©2014 LG Fuel Cell Systems Inc.

The information in this document is the property of LG Fuel Cell Systems Inc. and may not be copied or communicated to a third

party, or used for any purpose other than that for which it is supplied without the express written consent of LG Fuel Cell

Systems Inc.

This information is given in good faith based upon the latest information available to LG Fuel Cell Systems Inc. No warranty or

representation is given concerning such information, which must not be taken as establishing any contractual or other

commitment binding upon LG Fuel Cell Systems Inc. or any of its subsidiary or associated companies.

This document does not contain any Export Controlled Data.

LG Fuel Cell Systems SOFC Technology and SECA Program Update

2014 SECA Workshop, 22 July 2014

Richard Goettler

LG data

Outline

● LGFCS Business Activities - 220 kW test

● Degradation Mechanisms and Mitigation ● Cathode

● Anode

● Primary Interconnect

● Cell-Stack changes for lower cost

● Strip Reliability ● Probability of failure predictions

● Residual strength of substrates

● Block Testing Update

LG data

Phases of the business supported by SECA

Commercial Phase

• Facility expansion (all types)

• Supply-chain expansion

• Sales / Installation / Service

capability

• Product scaling

• Market expansion

EIS3) Phase

• Adjustments to key components /

subsystems from IST results

• Deploy up to five field test systems

at “friendly” locations in North

America

• Build initial manufacturing facility

• Active supply-chain management

• Secure first order for a

commercially available fuel cell

power system

500kW – 1MW Field Tests

SECA supported lower ASR, in-

block reforming and degradation

improvements

•1) IST : Integrated String Test 2) VOC : Voice of the Customer 3) EIS : Entry Into Service

IST1) Phase

• Design, Build and Demonstrate

a SOFC power system from

fuel in to AC power out (1MW

Design)

• Further development of key

components / subsystems

• Accelerate EIS activities in

parallel with development

• North America Market

Assessment (VOC Meetings)2)

~220 kW grid connected test

Cell/stack technology for IST reduced to

practice under SECA (19 kW testing)

LG data

LGFCS Integrated String Test Schedule

2014 Key Program Milestones Update Fuel Cell Vessel 1 (FCV-1): emulator blocks plus 1 active block for systems commissioning

Fuel Cell Vessel 2 (FCV-2): fully loaded with active block for 220 kW

Apr May Jun Jul Aug Sep Oct Nov Dec Jan‘15 Mar Feb Mar

•FCV-1

Build

•FCV-1 Installation

•FCV-1 Cold Commission

•(check point by points)

•FCV-1

Installation

•FCV-1

Commission •Hot Commission

•IST (FCV-2)

Demonstration •FCV-2

Installation

IST Test

•All Hardware Installed/Connected, Control and

Safety System Operational, HAZOP / Safety

Assessments Complete, Commissioning Plan

Complete, and Commissioning Team Resources

Identified and Allocated

•FCV-1 Build

•Substrate printing •Strip + Block/FCV Assembly

LG data

Commissioning of IST Subsystems is Progressing Fuel Processor commissioning completed

FCV1 turbogenerator assembly under test, controls system completed

FCV2 turbogenerator under test

Block assembly for FCV1 in progress

All substrates printed for FCV2, strip build underway

Power electronics installed, grid connected, commissioning starting

2013 CAD rendering 2014 System Integration

Outdoor IST Test Pad

LG data

Outline

● LGFCS Business Activities - 220 kW test

● Degradation Mechanisms and Mitigation ● Cathode

● Anode

● Primary Interconnect

● Cell-Stack changes for lower cost

● Strip Reliability ● Probability of failure predictions

● Residual strength of substrates

● Block Testing Update

LG data

Product Durability Strategy

● End of Life ASR = 0.42 ohm-cm2 to meet

efficiency requirement

● Assumes constant power over service life

● Degradation rate target based on starting

ASR and required stack life to meet cost

● Lifetime improved by reducing degradation

mechanisms and/or lowering initial ASR

Plant Operation Strategy

0%

10%

20%

30%

40%

50%

60%

70%

0 1 2 3 4 5

Time, Years

An

od

e L

oo

p E

ffic

ien

cy

50%

60%

70%

80%

90%

100%

110%

120%

Po

we

r O

utp

ut,

% R

ati

ng

0.0081 ohm-cm2/1000 hrs

2 Year Design Life

0.003 ohm-cm2/1000 hrsPower Output

Efficiency

0.2 0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28 0.29

2

3

4

5

Starting ASR, ohm-cm2

Serv

ice L

ife, y

ears

Required ASR Degradation Rate

ohm-cm2/1000 hours

0.0130-0.0140

0.0120-0.0130

0.0110-0.0120

0.0100-0.0110

0.0090-0.0100

0.0080-0.0090

0.0070-0.0080

0.0060-0.0070

0.0050-0.0060

0.0040-0.0050

0.0030-0.0040

0.0020-0.0030

0.013 0.012

0.004

0.005

0.006

0.0070.008

0.009

0.0110.010

0.003

For starting ASR 0.29 ohm-cm2

LG data

Ongoing durability testing at pentacell scale used to understand degradation contributions

● Impedance measured at ~ 1000 hour intervals

● Resistance, capacitance, and Warburg elements to represent behavior

● Estimates of degradation contributions can then be charted over the life of the test

● Cathodic mechanisms dominate

3

Secondary

Interconnect

Primary

Interconnect

Active Cell

Air Distributor

Bus Rod

Voltage Tap

Lead-outs

Fuel Inlet

Manifold

Fuel Outlet

Manifold

•PCT150 and PCT189: 925C, 4.0 Bara

800C 925C

LG data

Cathode Degradation Mechanisms

● Localized densification near electrolyte interface

● MnOx segregation and/or migration

● MnOx valence changes

● Moisture effect

● Cr effect

● Ionic phase degradation

● Material diffusion

LG data

Cathode Densification vs. Testing Conditions

● Kinetics is a key factor for baseline LSM cathode densification

PCT63B 16,000 hrs (860C)

5 µm

PCT63A 8,000 hrs(860C)

PCT89 16,000 hrs (800C)

PCT150 7,000 hrs(925C)

Tem

p, C

Time, hrs

8,000 16,000

800

900

850

Densification

Densification

TB

D

LG data

MnOx Segregation/Migration Observed Across Temp. Range

Epsilon 800C

As-fab 2,000hrs 8,000hrs 16,000hrs

800C

6,500 hrs

860C

900 -

925C

LG data

Minor amount of Mn exsolutes from LSM near interface

● Data from baseline LSM cathode

● Tested at 800oC for 16,000 hours under simulated system

conditions

TEM image

Cathode/CCC

interface

LG data

MnOx accumulation at interface not observed under OCV

● Tested ~5000 hrs at 925oC and 4 bar

Reference cell w/o current load - MnOx at cathode/CCC interface

Active cell with current load - MnOx at electrolyte

- MnOx elimination from bulk cathode

Mn

LSM

ele

ctr

oly

te

ele

ctr

oly

te

LG data

Accelerated Testing of Densification Mechanism

Footer

600hrs 2000hrs 400hrs

● Symmetric button cell tested under selected conditions to accelerate densification

● 860C, 16000 hr densification at NOC matched in 1200 hours accelerated

Thickness for NOC 860C/16,000 hrs

400hrs 600hrs 2000hrs

Ba

se

lin

e

Ca

nd

idate

LG data

Long-term cathode material studies ongoing at different temperatures

● Candidate EIS cathodes show benefit at low temperature, similar degradation rates at high temperature

● Still seeking understanding of major degradation mechanisms across temperature ranges

● Densification not a major contributor at low temp.

● Further documenting the variation of MnOx as function of temp. and LSM cathode composition

•Baseline Cathode

•Candidates

•Baseline Cathode

•Candidates

LG data

Triple bundle test with candidate cathodes showing improved durability trends

● Only change from baseline cell technology was the cathode

● Rates consistent with cathode degradation studies

● Projects to a 2-½ year life across block temp. profile and for block starting ASR

● Further durability extension with anode and interconnect changes

700

720

740

760

780

800

820

840

860

880

900

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0 1000 2000 3000 4000 5000

Ave

rag

e T

em

pe

ratu

re,

ºC

AS

R,

oh

m-c

m2

Elapsed Time, hours

Bundle ASR: ATBT3 - Cathode Study Triple Bundle Test

3167-5, Bundle Degradation Rate = 8.5 micro-ohm-cm²/hr

3167-52, Bundle Degradation Rate = 7.1 micro-ohm-cm²/hr

3168-164, Bundle Degradation Rate = 6.5 micro-ohm-cm²/hr

3167-5, Average Temperature = 834.5ºC

3167-52, Average Temperature = 858.3ºC

3168-164, Average Temperature = 882.2ºC

Mai

nte

nan

ce S

hu

tdo

wn

Ho

t St

and

-By

Mai

nte

nan

ce S

hu

tdo

wn

Time = 5082 Bundle 1: Bundle 2: Bundle 3:

hours 3167-5 3167-52 3168-164

Average Temperature 834.5 858.3 882.2 ºC

Bundle Degradation Rate 0.52% 0.43% 0.35% %Power/1000 hrs

Bundle ASR 0.0085 0.0071 0.0065 ohm-cm²/1000 hr

1 Bara

LG data

Single Layer Anode Selected for EIS Business Phase

925oC 7000hr 925oC 5000hr As reduced

● Exhibits more uniform microstructure than baseline bi-layer at similar test times

● Accelerated testing being developed for quicker screening of final anode compositions

H2: 14%, CO:7.5%, H2O: 50%, CO2: 25.5%, N2: 3%

LG data

Single Layer Anode Showing Improved Durability

● Lower ASR change and degradation rate after accelerated testing

● The results were repeated

TPB was generated from 3D database

770

790

810

830

850

870

890

910

930

950

970

0.20

0.30

0.40

0.50

0.60

0.70

0.80

0 200 400 600 800 1000 1200 1400

Te

mp

era

ture

, ºC

AS

R,

oh

m-c

m2

Time, hours

A1: PC98-3, Single Layer

A2: PC74-4, Baseline Bi-layer

BottomTemperature

Normal

operation

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

As-reduced 925C, 90%FU,1000hr

925C, 80% FU,5000hr

TPB

Den

sity

, m/m

3

Active TPB

Accel.

Test

Acceleration Testing at 925C/90% Fuel Util. Return NOC NOC

DASR, ohm-cm2

(before/after accel.)

Baseline Bi-layer anode 0.018

Single layer anode -0.003

Similar TPB for Accel. vs NOC Test

LG data

•Single cell test

Improved Redox Tolerance is Sought for Anode Protection Simplification

● Tolerate low probability of

occurrence emergency events

● Anodes tested

● Baseline single layer anode

● Modified 1: composition

modification

● Modified 2: microstructure

optimization

● Screening tests

● Pellet test

● Single cell test

•Pellet test: 5 redox cycles for different pellets

Baseline

Modification 2

•Redox Cycle: 900C, 3 hrs oxidation, N2 purge

LG data

650

700

750

800

850

900

950

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0.14

0 200 400 600 800 1000 1200

Tem

pera

ture

, ºC

AS

R,

oh

m-c

m2

Time, hours

PIC ASRs: PCT196_4X

PC101-2: baseline

PC106-1: Barrier A

PC106-4: Barrier B

Temperature

Primary Interconnection Modification to Further Reduce Materials Migration

● Barrier layer modification does not increase the ASR

● Longer-term testing at most aggressive bundle conditions to accelerate mechanisms

● Post-test evaluations versus time to confirm benefits

Via-based

interconnect design

LG data

Outline

● LGFCS Business Activities - 220 kW test

● Degradation Mechanisms and Mitigation ● Cathode

● Anode

● Primary Interconnect

● Cell-Stack changes for lower cost

● Strip Reliability ● Probability of failure predictions

● Residual strength of substrates

● Block Testing Update

LG data

Lower ASR technology demonstrated at bundle-scale

● ASR reduction at 4 bar of >0.04 ohm-cm2

● Meets ASR targets for initial products

● Optimized LSM compositions (lower Rp)

● Modified primary interconnect design

● Single layer anode

● Durability testing at higher current density design point

0.10

0.15

0.20

0.25

0.30

0.35

0.40

790 810 830 850 870 890 910

AS

Rs

, o

hm

-cm

2

Average Bundle Temperature, ºC

PBT12 (WRD3261-25) - Bundle ASR

PBT5 - Avg ASR @ 860ºC = 0.291 ohm-cm2

PBT12 - Avg ASR @ 860ºC = 0.243 ohm-cm2

20-Jun-14 19:45:56

Phase 1

selected IST technology

Combined Phase 2

ASR improvements

0

50

100

150

200

250

300

350

400

450

500

0 200 400 600 800 1000

Bu

nd

le P

ow

er,

Wa

tts

Elapsed Time, hours

Bundle Power: PBT12 (WRD3261-25)

4 Bara, 860ºC Average

380 mA/cm2 530 mA/cm2

4 Bara

LG data

Print pattern changes to optimize power output

● Smaller primary interconnect dimension has lower ASR contribution

● Decreased cell pitch gives a lower in-plane resistance

● Lower ASR combined with increased active area per tube gives a potential increase in power output up to 26%

● Printing trials with 0.95 mm PIC in process

0.20

0.22

0.24

0.26

0.28

0.30

0.32

0.5 0.6 0.7 0.8 0.9 1 1.1 1.2

Re

pe

at

Un

it A

SR

, o

hm

-cm

2

PIC Dimension, mm

Repeat Unit ASR Reduction vs PIC Dimension(Constant Efficiency)

300

320

340

360

380

400

420

50 55 60 65 70 75 80 85 90 95

Po

we

r p

er

6 T

ub

e B

un

dle

, W

att

s

Number of Active Cells per Tube

Bundle Power for Smaller PIC Dimension(Constant Efficiency)

0.65 mm PIC

0.80 mm PIC

0.95 mm PIC

1.1 mm PIC (current design)

LG data

Increasing In-Block-Reforming (IBR) to increase power density and manage Block ∆T

● Thermal integration enables operation at higher current density while maintaining reasonable stack temperature

● Higher power density means less stack, smaller package, reduced size of BOP components

● Single turbogenerator serves greater kW

● May also minimize stack temperature extremes at the hot and cold end which may be beneficial for performance and durability considerations.

0

10

20

30

40

50

60

70

80

90

100

Current/ISTTechnology

Next Generation CellASR

50% IBR and LowerASR

100% IBR and LowerASR

Block ASR = 0.32 Block ASR = 0.27 Block ASR = 0.27 Block ASR = 0.24

Bundle ASR = 0.29 Bundle ASR = 0.25 Bundle ASR = 0.25 Bundle ASR = 0.22

19.522.8 25.2

26.9 kW

81

94

73

Stack DT, ºC, 31

Impact of Lower ASR and IBR

Block Power

(5 strips)

Block ∆T

LG data

All reforming within bundle Current approach: reforming external to bundle

IBR development activities addressing Thermal Stresses and Carbon Avoidance

● Multi-physics modeling

● Bundle test at 50% and 100% IBR performed ● Nearly full conversion of CH4

● Lower power at 100% IBR from Nerst potential difference

200

220

240

260

280

300

320

340

360

380

400

0 200 400 600 800 1000 1200

Bu

nd

le P

ow

er,

Wa

tts

Elapsed Time, hours

Bundle Power Comparison with and without In Block Reforming

PBT5 (Simulated Reformate)

PBT8 (50% IBR after 300 hrs)

PBT11 (100% IBR from 390 to 590 hrs)

4 Bara, 860ºC Average

PBT11 on 100% IBRCase

Bundle

Power Bundle DT

Reformate 322 W 20ºC

50% IBR 320 W 12ºC

100% IBR 316 W 6ºC

Lower thermal gradients with

incorporation of in-block reforming

(inlet substrate shown)

LG data

Further Reduction in Cell ASR using Nickelate Cathodes

● Phase instability under operating conditions has been major issues

● Technical approaches to improve nickelate phase stability

● A-site doped Pr2NiO4+d

(Pr0.25Nd0.75) A-site ratio is phase stable1, (Pr0.5Nd0.5) exhibits instability

● Addition of B-site dopants provides phase stability for A-site (Pr0.5Nd0.5)

Nickelate provides ~0.02 ohm-cm2 lower ASR

than most favorable LSM-based cathode

1. Advances in Solid Oxide Fuel Cells III, Ceramic Eng. and Sci. Proc., 28(4) 2008.

LG data

Outline

● LGFCS Business Activities - 220 kW test

● Degradation Mechanisms and Mitigation ● Cathode

● Anode

● Primary Interconnect

● Cell-Stack changes for lower cost

● Strip Reliability ● Probability of failure predictions

● Residual strength of substrates

● Block Testing Update

LG data

FEA Validation and CARES Prediction ● FE Stress Modelling: Validation at RT

● CARES Prediction: 4pt bend test at RT

MMA Substrate Gen 2

Ratios (Exp./FE)

Kmax (N-mm)

Bare Substrate (avg. strength from 30 test)

1804/1777.6 =1.01

Glassed Substrate (120µm thick glass layer and avg. strength

from 6 test)

1831/2102.5 = 0.87

Full Printed Substrate (avg. strength from 15 test)

2504/2726.5 = 0.92

•Input from 4pt bend test on MMA

Substrate :

•σ0 = 57.48, m = 16.48

•CARES Output:

•Pf, CARES prediction = 63%

•Pf, expected = 63.2% (Good Agreement)

LG data

Very Low Pf of Substrate under Operating conditions (Fast fracture)

● Conservative assumptions of Weibull

parameters – used RT values under 2

conditions

● Tube specification (MoR= 29MPa,

m=15)

● Actual Tube MOR (MoR= 1.31MPa,

m = 14.98)

● Bundle thermal boundary conditions

mapped in ABAQUS.

● Peak stresses for substrate 2 of top

bundle in strip 5 (worst case)

MMA

Substrate

(Tube #)

Max. Stress

(MPa)

Pf (%),

Actual

Pf (%), Tube

Specification

1 6.40

0.86e-11 0.18e-11

2 15.27

0.51e-8 0.107e-5

3 9.10

0.13e-10 0.27e-8

4 7.40 0.10e-9 0.25e-7

5 5.95

0.95e-11 0.19e-8

6 7.54

0.16e-9 0.33e-7

LG data

Low Pf of Substrate under Normal Operating Conditions (Slow fracture)

● Conservative assumptions of Weibull parameters – used RT

values under 2 conditions

● Used actual high temperature SGC parameters from ORNL

MoR (MPa) m

Porous

MMA

41.31 14.98

Dense MMA 248.61 9.38

Future Work:

● FEA for dense parts+ CARES prediction for a full strip

● Low risk of failure of dense parts as strength 4X

substrate and similar SCG parameters and >Kic

● Block transient stress states

•SCG test- 900°C+Air

Pf in 10-4 range for substrate 2 Room Temp. Weibulls

LG data

Phase 2 Block Test: Post-test Reliability Assessment

Approach: Measure RT 4-pt and compare to

bare substrate of identical lot.

● The ratio of Tested Substrate: As-rec’d Bare

Substrate is ~1.3-1.5, typical of ratio for as-

processed substrates

● This indicates little or no loss in strength over the

nominal 3000 hours of operation.

Mechanical Properties

• Fracture can start from surface defect as well as

from volume imperfection.

• All the data (~600) from Strip 1, 3 and 5 put together

show a good linear fit.

Strip

No. Lot No.

No. of Test

Specimens

Strength Ratio (±

95% Conf. Int.)

1 22 186 1.32 ± 0.019

1 32-2 19 1.32 ± 0.048

3 32-1 196 1.46 ± 0.014

5 32-2 36 1.39±0.15

5 24 132 1.40±0.14

5 25 33 1.53±0.07

MoR (MPa) m

Post-test 46.76 13.43

(Mix of Gen1 and Gen2 substrates)

LG data

Outline

● LGFCS Business Activities - 220 kW test

● Degradation Mechanisms and Mitigation ● Cathode

● Anode

● Primary Interconnect

● Cell-Stack changes for lower cost

● Strip Reliability ● Probability of failure predictions

● Residual strength of substrates

● Block Testing Update

LG data

Block Testing Matching Product Cycle, Components and Operating Conditions

•Turbo-Generator

Fuel Cell

Cathode

Fuel

Cell

Anode

OGB

Anode Ejector

Cathode Ejector

Turbo-Generator

RRFCS NG “Dry Cycle” Configuration

Auxiliary

Ejector

R

E

F

O

R

M

E

R

R

E

F

O

R

M

E

R

Auxiliary

Heat Exchanger

Heat Source for Cathode Loop;

Partially-Spent Anode Gas,

Heated Cathode Loop Air,

and Hot Recycle

De-Sulfurized

NG

•Recuperator

•Initial design of block testing rigs

•Representative of cycle and components

•Not packaged for product

•One rig converted to match IST block design

•Allows testing of 3 blocks

•Fully representative of product

Derby, UK

LG data

3 Block Tests Supported by Current Program

● Two 15 kW tests – original block design ● Screening of cathode technology

● 1st test: Chromium mitigation, pipeline nat. gas and SCSO desulfurization (started July 2014)

● 2nd test: higher Chromium sources, pipeline nat. gas (starting Aug 2014) Similar Cr content as Phase 1 and Phase 2 block tests

● 3rd 4-strip test of combined cell technology for lower ASR and improved durability

● expected <0.75%/1000 hours

● Single layer anode, alternate cathode, primary interconnect redesign

0.00

0.20

0.40

0.60

Strip 1 Strip 2 Strip 3

Ch

rom

ium

(at

. %)

3000 hour Block Test (Ph. 2)1.1%/1000 hr power degrad.

Air flow, Temperature rise

through block

EIS

3

EIS

1

EIS

2

EIS

1

Baselin

e

EIS

2

Baselin

e

Baselin

e

LG data

Current Phase Block Test #1

● 4 Strip test with EIS cathode candidates

● 15.4 kW target value achieved

● ASR improved over Phase 2 test, especially at lower temp.

● Problems with BOP forced early shutdown

● NG-SCSO connectivity

● Air compressor failure

700

720

740

760

780

800

820

840

860

880

900

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

0 10 20 30 40 50 60 70 80 90

Cath

od

e A

vg

Tem

p, ºC

Blo

ck P

ow

er,

kW

Time on Load, hours

4-Strip Test Block Power

Total Power

Cathode Average Temperature

0.10

0.20

0.30

0.40

0.50

0.60

790 810 830 850 870 890 910 930

1/2

Str

ip A

vg

AS

R,

oh

m-c

m2

Temperature, ºC

1/2-Strip ASR vs Temperature

Phase 2 Block Test (343 hrs)

Current Program Test

Strip Manufacturing Test Data (1 Bara)

LG data

Conclusion

● Cell and stack developments supported by SECA are moving into 220 kW-scale system integration testing

● Degradation rates being reduced, further verification through accelerated and longer-term testing across testing platforms

● Active layer materials in final screening for inclusion in next business phase of system field testing

● In-block reforming coupled with lower ASR cell technology provides significant cost reductions – focus of next Phase.

LG data

Acknowledgements

● Special thanks to LGFCS project manager Patcharin Burke and the entire SECA program management team

● Current and former LGFCS SECA partners: Case Western Reserve University, University South Carolina, University Connecticut and Oak Ridge National Laboratory

LG data

Acknowledgements_Continued

● This material is based upon work supported by the U.S. Department of Energy, National Energy Technology Laboratory under Award Number DE-FE0000303 and DE-FE0012077.

● Disclaimer: This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of the authors expressed herein do not necessarily state or reflect those of the United States Government of any agency thereof.