D2.1 IMMEDIATE Report on OEM designed MEA test protocols final · EC FP7 FCH JU Project No. 303466 – IMMEDIATE IMMEDIATE Deliverable Report D2.1 – Version 07 2 D2.1 – Report

IMMEDIATE Deliverable Report D2.1 – Version 07 1

DELIVERABLE REPORT

D2.1 Report on OEM designed MEA test protocols

IMMEDIATE

Innovative autoMotive MEa Development

– implementation of Iphe-genie Achievements Targeted at Excellence

EC FP7 FCH JU Project No. 303466

SP1-JTI-FCH.2011.1.5 Next generation European MEAs for transportation applications

Project duration: 01.01.2013 – 31.12.2015 (36 months)

Coordinator: IRD Fuel Cells A/S, Denmark

EC FP7 FCH JU Project No. 303466 – IMMEDIATE


D2.1 – Report on OEM designed MEA test protocols

Due date M3

Author(s) Lars Carlhammar (Volvo), Madeleine Odgaard, Jacob L.. Bonde (IRD), Deborah Jones, Marc Dupont, Sara Cavaliere, David Bourgogne (CNRS)

Workpackage no. WP2

Workpackage leader Volvo

Lead Beneficiary IRD

Date released by WP leader 18.09.2013

Date released by Coordinator 19.09.2013

Dissemination level

PU Public X

PP Restricted to other programme participants (including the Commission Services)

RE Restricted to a group specified by the consortium (including the Commission Services)

CO Confidential, only for members of the consortium (including the Commission Services)

Nature of the deliverable

R Report X

P Prototype

D Demonstrator

O Other

Summary

Keywords High-temperature automotive MEA, Fuel cell test protocol, Fuel cell city bus, Accelerated stress test

Abstract

Test protocols for high-temperature automotive MEAs and stacks have been designed drawing on, as far as possible, existing test protocols previously described in literature and/or regularly and widely used. The tests include basic performance tests as well as tests for durability aimed particularly at MEA technologies being developed for operating temperatures above 100 °C. Performance tests include parametric studies of the influence of temperature, pressure, stoichiometry, humidity and fuel composition. Durability tests include protocols targeting specific known degradation mechanisms of MEAs such as, e.g., membrane (mechanical) stability, catalyst stability, and carbon corrosion mechanisms. Also, new duty cycles representative of a fuel cell city bus application have been derived from vehicle simulations and simplified so as to be easy to implement for stack testing.



Revisions

Version Date Changed by Comments

“00” May–July 2013 Involved partners Initial draft circulated for addition of partner inputs

01 06.07.2013 LC (Volvo) First draft compiled from all partner inputs

02 12.07.2013 LC (Volvo) Modifications accord-ing to agreements M6 meeting

03 15.07.2013 MOD (IRD) Slight modification in Section 5; humidity levels implemented

04 16.07.2013 MJL (IRD) Layout and proofreading

05a 24.07.2013 MD (CNRS) Addition of section 5.7.7, some comments, layout

05b 05.08.2013 LC (Volvo), MJL (IRD)

Addition of abstract and keywords

06 18.09.2013 LC (Volvo)

Integration of versions 5a and 5b. Correction of comments.

07 19.09.2013 JLB/MOD (IRD) Final Version



Contents

Contents 4

1 Introduction 6

2 Definitions and nomenclature 6

3 Reference test conditions 6

4 Test protocols for short stack 7

4.1 Leak test 7

4.2 Standard polarization curve test 7

4.3 Parametric studies 8

4.3.1 Temperature parameter test 8

4.3.2 Pressure parameter test 8

4.3.3 Air stoichiometry test 8

4.3.4 Fuel stoichiometry test 9

4.3.5 Fuel composition test 9

4.4 Duty cycle tests 9

5 Test protocols for single cells (MEA) 12

5.1 Tightness and gas crossover tests 12

5.2 Standard polarization curve test 12

5.3 Standard cycle tests 15

5.3.1 Durability test of catalyst 15

5.3.2 Load cycling test 15

5.4 OCV test 16

5.5 Carbon corrosion test 16

5.6 Relative humidity cycling test 17

5.6.1 Mechanical durability test 17

5.7 Parametric studies 19

5.7.1 Temperature parameter test 19

5.7.2 Pressure parameter test 19

5.7.3 Air stoichiometry test 19



5.7.4 Fuel stoichiometry test 19

5.7.5 Fuel composition test 19

5.7.6 Relative humidity test 20

5.7.7 Post-mortem ex-situ MEAs characterization tests 20

6 Bibliography 21



1 Introduction

This document defines the tests to be performed on the single cell MEAs and the 10-cell short stack to

be designed and tested in the IMMEDIATE project. The protocol relies heavily on test protocols

defined elsewhere, particularly those of References (1), (2), (3) and (4) for the short stack tests and

those of References (2), (5), (6) and (7) for the MEA tests.

In parallel to the preparation of this D2.1 report the members of the IMMEDIATE project participate

in the working group organized under JRC and FCH-JU with the subject “Harmonization of PEFC

testing protocols for automotive applications“. The document (2) from the above mentioned working

group is not finalized within the timeframe for submission of the D2.1 report. However, the

IMMEDIATE project will evaluate and adapt all relevant tests proposed and it is anticipated that

some specifics of the tests may need to be revised late in the project.

2 Definitions and nomenclature

Definitions, abbreviations and general nomenclature throughout this document follow that laid out in

References (8), (1) and (9).

3 Reference test conditions

Two sets of reference conditions have been defined for the tests. One (Table 1) represents what is

current state-of-art for automotive fuel cells. The other (Table 2) (represents the target performance of

the IMMEDIATE project as defined in the project description.

Table 1: SoA reference conditions.

Property Symbol Unit Value

Stack operating temperature Tstack °C 80

Fuel inlet temperature Tfuel,in °C 80

Air inlet temperature Tair,in °C 80

Fuel outlet pressure Pfuel,out bara 1.5

Air outlet pressure Pair,out bara 1.5

Fuel stoichiometry λH2 [] 1.5

Air stoichiometry λAir [] 1.8

Fuel inlet dew point temperature Tdew, fuel,in °C 59

Fuel composition

H2 xH2, fuel Mole fraction, dry basis 1

N2 [] Mole fraction, dry basis 0

Air inlet dew point temperature Tdew, air,in °C 59

Fuel inlet dew point temperature Tdew, air,in °C 59



As described in Chapter 5.2 a polarization single-cell MEA test is to be performed using the state-of-

art condition in order to get a baseline for comparison with test results using the IMMEDIATE target

reference conditions. Subsequent single-cell-MEA tests as well as the short stack tests are to be

performed at the IMMEDIATE target test conditions.

Table 2: IMMEDIATE target reference conditions.


Stack operating temperature Tstack °C 120








Fuel composition





4 Test protocols for short stack

4.1 Leak test

The stack should be tested to quantify leakages at least once before and once after the other tests are

performed. If there is reason to believe that the leakage rate of any fluid has increased during testing

additional leak tests should be performed. The tests should be performed according to the procedures

in Reference (4) (See also chapter 7.1.1 in Reference (2)).

4.2 Standard polarization curve test

The standard polarization curve test is the main performance test to be performed. It should be

performed according to the procedures described in Reference (1) at the reference conditions defined

in Table 1.

The standard polarization curve test is also the basis for the various parametric tests described in

Chapter 4.3.



4.3 Parametric studies

4.3.1 Temperature parameter test

This test is performed in order to quantify the change in performance of the FC when running at a

higher or lower temperature then the nominal. The FC should be tested at the operating conditions

listed in Table 3; parameters not listed should be kept at the reference condition described in Table 2.

For each test point in Table 3, a standard polarization curve test should be performed as described in

Chapter 4.2.

Table 3: Operating conditions for temperature parameter test.

Property Unit Value

Test point

1 2 3 4 5 6 7 8 9

Stack operating temperature °C 70 80 90 100 110 120 130 140 150

Fuel inlet temperature °C 40 50 60 70 80 90 100 110 120

Air inlet temperature °C 40 50 60 70 80 90 100 110 120

Fuel inlet dew point

temperature

°C 32 42 52 62 72 82 92 92 92

Air inlet dew point temperature

°C 32 42 52 62 72 82 92 92 92

4.3.2 Pressure parameter test

The aim of this test is to quantify how the performance of the FC depends on the operating pressure.

The pressure is varied in an interval around the pressure of the reference condition which is benign to

the FC. The pressure difference between anode and cathode compartment is kept constant at the same

level as in the reference condition. The fuel and air pressures to be used in the different test points are

listed in Table 4. Remaining parameters should be kept according to the reference condition defined

in Table 2. For each test point in Table 4, a standard polarization curve test should be performed as

described in Chapter 4.2.

Table 4: Operating conditions for pressure parameter test.

Property Unit Value

Test point

1 2 3 4 5

Fuel outlet pressure bara Open-ended 1.5 2.0 2.5 3.0

Air outlet pressure bara Open-ended 1.5 2.0 2.5 3.0

4.3.3 Air stoichiometry test

Due to the nature of the cathode kinetics and the low oxygen concentration in air a high stoichiometry

of air is usually needed to achieve good cell voltages. At the same time, for a pure hydrogen fuel cell

system, the air compressor constitutes the largest parasitic load in the system. Thus knowledge of the

impact of air stoichiometry on the performance of the fuel cell is important to make a correct system

level optimization of parameters such as the air stoichiometry and pressure. In this test the air

stoichiometry is varied around that specified in the reference condition. The operating parameters for

the different test points are listed in Table 5. Remaining parameters should be kept according to the



reference condition defined in Table 2. For each test point in Table 5, a standard polarization curve

test should be performed as described in Chapter 4.2.

Table 5: Operating conditions for air stoichiometry test.

Property Unit Value

Test point

1 2 3 4 5

Air stoichiometry - 1.4 1.6 1.8 2.0 2.2

4.3.4 Fuel stoichiometry test

In a fuel cell system with anode recycling the recycling rate determines the fuel stoichiometry seen by

the stack as well as the level of humidity at the fuel inlet. In this test the fuel stoichiometry is varied

around that specified in the reference condition. The operating parameters for the different test points

are listed in Table 6. Remaining parameters should be kept according to the reference condition

defined in Table 2. For each test point a standard polarization curve test should be performed as

described in Chapter 4.2.

Table 6: Operating conditions for fuel stoichiometry test.

Property Unit Value

Test point

1 2 3 4 5

Fuel stoichiometry - 1.2 1.3 1.4 1.5 1.6

4.3.5 Fuel composition test

In a fuel cell system with anode recycling there will be an accumulation of nitrogen in the anode

circuit from diffusion through the membranes. If the purge rate is to be kept at a minimum the fuel

inlet will contain a certain level of nitrogen. The operating parameters for the different test points are

listed in Table 7. Remaining parameters should be kept according to the reference condition defined

in Table 2. For each test point a standard polarization curve test should be performed as described in

Chapter 4.2.

Table 7: Operating conditions for nitrogen concentration test.

Property Unit Value

Test point

1 2 3 4 5 6

Fuel composition

H2 Mole fraction, dry basis 1 0.9 0.8 0.7 0.6 0.5

N2 Mole fraction, dry basis 0 0.1 0.2 0.3 0.4 0.5

4.4 Duty cycle tests

These tests aim to reproduce the actual usage of the FC stack in a fuel cell system of the chosen

application (city bus). Duty cycles have been generated through dynamic simulation of a fuel cell city



bus using actual road cycle data. The resulting duty cycles have been simplified in a way that will

make them easier to implement in a lab test rig while retaining the most important features.

The simplified load cycles are shown in Figure 1 and Figure 2.

Additionally a steady-state duty cycle is defined in chapter 6.1 of Reference (2).

The cycles, when implemented in a stack test, should be run repeatedly, without interruption between

repetitions, for as long as possible up to 15 h/day until a total of 500 operating hours is reached.

In the IMMEDIATE project it is suggested first to run the steady-state cycle from chapter 6.1 of

Reference (2) followed by the IMMEDIATE synthetic city bus cycle 1 (Figure 1). If the stack is still

in a sufficiently good condition, it is suggested to run also the IMMEDIATE synthetic city bus cycle 2

(Figure 2).

Figure 1: Synthetic test cycle based on fuel cell bus simulations with a small (50 kW) fuel cell system and a load-following control strategy with a minimum base load.



Figure 2: Synthetic test cycle based on FC bus simulations with a large (140 kW) fuel cell system and a load-following control strategy.



5 Test protocols for single cells (MEA)

The present section is intended to describe the evaluation methods for testing single-cell membrane–

electrode assemblies (MEAs) with the approach to assess the performance and durability of the

important components: electrolyte membrane, electrode catalyst and supports. The test protocols are

based on input from:

• FCTT: U.S. Drive Partnership, Fuel Cell Technical Team; Cell Component

Acclerated Stress Test and Polarization Curves protocols for Polymer Electrolyte

Membrane Fuel Cells, Revised August 2011 (5).

• USFCC: US Fuel Cell Council; Accelerated Stess Test (AST) Protocols for PEM

Fuel Cells (6).

• FCCJ: The Fuel Cell Commercialization Conference of Japan; Objectives, R&D

Challenge Topics and Proposed Evaluation methods for Polymer Eletrolyte Fuel

Cells, FCCJ, 2011 (7).

• JTI/FCH-JU: Draft version Generic Test protocol: Automotive PEFC single cell

performance, durability/endurance and accelerating testing (2).

The specific test protocols (AST) and performance metrics will be defined for electrocatalyst, catalyst

supports and membrane/MEA chemical and mechanical stability. The specific conditions and cycles

are intended to evaluate the individual effects and are based on assumptions but widely accepted

mechanisms (5), (10).

5.1 Tightness and gas crossover tests

Refer to section 7.1.1 of the document “Generic Test protocol: Automotive PEFC single cell

performance, durability/endurance and accelerating testing” (2).

5.2 Standard polarization curve test

In order to enable comparison to the present state-of-art MEA single-cell test for automotive

applications adapted in the global community, a reference polarization curve measured at cell

temperature of 80 °C will be used in the IMMEDIATE project (Table 8). The prime focus of

IMMEDIATE is to develop highly performing MEAs operating at 120 °C. In addition to the SoA

reference test a specific project test protocol is suggested (Table 9). Refer to Appendix 1 for the

individual steps.

Prior to the polarization curve a start-up procedure is to be used to condition the FC for subsequent

tests so as to reasonably minimize variation in test results due to differing initial conditions. Refer to

section 7.1.1 of the document “Generic Test protocol: Automotive PEFC single cell performance,

durability/endurance and accelerating testing” (2).

In addition to performance test the series resistance of the MEA single-cell shall at least be

determined at the specified operating conditions by either monitoring the HFR (high-frequency

resistance) or by EIS (electrochemical impedance spectroscopy).



Table 8: SoA reference polarization protocol (5).


Single-cell operating temperature Tcell °C 80








Fuel composition





Table 9: IMMEDIATE reference polarization protocol.


Single-cell operating temperature Tcell °C 120








Fuel composition

H2 xH2, fuel Mole fraction, dry basis

N2 [] Mole fraction, dry basis



The standard test load profile (current density versus test duration), when implemented in a single-cell

test, is displayed in Figure 3. Refer to Appendix 1 for details.



Figure 3: Load profile for the reference test protocol (OBS! Unit of current density should be [A/cm2].

Table 10: Electrocatalyst testing protocol recommended by FCTT (IMMEDIATE standard).



5.3 Standard cycle tests

5.3.1 Durability test of catalyst

It is known that platinum dissolution/sintering and electrocatalyst degradation occurs during potential

change (10). Regarding initial, final and intermediate diagnostic tests, measurement of

electrochemical surface area (ECSA), polarization curves and catalytic mass activity is defined as

standard.

The AST protocols applied and recommended by FCTT (Table 10) and FCCJ (10) (Table 11) differ,

but both are designed to separate well known MEA degradation mechanisms (11). The IMMEDIATE

project will use the cycle defined in Table 10 as standard.

Table 11: Electrocatalyst testing protocol recommended by FCCJ.

5.3.2 Load cycling test

The proposed test protocol from FCCT for determining cell durability corresponding to 5,000 hours

U.S. Drive comprises wet w/load and dry w/load cycling (Table 12).



Table 12: Wet w/load cycling and dry w/load cycling.

5.4 OCV test

Membrane/MEA chemical stability test protocol is based on steady state OCV (open cell voltage)

hold test (Table 13).

Table 13: OCV test protocol.

5.5 Carbon corrosion test

Concerning start/stop durability test carbon corrosion is the most representative phenomenon

observed in the cathode electrode influencing the MEA performance (10). Cathode potential cycle in

the range from 1.0 V to 1.5 V vs. RHE (Table 14) or OCV hold at 1.2 V (Table 15) is proposed for

testing catalyst support.



Table 14: Catalyst support AST (FCTT).

Table 15: Catalyst support (Nissan start/stop).

5.6 Relative humidity cycling test

5.6.1 Mechanical durability test

The test for the mechanical durability using a MEA proposed by FCTT used by DoE and the Nissan

protocol proposed by the FCCJ include, dry/wet cycle durability test and hydrogen crossover current

measurement as a diagnostic method. The cycle time between wet and dry proposed as AST by FCTT

is very fast, i.e. 2 min., and require high performance test equipment.



Table 16: Relative humidity cycle (5).



5.7 Parametric studies

The operating environment for the MEA significantly affects the performance of the overall fuel cell

systems. It is desired to design the auxiliary system simple and small; the operating temperature must

be raised for better radiation efficiency of the cooling system; lower humidity must be tolerated in

order to minimize the BoP components; and the lower the operating pressure and fuel/air

stoichiometry, the simpler the air compressor can be designed. Thus knowledge of the impact of the

operating conditions on the MEA performance is important. Various parametric MEA single cell test

will be applied in the project.

5.7.1 Temperature parameter test

The test is performed in order to quantify the change in performance of the MEA when running at a

higher or lower temperature than the nominal temperature defined as target in the IMMEDIATE

project. The MEA single cell should be tested at the same operating conditions as defined for the short

stack and listed in Table 3. Parameters not listed should be kept at the reference condition defined in

Table 9. The tests are performed similarly to the standard polarization test described in Chapter 5.2.

5.7.2 Pressure parameter test

The aim of this test is to quantify how the performance of the MEA depends on the operating

pressure. The pressure is varied in an interval around the pressure of the reference condition which is

benign to the FC. The pressure difference between anode and cathode compartment is kept constant at

the same level as in the reference condition (Table 9). The fuel and air pressures to be used in the

different test points are the same as in the corresponding short stack test and listed in Table 4.

Remaining parameters should be kept according to the reference condition defined in Table 9. The

tests are performed similarly to the standard polarization test described in Chapter 5.2.

5.7.3 Air stoichiometry test

Knowledge of the impact of air stoichiometry on the performance of the MEA is important to make a

correct system level optimization of parameters such as the air flow and pressure. In this test the air

stoichiometry is varied around that specified in the reference condition (Table 9). The operating

parameters for the different test points are the same as for the corresponding test on the short stack

and listed in Table 5. Remaining parameters should be kept according to the reference condition

defined in Table 9. The tests are performed similarly to the standard polarization test described in

Chapter 5.2.

5.7.4 Fuel stoichiometry test

In a fuel cell system with anode recycling the recycling rate determines the fuel stoichiometry seen by

the stack as well as the level of humidity at the fuel inlet. In this test the fuel stoichiometry is varied

around that specified in the reference condition (Table 9). The operating parameters for the different

test points are the same as for the corresponding test on the short stack and listed in Table 6.

Remaining parameters should be kept according to the reference condition of Table 9. The tests are

performed similarly to the standard polarization test described in Chapter 5.2.

5.7.5 Fuel composition test

In a fuel cell system with anode recycling there will be an accumulation of nitrogen in the anode

circuit from diffusion through the membranes. If the purge rate is to be kept at a minimum the fuel

inlet will contain a certain level of nitrogen. The operating parameters for the different test points are



the same as for the corresponding test on the short stack and listed in Table 7. Remaining parameters

should be kept according to the reference condition defined in Table 9. The tests are performed

similarly to the standard polarization test described in Chapter 5.2.

5.7.6 Relative humidity test

The aim of this test is to quantify how the performance of the MEA depends on the relative humidity

of the air and fuel. The humidity of the air and fuel can be kept constant at the same level or each

varied individually keeping the other side constant at the same level as in the reference condition

(Table 8 and Table 9). The fuel and air humidity to be used in the different test points are listed in

Table 17. Remaining parameters should be kept according to the reference condition defined in Table

9. The tests are performed similarly to the standard polarization test described in Chapter 5.2.

Table 17: Operating conditions for various humidification levels.

Property Unit Value

Test point

1 2 3 4 5 6 7 8 9 10

Fuel and/or Air % RH 25 35 40 45 50 60 70 80 90 100

5.7.7 Post-mortem ex-situ MEAs characterization tests

The following protocol allows the characterization of the MEAs in terms of GDL, catalyst, membrane

and backing layer after use according to a standard procedure.

Cross sections of the MEAs can be prepared by freeze-fracturing the entire assembly, previously pre-

cut with scissors, after immersion for 10 min in liquid nitrogen.

Ex-situ physico-chemical analysis post operation by:

- SEM-EDX or FESEM/EDX (catalyst dissolution into the membrane)

- TEM (particle size sintering)

- XPS (surface analysis)

- XRF (elemental analysis)



6 Bibliography

1. Malkow, T, et al., et al. Test Module PEFC ST 5-3; PEFC power stack performance testing

procedure. Measuring voltage and power as function of current density. Polarisation curve test

method. [Online] April 30, 2010. [Cited: May 13, 2013.] http://iet.jrc.ec.europa.eu/fuel-

cells/sites/fuel-cells/files/files/documents/Polarisation_Curve_TestProcedure_ST_5-3.pdf.

2. Malkow, T, et al., et al. Generic test protocol - Automotive PEFC single cell performance,

durability/endurance and accelerated testing. s.l. : JRC, Draft version in preparation.

3. Råberg-Hellsing, Monika, et al., et al. Specification of Test Procedures for Polymer Electrocyte

Fuel Cell Stacks. [Online] June 2004. [Cited: May 13, 2013.] http://www.ika.rwth-

aachen.de/fuero/temp/test/testprocedure_fc-stack.pdf.

4. US Fuel Cell Council. Fuel Cell Leak Testing Requirements and Procedure. 2005. 04-070.

5. FCTT: U.S. Drive Partnership, Fuel Cell Technical Team. Cell Component Accelerated Stress

Test and Polarization Curves protocols for Polymer Electrolyte Membrane Fuel Cells. Revised

August 2011.

6. USFCC: US Fuel Cell Council. Accelerated Stress Test (AST) Protocols for PEM Fuel Cells.

Revised August 2011.

7. Objectives, R&D Challenge Topics and Proposed Evaluation methods for Polymer Electrolyte Fuel

Cells. Iiyama, A, et al., et al. 2011. FCCJ: The Fuel Cell Commercialization Conference of Japan.

8. Malkow, T, et al., et al. Test Module PEFC SC 5-2. Testing the voltage and power as function of

current density. Polarisation curve for a PEFC single cell. [Online] April 30, 2010. [Cited: May 13,

2013.] http://iet.jrc.ec.europa.eu/fuel-cells/sites/fuel-

cells/files/files/documents/Polarisation_curve_TestProcedure.pdf.

9. Tsotridis, G, et al., et al. FCTESTNET Fuel Cells Glossary. s.l. : European Commission Joint

Research Centre, 2006. EUR 22295 EN.

10. ECS Transactions. 2011, Vol. 41, 1, pp. 775-784.

11. Randal, Perry L. V.E.7 Analysis of Durability of MEAS in Automotive PEMFC Applications. s.l. :

DoE Hydrogen and Fuel Cells Program, FY 2012 Annual Progress Report.



Appendix 1

The SoA test protocol to be used in the IMMEDIATE project is based on the protocol defined by U.S.

Drive Partnership, Fuel Cell Technical Team (5):

The IMMEDIATE reference test protocol for single-cell test is shown below:



Documents

D2.1 IMMEDIATE Report on OEM designed MEA test protocols final · EC FP7 FCH JU Project No. 303466 – IMMEDIATE IMMEDIATE Deliverable Report D2.1 – Version 07 2 D2.1 – Report