Do Solid Oxide Fuel Cells (SOFCs) still have a future ?

John ZhuSchool of Chemical EngineeringThe University of Queensland

Email: z.zhu@uq.edu.au

Outline

• Brief overview of SOFCs industry

• Research activities on SOFCs in our group

Ceramic Fuel Cells Ltd

• Ceramic Fuel Cells Ltd was formed in 1992 by

CSIRO and a consortium of energy and industrial

companies.

• The company listed on the ASX in 2004

• In 2009 a production facility opened in Melbourne

and in Germany.

• Voluntary bankruptcy of Ceramic Fuel Cells Ltd.

in March 2015

• Bought by CTCC and Solid Power

Topsoe Fuel Cells

• (Fuel Cells Bulletin August 2014) “Topsoe will put all

development of its SOFC technology on hold, and focus on the

development of selected applications in solid oxide electrolysis

cell (SOEC) development”.

• ‘Over the years we have invested close to DKK1.5 billion

(E200 million, US$270 million) in commercialising our

technology, but the route to market has proven far more

challenging and time-consuming than anticipated,’ says

Clausen. ‘As the sole owner of Topsoe Fuel Cell, we can no

longer justify the investments and risk needed to move the

company forward…’

Are SOFCs going to die?

• Still plenty of positive news in SOFCs

Positive - Funding from DOE

The US Department of Energy’s (DOE) National

Energy Technology Laboratory (NETL) has selected

for funding 16 solid oxide fuel cell technology

research projects. In Fiscal Year (FY) 2015, NETL

issued two funding opportunities announcements

(FOAs) to support programmes to enable the

development and deployment of this clean energy

technology.

From Fuel Cells Bulletin, Aug 2015

DOE: $6 million, Non-DOE: $4 917 887,

Total funding: $10.9 million (45% cost share).

SOFC prototype system test

FuelCell Energy in Danbury, Connecticut and its

subsidiary (Versa Power Systems in Colorado) will

design, fabricate, and test a state-of-the-art 400 kW

thermally self-sustaining atmospheric-pressure SOFC

prototype system.

Positive – FuelCell Energy inc (NASDAQ: FCEL)

Bloom Energy to Install First−Ever

Highrise Project at Morgan Stanley Global

Headquarters in New York City

NEW YORK, Jan. 12, 2016 /PRNewswire/ -- Morgan Stanley today announced that Bloom

Energy will install a fuel cell system at the Firm's global headquarters in New York City's

Times Square neighborhood. The fuel cell project at 1585 Broadway is expected to be fully

operational in late 2016 and will provide approximately 750 kW of 24x7 high quality power

to the Morgan Stanley building, equal to approximately 6 million kWh of clean electricity

each year.

Bloom Energy currently has over 200 projects across the United States and in Japan,

including ten operating projects in New York State

12 Jan 2016, PRNewswire

Positive – Bloom Energy is still going and growing

Big power company Constellation to

finance Bloom Energy's fuel cells

by

Katie Fehrenbacher

@katiefehren

August 12, 2015, 9:00 AM EST

Constellation, which is owned by Fortune 500 company Exelon EXC 1.34% , plans to

provide equity financing to deploy 40 megawatts worth of fuel cells made by Bloom Energy.

The forty megawatts would come from 170 fuel cell projects and is enough energy to power

32,000 average homes per year.

Positive - GE Threatens to Enter Fuel Cell

Market, Compete With Bloom

Photo Credit: GEby Eric Wesoff July 24, 2014

http://www.greentechmedia.com/articles/read/ge-threatens-to-enter-fuel-cell-market-compete-with-bloom

Earlier this week, General Electric announced that it is initiating an entrepreneurial effort to commercialize its solid oxide fuel cell (SOFC) technology for megawatt-scale stationary power applications. Billion-dollar fuel cell startup Bloom Energy also works with SOFC technology at this scale.

Development of thermal spray, redox-stable,

ceramic anode for metal-supported SOFC

GE Global Research in Niskayuna, New York and its partners

will develop a thermal-spray, redox-stable, ceramic anode that will enable

robust, largescale, metal-supported SOFCs. The project team will tailor the

thermal spray process and engineer the powder microstructure to produce

high-performance SOFCs. The project will culminate in the assembly of a 5

kW stack that will be tested for at least 1000 h using natural gas or simulated

natural gas fuel.

DOE: $2 481 141, Non-DOE: $827 047,

Total funding: $3.3 million (25% cost share).

Positive - Sunfire 50 kW SOFC for ship-

integrated fuel cell project in Germany

The Ship-Integrated Fuel Cell (SchiBZ) project in Germany

has achieved an important milestone, with the delivery to

ThyssenKrupp Marine Systems of an initial solid oxide fuel

cell manufactured by Sunfire GmbH. Land-based

commissioning is scheduled to take place before the end of

this year, with test operation at sea planned for 2016.

Fuel Cells Bulletin, Nov 2015

What are the major challenges for

SOFCs?

• Durability

• Cost

Estimated value model for a commercial

customer (for a 2 kW system by CFCL)

By Giles Parkinson, 2012

The cost can be brought down

significantly

• Optimized technologies

• Mass production

• Manufacture in different location

Durability

• Realistically, the life time of a commercial SOFC unit should be up to 10 years or more.

• Durability affected by

– Sealing

– Thermal cycling

– degradation

How does a Solid Oxide Fuel Cell (SOFC) work?

Schematic of working principle of SOFC based on oxygen ionic conducting electrolyte

17

Cross section of a SOFC

Conventional SOFCs normally work at high temperature 800 – 1000 oC

18

Disadvantages of high temperatureDifficult to maintain gas tight sealsElectrode sinteringInterfacial diffusion componentsHigh cost interconnect and construction materials

Faster start-up and operating response. A wider and cheaper range of materials can be used to construct the device. Increased material durability. And importantly, reduced overall cost.

Opportunity of SOFCs: Reducing operating temperature

Operated at lower temperature

19

Cathodic Polarization Resistance

20

Cathode resistance

RC

In order to decrease the operation temperature of SOFC, we need to develop effective cathode

metarials which can work at intermediate temperature

21

Critical Issues

Electronic/ionic mixed conductivity Catalytic activity for O2 reduction Long-term stability (microstructure, in CO2 containing

atmosphere) Compatibility (chemical/thermal expansion

coefficient) with the electrolyte and interconnection

No single cathode material can meet all these requirements.

3D Heterostructured cathode materials

Shell with high oxygen exchange rate and stability Core with high oxygen

diffusion rate

22

Two examples

• Amorphous iron oxide decorated

SrSc0.2Co0.8O3-δ 3D heterostructured electrode

• La2NiO4 decorated Ba0.5Sr0.5Co0.8Fe0.2O3-δ 3D

heterostructured electrode

23

Amorphous iron oxide decorated SrSc0.2Co0.8O3-δ

3D heterostructured electrode

Ar

Ferrocene (Fe(C5H5)2)Single cell

Temperature controller

Furnace

Cathode: SrSc0.2Co0.8O3-δ (SSC)

155 oC 600 oC

~ 2 L/min

24

Chemical Vapor Deposition (CVD)

Formation of amorphous iron oxide

No iron oxide can be observed by XRD (Chemistry of Materials, 2011, p4193)

25

The amorphicity of iron oxide is related to an ultrasmall dimension and “space restriction”, leading to the absence of a periodic lattice in iron oxide.

Formation of amorphous iron oxide

26

SSC SFC superstructure

Electrochemical Performance and Stability

SSC-Pt

SSC-Fe shows comparable ORR activity to SSC-Pt

SSC-Fe shows better stability than SSC-Pt at 650 degree C

27

28

Fuel cell performance

I–V and I–P curves of the complete cell based SSC-Fe cathode

La2NiO4 decorated Ba0.5Sr0.5Co0.8Fe0.2O3-δ 3D heterostructured electrode

a, A two-step infiltration process is employed to introduce porous LN precursor shell onto the surface of BSCF scaffold and followed by microwave plasma treatment to obtain hierarchical LN shell.

(scientific reports, 2012, v2, p327)

b, In the 1st infiltration of the two-step infiltration process, La(NO3)3 and Ni(NO3)2 aqueous solution is infiltrated into BSCF scaffold. The LN substrate shell is obtained after heating at 850oC for 5 h. In order to obtained hierarchical LN precursor shell, citrate added La(NO3)3 and Ni(NO3)2 aqueous is infiltrated and fired at 850oC for 5h. Finally, the microwave-plasma is used to heat the precursor shell to make hierarchical LN shell.

29

Microstructure of the BSCF with LN shellBefore microwave-plasma treatment

6wt% LN loading 12wt% LN loading 26wt% LN loading

After microwave-plasma treatment

Single layer film Hierarchical film 30

a b c

d e f

CO2 tolerance of LN protected BSCF

FT-IR CO2-TPD

Carbonates

CO2 desorption

31

the materials treated at 600oC in CO2 for 60 mins first

Electrochemical performance of LN-BSCF cathode

Arrhenius plots of ASRs of the various electrodes based on the symmetric cells (BSCF-6%LN and BSCF-26%LN are the BSCF-LN cathodes before MP treatment)

32

Stability of LN-BSCF in CO2 containing atmosphere at 600 degree C

26wt% LN loading after microwave plasma treatment. The time in the bracket indicates the time after the introduction of CO2 (10%) into air or after the removal of the CO2.

33

2.0 2.5 3.0 3.5 4.0 4.5 5.00.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

Air

Treated in air+CO2 (10 %) for 5 min

Z"

( c

m2)

Z' ( cm2)

ORR activity of BSCF cathode degrades dramatically after introduction of CO2

(10%) only for 5 min.

ASR increases 20 times

Conclusions

• Amorphous iron oxide decorated SSC shows comparable ORR activity with Pt-SSC

• Amorphous iron oxide decorated SSC shows higher stability than Pt-SSC

• The morphology of LN thin-film can be controlled (single layer film or hierarchical film)

• La2NiO4 decorated BSCF 3D heterostructured electrode shows higher ORR activity

• La2NiO4 decorated BSCF 3D heterostructured electrode shows high tolerance in CO2 containing atmosphere 34

Conclusions

• Still plenty of R&D and commercialization activities

on SOFCs are on-going

• Durability and cost are still the two major barriers to

SOFCs commercialization

• Development of low or intermediate temperature

SOFCs can help with the sealing and thermal cycling

issues