THE DEVELOPMENT OF A PEM
ELECTROLYSER AST ELECTROHYPEM SYMPOSIUM
11TH DECEMBER 2014
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Contents
• Introduction to ITM
• ElectroHyPEM Results
• Summary
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THE DEVELOPMENT OF A PEM
ELECTROLYSER AST ELECTROHYPEM SYMPOSIUM
11TH DECEMBER 2014
RAPID RESPONSE
HYDROGEN ENERGY SYSTEMS
RAPID RESPONSE ELECTROLYSER
ITM Electrolyser
Clean Fuel
Energy Storage Wind Power
Grid
Scalable| Rapid Response | Self pressurising
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COMMERCIAL DEAL FLOW
HYDROGEN ENERGY SYSTEMS
ENERGY STORAGE | CLEAN FUEL
ITM Electrolyser
Wind Power
Grid
P2G Thuega
HRS H2USA
Energy Storage Sale: The Thuga Group | Germany
Clean Fuel Bid: California Energy Commission
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Rapid response on-site electrolysis
• Modular design
• Input water clean-up
• Power conversion
• Pressurised electrolysis
• Thermal regulation system
• Hydrogen purification
• PLC control and data comms
• Remote operation
• CE Marked
• Assistance with site approvals
ELECTROLYSER PLATFORM
A MODULAR OFFERING
HYDROGEN ENERGY SYSTEMS
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REMOTE MONITORING
SUPPORT SERVICES
HYDROGEN ENERGY SYSTEMS
Support
• Operation is fully automated
• All plants include condition monitoring
• Data logging is available
• Remote upgrades & fault diagnosis
• Data connection via secure VPN tunnel
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MOTIVATION
DEVELOPMENT OF AST
STACK TESTING
ELECTROHYPEM
RESULTS
ELECTROHYPEM MATERIALS INNOVATION
Aim: Improvement of stack materials to increase
the performance with a focus on moving
technology from the laboratory to commercial
deployment
1. Increase performance
2. Lower cost MEA’s
3. Ensure long term durability
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
Electrolyser Stacks are expensive
Everything must be underpinned by quality
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MODELING OF PEM ELECTROLYSER
Performance Modelling
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Ce
ll V
olt
age
(V
)
Current Density (A∙cm-2)
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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MODELING OF PEM ELECTROLYSER
Performance Modelling
• At low current densities,
performance is dominated by
the catalyst.
• At high current densities the
biggest gains can be achieved
through the use of “better”
membranes
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Ce
ll V
olt
age
(V
)
Current Density (A∙cm-2)
Baseline
Improved Catalyst
Improved Membrane
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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MODELING OF PEM ELECTROLYSER
Performance Modelling
• At low current densities,
performance is dominated by
the catalyst.
• At high current densities the
biggest gains can be achieved
through the use of “better”
membranes
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Ce
ll V
olt
age
(V
)
Current Density (A∙cm-2)
Baseline
Improved Catalyst
Improved Membrane
Increasing current
density lowers cost
of infrastructure
Lowering over-
potential reduces the
cost of hydrogen
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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UNDERSTANDING DEGRADATION
Current cycling
• Intermittent current cycling does not cause
degradation
5
5.1
5.2
5.3
5.4
5.5
5.6
0 500 1000 1500 2000
Stac
k V
olt
age
Time [hours]
0
0.2
0.4
0.6
0.8
1
1.2
0 10 20 30 40
i (A
∙cm
-2)
Time (mins)
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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MEASURING DEGRADATION THROUGH EIS
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0 0.2 0.4 0.6 0.8 1 C
ell
Vo
ltag
e (
V)
Current Density (A∙cm-2)
EIS measured under operation
EIS modeled using standard equivalent
circuit models
• De Levie’s transmission line or
• a simple Randles–type circuit with two
time constants
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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Rct IS A CONSTANT – PROOF
At a distance away from the equilibrium potential the Butler-Volmer equation simplifies to
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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Rct IS A CONSTANT – PROOF
At a distance away from the equilibrium potential the Butler-Volmer equation simplifies to
The charge transfer resistance is the slope of this curve
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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Rct IS A CONSTANT – PROOF
At a distance away from the equilibrium potential the Butler-Volmer equation simplifies to
The charge transfer resistance is the slope of this curve
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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Rct IS A CONSTANT – PROOF
At a distance away from the equilibrium potential the Butler-Volmer equation simplifies to
The charge transfer resistance is the slope of this curve
This simplifies to:
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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Rct IS A CONSTANT – PROOF
At a distance away from the equilibrium potential the Butler-Volmer equation simplifies to
The charge transfer resistance is the slope of this curve
This simplifies to:
Therefore the Tafel slope is simply = 2.303 I Rct
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
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-0.1
0
0.1
0.2
0.3
0.4
0 0.2 0.4 0.6 0.8 1 1.2
Z''
Z'
Rct IS A CONSTANT
Note: EIS measured using a
reference electrode that was short
circuited to platinum wire through a
small capacitor
Same catalyst - OER
300% increase in surface area
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ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
IV CURVES USING A REFERENCE ELECTRODE
-0.5
0
0.5
1
1.5
2
0 0.2 0.4 0.6 0.8 1
Po
ten
tial
(V
)
Current Density (A∙cm)
Cell Voltage
Anode Potential (vs NHE)
Cathode Potential (vs NHE)
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Performance is dominated by the anode
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
TOWARDS A CATALYST A.S.T.
Current cycling
• Over short time periods the potential
of the cathode does not alter
dramatically
• This explains why we do not see
degradation despite tens of
thousands of cycles
-0.5
0
0.5
1
1.5
2
0 50 100 150 200
Po
ten
tial
(V
)
Time (s)
Cell Voltage
Anode Potential
Cathode Potential
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ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
TOWARDS A CATALYST A.S.T.
Current cycling
• Over short time periods the potential
of the cathode does not alter
dramatically
• Voltage cycling causes dramatic
swings in cathode potential
-1
-0.5
0
0.5
1
1.5
2
2.5
0 50 100 150 200
Po
ten
tial
(V v
s SH
E)
Time (s)
Cell Voltage
Cathode Potential
Anode Potential
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ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
IV AFTER A.S.T.
-0.5
0
0.5
1
1.5
2
0 0.2 0.4 0.6 0.8 1 1.2
Po
ten
tial
(V
vs
SHE)
Current Density (A∙cm-2)
Cell Voltage (S.O.L.)
Cell Voltage (E.O.L.)
Anode (S.O.L.)
Anode (E.O.L.)
Cathode (S.O.L.)
Cathode (E.O.L.)
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Loss of performance is all on the cathode
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
STACK TESTING
3 cell stack testing
• Three membranes tested
• Aquivion E98-09S was best overall
membrane
• Stack tested under pressure
• Gas crossover measured
• Catalysts tested by current cycling
• Voltage cycling in progress
1.00
1.10
1.20
1.30
1.40
1.50
1.60
1.70
1.80
1.90
2.00
0.00 0.20 0.40 0.60 0.80 1.00 1.20
Ave
rage
Ce
ll V
olt
age
Current Density (A∙cm-2)
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50C
80C
ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
STACK TESTING
3 cell stack testing
• Three membranes tested
• Aquivion E98-09S was best overall
membrane
• Stack tested under pressure
• Gas crossover measured
• Catalysts tested by current cycling
• Voltage cycling in progress
y = -1E-05x + 5.1986
0.0
1.0
2.0
3.0
4.0
5.0
6.0
0 200 400 600 800 1000
Stac
k V
olt
age
(V
)
Time (hours)
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ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
FUTURE WORK
• Optimised MEA containing
ElectroHyPEM cathode catalyst,
ElectroHyPEM anode catalyst, and
optimised Solvay membrane will be
manufactured at ITM.
• The MEA’s will be built into a 20 cell
stack and durability tested under
pressure
• Further work on the AST development
will be performed
• Upon completion of successful tests,
materials will be incorporated into
electrolyser products
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ENERGY STORAGE | CLEAN FUEL
ELECTROHYPEM
Summary
• New AST’s are being developed that will help the whole industry.
• Materials have been optimised and tested in a stack.
• Observations so far suggest the large stack test will be a success.
• ElectroHyPEM has been a great success pushing the performance
limits for a commercial PEM electrolyser!
THE DEVELOPMENT OF A PEM
ELECTROLYSER AST ELECTROHYPEM SYMPOSIUM
11TH DECEMBER 2014
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ACKNOWLEDGMENTS
ACKNOWLEDGEMENTS
ENERGY STORAGE | CLEAN FUEL
Dr Hakan Yildirim
Dr Tiziana Denaro
Elisabeth Payne-Johnson
James Dodwell
Dr Dan Greenhalgh
Andria McHale
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Rachel Lister
Dr Laura Platt
ACKNOWLEDGMENTS
ACKNOWLEDGEMENTS
ENERGY STORAGE | CLEAN FUEL
The research leading to these results has received funding from the
European Community's Seventh Framework Programme (7FP7/SP1-JTI-
FCH.2011.2.7) for the Fuel Cells and Hydrogen Joint Technology Initiative
under grant agreement ELECTROHYPEM no. 300081.
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THE DEVELOPMENT OF A PEM
ELECTROLYSER AST ELECTROHYPEM SYMPOSIUM
11TH DECEMBER 2014
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