a step toward the next generation of high temperature fuel cells: the eu project evolve...
TRANSCRIPT
A step toward the next generation of High
Temperature Fuel Cells: The EU project EVOLVE
22/05/2014
R. Costa
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 1
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 2
Beyond the 3rd generation SOFC…
1st gen. 2nd gen. 3rd gen.
ESC
Limited power density
Fuel flexibility
Robustness
Stationary
Transportation
High power density
Fuel flexibility
Sulfur poisoning
Thermal cycling
Redox Cycling
Stationary
Transportation
High power density
Fuel flexibility
Sulfur poisoning
Thermal cycling
Redox Cycling
Stationary
Transportation
4th gen.
High power density
Fuel flexibility
Sulfur resistant
Thermal cycling
Redox Cycling
Low cost
Stationary
Transportation
Which materials and architecture for the next
generation SOFC?
ASC MSC
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 3
Metallic alloy foam (such as FeCrAlY), capable of forming alumina protective scale Excellent mechanical properties, but high sensitivity to chemical reactions (high degradation)
Oxidized metal alloy foam, with stable aluminum oxide scale Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), but poor or no electronic conductivity
Anodization
Impregnation
Anode current collector - Oxidized alloy foam with impregnated conductive ceramic (LSCM or LST). Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), high electronic (and ionic) conductivity
Roughness Adjustment
Smooth current collector Low roughness surface ready for coating of functional layers of cell
Fabrication of functional layers on top of anode current collector+ infiltration of catalysts
Realization of Evolve Cell LSCF-CGO cathode CGO diffusion barrier layer YSZ or ScSZ Electrolyte LSCM-CGO anode (with infiltrated Ni)
Metal substrate resistant toward oxidation
The cell concept…… combines benefits from ASC and MSC cell architectures
Al rich alloys, on the basis of MCrAl(Y) with M being Fe,
Ni, Co or a mixture
Formation of an Al2O3
layer as a durable
protective coating
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 4
Metallic alloy foam (such as FeCrAlY), capable of forming alumina protective scale Excellent mechanical properties, but high sensitivity to chemical reactions (high degradation)
Oxidized metal alloy foam, with stable aluminum oxide scale Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), but poor or no electronic conductivity
Anodization
Impregnation
Anode current collector - Oxidized alloy foam with impregnated conductive ceramic (LSCM or LST). Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), high electronic (and ionic) conductivity
Roughness Adjustment
Smooth current collector Low roughness surface ready for coating of functional layers of cell
Fabrication of functional layers on top of anode current collector+ infiltration of catalysts
Realization of Evolve Cell LSCF-CGO cathode CGO diffusion barrier layer YSZ or ScSZ Electrolyte LSCM-CGO anode (with infiltrated Ni)
Hybrid current collector mechanically and chemically
stable in both oxidant and reducing atmosphere
The cell concept…… combines benefits from ASC and MSC cell architectures
Infiltration with an
electronic conductor
Hybrid Metal/Ceramic substrate without nickel having a mechanical or
structural role
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 5
Metallic alloy foam (such as FeCrAlY), capable of forming alumina protective scale Excellent mechanical properties, but high sensitivity to chemical reactions (high degradation)
Oxidized metal alloy foam, with stable aluminum oxide scale Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), but poor or no electronic conductivity
Anodization
Impregnation
Anode current collector - Oxidized alloy foam with impregnated conductive ceramic (LSCM or LST). Excellent mechanical properties and stable oxide scale to protect against chemical reactions (low degradation), high electronic (and ionic) conductivity
Roughness Adjustment
Smooth current collector Low roughness surface ready for coating of functional layers of cell
Fabrication of functional layers on top of anode current collector+ infiltration of catalysts
Realization of Evolve Cell LSCF-CGO cathode CGO diffusion barrier layer YSZ or ScSZ Electrolyte LSCM-CGO anode (with infiltrated Ni)
Use of perovskite
materials at the anode
and cathode, being
modified by addition of
suitable catalysts
High power density, Sulfur resistant, Fuel flexibility, Thermal cycling,
Redox Cycling???
Stationary, Transportation???
The cell concept…… combines benefits from ASC and MSC cell architectures
Manufacturing of thin active layer (Anode/Electrolyte/Cathode) as for
ASC
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 6
Identified Challenges
• Formation of a protective Al2O3 coating without hindering the
electronic conductivity…
• Manufacturing of a thin dense electrolyte (<5µm) without
damaging the metal substrate and high T sintering…
• Increase of electronic conductivity in perovskite material for
current collection…
• Improvement of catalytic properties of perovsite anode
materials…
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 7
The project EVOLVE
Evolved materials and innovative design for high performance,
durable and reliable SOFC cell and stack
• European project funded by the FCH JU under Grant Agreement 303429
• Coordinator: German Aerospace Center (DLR)
• Starting date November 2012
• Duration 48months
1. 550mW/cm² at 0,7V and 750°C with hydrogen as fuel gas, with
perovskite based anode material, demo at stack level up to 250W
2. Industrial relevant size up-scaling
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 8
Raw
Materials
Processing of raw
materials into core
component
Evolve cells
Enhancement of performance
and life time of cells by analyses
Integration of cells into
market relevant product
Evolve stack
Promotion of the product by outreach,
dissemination and market
oriented
activities
Value Added Chain Approach of the Project
WP 2 WP 3 WP 4 & 5 WP 6 WP 7
EVOLVE: value added chain
From the raw materials up to the stackable cells
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 9
WP3
WP6
WP5 WP4
WP2 Development of powders
(G1, G2 and G3)
Development of Inks and Colloids
Materials compatibility
Development of metallic foams (MF1, MF2 and MF3)
Shaping of button cells (Evolve I, II and III)
3D Microstructural characterization
Electrochemical characterization
Microstructural Modelling
Electrochemical Modelling
Optimization
Stack integration and testing
Up-scaling of cells and testing
WP
1
WP
7
EVOLVE: strategy
Iterative strategy
Extensive use of
modeling
Reduce the number of
trial/error cycles
Shorten the process of
development and
integration of new
material
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 10
(France)
(France)
(Sweden)
(Germany)
(Germany)
(Germany)
(Italy)
(Norway)
The consortium EVOLVE
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 11
Reference materials
Open pore NiCrAl foam (© Alantum)
Composition of the anode: Ce1-xGdxO2-α / La0,1Sr0,9TiO3-α
Electrolyte: 8-YSZ
Cathode : Ce1-xGdxO2-α / La0,4Sr0,6Co0,2Fe0,8O3-α
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 12
EVOLVE: development strategy
1cm² 15-20 cm² 100 cm²
- Reactivity tests
- Conductivity measurement
- Understanding the
behaviour
- Shaping strategy
- Prototype
- Testing and optimization
- upscaling
(CNR ISTEC)
(DLR)
10mm
10mm
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 13
EVOLVE: development strategy
1cm² 15-20 cm² 100 cm²
- Reactivity tests
- Conductivity measurement
- Understanding the
behaviour
(CNR ISTEC)
10mm
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 14
Were we are after 15 months
Compatibility tests (DLR)1cm²
No reactivity detected between anodic materials(at least with used methods)
Conductivity of pure LST at about 60 S/cm at 750°C in H2
(CNR)
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 15
750°C, H2/H2O, 50 mL/min/cm2
0
10
20
0 10 20 30 40 50 60
Re(Z) / W.cm2
-Im
(Z)
/ W
.cm
2
0 -1
-2
12
34
0-1
-212
0
5
20 25 30
-21
-1
-2-14 4
4
21
3-2
1
0-1
-2
10 -1
23
750°C, H2/H2O, 50 mL/min/cm2
Re(Z) / W.cm2
-Im
(Z)
/ W
.cm
2
0
5
10
15
20
25
30
35
0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5h / V
i /
10
-3A
.cm
-2
750°C, H2/H2O, 50 mL/min/cm2IST20, 5mm,1100°C
ARM20, 1000°C
ARM20, 1100°C
DLR10, 20 mm, 1100°C
DLR10-Ni, 20mm, 1100°C
Kinetic limitation of the reponse of the anode
Major improvement of the performance by
adding metal catalyst
Nyquist plot of symetricall cells by varying microstructure
1cm²
Were we are after 15 monthsUnderstanding perovskite as anode material (Grenoble INP)
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 16
Were we are after 15 monthsUnderstanding perovskite as anode material: Modeling (DLR)
Nyquist plot, T = 924 K
Bode plot
Nyquist plot, T = 1125 K
924 K
LF arc: hydrogen adsorption and formation of OH groups
IF arc: oxygen charge-transfer through LST/CGO-YSZ interface
1125 K
LF arc: LST surface charge-transfer
IF arc: oxygen charge-transfer through LST/CGO interface
H2 adsorption
OH formation
Surface
charge-transfer
Interstitial
charge-transfer
Interstitial
charge-transfer
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 17
Were we are after 15 months
Cathodic compartment (DLR)1cm²
development of PVD CGO barrier layer to prevent
reactivity between LSCF and YSZ (cathode)
CGO coated at 700°C / LSCF brushed and sintered at 1100°C
LSCF
CGO
YSZ
La Sr
Co
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 18
EVOLVE: development strategy
1cm² 15-20 cm² 100 cm²
- Shaping strategy
- Prototype
- Testing and optimization
(DLR)
10mm
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 19
Shaping Strategy
Low risk approach
Short term / Prototype demonstration
Plasma Spraying approach
1
High risk / high impact
Long term
PVD Electrolyte
2
EVOLVE: development strategy
Key challenge: produce a thin hermetic electrolyte
Sintering route discarded because of High Temperature problematic due to
differential shrinkage
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 20
EVOLVE: shaping
1 Plasma spray approachLow risk approach using the know how from DLR for spraying YSZ
layers. No need of sintering step.
100µm thick electrolyte
Cathode
Co-pressed LST-CGO infiltrated
NiCrAl foam
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 21
Power density : 20mW/cm² at 0,7V at 750°C H2-N2 (50-50) / Air
No significative degradation over 180h in galvanostatic condition
OCV for 140h
At 180mA for 180h
Where we are…
Situation at M15
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 22
No significative degradation over 180h in galvanostatic condition
Compatibility of used materials. Succesfull achievement of milestones criteria
planed at M18
Improvement of performance requires major optimization of microstructure
Where we are…
Situation at M15
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 23
EVOLVE: shaping
2 Toward the next generation: PVD electrolyteHigh risk approach. Breakthrough technology.
- Incorporation of active anode layer
- Large reduction of the electrolyte thickness <5µm
Current collector
Active Anode
Active Anode
Buffer YSZ layer
CGO Layer3µm
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 24
EVOLVE: shaping
Toward the next generation: PVD electrolyte
Still survive
further thermal
treatment at
1000°C
Note : First bi-layer 3µm thick electrolyte have been produced with leak-rate comparable or
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 25
1E-3
0,01
0,1
1
10
NS YSZ @ 900o
C-2
+PVD 2um @ 600o
C
co-fired @ 1000 o
C
NS YSZ @ 900o
C-2
+PVD 2um @ 600o
C
co-fired @ 900 o
C
NS YSZ @ 900oC-3
+PVD 4um @ 600o
C
NS YSZ @ 900oC-2
+PVD 2um @ 600o
C
NS YSZ @ 900oC-1
+PVD 2um @ 600o
C
NS YSZ @ 600oC-3
+PVD 4um @ 600o
C
NS YSZ @ 600oC-2
+PVD 2um @ 600o
C
NS YSZ @ 600o
C-1
+PVD 2um @ 600o
C
co-fired @ 900 o
C
NS YSZ @ 600o
C-1
+PVD 2um @ 600o
C
Leak r
ate
(hP
a*d
m3)/
(s*
cm
2)
Sample
quality control threshold
Note : First bi-layer 3µm thick electrolyte have been produced (48mm roud shape
cells) with leak-rate comparable or better than state of the art plasma sprayed
electrolyte. Test on going.
Degradation of
leak rate in case of
further thermal
treatment
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 26
Improvement of coating processes to increase the active surface area of anode
material and implement succesfully PVD coatings for Electrolytes for next
generation SOFC
Conclusion:
Toward the next generation of SOFC
• Possibility of use of perovskite materials in electrode supported cell
• Feasibility of the cell architecture have been proved by means of plasma spraying
• No sintering step in reducing atmosphere
• No over reactivity between cell components have been shown in the tested conditions
• Stability of the cell for at least 100hrs of operation at 0,8V
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 27
Thank You !
> Workshop MSC > R.Costa • Evolve > 22/05/2014DLR.de • Chart 28
Acknowledgement:
FCH JU for funding under the grant Agreement n°303429
DLR: F. Han, A. Hornes, V. Yurkiv, and the whole HTE Group
Alantum: R.Poss, A. Tillmann
ARMINES: A. Chesnaud, D. Masson, F. Willot, B. Abdallah, A. Thorel
CerPoTech: R. A. Strøm, G. Syvertsen, A. Solheim
Ceraco: R. Semerad
CNR: A. Sanson, E. Mercadelli, A. Gondolini, M. Viviani, P. Piccardo,
S. Presto, F. Perrozzi
Grenoble INP: L. Dessemond, G. Constantin
Saan Energi: A. Ansar