AST Protocols for PEM Water Electrolyis : Insight on … · 2nd international workshop on...
Transcript of AST Protocols for PEM Water Electrolyis : Insight on … · 2nd international workshop on...
2nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
• 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 Union » L. Bertuccioli, Feb 2014
European KPI objectives*
| 52nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
• 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 durabilityNeed Accelereted stress test (AST)
| 62nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
• PEM WE suffer from less intensive researches on durability and degradation than PEM FC
CONTEXT
Web of science:Citation report on 01/27/2016
0
50
100
150
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
PEM WE vs. PEM FCon
Research activities on Degradation
PEM WE (40 citation report) PEM FC (1051 citation report)
Keywords: degradation (PEM WE or PEM FC)
| 72nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
OUTLINE
Short introduction on main degrading components in PEM WE
Analytical Methods and main outcomes
Summary and recommendations
| 82nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Short introduction on main degrading components in PEM WE
H+
H2O
O2H2
PorousTi
Pt IrO2
Membrane
H2
H+
H2O
O2H2
PorousTi
Pt IrO2
Membrane
H2
Anode catalystdegradation
BP degradation
Membrane degradation
Cathode catalystdegradation
Center Edge
Most of the cellcomponents may age
| 92nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 / hj = 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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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-3y = 1,46E-04x + 1,47E+00
R² = 6,87E-01
y = 5,36E-04x + 1,69E+00R² = 7,02E-01
y = 1,38E-03x + 1,92E+00R² = 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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
AST-4H2O + 5 ppm Fe
AST-4 : was stopped earlier
5 ppm Fe3+ is a too high concentration
200 mV in 48h
Few tens of ppb might be enough
Analytical Methods and main outcomes
| 162nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 wihout further analyses
| 172nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
Cyclic voltammetry
IrO2(OH)y ↔ IrO2+δ(OH)y-δ + δ (H+ + e-)
| 182nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
Cyclic voltammetry
Qtot= Qinner + Qouter Ardizzone et al. Electrochimica acta vol 35 n° 1- 263-267 (199
| 192nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
Cyclic voltammetry
10 mV/h scan rate
The different shapes of CV do not affect the Pol.Curve (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 VRHE)
| 202nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
-40
-30
-20
-10
0
10
20
30
40
50
0 0,5 1 1,5j / m
A/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
Curr
ent d
ensit
y mA/
cm2
Cell voltage / V
BoL _ AST-3t0 + 47,5h AST-3t0 + 95h AST-3t0 + 142,5h AST-3t0 + 190h AST-3t0 + 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 Hupd peak
| 212nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
| 222nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 behaviour)
| 232nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
With ageing RΩ decrease at high current density
RHFLoop and RLFLoop do not change with ageing (consistent with activation part Pol.curves)The increase of Rpol is due to RΩ
| 242nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
fc = 1 / (2π RC)
Effect of the polarization reduces the charge transfer resistance (LFloop) 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 with the ageing)
-15
-10
-5
00 1 10 100 1 000
Phas
e / °
Freq / Hz
BoL@1A/cm2
BoL@2A/cm2
-15
-10
-5
00,10 1,00 10,00 100,00 1 000,00
Phsa
e °
Freq /Hz
BoL AST-1 @ 0.1A/cm2After 48h AST-1 @ 0.1 A/cm2After 96h AST-1 @ 0.1 A/cm2After 144h AST-1 @ 0.1 A/cm2After 192h AST-1 @ 0.1 A/cm2
| 252nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
Analyses from Bode representation-16-14-12-10
-8-6-4-20
0 1 10 100 1 000
Phsa
e °
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
0,01 10 100 1 000
Phas
e / °
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
Phas
e / °
Freq / Hz
BoL@ AST-2 @ 2 A/cm2After 47.5h AST-2 @ 2A/cm2After 95h AST-2 @ 2 A/cm2After 142,5 h AST-2 @ 2 A/cm2After 190 h AST-2 @ 2 A/cm2After 237.5h AST-2 @ 2 A/cm2After 285h AST-2 @ 2 A/cm2
-16
-14
-12
-10
-8
-6
-4
-2
00 1 10 100 1 000
Phas
e / °
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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
Fluo
ride
ppm
water cathode side
water anode side
Current density / mA/cm2
| 272nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Analytical Methods and main outcomes
30 µm lost 1500 h (20 nm/h)
| 282nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 (contrary to expectations)
Erratic points
| 292nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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 mΩ .cm2GDL // aged (IrO2/CC) // BP 68 mΩ.cm2
GDL // aged (CC/IrO2) // BP 426 mΩ.cm2
GDL // fresh CC) // BP 79 mΩ .cm 2
// InterfaceCC/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 | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Increase of RΩ is mainly caused by the interface « soft material »// Curr.Coll.
Results from G-EIS
Results from contact resistance
Analytical Methods and main outcomes
| 322nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
SEM qualitative analyses
BoL (Après conditionnement)
H2O H2O + O2
H2O + H2
Analytical Methods and main outcomes
| 332nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
BoL
EoL AST-1
Analytical Methods and main outcomes
| 342nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
BoL
EoL AST – 2
Analytical Methods and main outcomes
| 352nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
BoL
EoL AST-3
Analytical Methods and main outcomes
| 362nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
BoL
EoL AST-4
Analytical Methods and main outcomes
| 372nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
Summary and recommendations
Conclusion
AST are more agressive than steady state ageing (40 times faster in comparison with 5 cellules – 300 cm2 for 4000h)
AST-2 able to thin the membrane and oxidized CCMost complete ageing protocols from those tested
2nd | Fouda-Onana Frédéricinternational workshop on durabiltiy and degradation issues in PEM electrolysis cells and its components
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