Hossein Ghezel-Ayagh (PI)

June 13, 2018

SOFC Development Update at FuelCell Energy

19th Annual Solid Oxide Fuel Cell (SOFC) Project Review Meeting Washington, DC

2

SOFC Technology Development & Deployment Roadmap

• Ongoing technology development and system field testing is laying the foundation for cost-competitive DG and centralized SOFC power systems

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027

Year

MW-Class Demonstration

Utility-Scale (>100 MW) IGFC and NGFC Systems

50 kW System

Technology Development

30 kWStack Tower

10 kWStack

60 kWStack Module

200 kW System

Field Test

NG and Biogas Based DG Systems

IGFC/NGFC Systems

100 kW System Test

3

Cell and Stack Technology Overview

• Cell: − Planar anode supported − 0.6 X 254 X 254 mm with 550 cm2

active area− Manufactured by tape casting,

screen printing and co-sintering• Stack:

− Ferritic stainless steel sheet Interconnect

− Compressive ceramic seal − Integrated manifolding with formed

flow field layers− 120 Cells in a standard stack with

16 kW output @ 160 A

4

Advances in Cell Technology:Redox Tolerance Improvement

Anode Mechanical

Property Improvement

Anode Microstructure Improvement

Cell Improvement

• A wide range of anode microstructures with enhanced mechanical properties were studied for improvements in redox tolerance

• Redox tolerance improved from 15% performance loss (baseline cell) down to 0.2% loss after 6 redox cycles with varying extent of nickel oxidation within the anode

5

Accelerated Redox Tolerance Test Results

Multi-prong approaches were implemented to reduce anode strain upon Ni re-oxidation for achieving improvements in redox tolerance

• Redox cycle conditions designed for accelerated degradation:− Polarization curves to 0.74 A/cm2

− 10 thermal cycles red lines− 10 redox cycles green lines

• Accelerated tests showed:− Baseline TSC3 cell failed after

5 redox cycles− Recent cell with modified

anode structure is still running well after 10 redox cycle

Redox Cell

10 Redox Cycles

Baseline TSC3 Cell

Failed After 5 Redox Cycles

6

Post-Redox Cycles Evaluation

• Standard cell (left) failed catastrophically after 5 redox cycles

• Autopsy showed broken cell with significant oxidation

• Modified redox tolerant cell (right) is fully intact

• Autopsy showed no sign of cracks and no oxidation in active area

7

In-House Interconnect (IC) Coating• Studied both in-situ and ex-situ MCO applications

as protective layers for cathode interconnects• A 16 cell stack using baseline 550cm2 TSC3 cells

with alternating interconnect coatings was used to provide behavioral comparison of the two types of coatings

• Ex-situ MCO coatings provided better protection against Cr evaporation and lower performance degradation rate as compared to in-situ coatings

Sheet Metal

• PVD Co-Coating

Co-coated Sheet Metal

• IC Cutting and Forming

Co-coated IC

• Stack Assembly

MCO Coated IC

• MCO Formed In-Situ during Stack Operation

Sheet Metal

• IC Forming

IC• MCO Coating

Porous MCO

Coated IC

• Densification

Dense MCO

Coated IC

• Stack Assembly

Stack fabrication process using in-situ MCO IC coating

Stack fabrication process using ex-situ MCOIC coating

8

Enhanced Cathode Performance Stability Using Atomic Layer Deposition (ALD)

ALD coated LSCF powders resulted in reduced cathode degradation rate

Sonata

0

0.2

0.4

0.6

0.8

1

1.2

0 500 1000 1500 2000

Pote

ntia

l (V)

Time (hr)

Galvanostatic Hold @ 500 mA/cm2

ALD Coated LSCF Powder

Baseline LSCF

-0.2

-0.15

-0.1

-0.05

00 0.1 0.2 0.3 0.4 0.5 0.6

Z im

, Ω·c

m2

Zre, Ω·cm2

Nyquist PlotCoated-555 hr, 0.5 A/cm2Coated-1065 hr, 0.5 A/cm2Coated-1465 hr, 0.5 A/cm2Baseline-48 hr, 0.5 A/cm2Baseline-800 hr, 0.5 A/cm2

-0.2

-0.15

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-0.05

00.1 10 1000 100000

Z im

, Ω·c

m2

Frequency

Bode PlotCoated-555 hr, 0.5 A/cm2Coated-1065 hr, 0.5 A/cm2Coated-1465 hr, 0.5 A/cm2Baseline-48 hr, 0.5 A/cm2Baseline-800 hr, 0.5 A/cm2

9

80-Cell Stack Test

Cell Active Area: 550 cm2

Furnace Temperature: 690°C

Fuel: Simulated reformate, DIR= 36%, Uf = 68%

Oxidant: Air, Ua = 15%

Current: 160A (0.291 A/cm2)

Test in ProgressDegradation Rate: 0.4%/1000 hours for 11,700 hours

• Recent cell and stack design/manufacturing advances incorporated into 80-cell stack

• Ongoing testing at system conditions shows 0.4%/1000 hours degradation rate

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200 kW SOFC System

200 kW system is designed to validate stack reliability and scalability of stack-module design

Moderate temperature recycle loop to reduce cost and footprint while increasing reliability

SOFC Gross Power

DC Power 225.0 kW 244.0 kWEnergy & Water InputNatural Gas Fuel Flow 19.7 scfm 21.6 scfmFuel Energy (LHV) 323.2 kW 355.5 kWWater Consumption @ Full Power 0 gpm 0 gpmConsumed PowerAC Power Consumption 10.8 kW 12.5 kWInverter Loss 11.3 kW 12.2 kWTotal Parasitic Power Consumption 22.0 kW 24.7 kWNet Generation &Waste Heat AvailabilitySOFC Plant Net AC Output 203.0 kW 219.3 kW

Available Heat for CHP (to 48.9°C) 84.7 kW 90.8 kWExhaust Temperature - nominal 370 °C 370 °C

Efficiency

Electrical Efficiency (LHV) 62.8 % 61.7 %Total CHP Efficiency (LHV) to 48.9°C 89.0 % 87.2 %

200 kW SOFC System Performance SummaryNormal

Operating Conditions

Rated Power

11

200kW SOFC Power System Layout

100kW SOFCIntegrated Modules

Cathode Air System

Fuel Desulfurizer

Integrated Anode Recycle System

EBoPInverter/Transformer

& Plant ControlsGas ControlsFuel and Purge

System Start-Up Water Treatment System

• Includes (2) 100kW SOFC stack modules designed to operate independently • Factory assembled & shipped as a standard ISO 20’ x 8’ container

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• Excellent stack to stack performance reproducibility

• Stacks for 200 kW system meet cell voltage criteria

• Stacks shipped to FCE Danbury, CT and integrated into 100 kW modules

200 kW System Stack Manufacturing

13

100 kW Module Design & Fabrication

100 kW Stack Module Architecture:• Fully integrates all hot BoP equipment within the module• Eliminates high-temperature plant piping & valves• Reduces Cr evaporation protective coatings within plant/module • Integrated anode blower & module-specific instruments greatly decreases plant footprint

Removable Vessel Shell

I&C Panels

Cathode Process Air Connections

Anode Recycle System

14

200 kW BoP Fabrication

Desulfurization Units

Start-up Water System

Skid Support-Integrated Piping

Air Delivery System

Process ControlSystem

Control Hardware Cabinet

15

Stack Module Integration

Two 100-kW stack modules have been incorporated within the 200 kW system BoP, resulting in one transportable integrated system

200 kW Bop

100 kW Stack Module

100 kW Stack Module Integration

16

200 kW SOFC System Factory Testing

200 kW system installed at FCE’s Danbury, CT Test Facility.

Factory Acceptance Testing is underway.

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Example of 100kW Stack Module Acceptance Test Results

Screen Shot of the Power Plant HMI

18

200 kW System Demonstration Site Preparation

NRG Energy CenterPittsburgh, PA

• Permitting Process Complete• Site Preparation was completed

19

Next Generation Stack Technology

PropertyCSA Stack Scale

CommentsShort Mid Full

Cell count 45 150 350

Fuel cell voltage, V 38 128 298 At 0.85 V/cell

Stack Power, kW 0.9 3.0 7.0 At 0.29 A/cm2

Height, mm (in)

91

(3.6)

211

(8.3)

440

(17.3)

Compact SOFC Architecture (CSA)

Full Height CSA Stack:

• 470 W/kg• 780 W/L

Baseline Large Area Stack (LAS):

• 76 W/kg• 185 W/L

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Example Fuel Cell Run 68%Uf 40%Ua 25% internal reforming, 0.3 A/cm2

CFD Model of CSA Stack

• Fully coupled CFD/electrochemical CSA stack model was developed– Full stack (lumped porous

body model)• High current operation and

complex geometry of CSA stack requires large number of calculations

• ANSYS HPC Pack licensing and cluster computing services were used to run the model

350-cell stackSelect cell layers shown

21

Automated Work Cell for CSA Stack Fabrication

Current production rates achieved equivalent of up to 4 stacks per shift/day

Automated work cell commissioned for:• Stack builds• Cell and interconnect

QC

22

CSA Stack Fabrication

• Initial stacks of new design (CSA Stack) has been built and tested in both fuel cell and electrolysis modes

In-stack thermocouples (4)

Current collector (+)

Voltage instrumentationleads

45-cellStack

0%

10%

20%

30%

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90%

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Utili

zatio

n

Cell

Volta

ge (V

)

Elapsed time (hours)

45 Cell CSA , TS1

Average Cell 1-5

Average Cell 6-10

Average Cell 11-15

Average Cell 16-20

Average Cell 21-25

Average Cell 26-30

Average Cell 31-35

Average Cell 36-40

Average Cell 41-45

uf

ua

• Very strong utilization performance (>900 mV) at 80% fuel utilization at 0.25 A/cm2

– Demonstrates good flow distribution and even thermal conditions within the stack

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CSA Testing

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0 200 400 600 800 1000 1200 1400 1600 1800

Cell

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GT060248-0007 TC1 FC Hold - 28/Mar/1845 cell CSATest stand 1

Average Cell 1-5

Average Cell 6-10

Average Cell 11-15

Average Cell 16-20

Average Cell 21-25

Average Cell 26-30

Average Cell 31-35

Average Cell 36-40

Average Cell 41-45

65% fuel utilization40% air utilization0.25 A/cm2

830 W output0.66 % /khr degradation

65% fuel utilization40% air utilization0.29 A/cm2

935 W output0.61 % /khr degradation

• Good performance and stability• Tight voltage spread shows good flow distribution• Aggressive thermal conditions (lower air flow, lower pressure drop)

Fuel composition:53% H244% N23% H2ONon-reforming surrogate gas

Stack -0007 exceeding 1600 hours at 830-935 W output (with >70% LHV efficiency)

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CSA Stack Factory Cost Estimate

CSA Stack Factory Cost Estimate as a Function of Production per Year

25

Summary

Cell

• New redox tolerant cell stability was demonstrated after 10 redox cycles• ALD coated cathode materials showed improved endurance• In-house developed ex-situ MCO coating showed significant protection

against Cr poisoning

Stack• Baseline stack tested for >11000 hours showed <0.4%/kh degradation rate • 17 baseline stacks were fabricated for a 200 kW SOFC power plant• Initial trials of next generation CSA stacks have been successful

System

• 2 stack modules were built each with 8 stacks of 120 cells• Factory tests of the 200kW SOFC system was initiated• Preparation of the demonstration site for the 200kW SOFC system was

completed

26

Acknowledgements

The progress in SOFC technology was supported by DOE/NETL Cooperative Agreements: DE-FE0011691, DE-FE0023186, DE-FE0026199, and DE-FE0026093

Guidance from NETL Management team: Shailesh Vora, Joseph Stoffa, Patcharin Burke, and Heather Quedenfeld