I2CNER’s 10th Anniversary Symposium in TokyoIn December 2019, I2CNER’s 10th Anniversary Symposium in Tokyo
was held at Hitotsubashi Hall in Tokyo, away from Kyushu, to present
and promote I2CNER’s research outcomes that has been focused anddeveloped as part of the World Premier International Research Center
Initiatives (WPI) over the last 10 years.
It was attended by academics, researchers from industries andmembers of the public. The theme of the symposium was Energizing
the world and the future by strengthening research and cultural
bridges across the Pacific.
The symposium started with a greeting from the President of Kyushu
University, Dr. Chiharu Kubo, followed by the researchers from eachdivision, who presented their research development, implementation
and achievements.
In the following session, session II, the topic was about energy
transition in the United States, Japan and the world, and thepresentations reviewed about current energy trends, such as electricvehicle and hydrogen powered vehicle. Lastly in session III, theresearchers from Japan and across the world presented the futureenergy and its development.

Chiharu Kubo
President, Kyushu University

Yoshio Yamawaki
Senior Deputy Minister, MEXT

Masanobu Kubota
Principal Investigator, I²CNER

Akihide Nagao
WPI Visiting Scholar, I²CNER

Tatsumi Ishihara, Nicola Perry
Lead Principal Investigator, I²CNER
University of Illinois at Urbana-Champaign, I²CNER

1 

Akira Ukawa
Program Director, WPI

Nicholas M. Hill
Deputy Chief of Mission,
The U.S. Embassy in Japan

Petros Sofronis
Director, I²CNER

Miho Yamauchi
Principal Investigator, I²CNER

Shigenori Fujikawa
Lead Principal Investigator,
I²CNER

Takeshi Tsuji
Lead Principal Investigator,
I²CNER

Seiji Ogo
Lead Principal Investigator,
I²CNER

George W. Crabtree
Director, Joint Center for Energy
Storage Research, Argonne National
Laboratory

Michael Celia
Director, Princeton Environmental
Institute, Princeton University

Ross Matzkin-Bridger
Energy Attaché, DOE Director,
U.S. Embassy Tokyo

Ken Okazaki
Leader, Global Hydrogen Energy Unit,
Tokyo Institute of Technology

Katsuhiko Hirose
CEO, HyWealth Co.

Toyoki Kunitake
University Professor, Institute forAdvanced Study, Kyushu University

During the panel discussion, researchers of theenergy systems and the thermal science andengineering joined the discussion, and debated theseveral technologies to solve the issue of CO 2
emissions. The invited speaker, Dr Crabtree fromthe Joint Center of Energy Storage Research(JCESR), talked about the importance ofcommunicating with the community, government
agencies and private companies together todecarbonize society for energy need.
Participants heard the discussion concerning thestate-of-the-art technologies such as the batteries
for energy storage or hydrogen energy that thescientists are researching on, and the societal
issues that may be the cause of climate change,
and their effects on the people of the earth.

James Stubbins
University of Illinois
at Urbana-Champaign

Kathryn Huﬀ
University of Illinois
at Urbana-Champaign

Yukihiro Higashi
NEXT-RP, I²CNER

Andrew Chapman
I²CNER

Rashid Bashir
Dean, Grainger College ofEngineering, University of
Illinois at Urbana-Champaign

2

Special Interview
Future Energy

Putting our energy into the fight against climate change
As the climate change crisis worsens, scientists are searching for ways to reduce the amount of CO 2 being
emitted into the atmosphere. In this eﬀort, energy storage technology is crucial. One promising solution ishydrogen power, which researchers at I 2 CNER have been working to develop. Another is new types oflong-discharge batteries, which can even out the intermittent power supply from renewable resources like windand solar.
In conjunction with I2CNERʼs 10th anniversary symposium in Tokyo in December 2019, Dr. James Stubbins ofUniversity of Illinois at Urbana-Champaign, and also a professor at I 2CNER, sat down for an interview with Dr.
George Crabtree, Director of the Joint Center for Energy Storage Research (JCESR), Argonne National
Laboratory, in the U.S. Dr. Crabtree shared JCESRʼs research on energy storage, several ways to solve
decarbonization problems and what scientists can oﬀer to society.

The latest trends in battery research

James Stubbins: Thank you for coming today. First, canyou tell us about the Centerʼs goals and accomplishments?
George Crabtree: Weʼre trying to promote energy storage
for many reasons ‒ the coming transition in the grid, as
well as in electric vehicles and in aviation. Each of theseapplications requires different kinds of batteries. The mostpopular and the best battery we have now, lithium-ion, is
an excellent battery, but is not capable of doing all of thosejobs. So, our mission is to invent a diversity of batteries fora diversity of uses.
Stubbins: Where does this stand in terms of where JCESR
is going?
Crabtree: We have started work on specific batteries, suchas lithium sulfur, as well as magnesium batteries, which aresimilar to lithium-ion, except that magnesium has two
chargers instead of the usual one, and you get twice theGeorge Crabtree

Director
Joint Center for Energy Storage Research
Argonne National Laboratory3 

energy stored or released whenever a chemical reaction
occurs.
O ne ver y i ntere st i ng bat ter y i s c a l le d t he aque ou s
air-breathing sulfur battery, which has two positive things
going for it. Firstly, the material cost is the lowest of any ofthe proposed batteries because it uses sulfur, water as theelectrolyte and oxygen from the air as the cathode. Nothing
could be cheaper, more abunda nt or moreenviron ment-friendly. A nd secondly, it is capable oflong-duration storage, and able to discharge for 50 or even100 hours, which lithium-ion cannot do.
As the transition to a more advanced grid progresses, wewill have more wind and solar, which do not produce
energy when it is overcast or calm, so we need something
to back them up, and one possibility is batteries. These aresome of the things we have been doing.
Stubbins: Most people think of batteries as appropriate forsmal l-scale appl icat ions, cars or even air pla nes. IʼmJames Stubbins

Professor
Department of Nuclear, Plasma and Radiological Engineering
University of Illinois at Urbana - Champaign

wondering where you see the battery technology having an
impact on large-scale, centralized power production.
Crabtree: When the lithium-ion battery was born, nobody
foresaw that it would be the king of personal electronics,
and now it is moving on to other applications ‒ electricvehicles (EVs) are the most notable and will become thefastest and biggest in the next five years. To store thatmuch energy, the grid needs a thousand times more battery
than an EV. A lthough there are plent y of lithium-ion
deployments on the grid and in the pipeline, the batteries
are not suitable for such large-scale use.
There is another battery called the flow battery which,instead of a solid electrode for the anode and cathode, hasa tank of liquid. All the chemical reactions take place inthe liquid, and redox (reduction‒oxidation) active materials
release electrons into the solution. Because energy is stored
in the electrolyte, the storage capacit y can be scaled
linearly. If you want 10 times more energy, you just makethe tank 10 times bigger.
T h i s i s t h e w ay t h e g r i d i s g o i n g a s a l a r g e - s c a l eapplication. However, the challenge is that the cost is toohigh. JCESR, along with scientists elsewhere, is working
on organically active materials, such as hydrogen, oxygenand nitrogen, which are plentiful, cheap and usuallyenvironment-friendly, instead of vanadium, which is usedin the flow battery. You can design organic molecules toperform much better than either lithium or vanadium.
Stubbins: You ment ioned renewables, which are anintermittent power supply. What about leveling out thedemand cycles for large-scale systems like nuclear or coal,
which are not good at load-following but could be operated
at a regularly steady rate with the right amount of storage?
Crabtree: With renewables you need storage to take careof their intermittency. Nuclear doesnʼt emit any carbon, so
it might be a good candidate for decarbonizing the grid,since it does not need storage the way renewables do. Thisis getting more attention.

Working toward a decarbonizedenergy future

Stubbins: What about industrial activities? High-temperatureprocesses seem to be a major part of the carbon footprint of
most industrial processes. Do you see batteries playing arole?
Crabtree: Decarbonization in the industrial sector isprobably the most difficult, because high temperatures ‒1,000°C to 1,400°
C ‒ are required, and CO 2 is released

during production of feedstock materials, such as withcement production. This CO 2 does not come from simply
producing heat; it is an inherent part of the process. So,
batteries will have to play a role. They can be applied on
the electrical cycle to retrofit industrial processes when you
have low-temperature heat. You can do that with resistive
heating. At a bit higher temparatures you can do it withelectric arc heating, and these require controlling inaccordance with the process. The batteries can help tomodulate that up and down as required.
The other side is how to replace and decarbonize theinherent carbon emissions from processes themselves.
Carbon capture and sequestration and, even better, using
CO 2 to make useful, high-value chemicals would be someof the solutions.
Stubbins: How will the carbon footprint of all theseenergy sources evolve in the next decade or two?
Crabtree: Some areas are easy to imagine decarbonizing.
One is the electrical grid: people talk about having 85-90%
driven by wind and solar, and that is only possible withbatteries. Although we are far from that stage, we have thetechnology to do it, in principle. The second big area iselectric vehicles. That will blossom enormously and will
not only ease the carbon problem but could be an economic
solution as well, as they achieve cost parity with gasoline
engines.
However, for long-haul trucking or shipping, itʼs hard to
imagine batteries supplying power to do that without lots ofinconvenience, namely lots of recharging. That could mean
hours of downtime for trucks. And aviation uses a lot of jet
fuel, which also emits carbon. What do we do about that?
There is a solution, and that is hydrogen. It is produced
electrolytically by splitting water, is completely carbon-free,and can be used as a combustible fuel. Hydrogen can beused for example in the industrial sector, burned to produce
high temperatures or in conjunction with fuel cells to makeelectricity, or to fuel long-distance freight trucks and ships.
That is an opportunity to further decarbonize most of theeconomy. The Intergovernmental Panel on Climate Change(IPCC) says we need to do it by 2050, so there is still time
to develop t he tec h nolog y. T h i s i s one of t he mo st
promising areas.

Transition to a future energy system

Stubbins: This is one of the things that I 2CNER has beenheavily concentrating on. Japan in particular has beenleading a lot of the effort into fuel cell vehicles and otherhydrogen applications, as well as home applications for

4

hydrogen or fuel cells. We need technologists and scientists
to work with policy makers to make them aware of thispossibility.
Stubbins: Do you think investment in these technologies
is at the right level? Should we be doing more?
C r a b t r e e : We s h o u l d d o m u c h m o r e . J C E S R h a sdeveloped a long-discharge battery that is inexpensive andenvironment-friendly, but many technologies of this kind
are not yet commercially mature. If we want to make thath app e n , we ne e d to pr o mote t he m a nd m a ke t he m
attractive to the private sector.
Stubbins: Do you think we have done enough in thebattery area and hydrogen area?
These large infrastructure investments donʼt necessarily
pay off and require government support until they can havean impact.

heating and electricity generation. How can these be madecomplementary rather than competing technologies?
Crabtree: Hydrogen can take that model to new heights. It
could be completely connected to the electrical system. If
you had excess electricity, you could split water to producehydrogen; if you needed more electricity, you could turnhydrogen back into electricity through fuel cells, or simply
by burning it in combustion turbines that use hydrogen to
replace natural gas to generate electricity. This is a very
flexible system and could be a huge benefit to the entire
energy system.
Stubbins: This is certainly something that could happen
in the U.S. and Japan, and some other places in the world,
but the biggest impact on fossil fuels will be in China, India
and other big economies where there is a similar kind ofgrid system.
Things you are working on are leading-edge technology.
What will be their international impact?
Crabtree: A United Nations report in 2019 says thatcarbon emissions in the electricity sector in the European
Union and the U.S. have gone down significantly because
they both have begun to phase out coal, but not in Asia,
which still relies on coal. We need to find a way to deal
with the need for more energy, especially in developing
countries without pumping out more carbon emissions. For
example, India only has a basic grid, which needs to be
u p g r a d e d w i t h w i n d , s o l a r a n d b a t t e r i e s t o s o l ve
decarbonizing problems. These countries do not need torepeat the path that the EU and U.S. have followed. Insteadof legacy grids and their problems, letʼs go straight totomorrowʼs grid.

A solution for climate change issues

Stubbins: You have been very active in the scientificcommunity. How effective is our community in helping
people understand the carbon issue and climate change?
Have we done enough? What else should we be doing?
Crabtree: I think a lot of this is communication.
Scientists need to communicate much more effectively andsimply to policy makers, to countriesʼ decision makers andto the general public. The other thing that scientists canoffer is technological solutions, such as hydrogen power,
batteries, fuel cells and long-duration discharge storage.
The cost of solar energy and wind power has gone down
dramatically in the last 10 years, because of the learning
curve. However, the learning curve has not happened yet in5 

Crabtree: We do need to be more persistent and moredeliberate. We need to devise new, more specific andfinancial incentives for hydrogen and long-duration storage.
In the West, itʼs the private sector that brings technology tosociety.
We should be looking at developing countries. Thatʼs where
the biggest impact is going to be. Developing countries can
put in advanced grids, and that is something we haveexperience in. We can certainly innovate to make themeven more resilient, such as by digitizing them and puttingenergy management systems in place that automaticallyshift power around as needed and deal with emergencies
much more efficiently.
Stubbins: Since we have had such a good conversation
about the impact of carbon, how about geoengineeringsolutions, such as carbon capture and storage, sulfur
aerosols and mirrors in space?
Crabtree: People were talking about geoengineering 10
years ago, but in t hose days, it was looked on rat her
suspiciously. Not because it wouldnʼt work, but because
there could be serious unintended consequences, andcarbon m ight cont i nue to be released at h igh levels.
Countries all over the globe would have to cooperate.
The climate change issue is serious, and itʼs not going away.
The most important thing is communicating and acting on
it. As you mentioned, there are two ways to act: stopemitting carbon and mitigating its effects. There will besome effects of climate change that we have to minimize,
but what do we do about them? It seems to be far in the
future and it is hard to deal with. We, the citizens of theworld, need to change the way we think about these things.

I2CNER
10 Years Accomplishments

Air electrodes in high temperature electrochemical devices:
An atomistic study of composition and mechanisms
Tatsumi Ishihara, Molecular Photoconversion Devices Division

Solid Oxide Fuel Cells are highly efficient and reliable power sourcesa)b)c)already deployed in the markets. However, for increased service lifeand reduced cost, decrease in operating temperature or further increasein power density are still required and for this, increase in theperformance of the air electrode is critically important. Cross divisionalteam efforts in I2CNER tackled the very difficult problem ofunderstanding the surface properties of multicomponent oxide air
electrodes in the complex gaseous environment of ambient air. Air
electrodes can typically experience degradation under operation,consequently limiting the commercialization of high temperature Figure a) Measured compositional profile shows segregation of cations to theelectrochemical devices for efficient energy conversion. The evolution surface, b) Schematic of measured composition profile. The segregation isof surface composition, surface reactions, and the degradation closely linked to performance degradation, c) Atomistic modelling has unveiled amechanism shows that the most common materials used as air vacancy-assisted mechanism for surface oxygen exchange involved in the ORR.
electrodes are the mixed ionic electronic conducting perovskite oxides
with a general formula of A1-xAʼxBO3, where the transition metal B
cations such as Co or Fe are thought to be essential to the ORR/OER process and the large A and Aʼ atoms, most usually La and Sr respectively,
were both thought to be inert. Under operating conditions, the surface quickly reorganizes to a termination consisting entirely of A type cations
and O ions, covering the catalytically active B cations. In addition, there is a rapid segregation of substituted Aʼ cations to produce a majority AʼO(e.g. SrO) rich near-surface region. Using this knowledge of the surface composition, we computationally modelled the adsorption andincorporation of molecular oxygen onto these segregated electrode surfaces. Our analysis shows that pristine segregated SrO surfaces are inactive
for oxygen adsorption and the surface oxygen vacancies provide a window to access the active B site transition metals. According to these results,
we have shown that in related Aʼ free materials, e.g. La2NiO4, the surfaces are again AO dominated and that, in this case, and contrary toconventional understanding, the surface La cations are the active participant in the ORR reaction.

References
J. Druce, H. Tellez, M. Burriel, M.D. Sharp, L.J. Fawcett, S.N. Cook, D.S. McPhail, T. Ishihara, H.H. Brongersma, J.A. Kilner (2014) Surface termination and subsurface
restructuring of perovskite-based solid oxide electrode materials, Energy & Environmental Science, 7(11), 3593-3599.
A. Staykov, H. Tellez, T. Akbay, J. Druce, T. Ishihara, J. Kilner (2015) Oxygen Activation and Dissociation on Transition Metal Free Perovskite Surfaces, Chemistry ofMaterials, 27(24), 8273-8281.

Mitigation of Hydrogen Embrittlement
Brian P. Somerday, Masanobu Kubota, Hydrogen Materials Compatibility Division
One of the safety considerations for hydrogen fuel technology is the phenomenonof hydrogen embrittlement, in which hydrogen permeates into the containment
component and degrades its material strength. While many hydrogen
embrittlement mitigation strategies focus on modifying material properties, it isalso possible to manage this detrimental phenomenon by preventing hydrogen
permeation into the material. Conventional approaches to preventing hydrogen
permeation involve engineered coatings applied to material surfaces, however theirperformance can deteriorate as a result of cracking or debonding. Since theinception of I2CNER, researchers have focused on an alternative method of
preventing hydrogen permeation, which involves “chemical inhibitors”. The
principle of this method is that extremely small concentrations (parts-per-million)of certain species that are typically considered impurities in hydrogen gas canactually interfere with hydrogen permeation. By applying state-of-the art modelingat the molecular level, I2CNER researchers demonstrated that species such as
oxygen and carbon monoxide can restrict the splitting of hydrogen molecules into
individual hydrogen atoms on the surface of materials. Since only hydrogen atoms
can permeate into the material, the oxygen and carbon monoxide are effectively
mitigating hydrogen embrittlement. In addition to advancing the fundamental
understanding of how chemical inhibitors function, I2CNER researchers have
performed comprehensive material strength experiments and developed
physics-informed engineering models to enable the practical application of thismethod. As a result, I2CNERʼs industry partners are now considering deploying
this concept of chemical inhibitors to enhance the safety of hydrogen-containment
components.

Figure Results from material strength experiments
showing that small concentrations of carbon
monoxide (100 to 10,000 parts-per-million) improve
the fracture resistance of steel in hydrogen gas. The
inhibiting effect of carbon monoxide is more
pronounced for low-strength steel (HV329)
compared to high-strength steel (HV613).
References
B.P. Somerday, P. Sofronis, K.A. Nibur, C. San Marchi,
R. Kirchheim (2013) Elucidating the Variables
Affecting Accelerated Fatigue Crack Growth of Steels
in Hydrogen Gas with Low Oxygen Concentrations,Acta Materialia, 61(16), 6153-6170.
R. Komoda, M. Kubota, A. Staykov, P. Ginet, F. Barbier,J. Furtado (2019) Inhibitory Effect of Oxygen on
Hydrogen-Induced Fracture of A333 Pipe Steel,
Fatigue & Fracture of Engineering Materials &Structures, 42(6), 1387-1401.
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46

I2CNER 10 Years Accomplishments
Highly-Conductive Proton-Conducting Oxide
for Intermediate temperature steam electrolysis:
Temperature / 0C
800 700 600
500

Hiroshige Matsumoto, Electrochemical Energy Conversion Division

References
K. Leonard, Y. Okuyama, Y. Takamura, Y-S. Lee, K. Miyazaki, M. E. Ivanova, W. A. Meulengberg,
H. Matsumoto, “Efficient intermediate-temperature steam electrolysis with Y:SrZrO3‒SrCeO3
andY:BaZrO3‒BaCeO3 proton conducting perovskites” J. Mater. Chem. A, 6, pp19113 (2018)
K. Leonard, Y. Okuyama, Y. Lee K. Miyazaki, H. Matsumoto, “The Inﬂuence of Dopant Levels
on the Hydration Properties of SZCY and BZCY Proton Conducting Ceramics for Hydrogen
Productions” Int. J. Hydrogen Energy, 42, pp3926 (2017)400

BZCY54
BZCY
8/92
Ba(Zr
CeCe
)8/9Y
Y0.2
(BaZr0.5
O2.9
0.40.36
0.2O
3-δ )
0.44

10-1
Conductivity {σ(Scm-1)}

Steam electrolysis is the most energy-efficient approach of water splitting forhydrogen production that can be used as a storage medium for renewable energy.
We newly developed an ideal proton conducting electrolyte BZCY548/92 exhibiting
high performance at intermediate temperatures (400-600 °C). The conductivities
in this temperature region are higher than other state-of-the-art solid electrolytes.
This composition was determined to be the best in the series of perovskite-type
BaZrxCe1‒x‒yYyO3−δ (BZCY) electrolyte materials with respect to conductivity andthermodynamic stability. The previously reported BaZr0.1Ce0.7Y0.2O3-δ (9 ×10-3 S/cm at 500°C), as holding the benchmark conductivity, is disadvantageous due to
its low stability in CO2 and H2O environments. We discovered that thecerium/zirconium ratio of 5/4 at the B-site of the perovskite exhibits both a higher
conductivity and stability than the benchmark. We also succeeded in reducing theoperating temperature of electrolysis to 500°C without compromising thehydrogen production rate. Hydrogen is directly produced at a current density of 0.5
A/cm2 at 500°C and 600°C with an applied voltage of 1.45 and 1.2 V. In addition,
we have established a standard protocol for highly efficient intermediate
temperature steam electrolysis, which has been shared with Nippon Shokubai Co.,
Ltd. through collaborative research initiated in 2013 toward commercialization.

10-2
10-3

GDC

(Ce0.8Gd0.2O1.9)

LSGM

10-4
10-5

(La0.8Sr0.2Ga0.8Mg0.2O2.9)

YSZ((ZrO3)0.92(Y2O3)0.08 )

1.0

1.2
10 3 T -1 / K -1

1.4

1.6

Figure Ionic conductivity of (BZCY54 8 / 9 2) compared withexisting oxide-ion-conducting electrolyte materials.

Novel electrocatalyst design based on polymer-wrapping of carbon supports:
Tsuyohiko Fujigaya, Electrochemical Energy Conversion Division
To realize polymer electrolyte fuelcells (PEFC) with high durability
and high activity, Professors
Nakashima and Fujigaya developed
a novel electrocatalyst structure, inwhich the carbon supports arewrapped with polymer prior tothe catalyst loading. One of thepowerful advantages of this strategy
is that various types of carbon
materials can be loaded withcatalyst nanoparticles, e.g. platinum,
homogeneously and uniformly(Advantage 1). The team managed
to realize by this approach the mostdurable PEFC catalyst structure
worldwide and for the first timethrough using unoxidized carbon
nanotube (CNT) as a carbon
support (Advantage 2). In addition,
this new structure enabled theremarkably stable dispersion of
the electrocatalyst due to thehomogeneous and stable coatingof the electrocatalyst surface by
the electrolyte based on thepolymer-electrolyte
interaction(Advantage 3). Due to such ahomogeneous coating, a higher Ptutilization efficiency of 20-30%
in comparison to that withconventional electrocatalyst approach
was achieved, leading the dramatic
cost reduction of PEFC (Advantage
4).

7 

Figure New approach to highly durable electrocatalysts for polymer electrolyte fuel cells based on polymer wrapping, andassociated advantages.
References
T. Fujigaya et al., Sci. Rep. 5, art. no. 16711 (2015).
T. Fujigaya et al., Electrochimica Acta. 312, 349-357 (2019).

Surface engineering for enhanced heat transfer in power generation
Yasuyuki Takata, Nenad Miljkovic, Thermal Science and Engineering Division
Dropwise condensation of steam on metallic surfaces
(a)
(b)
(c )
(d)
coated with hydrophobic films has the potential to achieve
remarkable heat transfer coefficients resulting in 4%
efficiency enhancement on 85% of the baseload
power-generating infrastructure globally. However, themain challenge of using these coatings for the past century
20 µm
is their lack of long-term durability. The Miljkovic and
Takata team has developed the worldʼs first fundamental
understanding of degradation of hydrophobic thin films(e)(e)
during condensation. They quantitatively elucidated the(f)(f)
fundamental failure mechanisms governed by themechanics of blister formation beneath hydrophobic
thin-films due to nanoscale pinholes. They used theirunderstanding to develop, for the first time, scalable anddurable hydrophobic coating approaches, in collaboration
with the biggest coatings and paints companies in the world(PPG and Chemours), that can be applied to a variety ofindustrial energy systems.
Figure (a-b) Droplet growth and (c-d) blistering on a hydrophobic thin film. (e)Another grand challenge in the energy field is the inability
Dropwise condensation of a low surface tension fluid (hexane). (f) TEM images of ato develop engineered surfaces that can enhance thesuspended water film in a CNT under high vacuum conditions.
condensation heat transfer with low surface tension
working fluids (refrigerants). The Miljkovic group has
overcome this challenge for the first time ever throughutilizing liquid infused surfaces (LIS). They rigorously investigated lubricant-condensate pairs to develop rational design guidelines for LIS withlow surface tension fluids to develop, for the first time in the world, an engineered surface coating that can achieve stable dropwise
condensation of an alkane, attaining a 200% enhancement in condensation heat transfer coefficient for both fluids compared to filmwise
condensation on hydrophobic surfaces.
Condensation and boiling on smooth and engineered surfaces have received much attention in the past century due to its inherently high heattransfer efficiency. Although widely used in a plethora of industries, the fundamental mechanisms governing the physics of phase change heattransfer are poorly understood. The Takata group, working with international collaborators, have challenged this by observing water confinedin open hydrophilized CNTs with diameter of tens of nanometers using transmission electron microscopy. The stability of these water phases
could not be explained by existing thermodynamics-based theories. The results advance the understanding of water behavior at the nanoscaleand open the door for new applications of phase-change heat transfer.
References
Ma, J., Cha, H., Kim, M.-K., Cahill, D. G., and Miljkovic, N., Condensation Induced Delamination of Nanoscale Hydrophobic Films. Advanced Functional Materials
2019, 29 (43), 195222.
Sett, S., Sokalski, P., Boyina, K., Li, L., Rabbi, K. F., Auby, H., Foulkes, T., Mahvi, A., Barac, G., Bolton, L. W. and Miljkovic, N, Stable Dropwise Condensation of Ethanol
and Hexane on Rationally Designed Ultrascalable Nanostructured Lubricant-Infused Surfaces. Nano Letters 2019, 19 (8), 5287-5296.
Tomo, Y., Askounis, A., Ikuta, T., Takata, Y., Sefiane, K. and Takahashi, Superstable Ultrathin Water Film Confined in a Hydrophilized Carbon Nanotube. Nano Letters
2018, 18 (3), 1869-1874.

Biomimetic activation of hydrogen and carbon monoxide
for future fuel cell technology
Seiji Ogo, Catalytic Materials Transformations Division
Professor Ogo and his group have invented the first catalyst that can oxidize both hydrogenand carbon monoxide. Carbon monoxide is a common pollutant in commercially availablehydrogen gas and it significantly reduces the catalytic activity in todayʼs fuel cells bypoisoning the platinum catalyst. However, the new I2CNER catalyst, based on anickel-iridium complex, was designed to act as mid-point between two naturally occurring
enzymes: hydrogenase which oxidizes hydrogen and carbon monoxide dehydrogenase
which oxidizes carbon monoxide. Instead of approaching the issue from the conventional
standpoint of protecting the catalyst from the carbon monoxide, the Ogo group designed acatalyst that facilitates the use of carbon monoxide as a fuel (electron source) in the samemanner as hydrogen. Indeed, the group managed to showcase a proof-of-concept for a fuelcell that uses poisonous carbon monoxide as a fuel to generate energy from a 50:50 mixture of
the two gases. Significantly, since this system can operate in water, it is also environmentallyfriendly.

References
S. Ogo, Y. Mori, T. Ando, T. Matsumoto T. Yatabe, K-S Yoon, H. Hayashi, M. Asano. One Model, Two
Enzymes: Activation of Hydrogen and Carbon Monoxide. Angew. Chem. Int. Ed. 2017, 56(33), 9723‒9726.

Figure The anode of a fuel cell that uses a 50:50
mixture of hydrogen and carbon monoxide gases
as fuel.

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8

I2CNER 10 Years Accomplishments
Nano membrane for CO2 separation in power generationand industrial processes
Shigenori Fujikawa, CO2 Capture and Utilization Division
Efficient CO2 capture technologies are indispensable and urgently needed for carbon-neutral energy systems. CO2 capture by permselective
membranes is a new promising technology that involves smaller and simpler set-ups, but the associated permeation throughput is not yet
satisfactory for operation under economically-feasible conditions. Improvement of the gas permeance toward reducing the cost of CO2 capture
from flue gas in power plants is more important than enhancing selectivity. Industrial requirements for membranes for CO2 separation overnitrogen require that the CO2 permeance exceeds 4,000 GPU, which is the I2CNER target. Professor Fujikawa and his group developed
well-defined, free-standing polydimethylsiloxane (PDMS) nanomembranes with thickness of 34 to 6700 nm for the systematic investigation of
the thickness effect on the gas permeance. Generally, the gas permeability of polymeric materials is inversely proportional to the membranethickness, since gas permeability is essentially determined by the diffusion process within the polymer matrix. However, the CO2 permeabilityof thinner nanomembranes, i.e. with thickness less than 1 μm, decreases with decreasing thickness. Apparently, the overall rate of the gas
permeation is determined by the surface adsorption process and the gas selectivity may be mainly controlled by the surface adsorption process.
Professor Fujikawaʼs group succeeded in
manufacturing free-standing membranes
with thickness of 34nm and associated CO2
permeance of more than 40,000 GPU, whichis the worldʼs highest, better than thecurrent benchmark of 2,000 GPU held by
MTR Inc., USA, and with a moderate 10 to
11 CO2/N2 selectivity. Additionally, whentestedunder
atmosphericpressureconditions, the membranes captured CO2
from CO2/N2 mixture with a CO2
concentration of 1000 ppm. This finding
expands the relevance of our research goals
beyond capturing CO2 from fire-poweredplants to the entirely new area of CO2
capture directly from the atmosphere.
References
S. Fujikawa, M. Ariyoshi, R. Selyanchyn, T. Kunitake (2019) Ultra-fast,
selective CO 2 permeation by free-standing siloxane nanomembranes,
Chemistry Letters, 48(11), 1351-1354.

Figure CO2 separation nanomembrane and its gas separation performance: (a) afree-standing and 150-nm thick PDMS nanomembrane (orange O-ring is a frame);(b) gas permeance of CO 2 (blue squares), N 2 (green triangles), and CO 2 /N 2
selectivity (red crosses) as a function of thickness.

Co-electrolysis of CO2 and waste glycerol
to enhance economic viability of CO2 valorization
Paul Kenis, CO2 Capture and Utilization Division
Professor Kenisʼ research focuses on ways to reduce the energy required to convert
carbon dioxide to value-added chemicals. Surplus industrial carbon dioxide createsan opportunity to convert waste into a valuable commodity. Excess CO2 can be afeedstock for chemicals typically derived from fossil fuels, but the process isenergy-intensive and expensive. The I2CNER team has assessed the economic
feasibility of a new co-electrolysis approach that uses the oxidation of a cheap
biofuel byproduct, glycerol, to reduce the energy consumption of the overall
waste-to-value process by 50 percent. Conversion of CO2 to chemicals like
ethylene for plastics is possible through a process called electrochemical reduction.
Typically, a stream of CO2 gas and a fluid electrolyte move through an electrolysis
cell that breaks the CO2 down into molecules like ethylene on the cathode, but it
also produces oxygen from water on the anode. However, about 90 percent of theenergy required in conventional CO2 reduction is used up by the oxygen-producing
Figure Flow electrolyzer for the co-electrolysis of CO2 to CO or
anode side of an electrolysis cell. But since there is no big market for the excess
ethylene on the cathode, and glycerol to lactate and/or formate
oxygen, 90 percent of the energy is essentially wasted.
on the anode
Professor Kenisʼ new approach uses the anodic oxidation of glycerol ‒ a byproductof sugar cane biofuel production ‒ as an alternative to the energy-intensive oxygen-producing step. Life-cycle analysis reveals that thisco-electrolysis approach has the potential to push the full CO2 conversion process to be close to carbon neutral, whereas the current
thermo-chemical processes used to convert fossil fuels into the same products are heavily carbon positive. The analysis includes best- andworst-case CO2 emissions and energy consumption scenarios and concludes that the prospects of CO2 reduction, in terms of CO2 emissions andeconomics, can drastically improve by replacing conventional anode reactions (oxygen evolution) with oxidation of organic waste materials.
Looking beyond oxygen evolution at the anode seems like a win-win situation, as this not only reduces the processesʼ energy consumption by
40-50%, but it also has the potential to produce a second valuable product stream.
References
S. Verma, S. Lu, P.J.A. Kenis (2019) Co-electrolysis of CO2 and glycerol as a pathway to carbon chemicals with improved technoeconomics due to low electricity
consumption, Nature Energy.
(DOI: 10.1038/s41560‐019‐0374‐6)

9 Continuous and accurate monitoring system for injected CO2:
Takeshi Tsuji, CO2 Storage Division
In carbon capture and storage (CCS), the monitoring of injected CO2 iscrucial for i) predicting the risk of CO2 leakage from reservoirs, ii)
increasing the efficiency of CO2 injection and reducing the cost, and iii)
reducing the risk of injection-induced seismicity. To date time-lapse
seismic surveys have been used to monitor injected CO2 distribution.
However, the interval of the time-lapse monitoring surveys is long due totheir high cost and it is difficult to continuously monitor the injected
CO2. In addition, continuous monitoring of the dynamic CO2 behavior is
crucial for detecting accidental incidents, such as CO2 leakage. To
address these issues, we first developed a continuous monitoring
approach to estimate spatio-temporal variation of seismic velocity using
ambient noise (or microtremor). Since this method constructs virtual
seismic data from noise, we can extract subsurface information using
only passive seismometer data. However, the disadvantage of thismonitoring system that relies on ambient noise is that the temporal
Figure Results from our continuous monitoring system of seismic
variation of ambient noise would decrease the monitoring accuracy. To
velocity for all Japanese Islands on (a) 2 February 2016, (b) 26 April
overcome this problem, we have developed a new novel monitoring2016. Warm colors indicate regions where the seismic velocity was
method for injected CO2 using a continuous and controlled seismic
decreased (materials weakening). Seismic velocity in Kyushu Island wassource. This new monitoring system generating controlled seismic signal
decreased in panel (b) due to subsurface stress changes caused by theis cost-effective, with high temporal resolution and accuracy. By using
Kumamoto earthquakes (Mw7) on April 16.
this system to the ongoing CCS project in Canada, we successfully
identified spatial and temporal variation in the shallow subsurface. To
further reduce the cost of seismometers, we deployed fiber-optic type seismometers (i.e., distributed acoustic sensor (DAS)) in a geothermal
field in the Kyushu Island. By recording the signal of continuous seismic source system by DAS, we successfully monitored geothermal
reservoirs with high accuracy. High spatial resolution of our approach makes it possible to identify leaked CO2. Also, the systemʼs low cost andhigh temporal resolution are particularly attractive for long-term monitoring of sequestered CO2.
References
T. Tsuji, T. Ikeda, T.A. Johansen, B.O. Ruud (2016) Using seismic noise derived from fluid injection well for continuous reservoir monitoring, Interpretation, 4(4),SQ1-SQ11.
(DOI: 10.1190/INT-2016-0019.1)
H. Nimiya, T. Ikeda, T. Tsuji (2017) Spatial and temporal seismic velocity changes on Kyushu Island during the 2016 Kumamoto earthquake, Science Advances, 3(11),e1700813.
T. Ikeda, T. Tsuji, M. Nakatsukasa, H. Ban, A. Kato, K. Worth, D. White, B. Roberts (2018) Imaging and monitoring of the shallow subsurface using spatially windowed
surface-wave analysis with a single permanent seismic source, Geophysics, 83(6), EN23-EN38.

Hydrogen station deployment for fuel cell vehicles:
Kenshi Itaoka, Andrew Chapman, Energy Analysis Division
Deployment of FCV (fuel cell vehicles) as well as BEV (battery electric vehicles) is essential
for the energy transition in the transportation sector. FCV deployment relies on the efficient
location of hydrogen refueling stations. The objective of this study was to develop an
effective model for domestic hydrogen station deployment and identify prospective areas forhydrogen station locations to meet the future refueling demands of FCVs. A deployment
model employing location allocation theory using GIS (geographic information systems) wasused to consider user convenience and FCV penetration phases.
Based on our model results, we concluded that the most effective approach was to locate thehydrogen stations in a way that minimizes average distance between potential customers andthe nearest hydrogen station. The study also identified gaps between existing and planned
stations, and the suggested station sites. This gap analysis identified certain cities,
particularly prefectural capital cities, in need of coverage. The results were directly reported
to the Ministry of Economy, Trade and Industry and shared with hydrogen station
stakeholders to support hydrogen deployment policy and planning in Japan. Also, the model
results of follow-up analyses are currently used by JHyM (the Japan Hydrogen Station
Network Joint Company), created by major car companies and energy companies to develop
future hydrogen refueling infrastructure. In addition to this study, The energy analysis teamof I2CNER is also pursuing a global hydrogen penetration model, which has identified astrong future potential for FCV deployment, up to 50% of the future passenger vehicle fleet
by 2050[2]. Of particular interest is the consistently strong end use case for FCVs under anumber of ʻHydrogen Societyʼ scenarios, extolling the value of this hydrogen station
deployment research.
References
K. Itaoka, S. Kimura, K. Hirose (2019) Methodology Development to Locate Hydrogen Stations for theInitial Deployment Stage, E3S Web of Conferences, 83(01014), 18.
(DOI: 10.1051/e3sconf/20198301014)
A. Chapman, K. Itaoka, H. Farabi-Asl, Y. Fujii, M. Nakahara (2020) Societal Penetration of Hydrogen into
the Future Energy System: Impacts of Policy, Technology and Carbon Targets. International Journal of
Hydrogen Energy.

Figure Red dots and red areas show existing/planned
station sites and their 10 minute driving radiuses. The
additional stations that will be created, bringing thetotal of initial stations to 100, are indicated by green
dots (10 minute driving radiuses indicated by green
areas). The additional stations (initial 100 to 200
stations) and their 10 minute driving radiuses areindicated by yellow dots and yellow areas. The initial
5000 customers are represented by blue areas. The
additional 15000 customers, which will bring the total
to 20000 early customers, are represented by light
blue areas. Lastly, the additional 30000 customers,
which will bring the total to 50000 early customers,
are represented by pale blue areas.

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