PremiumAct PEMFC DegradationWorkshop 2013-04-03 OK · 2014. 11. 17. · Sylvie Escribano (CEA) •...

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PREMIUM ACT

Sylvie Escribano (CEA)

FCH-JU Projects workshop - PEMFC Degradation Sintef/OSLO – 3rd April 2013

PEMFCDegradation under load cycles with reformate fuel


Programme Review Day 2012 - Brussels, 28 & 29 November

Premium Act

PREdictive Modelling for Innovative Unit Management and ACcelerated Testing

procedures of PEFC

(256776)

Sylvie EscribanoCEA

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Premium Act/11. project & partnership description

Improvement of stationary PEFC systems durability (40000h required!)

�� A reliable method to predict system lifetime, benchmark components and

improve operating strategies

WP6 - Dissemination WP7 - Management

WP1 - SpecificationsWP1 - Specifications

WP2 – Experiments

under real operating

conditions

WP2 – Experiments

under real operating

conditions

WP5 – Lifetime

prediction

methodology

WP5 – Lifetime

prediction

methodology

WP3 – Quantification of

components degradation

WP3 – Quantification of

components degradation

WP4 – Predictive ModellingWP4 – Predictive Modelling

IRD

IRD

DLRPOLIMI

CEA

CEACEA



• Technical aspects

Two fuel cell stack technologies for

stationary power applications:

� DMFC and H2 reformate PEMFC

CHP systems

Experimental investigation

� Tools to quantify & correlate

performance and components

degradation to operating conditions

Multi-physics modelling

� Tools to combine degradation

phenomena and analyse their global

impact on durability

• Technical aspects

Two fuel cell stack technologies for

stationary power applications:

� DMFC and H2 reformate PEMFC

CHP systems

Experimental investigation

� Tools to quantify & correlate

performance and components

degradation to operating conditions

Multi-physics modelling

� Tools to combine degradation

phenomena and analyse their global

impact on durability

• Expected achievements

�� Operating strategies, enhancing lifetime of given MEAs in given stack and system

�� Design of a lifetime prediction methodology based on coupled modelling and composite

accelerated tests experiments (ranking of selected MEAs in real conditions and then following

accelerated tests)

• Expected achievements

�� Operating strategies, enhancing lifetime of given MEAs in given stack and system

�� Design of a lifetime prediction methodology based on coupled modelling and composite

accelerated tests experiments (ranking of selected MEAs in real conditions and then following

accelerated tests)

Premium Act/2

1. Project objectives & Approach

WP1 – Specifications

(from systems)


(from systems)WP2 –

Experiments under real operating

conditions

(systems, stacks & single cell real

ageing tests)

WP2 –Experiments under

real operating conditions


ageing tests)

WP5 – Lifetime prediction

methodology

(SC specific tests: coupling,

validation, Acct)


methodology


validation, Acct)

WP3 – Quantification of components degradation

(Ex-situ characterizations, locally resolved analysis)



WP4 – Predictive Modelling

mechanistic model

+ MEA & cell model


mechanistic model

+ MEA & cell model


(from systems)


(from systems)WP2 –

Experiments under real operating

conditions


ageing tests)

WP2 –Experiments under

real operating conditions


ageing tests)


methodology


validation, Acct)


methodology


validation, Acct)






mechanistic model

+ MEA & cell model


mechanistic model

+ MEA & cell model

Sylvie Escribano (CEA) • FCH-JU projects Workshop PEMFC Degradation • Sintef (Oslo) • 2013/04/035


Outline

� Introduction of objectives and components

� Single cells performance and durability tests � Stack durability tests

� Load cycles� Voltage losses� Electrochemical diagnostics� Focus on fuel composition effect

� Ex-situ investigations



Performance and ageing tests

� Premium Act tests objectives (experimental WP tasks )� Tests following applications specifications� Specific tests representative of critical operating conditions � Sensitivity studies on local & coupling effects � Development of specific accelerated tests

� IRD MEAs

� Single cells 25cm²� IRD Stack tests at CEA

� 10 cells stack – 150 cm²

Description Product ID Catalyst loading Anode GDL Sigracet 35DC

Anode Catalyst Hispec 10000 0.3 mg PtRu/cm2

Membrane Nafion® XL100

Cathode Catalyst Hispec 9100 0.5 mg Pt/cm2

Cathode GDL Sigracet 35DC



Performance and ageing tests

� Performance tests• IRD - 70°C, 100%HR, Patm – pure H2

• 75°C, 100/50%HR, 1,2 bars – pure H2

• 75°C, 100/50%HR, 1,2 bars – Reformate

� Ageing tests – Load cycles� Pure H2 (� reference test)� Reformate: 26ppm then 50ppm CO (extreme case)

� Various fuel composition : effect of CO content during short term cycling tests



Durability tests in single cells

� Durability tests � Representative ageing tests in conditions based on systems

nominal specifications� Then, other conditions & cycling modes




�Cycling tests

Imin: 65 mA/cm²

6h

Imax: 400 mA/cm²

18h

Reformate: average composition

H2: 75%

CO2: 24%

CH4: 1%

5 < CO < 50 ppm

St anode : 1, 2 - 1,3 /St cathode: 2

Panode=Pcathode 1,2 bar

Anode : RH 90-100%

Cathode : RH 40-50%

T : 65 - 75°C

Objective : identification of accelerating parameters (incl. fuel composition, operating conditions, cycles features)

Premium Act reference protocol




Cycling test with pure H2

AME IRD 1619_test validation AME+Cycle_PREMIUM ACT

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 200 400 600 800 1000 1200 1400 1600

i(mA/cm²)

U(V

)

75°C 100/40%RH 1.2b H2 pur

75°C 100/40%RH 1.2b H2 pur 890h

75°C 100/40%RH 1.2b H2 pur_après redemarrage

75°C 100/40%RH 1.2b H2 pur_1065h_avant arrêt

75°C 100/40%RH 1.2b H2 pur_après redemarrage_1066h

� important part of reversible degradation

� possible cross-over increase

� catalyst or catalyst layer operation modifications

� Ex-situ analyses to be conducted (check µstructure and comp. with reformate operation)

-38 µV/h (Imax)

-23 µV/h (Imin)




Cycling test with reformate

@Imax= 89µV/h

@Imin= 30µV/h

H2: 79%

CO2: 20%

CH4: 1,3%

CO: 26 ppm

H2: 79%

CO2: 20%

CH4: 1,3%

CO: 26 ppm

SC voltage / load cycles � high performance degradation rate

-1

-0,8

-0,6

-0,4

-0,2

0

0,2

0,4

0,6

0,8

0 0,2 0,4 0,6 0,8

U(V)

I(A

)

CV CAT BoT

CV CAT EoT

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 200 400 600 800 1000 1200 1400

i(mA/cm²)

U(V

)

75°C 100/40%RH 1.2b H2 pur

75°C 100/40%RH 1.2b H2 pur 1000h-2

75°C 100/40%RH 1.2b H2 reformé

75°C 100/40%RH 1.2b H2 reformé 1000h

� but low permanent degradation of components properties (EoTdiagnostics)

0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)1A reformate 1000h1A H2 1000h1A H2 BoT

BoT H2 BoT reformate

EoT H2 EoT reformate

BoT H2 BoT reformate

EoT H2 EoT reformate

reminder

Maybe some active layer modification (to be identified)

Ex-situ analyses conducted � To be completed for comp. with pure H2 and more CO

Cross Over: not enough membrane damage to explain voltage instabilities



Sensitivity analysis of PEMFC degradation

Self-cleaning oscillations related to full CO coverage

Performance loss but no dramatic increment of degradation (~ slope)

Effect of high [CO]

MEA IRD 1617 / 70°C 100%RH Patm - 75°C 100-50%RH 1.2b / Premium Act "ref" cycles (50ppm CO)

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 20 40 60 80 100 120 140 160 180

t (h)

U (

V)

50 ppm CO

26 ppm CO

MEA IRD 1617_Cycle_PREMIUM ACT

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 200 400 600 800 1000 1200 1400 1600

i(mA/cm²)U

(V)

ref cycles pure H2 1617 BoT

ref cycles 50ppm 1617 BoT

ref cycles pure H2 1617 EoT

ref cycles 50ppm 1617 EoT

�� Study of [CO] on performance degradation & as accelerating factor�� Study of [CO] on performance degradation & as accelerating factor



Effect of [CO]: current tests on SC and stack

• Test on single cell:

• reference load cycles

• [CO] = 0, 10, 20, 50ppm

� Effect on the cell voltage value, decrease, and slope over ~200hours

� Study of 50 ppm as accelerating factor

• Test on IRD stack:

• reference load cycles

• [CO] = 0, 10, 10+Air bleed, 5, (planned 20+Air bleed, 20ppm)

� Effect on the 10 cells voltage values, decrease, and slope over ~200 hours

� Study of 20 ppm or study of T as accelerating factor



SC test - CO concentration effect

Cycling test �� Accelerating effect of high CO concentrations?

0 10 20 50 0 10 50 0 10 50ppmof CO

Phase 1 Phase 2 Phase 3

Compared effect for pure H2 and 10ppm CO case




Cycling test �� Accelerating effect of high CO concentrations?

0 10 20 50 0 10 50 0 10 50ppmof CO

Phase 1 Phase 2 Phase 3

BoT

EoT(~1000h)

Compared effect for pure H2 and 10ppm CO case




31

118

42

347

144 144144 1440

50

100

150

200

250

300

350

400

450

500

i min i max

Vol

tage

loss

rat

e (µ

V/h

)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Duration of the period (h)

BoT V loss rate (µV/h) EoT V loss rate (µV/h)

Duration Duration

Voltage loss / 7 cyclesat BoT and EoT (~ 1000h)

Reformate 10 ppm CO

28

63

14

35

144 144144 144

0

10

20

30

40

50

60

70

80

90

100

i min i max

Vol

tage

loss

rat

e (µ

V/h

)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

Duration of the period (h)

BoT V loss rate (µV/h) EoT V loss rate (µV/h)

Duration Duration

Voltage loss / 7 cyclesat BoT and EoT (~ 1000h)

BoT EoT (~1000h)

Pure H2 Reformate with 10 ppm CO



SC test - CO concentration effectAME IRD 1620_PREMIUM ACT

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 500 1000 1500

i(mA/cm²)

U(V

)

75°C 100/40%RH 1.2b H2 pur-375°C 100/40%RH 1.2b H2 pur 217h75°C 100/40%RH 1.2b H2 pur 457h 75°C 100/40%RH 1.2b H2 pur 696h 75°C 100/40%RH 1.2b H2 pur 926h75°C 100/40%RH 1.2b H2 pur 1105h75°C 100/40%RH 1.2b H2 pur 1285h75°C 100/40%RH 1.2b H2 pur 1468h75°C 100/40%RH 1.2b H2 pur 1473h H2 pur ap redemarrage75°C 100/40%RH 1.2b H2 pur 1687h H2 pur ap 168h de cycles75°C 100/40%RH 1.2b H2 pur 1885h75°C 100/40%RH 1.2b H2 pur 1887h75°C 100/40%RH 1.2b H2 pur 2088h ap redemarrage75°C 100/40%RH 1.2b H2 pur 2111h75°C 100/40%RH 1.2b H2 pur 2112h

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1

0 200 400 600 800 1000 1200

i(mA/cm²)

U(V

)

75°C 100/40%RH 1.2b H2 ref 10ppm 445h

75°C 100/40%RH 1.2b 20ppm 677h

75°C 100/40%RH 1.2b H2 ref 10ppm 1276h

75°C 100/40%RH 1.2b H2 ref 10ppm 1481h

75°C 100/40%RH 1.2b H2 ref 10ppm 1882h

75°C 100/40%RH 1.2b H2 ref 10ppm 2092h

Losses after cycles under pure H2Additional losses after cycles under 50ppm




� CV at BoT & after 1st cycles under pure H2

-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)

AME 1620 Cv CAT avt cycles

AME 1620 CV CAT ap 216h de cycles




� CV after pure H2

-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)



-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)



CV CAT ap 168h de cycles_2e phase





� CV after pure H2 & 10 ppm

-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)



-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)





-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)



CV CAT ap 216h de cycles en H2 ref 10ppm

CV CAT ap 168h de cycles en H2 ref 10ppm_2e phase





� CV after pure H2 & 10 ppm & 50 ppm

-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)



-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)





-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)





CV CAT ap 168h de cycles en H2 ref 10ppm_3e phase-0,9

-0,6

-0,3

0

0,3

0,6

0,9

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9U(V)

I(A

)









� CV after pure H2 & 10 ppm & 50 ppm

-0,3

-0,2

-0,1

0

0,1

0,2

0,3

0,4

0 0,2 0,4 0,6 0,8

U(V)I(A

)

CV ANO 1620 avt cycles

CV ANO 1620 ap 216h de cycles en H2 ref 10ppm

CV ANO ap 168h de cycles en H2 ref 10ppm 2e phase


-0,4

-0,3

-0,2

-0,1

0

0,1

0,2

0,3

0,4

0 0,2 0,4 0,6 0,8 U(V)I(A

)

CV ANO 1620 avt cycles

CV ANO ap 216h de cycles en H2 pur





0

0,0025

0,005

0,0075

0,01

0 0,005 0,01 0,015 0,02 0,025 0,03

Re (Z)

- Im (Z)

4.5A 4.5A ap cycles H2 pur

4.5A ap cycles H2 ref 10 ppm 4.5A ap cycles H2 ref 10 ppm_phase 2

4.5A ap cycles H2 ref 10 ppm_phase 3

0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)

1A 1A ap cycles H2 pur

1A ap cycles H2 ref 10 ppm 1A ap cycles H2 ref 10 ppm_phase 2

1A ap cycles H2 ref 10 ppm_phase 3


� EIS pure H2

Consistent with i-V curves



0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)

1A ap 216h de cycles1A ap 168h de cycles_phase 21A ap 168h de cycles_phase 3


� EIS 10 ppm

0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)

4.5A ap 216h de cycles4.5A ap 168h de cycles_phase 24.5A ap 168h de cycles_phase 3

Anode activity degradation



0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)

4.5A ap 216h de cycles4.5A ap 168h de cycles_phase 24.5A ap 168h de cycles_phase 3

0

0,005

0,01

0,015

0,02

0 0,01 0,02 0,03 0,04 0,05 0,06

Re (Z)

- Im (Z)

8A ap 216h de cycles8A ap 168h de cycles_phase 28A ap 168h de cycles_phase 3


� EIS 10 ppm




• Main causes for performance degradation

Active layers & Catalyst

Size increase cathode side

In addition surface structure modifications anode side

� to be checked with local post-test analyses



Fuel composition effect – PEMFC stack

� CEA test bench for synthetic reformate H 2

• 1kW electrical power

• Stack temperature : up to 90°C

• Gas mixture available at the anode side:

• Pure H2

• Pure CO2

• H4 + CO (2000 ppm)

• Air + CO (2500 ppm) for air bleeding tests

• Air: 0-100%RH by vapor injection

• Temperature, Pressure and RH measured at the stack inlet/outlet

• Open-end configuration

IRD 10 cells stack




� Stack tests with different fuel compositions

• Durability tests

Current cycles with reformate (10 cells)

T = 65°C - RH90%/50% (fuel/air)P = 1,2 bar, St1,5/275%H2 + 24% CO2 + [CO + (CH4 or Air)]

Imin: 6h

Imax: 18h

< 10 µV/h @ imin & < de 20 µV/h @ imax

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

0.55

0.6

0.65

0.7

0.75

0.8

0.85

0.9

0.95

1

j / (A.cm²)

Mea

n ce

ll vo

ltage

/ V

Before 1rst H2 cycles : 37 hPost 1rst H2 cycles : 178 hBefore 2nd H2 cycles : 1029 hPost 2nd H2 cycles : 1164 hPure H2

i-V curves

BoT and EoT





C5

CV - Cathodes


Imin: 6h

Imax: 18h

CV - Anodes






Imin: 6h

Imax: 18h

6

6,5

7

7,5

8

8,5

9

9,5

10

0 200 400 600 800 1000 1200

t / h

QH

upd

cath

ode/

C

Cellule 1 Cellule 3

Cellule 5 Cellule 8

Cellule 10

0

0,1

0,2

0,3

0,4

0,5

0,6

0 200 400 600 800 1000 1200t / h

I H2/

A

Cellule 1 Cellule 3

Cellule 5 Cellule 8

Cellule 10

0,8

1

1,2

1,4

1,6

1,8

2

2,2

2,4

0 200 400 600 800 1000 1200t / h

QH

upd

anod

e/ C

Cellule 1 Cellule 3

Cellule 5 Cellule 8

Cellule 10

�� Conclusions about causes similar to SC



Ex-situ characterisation by electron microscopy

•New MEA

•MEA aged following reference cycles with reformate 26ppm of CO



SEM: PEMFC MEAs (CEA)

Fresh MEA - IRD 1611

Cathode : Pt

Anode : Pt-Ru (PtL 50% RuL 50% )

Membrane : reinforced

500 x 3000 x

CathodeMembrane

Anode



SEM: PEFC MEA (CEA)

Cathode Air inlet



Task 3.1 – TEM: PEFC MEA (CEA)

Cathode

Anode

fresh aged

Increase of catalyst sizeon cathode



TEM: PEFC Membrane (CEA)

1 µm 0.1 µm

SiO2 particlesFresh MEA - IRD 1611

aged MEA - IRD 1616



Observed degradation

No membrane mechanical degradation

Different alteration of the properties at inlet and outlet zone

Alteration in the catalysts

Increase of the catalyst particle size on the cathode

Ru from anode to membrane (?)



Thank you for your attention

Work supported by the European’s Union’s seventh programme (grant agreement 256776)

PremiumAct PEMFC DegradationWorkshop 2013-04-03 OK · 2014. 11. 17. · Sylvie Escribano (CEA) •...

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Transcript of PremiumAct PEMFC DegradationWorkshop 2013-04-03 OK · 2014. 11. 17. · Sylvie Escribano (CEA) •...