LSM) and YSZ with a current
T. Fukui: Solid State Ionics 139(1/2) 145-152
J. Will, M.K.M. Hruschka, L. Gubler, L.J.
collector of LSM has been studied at 1000°C in air. The microstructure was less dense and
(2 January 2001).
Gauckler: 1. of American Ceramic SOL. 84(2) 328-332 (February 2001).
contained smaller grains as the sintering temperature was reduced from 1300 to 1150°C. This increased the active triple-phase boundary line between electrode, electrolyte and gas phase, leading to reduced polarization resistance with decreasing
sintering
temperature. When
measuring at a reference temperature of 850°C the lowest polarization resistance was found for
Hysteresis in SOFC cathode reaction The oxygen electrode reaction at the PtlYSZ interface was investigated at 1000°C on Pt point electrodes on YSZ and YSZ point contacts on Pt. Linear potential sweeps showed a pronounced nonlinear current/voltage relation and inductive hysteresis, in particular at low sweep rates (- 1
sintering temperatures of 950-1000°C. M.J. Jorgensen, S. Primdahl, C . B a g g e r ,
pV/s). Inductive behaviour at low frequency was attributed to current-induced activation and
M. Mogensen: S&d State Ionics 139(1/Z) l-l 1
subsequent deactivation at equilibrium.
(2 January 2001).
T. Jacobsen, 8. Zachau-Christiansen, L. Bay, M. Juhl Jorgensen: I&ctrochimica Acta 46(7)
Interactions of LSGM electrolyte with different anode materials This study investigated the interactions of an Srand Mg-doped lanthanum gallate (LSGM with composition La,,,Sr,,,Ga,,,M~,zO~) electrolyte with Fe,O,, Co,O, and NiO as the anode starting materials. The order of reactivity of the
Fuel Cells Bulletin No. 35
1019-1024 (15 January2001).
Ele~rophoretic deposition of zirconia on porous anodic substrates
demonstrate the method’s potential.
Graphite nanofibre fuel cell electrode The potential of graphite nanofibre (GNF)supported Pt catalysts as an electrode for fuel cell applications was investigated using electrochemical oxidation of methanol at 40°C as a probe reaction. Catalysts consisting of 5 wt% Pt supported on ‘platelet’ and ‘ribbon’ type GNFs, which expose mainly edge sites to the reactants, exhibited activities comparable to 25 wt% Pt on Vulcan carbon. The GNF-supported metal particles were significantly less susceptible to CO poisoning than traditional catalysts. This improvement is linked to the metal particles adopting specific crystallographic orientations
Thin (<20 pm) zirconia layers were prepared on
when dispersed on the highly tailored GNF structures. C.A. Bessel, K. Laubernds, N.M. Rodriguez,
porous substrates using electrophoretic deposition, with a cosintering step of substrate and
R.T.K. Baker: j of Physical Chemistry B 105(6) 1115-l 118 (February 2001).
0