ast protocols for pem water electrolyis ...ast-1: 48h ast signal @ 90 c repetaed at least 4 times...
TRANSCRIPT
2nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
AST PROTOCOLS FOR PEM WATER ELECTROLYIS :INSIGHT ON PERFORMANCES AND COMPONENTS DEGRADATION
| 2
Fuel Cells&
ElectrolyzersBattery Solar Biomass
| 3
EXPERIMENTAL RESOURCES AT DIFFERENT SCALES
| 42nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
• High performing and durable PEM WE are need.
A linear voltage degradation of 1µV/hr translates into an additional electrical energy input of ~2 kWh/kgH2after 60,000 hours of continuous operation.
CONTEXT
* FCH JU Report « Development of Water Electrolysis in the European Unio n » L. Bertuccioli, Feb 2014
European KPI objectives*
| 52nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
• Most of PEM WE show a degradation voltage between 0,5 and 15 µV/h
CONTEXT
4 µV/h after 60 kh
Highly time consumming to investigate system durabilit y
Need Accelereted stress test (AST)
| 62nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
• PEM WE suffer from less intensive researches on durability and degradation than PEM FC
CONTEXT
Web of science:Citation report on 01/27/2016
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PEM WE vs. PEM FC
on
Research activities on Degradation
PEM WE (40 citation report) PEM FC (1051 citation report)
Keywords: degradation (PEM WE or PEM FC)
| 72nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
OUTLINE
Short introduction on main degrading components in PEM WE
Analytical Methods and main outcomes
Summary
| 82nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Short introduction on main degrading components in PEM WE
H+
H2O
O2H2
Porous
Ti
Pt IrO2
Membrane
H2
H+
H2O
O2H2
Porous
Ti
Pt IrO2
Membrane
H2
Anode catalystdegradation
BP degradation
Membrane degradation
Cathode catalystdegradation
Center Edge
Most of the cellcomponents may age
| 92nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Pol.Curve
ECSA
G-EIS
FRR
Contact Resistance
SEM
AST Protocol
AfterIn situ analyses
In situ analyses Ex situ analyses
| 102nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
AST-1: 48h AST signal @ 90°C repetaed at least 4 times
AST-2: 48 h AST@ 90°C repeated at leat 4 times
AST-3: : 48 h AST@ 90°C repeated at leat 4 timeswith ∆P (PO2 = 4 bar vs. PH2 = 1 bar )
AST- 4: 48 h AST@ 90°C repeated at leat 4 times with 5ppm Fe ions
• 3 A/cm2 (E > 2V) : speed up BP corrosion• 0,3 A/cm2 : speed up membrane attack
• Longer step time at low current density to amplify the membrane chemical attack
• Suppose to amplify the oxygen permeationand accelerate the membrane attack
• Adding metal ion impurities may catalyse the Fenton reaction.
| 112nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Pol.Curve
ECSA
G-EIS
FRR
Contact Resistance
SEM
AST-1AST-2AST-3AST-4
AfterIn situ analyses
In situ analyses Ex situ analyses
| 122nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
AST-1
Higher efficiency losses at high current density.
No clear impact in the « activation zone » of the Pol.Curv.
y = 1,25E-04x + 1,472E+00
y = 6,25E-04x + 1,68E+00
y = 1,02E-03x + 1,90E+00
1,3
1,5
1,7
1,9
2,1
2,3
0 50 100 150 200 250
E /
V
Time / h
j = 200 mA/cm2 j = 1000 mA/cm2 j = 2000 mA/cm2
Efficiency loss
12,1 %
7,1 %
1,6 %
1,3
1,5
1,7
1,9
2,1
2,3
0 500 1000 1500 2000 2500
E /
V
j / mA.cm-2
BoL-AST-1
After 48 h of AST-1
After 96 h of AST-1
After 144 h of AST-1
After 192 h of AST-1
1,4
1,45
1,5
1,55
1,6
10 100 1000
E /
V
j / mA.cm-2
| 132nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Efficiency losses every 100h
Efficiency losses
18,3 %
10,5 %
3,4 %
AST-2
Again higher efficiency losses at high current density
1,3
1,5
1,7
1,9
2,1
2,3
0 1000 2000
E /
V
J / mA.cm-2
BoL AST-2
After 47.5h AST-2
After 95h AST-2
After 142.5h AST-2
After 190h AST-2
After 237.5h AST-2
After 285h AST-2
Analytical Methods and main outcomes
| 142nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Efficiency losses every 100h (close to AST-2)
Efficiency losses
17 %
7,5 %
2,3 %
AST-3
Again higher efficiency losses at high current density
1,3
1,5
1,7
1,9
2,1
2,3
0 500 1000 1500 2000 2500
E /
V
j mA/cm2
BoL AST-3
After 47.5h AST-3
After 95h AST-3
After 142.5h AST-3
After 190h AST-3
After 237.5 h AST-3
y = 1,46E-04x + 1,47E+00
R² = 6,87E-01
y = 5,36E-04x + 1,69E+00
R² = 7,02E-01
y = 1,38E-03x + 1,92E+00
R² = 7,57E-01
1,3
1,5
1,7
1,9
2,1
2,3
0 100 200 300
E /
V
Time / h
@ 0.2 A/cm2 @ 1 A/cm2 @ 2 A/cm2
Analytical Methods and main outcomes
∆P (PO2 = 4 bar vs. PH2 = 1 bar )
| 152nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
AST-4H2O + 5 ppm Fe
AST-4 : was stopped earlier
5 ppm Fe 3+ is a too high concentration
200 mV in 48h
Few tens of ppb might be enough
Analytical Methods and main outcomes
| 162nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Conclusion from Pol.Curve
Deg
rada
tion
slop
eµV
/h
Ageing more important at high current(caused by the resistance ).
Cannot conclude without further analyses
| 172nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Cyclic voltammetry
IrO2(OH)y ↔ IrO2+δ(OH)y-δ + δ (H+ + e-)
| 182nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Cyclic voltammetry
Qto t= Qinner + Qouter Ardizzone et al. Electrochimica acta vol 35 n° 1- 263-267 (1990)
| 192nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Cyclic voltammetry
10 mV/h scan rate
The different shapes of CV do not affect the Pol.Curv e (activation part)
After 196 h(EoL) CV unusal shape, probably too resitive contact resistance
After 144 h appearence of Hupd peak (0 < E < 0,3 V RHE)
| 202nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
-40
-30
-20
-10
0
10
20
30
40
50
0 0,5 1 1,5j /
mA
/cm
2
E /V
BoL
t0 + 47.5 h _ AST-2
t0 + 95h _ AST-2
t0 + 142.5 h _ AST-2
AST – 2
-100
-50
0
50
100
150
0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6
Cu
rre
nt
de
nsi
ty m
A/c
m2
Cell voltage / V
BoL _ AST-3
t0 + 47,5h AST-3
t0 + 95h AST-3
t0 + 142,5h AST-3
t0 + 190h AST-3
t0 + 237,5h AST-3
AST – 3
AST – 1
Same conclusion for AST2 and AST-3 than AST-1
No effect of the active surface area change on the Pol.Curves
With ageing, appears H upd peak
| 212nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
| 222nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
RΩ independant of the current density (ohmic behaviour)
RHFLoop decrease with polarization (charge transfert behaviour )
RLFLoop decreases with polarization (charge transfert behaviou r)
| 232nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
With ageing R Ω decrease at high current density
RHFLoop and RLFLoop do not change with ageing (consistent with activation part Pol.curves)
The increase of R pol is due to R Ω
| 242nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
fc = 1 / (2π RC)
Effect of the polarization reduces the charge transfer resistance (LF loop ) that increases Cutt-off Frequency
Analyses from Bode representation
Effect of the ageing reduces the Cdlthat increases Cutt-off frequency(consistent with the outer capacitance diminution wit h the ageing)
-15
-10
-5
0
0 1 10 100 1 000
Ph
ase
/ °
Freq / Hz
BoL@1A/cm2
BoL@2A/cm2
-15
-10
-5
0
0,10 1,00 10,00 100,00 1 000,00
Ph
sae
°
Freq /Hz
BoL AST-1 @ 0.1A/cm2
After 48h AST-1 @ 0.1 A/cm2
After 96h AST-1 @ 0.1 A/cm2
After 144h AST-1 @ 0.1 A/cm2
After 192h AST-1 @ 0.1 A/cm2
| 252nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Analyses from Bode representation-16
-14
-12
-10
-8
-6
-4
-2
0
0 1 10 100 1 000
Ph
sae
°
Freq /Hz
BoL @ 0.1A/cm2
BoL + 48h AST-1 @ 0.1 A/cm2
BoL + 96h AST-1 @ 0.1 A/cm2
BoL + 144h AST-1 AST-1 @ 0.1 A/cm2
BoL + 192h AST-1 @ 0.1 A/cm2
-1,8
-1,6
-1,4
-1,2
-1,0
-0,8
-0,6
-0,4
-0,2
0,0
1 10 100 1 000
Ph
ase
/ °
Freq / Hz
BoL AST-1 @ 2 A/cm2
After 48 h AST-1 @ 2 A/cm2
After 96 h AST-1 @ 2 A/cm2
After 144h AST-1 @ 2 A/cm2
After 192 h AST-1 @ 2 A/cm2
-2,9
-2,7
-2,5
-2,3
-2,1
-1,9
-1,7
-1,5
-1,3
-1,1
-0,9
-0,7
-0,5
1 10 100 1 000
Ph
ase
/ °
Freq / Hz
BoL@ AST-2 @ 2 A/cm2
After 47.5h AST-2 @ 2A/cm2
After 95h AST-2 @ 2 A/cm2
After 142,5 h AST-2 @ 2 A/cm2
After 190 h AST-2 @ 2 A/cm2
After 237.5h AST-2 @ 2 A/cm2
After 285h AST-2 @ 2 A/cm2
-16
-14
-12
-10
-8
-6
-4
-2
0
0 1 10 100 1 000
Ph
ase
/ °
Freq / Hz
After 1st AST-2 @0.1A/cm2
After 2nd AST-2 @0.1A/cm2
After 3rd AST-2 @ 0.1A/cm2
After 4th AST-2 @0.1A/cm2
After 5th AST-2 @0.1A/cm2
After 6th AST-2 @0.1A/cm2
Cut-off frequency shitf might be linked to the electrodedegradation
AST-1
AST-2
| 262nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Fluoride is found mainly on thecathode side
Temperature and Setting currenteffect on FRR*
These results lead us to define AST parameters(0,3 A/cm 2 and high temeprature 90°C )
* M.Chandesris et al. Int.J.Hyd. Energy, 40 (2015) 1353 - 1366
Flu
orid
epp
m
water cathode side
water anode side
Current density / mA/cm 2
| 272nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
30 µm lost 1500 h (20 nm/h)
| 282nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
AST-2 and AST-3 more degrading than AST-1
AST-3 do not age more the membrane than AST-2 (contr ary to expectations)
Erratic points
| 292nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Pol.Curve
ECSA
G-EIS
FRR
Contact Resistance
SEM
AST-1AST-2AST-3AST-4
AfterIn situ analyses
In situ analyses Ex situ analyses
| 302nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Analytical Methods and main outcomes
Contact resistance BPP/Curr.Coll Résistance de contact « soft material » // Curr.Coll
Bulk measurement Interfacial Contact Resistance
Aged CC 20 µΩ.cm2
Fresh CC 20 µΩ.cm2
Aged (CC/IrO2) // BP 13,9 mΩ.cm2
Aged (IrO2/CC) // BP 22,6 mΩ.cm2
Fresh CC // BP 1 m Ω .cm2
GDL // aged (IrO2/CC) // BP 68 mΩ.cm2
GDL // aged (CC/IrO2) // BP 426 mΩ.cm2
GDL // fresh CC) // BP 79 m Ω .cm2
// Interface
CC/IrO2 // BP: IrO2 facing CC in contact with the BP
No bulk resistance difference
IrO2 remaining particles improve interface resistance BP/Curr Coll.
Higher contact resitance witha «soft material ».
Contact Resistance
| 312nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Increase of R Ω is mainly caused by the interface « soft material »// Curr.Coll .
Results from G-EIS
Results from contact resistance
Analytical Methods and main outcomes
| 322nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
SEM qualitative analyses
BoL (After conditioning)
H2O H2O + O2
H2O + H2
Analytical Methods and main outcomes
| 332nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
BoL
EoL AST-1
Analytical Methods and main outcomes
| 342nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
BoL
EoL AST – 2
Analytical Methods and main outcomes
| 352nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
BoL
EoL AST-3
Analytical Methods and main outcomes
| 362nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
BoL
EoL AST-4
Analytical Methods and main outcomes
| 372nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
Summary
Conclusion
AST are more agressive than steady state ageing (40 ti mes faster in comparison with 5 cells – 300 cm 2 for 4000h)
AST-2 able to thin the membrane and oxidized CCMost complete ageing protocols from those tested
2nd international workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components| Fouda-Onana Frédéric
AST PROTOCOLS FOR PEM WATER ELECTROLYIS :INSIGHT ON PERFORMANCES AND COMPONENTS DEGRADATION
Acknowledgements
CEA :S. ChelghoumD. Thoby
Fraunhofer :
A. Georg
Under grant agreement n° [303484]
for the Novel project
European funding:
JM :E. PriceE. Wright
Thank you for the attention