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JACQUES Pierre-André, PAUCHET Joel, NAYOZE Christine, GUETAZ Laure MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré[email protected]

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Page 1: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

JACQUES Pierre-André, PAUCHET Joel, NAYOZE Christine, GUETAZ Laure

MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES

pierre-andré[email protected]

Page 2: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

| 2

MEA: THE DIFFERENT STEPS OF MANUFACTURING

7 layers assembly

CCM + rim + GDL GDE + membrane +rim

AL printing

Ink formulation

Catalyst ionomer+ Material technology choice

Process

Technology

choice

ProcessImpact on:

- performance

- durability

- cost stack

design

Page 3: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

| 3

FIRST: 7 LAYERS ASSEMBLY

misaligned GDL

Air pocket under subgasket Dust on the subgasket

Alignement of the MEA (GDL + CCM + rim) is a requirement.

1 defected MEA (misaligned, issue on the rim) causes failure on the whole stack:

- Leakage, gas by pass, not homogenous compression

Check tolerance of MEA alignment Vs Stack tolerance chain.

At lab scale : not an issue, what about high speed manufacturing ?

wrinkle

2D control

on 50 points

Page 4: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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GDL: A KEY ELEMENT

Understanding the impact of GDL properties on stack performance

is still to be improved : Defect definition

43%

18%

21%

2%16%

47%

20%

23%

1%9%

50%HR

100%HR

ChannelsDMMPLAL

Ionomere

Influence on

performance

Thermal property of different GDL

with defects and without defects

Manufacturing

• Process/parameters

• Requirements

• Selection (criteria)

Assembling

• Process/parameters

• Requirements

Testing

• Performance

• Durability

• Requirements

• Acceptance (criteria)

1. Better understand the link between (local) properties of GDL to their performance/durability

2. Propose improvements

1. What is a defect?

2. Define selection/acceptance criteria as a trade-off

quality/price:

• General ones?

• Specific ones depending on the MEA, BPP, OC…

3. On-going DIGIMAN project as an example

Off-line characterization

On-line characterization

3D image of a commercial GDL

Performance w/wo defects

Samples batch 1

Samples batch 2

Page 5: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

| 5CEA LITEN DEHT | June 2014

ACTIVE LAYER: IN PLANE

Electrode characterization

Pilot line of electrode manufacturing in line detection

CCM

Macro defect:

optical check thanks to contrast AL Vs support

Hot spot thicker smudge

Cool spot thinner coating

Defects detection on GDE with

Reactive Impinging Flow Excitation (RIF)

Link between defects detection and

catalyst loading on GDE : On line

adaptation of the ink for each :

- Process

- Material technology (ionomer, catalyst)

- Electrode design

numbering

Page 6: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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Active Layer inhomogeneity

- no AL membrane penetration

No Pt band in the membrane:

validates the sample preparation

Pt band Might cause issue on durability

Impact on BoL performance ?

Not or only few(reinforced membrane)

SEM observation after : 150 hrs – 10,000 km in HyKangoo

Pt band

CCB Membrane stress

ACTIVE LAYER:

IMPACT OF THE PROCESS

Holes and cracks in the AL impact

the membrane integrity;

Cracks from : MPL and/or process

20 µm

Inactive Pt

MEA cross section

AL front view

Page 7: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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ACTIVE LAYER: THROUGH PLANE

CCM cross section : SEM characterization

Aggregates without polymer inactive Pt, loss of ECSA

Membrane penetration in AL crack membrane weak point ?

AL aggregates penetration in AL thinner membrane, weak point ?

10 µm 10 µm

Catalyst aggregates :

- no ionomer,

- no catalyst ripening

- Inactive Pt

impact on Pt loading

Impact on ageing

- Deformation

of the membrane

- Short circuit / hole

Impact on ageing

failure

CCM

Membrane stress

F in green

Pt in red

Page 8: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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INK FORMULATION

The ink preparation process affecting:

- the numbers of aggregates and the viscosityTo be tuned for each material technology (ionomer, catalyst) and process

Impact of dispersion process parameter

0

0,5

1

1,5

2

0,01 0,1 1

Po

pu

lati

on

wt%

Size (µm)

Avant dispermat

5 min dispermat

15 min dispermat

80 nm -> 120 nm520 nm -> 1050 nm

0

10

20

30

40

0,1 1

po

pu

lati

on

wt%

Size (µm)

Après dispermat

Après aquivion

780 nm

Init

ial

ink

Modification of solvent ratio and

components introduction

+ Modification of ratio components

Op

tim

ize

d i

nk

After dispersion

After complete

formulation

CATALYST AND INK PREPARATION

Electroacoustic + zeta probe :

chasing the granulometry of the ink

Ink validation before AL printing

0

0,2

0,4

0,6

0,8

1

1,2

1 10 100 1000

Po

pu

lati

on

wt%

Size (µm)

Essai 1

Essai 2Essai 3

39 µm

Trial 1

Trial 2

Impact of solvent and ratio components

Page 9: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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OPERANDO CHARACTERIZATION OF MEA :

SEGMENTED BOARD

Textured electrode

Current density distribution mapping CDDM

MEA homogeneity

impact of RH, stoichio, fuel composition

Uniformed electrode

2

1

A tool to study the impact of one

« defected » MEA on the stack

and « defect » propagation

Different AL designs give different CDDM

Page 10: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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OPERANDO CHARACTERIZATION OF MEA :

MAGNETIC FIELD AND ELECTROCHEMICAL IMPEDANCE

Instrumented stack integrating a « defected MEA »

0 0.2 0.4 0.6 0.80

0.2

0.4

0.6

0.8

1

1.2

Re(Z) (.cm²)

-Im

(Z)

( .c

m²)

segment n°10

data

fit

0 0.2 0.4 0.60

0.2

0.4

0.6

0.8

1

1.2

Re(Z) (.cm²)

-Im

(Z)

( .c

m²)

segment n°10

data

fit

Evolution of EIS between :

homogeneous AL and voluntary defected AL

Lyes IFREK, Thesis, 2017

Thomas Gaumont, Thesis, 2017

Page 11: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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SEM on MEA cross section

after 900 hrs (stationary + Fc-DLC) CEA CCM:

- cathode loading 0,35 mgPt/cm2

- Anode loading 0,1 mgPt/cm2

DURABILITY TEST WITH HIGH QUALITY ACTIVE LAYER

@ 0,6 A/cm2

@ 0,4A/cm2

Page 12: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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• What is a defect ?

Need to establish defect specification and ranking

- Failure of the stack

- Decrease of BoL performance

- Decrease of durability decrease of EoL performance Vs failure

- Next generation material

Understanding the link :

1\ material and component specification stack performance

2\ material and component specification stack durability

Material and component validation :

- Definition of the main parameters to be tracked

- Definition of the quality assurance (on line Vs off line)

- 100 % areal checking Vs selected validation points

- Available tools for defect detection ?

CONCLUSION

Page 13: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

Defect < Component specification < over quality

MEAIntegration

Full stack characterisation

In situ and integrated component characterisation

Ex situ and single component characterisation

Modelling as a tool

Ink processing & manufacturing

Cell performance

Component structure

Inferfaceoptimisation

Impact on each physical parameter

Inspection of the main parameterquality management policy

Page 14: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

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• Irina Profatilova• Frédéric Fouda-Onana

• Marie Heitzmann• Sebastien Rosini• Fabrice Micoud

• Sylvie Escribano• Dominique Thoby• Arnaud Morin

• Claude Bonin• Pierrick Buvat• PEMFC team @ CEA-Liten

• Michael Ulsh

• Guido Bender

THANKS TO :

• Yann Bultel

• Lyes Ifrek

• Thomas Gaumont

• Olivier Lottin

• Steffen Theuring

• Coen Van Aken

Page 15: MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES · MEA; MANUFACTURING PROCESSES & QUALITY TECHNIQUES pierre-andré.jacques@cea.fr | 2 MEA: THE DIFFERENT STEPS OF MANUFACTURING 7

Commissariat à l’énergie atomique et aux énergies alternatives

17 rue des Martyrs | 38054 Grenoble Cedex

www-liten.cea.fr

Établissement public à caractère industriel et commercial | RCS Paris B 775 685 019

MERCI POUR VOTRE ATTENTION

THANKS FOR YOUR ATTENTION