Science on Interfacial Ion Dynamics for Solid State Ionics Devices

Newsletter Vol.4
September 2021

Interface lonics toward
Sustainable Society
2019 – 2023 Japan Society for the Promotion of Science
Grant-in-Aid for Scientific Research on Innovative Areas

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Preface | Contents

Preface
Vaccination rates are accelerating worldwide, and there is hope for a
return to the daily life we enjoyed before COVID-19. In March 2021, we
conducted a 4 hour international online symposium and enjoyed discussions.
We hope that we can resume face-to-face international collaboration in
2022.
Within the Interface IONICS community, collaborative research related toexperiments, advanced analyses, and computational science has actively
progressed and the number of papers resulting from collaborative research
has increased. In 2021, we will continue to deepen our understanding of theequilibrium state; in 2022, with the addition of new members, we will begin
research to clarify our understanding of the steady state. Currently, we aredeveloping a strategy for new activities, including new international
collaborations.
Yasutoshi Iriyama, Principal Investigator
Nagoya University

Contents

Member Introductions
		 Postdoctoral Researchers

3		 Research Assistants (PhD Students)

4

Research Achievements
		 Model Interface (Gp-A01)
Advanced Analysis (Gp-A02)

5
6

		 Computational & Data Science (Gp-A03)

7

Design of Functional Interface (Gp-A04)

8

Activity Reports
		 Conferences Partially Supported
		 by the Interface IONICS Project9

Symposiums and Seminars

9

Domestic Training Program Reports

10Award Winners

11Member Introductions 3

Member Introductions
Postdoctoral Researchers
Gp-A02

Satoshi Hiroi

4.0

JASRI (Ohara Gr.)
/Local structural analysis, Amorphous structure

3.0
2.5
S(Q)

I received my PhD in 2014 from Niigata University, where I analyzed
the structures of liquid chalcogen materials. I was later involved in thedevelopment of high-efficiency thermoelectric materials as a postdoctoral
fellow at Toyota Technological Institute under Professor Tsunehiro Takeuchi.
Since April 2020, I have been working in JASRI under researcher Koji Ohara
through research at NIMS. I am currently conducting structural analyses
for mixtures of crystalline and amorphous phases as practical materials.
I recently developed a dedicated software for the mixtures using X-ray/
neutron total scattering data, where I addressed several known problems
related to the instrumental resolution function and momentum-transferdependent parameters. This software enabled the extraction of structural
information for an amorphous phase in a mixture such as the Li-rich Li2VO2F
cathode material shown in the figure. I hope this technique contributes tothe development of mixed electrode materials by facilitating local structural
analysis.

Li2VO2F charged
Extracted amorphous phase

3.5

2.0
1.5
1.0
0.5
0.0
−0.5

0

2

4

Crystalline phase6−1

Q [Å ]

8

10

12

Amorphous phase

Figure. S(Q) of charged Li 2VO 2F and the threedimensional atomic configuration of crystalline andamorphous phases.

Gp-A04

Kosuke Kawai
Waseda Univ. (Okubo Gr.)
/Energy storage materials

I graduated from the Undergraduate School of Industrial Chemistry,
Kyoto University in 2016 and received my PhD from The University of Tokyoin 2021 under the supervision of Professor Atsuo Yamada. My research
focuses on electrode materials for electrochemical energy storage. In my
PhD course, I explored high-voltage cathode materials for rechargeable
batteries. For example, using electrochemical measurements, X-ray
diffraction, soft X-ray absorption spectroscopy, and first-principles
calculations, I identified an extremely high operating potential of 4.7 V vs.
Na/Na+ in Na3−x Cr2(PO4)2F3 (0 ≤ x ≤ 1), which is attributable to the Cr4+/Cr3+
redox couple (Fig. 1). In the Interface IONICS project, I explore electrodematerials such as 2D metal carbides (MXenes, Figure 2) for solid-stateenergy storage devices and clarify the ion dynamics across electrode/electrolyte interfaces. I am grateful for this opportunity to participate in
the Interface IONICS project and collaborate with excellent researchers invarious fields.

14

Figure 1. Research theme in my PhD course.

Figure 2. Research theme in my current project.

4

Member Introductions

Research Assistants (PhD Students)

Gp-A02

Yuta Hibe
Kyoto Univ. D3 (Noda Gr.)
/Magnetic resonance, Physical chemistry
Observing electric field distributions in solid electrolytes is difficult
because the electric field is perturbed if a probe for observation contacts theelectrolyte. Nuclear quadrupole resonance (NQR) provides clues about theelectronic structure of materials through the electric-field gradient tensor
at the site of a quadrupole nucleus, without requiring contact. However,finding unknown resonance frequencies, which are often scattered overa wide range, is a major challenge in NQR. Recently, we developed anefficient two-step NQR method by utilizing rapid scan and frequency comb
techniques, which are based on the fact that NQR lines appear sparsely
within the entire spectral range (right figure). This method, known as
rapid-scan with gapped excitation with dual-mode operation (RASGADO)NQR, enables the rapid and easy acquisition of NQR spectra and can thus
be used to observe the electric-field distribution in solid electrolytes.

Figure. Profile of the radio-frequency pulse (left) andexcitation frequency (right) of a hyperbolic secant (HS)pulse (top) and a comb-modulated HS pulse (bottom). The
inset describes the timing of sampling in RASGADO NQR.
Y. Hibe et al., Phys. Chem. Chem. Phys. 22, 25584–25592.
(2020).

Gp-A04

Akira Nishio
Kyushu Univ. D3 (Inoishi Gr.)
/ Polyanionic materials, Electrochemistry, X-ray
analysis
Since joining the Okada–Kitajou–Inoishi group in 2017 for amaster’s course, I have been working on single-phase all-solid-statebatteries constructed from a single material. The underlying objectiveof developing single-phase all-solid-state batteries is to reduce theinterfacial resistance between the electrode/electrolyte in oxide-typebatteries. Interfacial resistance is unavoidable in conventional oxide-typebatteries because of side reactions during high-temperature sinteringand impedance mismatching. Single-phase all-solid-state batteries
enable the self-generation of electrodes from solid electrolytes as insitu-formed electrodes; thus, a dense interface is expected to form
between the electrode and electrolyte. The materials of focus were mainly
Li1.5Cr0.5Ti1.5 (PO4) 3 and Na 3V2 (PO4) 3 , which individually function as acathode, anode, and electrolyte. We confirmed that the materials worked
as single-phase all-solid-state batteries with a large current density,and we improved their electrochemical properties by adding borate
salts. Having entered a doctoral course, I am now interested in cathodematerials for high-voltage operation in all-solid-state Na+-ion batteries.
I highly appreciate this opportunity and look forward to contributing tothis project.

Current collector
Electrolyte

Current collector
Discharge

ChargeIn-situ formed cathode
Electrolyte
In-situ formed anode
Figure. Scheme of a single-phase all-solid-state battery
during the charge/discharge process. The initial state isshown in the top schematic.

Research Achievements 5

Research Achievements
2021.1– 2021.6

Gp-A01 Model Interface
Gp-A01 has provided model electrode materials
such as epitaxial thin-film electrodes and singlecrystalline solid electrolytes to the members of Gp-A01,
and collaborative research with Gp-A02 and Gp-A03
has also progressed. Relaxation analysis of charge
accumulation in solid electrolytes and low-temperaturematerials synthesis have provided new ideas. A novel
approach for developing low-resistive electrode-solidelectrolyte interfaces using powdered materials andthe results of our investigation regarding the effect ofstress on the phase-transition mechanism of electrodematerials are highlighted as follows.

Highlight 1 A01-A03 joint paper

Low-resistive LiCoO2/Li1.3Al0.3Ti2(PO4)3 interface formation by low-temperatureannealing using aerosol deposition
M. Sakakura, Y. Suzuki, T. Yamamoto, Y. Yamamoto, M. Motoyama, Y. Iriyama.
Energy Technology. vol. 9, 2001059 (2020)
https://doi.org/10.1002/ente.202001059

Abstract
Crystalline electrode films of LiCoO2 (LCO) areformed on a high Li+ conductive crystalline-glass solid
electrolyte sheet, LATP (σ25 ˚C = 1×10-4 S cm-1), at room
temperature by aerosol deposition (AD), and weinvestigate the effects of annealing temperature on
the interfacial resistivities (Rint) at the LCO/LATP. The
Rint visibly increase by the annealing over 500 ˚C withthe growth of Co3O4 as a reactant. On the other hand,
the Rint is reduced to〜100 Ωcm2 by low-temperatureannealing at 250-350 ˚C due to superior contact throughthe structural rearrangement of an artificial metastableinterface formed by the AD. We apply these results
to bulk-type Ox-SSB, Li/LLZ/LCO-LATP, and our best
Ox-SSB delivers discharge capacity at 100 mA/cm2 at
100 ˚C. [Reproduced with permission of Wiley-VCH.]

Highlight 2 A01-A02 joint paper

Experimental evaluation of influence of stress on Li chemical potential andphase equilibrium in two-phase battery electrode materials
Y. Kimura, K. Funayama, M. Fakkao, T. Nakamura, N. Kuwata, T. Kawada, J. Kawamura, K. Amezawa.
Electrochemistry. vol. 89, issue 4, pp. 355-362 (2021)
https://doi.org/10.5796/electrochemistry.21-00033

Abstract
We experimentally evaluated the influence of stresson Li chemical potential (µLi) and phase equilibriumin two-phase battery electrode materials throughthe emf measurements under a mechanical load, in
collaboration with Advanced Analysis group (Gp-A02).
Our results indicated that µLi in the two-phase electrodematerials (LiFePO4 or LiCoO2 in the two-phase region)
immediately changed just after loading and graduallychanged under a constant mechanical load. Besides,
the loading/unloading led to the opposite µLi variation.
Such characteristic µLi variations were explained by
the change in the phase equilibrium between the twophases, i.e. variations of the Li content and the volume
fraction in the two phases. Our results can provide
insights into the influence of stress on the performancesof two-phase electrode materials. [Reproduced withpermission of the Electrochemical Society of Japan.]6

Research Achievements

Gp-A02 Advanced Analysis
In this group, we aim to understand unique ion transport/
storage phenomena at solid-state interfaces throughcomprehensive analyses. We have been establishing andimproving various novel and advanced analytical techniquesand systematically applying them to model solid-stateinterfaces, such as a well-defined film electrode on a solid

electrolyte and glass-ceramic electrolytes, which were
supplied by Gp-A01 and Gp-A04, respectively. Using theobtained results, together with the results of theoretical
calculations and simulations carried out by Gp-A03, we
will establish scientific principles that enable the design ofhigh-performance solid-state interfaces.

Highlight 3 A02-A03-A04 joint paper

Visualization of structural heterogeneities in particles of lithium nickel
manganese oxide cathode materials by ptychographic X-ray absorption
fine structure
H. Uematsu, N. Ishiguro, H. C. Dam, M. Okubo, Y. Takahashi, et al.
J. Phys. Chem. Lett. vol. 12, pp. 5781–5788 (2021)
https://doi.org/10.1021/acs.jpclett.1c01445

Abstract
A heterogeneous phase/structure distribution in the bulkof active materials is the key to maximize the performanceand stability of cathode/anode of lithium-ion batteries.
In this paper, we report the use of two-dimensional
ptychographic X-ray absorption fine structure to visualize
the density and valence maps of manganese and nickel in
as-prepared lithium nickel manganese oxide particles andunsupervised learning to classify the three-phase group interms of different elemental compositions and chemical

the design of suitable structural domains to maximize thestates. The described approaches may increase the supply

performance and stability of batteries. [Reproduced withof information for nanoscale characterization and promotepermission of the American Chemical Society.]

Highlight 4 A02-A04 joint paper

Microstructure and charge–discharge mechanism of a Li3CuS2 positiveelectrode material for all-solid-state lithium-ion batteries
T. Ayama, H. Tsukasaki, A. Hayashi, S. Mori, et al.
ACS Appl. Energy Mater. vol. 6, pp. 6290–6295 (2021)
https://doi.org/10.1021/acsaem.1c01074

Abstract
Li 3 CuS 2 is a promising candidate for positiveelectrodes for sulfide-based all-solid-state batteries
exhibiting excellent cycle characteristics. To clarify
the charge–discharge mechanism of Li 3 CuS 2 , weexamined the microstructural changes during
charge–discharge cycles by transmission electron
microscopy (TEM). The hollow-corn dark-field imaging
technique was employed to evaluate the crystallite
size distribution. The result shows that the crystallite
size of Li 3 CuS 2 reversibly decreases/increases
in the charging/discharging state, respectively.
The electron diffraction pattern shows that LiCuS 2
was formed during charging by Li+ extraction fromLi 3 CuS 2 . In discharging, the crystallite size increasedand Li 3 CuS 2 was reproduced. The TEM results
suggest that such reversible structural changes of
Li 3 CuS 2 would contribute to high charge-discharge
characteristics. [Reproduced with permission of theAmerican Chemical Society.]

Research Achievements

Gp-A03 Computational & Data Science
To construct a theoretical framework for Interface
IONICS, Gp-A03 has introduced two strategies: acomputational approach and a data science approach.
With the development of novel technqiues and deep
collaboration with the experimental groups (Gp-A01,-A02, and -A04), we have achieved new understandingof interfacial phenomena. Recently, a new simulation
approach was developed to understand mesoscale
fabrication and degradation behaviors. Besides, amicroscopic electrochemistry concept has been
demonstrated via density functional theory simulations.

Highlight 5

Simulation of fabrication and degradation of all-solid-state batteries withductile particles
M. So, G. Inoue, R. Hirate, K. Nunoshita, S. Ishikawa, Y. Tsuge.
J. Electrochem. Soc. Vol. 168, pp. 030538 (2021)
https://doi.org/10.1149/1945-7111/abed23

Abstract
We simulated cold press fabrication and intercalation
damage in a sulfide All-Solid-State Battery (ASSB)
electrode using the Discrete Element Method. We
developed a new cohesive hybrid-particulate modelthat both can simulate particle consolidation during
fabrication and material failure during intercalation
expansion. In this way, the effect of the fabrication
conditions on the mechanical degradation of theelectrode can be simulated. The high pressure in thecold press fabrication cause plastic deformation andbuild-up of cohesive contacts between the particles,
consisting of Si active material (AM) and sulfide solid
electrolyte (SE), resulting in densification of theelectrode. During charging, when AM expands duringlithiation, the AM-SE contact area increases but theeffective SE conductivity decreases. When the
expansion is small, the contact area and conductivity
may recover to their original value. However, large
expansion may cause plastic deformation and cracking
that cause permanent reduction of both contact areaand SE conductivity. This type of mechanicaldegradation was significantly less for electrodes
fabricated at higher pressures. This model can become
a valuable tool to improve the durability andperformance of future ASSBs. [Reproduced withpermission of IOP Science.]

Highlight 6First-principles study of microscopic electrochemistry at the LiCoO2 cathode/
LiNbO3 coating/ß-Li3PS4 solid electrolyte interfaces in an all-solid-state battery
B. Gao, R. Jalem, Y. Tateyama.
ACS Appl. Mater. Interfaces vol. 13, pp. 11765 (2021)
https://doi.org/10.1021/acsami.0c19091

Abstract“Microscopic electrochemistry” for the electrochemical
potential and the distribution of Li+ around the interface
has not been well established yet. Herein, we haveintroduced a potential energy profile for Li+, ηLi , anddemonstrated that the interfacial ηLi can be evaluatedfrom the calculated interfacial Li vacancy formationenergy or the bulk vacancy formation energy and theinterface band alignment. Through computational
analysis of LiCoO2 cathode/LiNbO3 coating/ß-Li3PS4
solid electrolyte interfaces, we found that ηLi at the
LiCoO2 /ß-Li3PS4 interface is highly disordered under
the influence of the interface reconstruction and is+++rather electronic conductive. LiNbO3 coating results inthe appropriate changes in band alignments, leading to
a decrease of difference in the interfacial ηLi and thus
lower resistances at the interfaces. [Reproduced withpermission of the American Chemical Society.]
+

7

8

Research Achievements

Gp-A04 Design of Functional Interface
Gp-A04 designs innovative solid-state ionics
materials (SSIMs) through interface engineering. Withan increase in the concentration of grain boundaries,
charge carriers are efficiently accumulated in SSIMs,
resulting in new structures and functionalities. Suchfunctionalities have been applied to new solid-state
ionics devices. Collaborative studies with members of
Gp-A02 and Gp-A03 have further accelerated thedevelopment of new solid-state devices.

Highlight 7

Nonpolarizing oxygen-redox capacity without O-O dimerization in Na2Mn3O7
A. Tsuchimoto, X.-M. Shi, K. Kawai, B. M. Boisse, J. Kikkawa, D. Asakura, M. Okubo, A. Yamada.
Nature Communications vol. 12, Article number: 631 (2021)
https://doi.org/10.1038/s41467-020-20643-w

Abstract
Reversibility of an electrode reaction is importantfor energy-efficient rechargeable batteries with a long
battery life. Additional oxygen-redox reactions havebecome an intensive area of research to achieve a larger
specific capacity of the positive electrode materials.
However, most oxygen-redox electrodes exhibit a large
voltage hysteresis >0.5 V upon charge/discharge, andhence possess unacceptably poor energy efficiency.
The hysteresis is thought to originate from the formationof peroxide-like O22− dimers during the oxygen-redox
reaction. Therefore, avoiding O-O dimer formation isan essential challenge to overcome. Here, we focus on
Na2-xMn3O7, which we recently identified to exhibit a large

reversible oxygen-redox capacity with an extremely
small polarization of 0.04 V. Using spectroscopic
and magnetic measurements, the existence of stableO−• was identified in Na2-xMn3O7. Computations revealthat O−• is thermodynamically favorable over theperoxide-like O22− dimer as a result of hole stabilization
through a (σ + π) multiorbital Mn-O bond. [Reproducedwith permission of Springer Nature.]

Highlight 8

Why is O3 to O1 phase transition hindered in LiNiO2 on full delithiation?
N. Ikeda, I. Konuma, R. H. Basappa, T. Aida, N. Yabuuchi.
Journal of Materials Chemistry A vol. 9, pp. 15963-15967 (2021)
https://doi.org/10.1039/D1TA03066C

AbstractNi-enriched layered materials are utilized as positiveelectrode materials of high-energy Li-ion batteries.
Because electrode reversibility is gradually lost forstoichiometric LiNiO2 on continuous cycles, Ni ions are
partly substituted by other metal ions (Co, Mn, Al etc.).
However, the origin of deterioration in stoichiometric
LiNiO2 is still not fully understand yet. Moreover, the lossof capacities is observed only for a high voltage region(> 4.1 V), which is obviously different from a failuremode observed in other electrode materials. Here, wefirst report the origin of deterioration, which is revealed
by in-situ X-ray diffraction study. For fully charged NiO2,
Ni ions migrate from original octahedral sites in NiO2
slabs to face-sharing tetrahedral sites in Li layers,
by which the O3 to O1 phase transition is suppresed.
Note that Ni migration is a reversible process, and theNi ions migrate back to the original octahedral sites

on discharge. However, after continuous cycles, thereversibility of Ni migration is gradually lost, and Ni
ions are partially left at the tetrahedral sites in Li layers.
Electrode kinetics are also deteriorated because of theNi occupation in Li layers, and the accumulation of Ni
ions at tetrahedral sites results in the loss of reversible
capacities at the high voltage region. This finding opens
a new way to design high-capacity Ni-enriched electrodematerials, leading to the development of high-energy
Li-ion batteries. [Reproduced with permission of Royal
Society of Chemistry.]

Activity Reports

Activity Reports
Conferences Partially Supported by the Interface IONICS Project

Co-organized Symposium “Science on Interfacial Ion Dynamics for
Solid State Devices” of the 101st CSJ Annual Meeting (Online)
Mar. 20, 2021

Prof. Kaoru Dokko, Yokohama National Univ.

The Symposium on Science on Interfacial Ion
Dynamics for Solid-State Devices was held as aco-organized session during the 101st Chemical Societyof Japan (CSJ) Annual Meeting. Seven members of the
project delivered talks on recent progress in researchon new solid-state ionics materials and their interfacialcharacteristics. Approximately 200 people participatedin the online meeting. The Q&A session allowed the
project members to discuss their work with symposium
participants, including both those within and thoseoutside the project, and led to insightful comments.
The meeting was a fruitful opportunity to share recent
results of the project.

Symposiums and Seminars

Interface IONICS Online Symposium 2021 Spring
Mar. 9, 2021
The Interface IONICS Online Symposium 2021 Spring
was held on March 9, 2021. The symposium provided an
opportunity for scientists, engineers, and students toengage in deep discussions on specific topics. The
Interface IONICS members and global scientists inacademia discussed the following two topics: “Thelithium metal/garnet-type solid-state electrolyte
interface” and “the compositional nonstoichiometryissue at the solid–solid interface.” More than 60
participants, including 23 from overseas, joined themeeting.
The Keynote Lecture by Prof. Weppner of Kiel
University provided an overview of the garnet/Li metalinterface from a thermodynamics perspective. Prof.
Zeier of the University of Münster presented a talkconcerning the relationship between electrolyte
degradation and ionic transport properties. Dr.
Tateyama and Prof. Motoyama from Interface IONICS
discussed the garnet/Li metal interface fromtheoretical and experimental perspectives. Prof.
Amezawa delivered a talk about the thermodynamics
of the solid–solid interface. Prof. Iriyama discussed

Assoc. Prof. Masaki Matsui, Kobe Univ.
the influence of the change in Li concentration at theinterface.
The symposium finished past the scheduled time
because of the very active discussions related to each
topic. We thank all of the participants and look forward
to our next opportunity to host a topical symposium.

910

Activity Reports

Domestic Training Program Reports

Visiting the Iriyama group in Nagoya University
Nov. 27, 2020
We (Matsui and his student, Shuang Li) visited
Prof. Iriyama’s group at Nagoya University to learn
the electrode fabrication process for Li-metal anodes
using thermal vapor deposition. Because Li metal ishighly reactive toward O2 and moisture, even in an
Ar-filled glove box, the deposition process must be
carefully controlled to avoid unexpected passivationof the deposited Li. Mr. Kitagawa and Mr. Sugiura ofProf. Iriyama’s group generously described the details of
the experimental conditions and shared their expertiseon Li deposition. They also demonstrated the Li-vapor
deposition process on sintered pellets of our garnettype solid electrolyte Li6.5La3Zr1.5Ta0.5O12 (LLZTO).
Because of their informative lecture and demonstration,
we can now prepare Li-deposited LLZTO samples for

Assoc. Prof. Masaki Matsui, Kobe Univ.
electrochemical measurements in our lab. We also
discussed the synthesis process of layered lithium cobalt
oxide (LCO) at low temperatures with Prof. Iriyama. The
low-temperature process enables us to avoid any side
reaction between LCO and a solid-state electrolyte suchas LATP or LLZTO. We expect to use the new electrodefabrication process to prepare a model solid–solidinterface. We are grateful to the Interface IONICS projectfor providing excellent collaboration opportunities.

Domestic Training Program Reports

Visiting the Kawada, Amezawa, and Kumatani groups in Tohoku University
Dec. 2 – 3, 2020
From December 2 to 3, 2020, two graduate students
and I visited three laboratories at Tohoku University. On
the first day, we wanted to learn more about “chemicalcapacitance” and visited Prof. Tatsuya Kawada andAssociate Prof. Keiji Yashiro, who have publishednumerous papers on the chemical capacitance ofsolid oxide fuel cells, on the Aobayama Campus. We
discussed with Prof. Kawada and Prof. Yashiro whether
chemical capacitance is negligible in all-solid-state Li
batteries. After a few hours of discussion, we toured
their laboratory. The opportunity for us to ask Prof.
Kawada and Prof. Yashiro about their expertise inelectrochemical measurements of solid-state cells
was meaningful. We later visited Prof. Koji Amezawa’slaboratory on the Katahira Campus, where we discussed
the results of numerical simulations for the voltage
profile of thin-film all-solid-state Li batteries during

Lect. Munekazu Motoyama, Nagoya Univ.
charging and discharging. I also delivered a talk on our
research on Li plating/stripping reactions on oxide solid
electrolytes.
On the second day, we visited Associate Prof.
Akichika Kumatani (Y. P. Chen–Kumatani–Tanigakigroup) on the Katahira Campus and were granted a tourof his laboratory. We were fascinated by the numerous
instruments and microscopes fabricated in the lab. We
discussed new experiments and proposed new joint
research themes. During this visit, we rediscovered thesignificance of face-to-face interactions.

Domestic Training Program Reports

Visiting the Aso group in Kyushu University
Apr. 1 – 2, 2021
Mr. Yuki Nojima (Prof. Iriyama’s lab, Nagoya University)and Dr. Kazuo Yamamoto (Japan Fine Ceramics Center)
visited the Ultramicroscopy Research Center (URC) in
Kyushu University on April 1–2, 2021. The URC offers
shared-use facilities for electron microscopy. During
this visit, we used the atomic-resolution analytical

Assoc. Prof. Ryotaro Aso, Kyushu Univ.
transmission electron microscope (JEOL JEMARM200CF) and an in situ electric-biasing TEM sample
holder. We had previously discussed the shape of the
TEM sample and how to set it on the TEM holder andconnect it to a potentiostat. Thus, we could conduct insitu observations as a voltage was applied to the sample

Activity Reports
in the transmission electron microscope (see figure).
We observed the atomic structures in the vicinity of
the interfaces in a Cu/LiLaNbO/Cu cell using scanningtransmission electron microscopy (STEM). In addition,
by applying the voltage in situ, we could observe thenanostructures at the atomic scale during the charge–
discharge process. This visit was productive, and wehope that the technique established during this visit will
be useful for observing various solid-state interfaces.

Domestic Training Program Reports

Visiting the Mori group in Osaka Prefecture University
Mar. 1 – Apr. 23, 2021

Dr. Satoshi Hiroi, JASRI

I visited Mori laboratory at Osaka Prefecture
University in Osaka from March 1st to April 23rd. The
purpose of this visit was to share the X-ray experimental
data obtained by the Ohara group and the electronbeam experimental data obtained by the Mori group.
Assembling the structural information obtained by
Gp-A02 is expected to contribute to the material
development by Gp-A04. My discussions with themembers of the group and observations of the electronbeam measurements were exciting experiences.
During this visit, we shared information related to thestructural analysis of Li3PS4 glass–ceramic electrolytes
and Na3PS4 electrolytes. The Ohara group has alreadyperformed total X-ray scattering measurements onthese electrolytes and have obtained the atomic pair
distribution functions (PDFs). By contrast, the Morigroup has been carrying out structural analyses of the
Li3PS4 and Na3PS4 electrolytes using electron-beammeasurements. The results of each measurement
technique have unique features depending on the probe.
We expect that understanding of the atomic arrangementof solid electrolytes will be improved by thecomplementary use of these data. Through this visit, wehave achieved an understanding of the structural
analysis data of both groups.
To deepen the group members’ understanding ofstructural analysis techniques, seminars on X-ray
diffraction/total scattering measurements were conductedby the Mori group and the Hayashi group (Gp-A04)
during this visit. In this seminar, I discussed theprinciples of the X-ray total scattering measurements,
the calculation procedures and interpretation of theatomic PDFs, structural analysis methods for amorphousmaterials using reverse Monte Carlo modeling, and theapplication of the PDF method to the analysis of
crystalline materials. The local structure information
obtained by the atomic pair correlation function ispromising for investigating the changes caused by the
charging and discharging processes of energy storage
devices. Therefore, X-ray total scattering is expected toplay a critical role as an analysis method in the future
development of materials. By sharing these analysis
techniques with other researchers, I hope to contributeto the development of new processes for synthesizing
and improving the performance of energy storage
devices from the viewpoint of the local structure.

A basic seminar held at Osaka Prefecture University for undergraduate students in
the Mori group.

Award Winners
The Chemical Society of Japan Award for Creative Work for 2020

Akitoshi Hayashi (Gp-A04)

Professor / Osaka Prefecture Univ.

“Solid electrolytes based on inorganic chemical process and their application to all-solid-state batteries”

The 75th CerSJ Awards for Academic Achievements in Ceramic Science and Technology

Masanobu Nakayama (Gp-A03)

Professor / Nagoya Institute of Technology“Materials informatics for discovery of ion-conductive ceramics for batteries”

11Newsletter vol.4
Publisher/Contact
Office for Scientific Research on Innovative Areas:
Science on Interfacial Ion Dynamics for Solid State Ionics Devices
TEL: +81-52-789-3576
E-mail: office@int-ionics.material.nagoya-u.ac.jp
https://interface-ionics.jp/en/index.html

Date of issue: September 2021