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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