Science on Interfacial Ion Dynamics for Solid State Ionics Devices

Newsletter Vol.1

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

2Greetings | Contents

Greetings
Solid-solid interfaces generate entirely new functions that differ from theintrinsic nature of the solid material. In this project, the unique interfacial ion
dynamics around the hetero/homo interfaces of solid-state ionics materials(SSIMs) are systematically investigated. The goal is to establish design principles for fast ion transport and concentrated ion storage around interfaces,that is, “Interface IONICS.”“Interface IONICS” is closely related to the development of a sustainable
society. For example, “Interface IONICS” clarifies issues related to electrode/solid electrolyte interfaces in advanced energy storage devices such as allsolid-state batteries and all-solid-state capacitors. Additionally, it provides
clear guidelines of interface regulations to further improve devices toward
faster charge-discharge reactions and higher energy densities.
We appreciate your support.
Principal Investigator
Nagoya University, Yasutoshi IRIYAMAContents

Project OutlineResearch Objectives
Missions and Members

3		 Model Interface (Gp-A01)

67 Advanced Analysis (Gp-A02)

78 Computational & Data Science (Gp-A03)

89 Design of Functional Interface (Gp-A04)

9Research Achievements

1034

Project Outline | Research Objectives 3

Project Outline
Project Title : Science on Interfacial Ion Dynamics for Solid State Ionics Devices(Interface IONICS)
Research Project Number : 19H05812 (Grant-in-Aid for Scientific Research on Innovative Areas)
Researcher Number : 30335195
Project Term : FY2019–2023
Budget Allocation : 1,127,800 Thousand Yen (ca. 10 million dollars)
Homepage Address : https://interface-ionics.jp/en/index.html

Research Objectives
There are two types of solid-state ionics materials(SSIMs): insertion electrode materials (electrodes) andsolid electrolytes. In the former, electrons or holes
move faster than ions. In contrast, ions move fasterthan electrons or holes in the latter. When these two
SSIMs combine, an equilibrium state is reached throughthe rearrangement of all charged carriers (electrons,holes, and ions). At equilibrium, their electrochemical
potentials become equal. Consequently, the electrode/solid electrolyte interface realizes unique properties
with each intrinsic SSIM due to factors such as spacecharge layer formation and mechanical relaxation(strain distribution) that provide unique interfacial iondynamics. The aim of this project is to investigate thephysical and chemical modulations around interfaces
in detail and establish interface design principles, which
will make it possible to generate novel functions aroundinterfaces. This project integrates chemistry, physics,advanced measurements, computational and data science, and material science. It consists of four researchgroups.
Gp-A01 fabricates model interfaces using materials
such as single crystalline substrates and epitaxial thinfilms and investigates their interfacial ion dynamics.
Gp-A02 analyzes the properties around the interface
including the modulation and distribution of voltage,ion concentration, chemical potential, and local structure using advanced measurements. Gp-A03 clarifies
the distribution of ions and electrons and their dynamics around the interface using multi-scale theoretical
calculations and informatics analyses. Gp-A04 develops advanced materials with an emphasis on metastable phases with lattice defects and lattice strains by
combining crystalline and amorphous SSIMs.

Interface

Insertion Electrode Solid Electrolyte

Electron Energy

VConduction Band
Valence Bandp -Type

Semiconductor

Mechanical(or Structural)
FactorEF

Valence Band

StrainOrientation
Mutual Diffusion
Layer

Chemical Factor

ElectrochemicalFactor

Conduction Band

Reaction Phase
Formation

M+Activity
Concentration

Correlation Image of Complex Factors
e.g. Insertion Electrode/Solid Electrolyte Interface

Interface IONICS

Solid-State IONICS Materials (SSIMs)

Electrical Factor

φEL

Semiconductor Engineering

φSEIon4

Missions and Members

Missions and Members
Collaborative network for research on Interface IONICS

A01 ModelInterface

Fabrication of Model Interfaces of Solid-State Ionics
Materials and their Fundamental Research on Interfacial
Ion Dynamics
Principal Investigator

Co-Investigators

Yasutoshi IRIYAMA

Tsuyoshi OHNISHI NIMS, Thin-Film Growth
Toshinori TAISHI		Shinshu Univ., Bulk Crystal

Nagoya Univ.,
Electrochemistry

MopSamd elles

GrowthYumi TANAKA		Tokyo Univ. of Science, Solid-Da

Kaoru DOKKO		Yokohama National Univ.,
ElectrochemistrytalState Ionics

taen

Masaki MATSUI		Kobe Univ., Inorganic Materials

Theoretica

Ex pe rim

ChemistrylAna l ys i sA03
Theoretical, Computational, and Data Science of theComputational Interfacial Ion Dynamics in Solid-State Ionics Materials& Data Science
Principal Investigator

Co-Investigators

Yoshitaka TATEYAMAGen INOUE		Kyushu Univ., Macro-Transport

NIMS, Computational
Interface Science

Simulation

JAIST, Data-Driven AI
Hieu Chi DAM		
Masanobu NAKAYAMA	Nagoya Institute of Technology,
Materials Simulation

Shunsuke MUTO		Nagoya Univ., Properties ofNanomaterials

Evaluation Committees
Minoru INABA

Shigeaki ZAIMA

Professor
Doshisha Univ.
Electrochemistry,
Inorganic Industrial
Chemistry

Professor
Meijo Univ.
Semiconductor
Engineering

Masahiro
TATSUMISAGOPresident
Osaka Prefecture Univ.
Inorganic Materials
Chemistry

Shinji TSUNEYUKI
Professor
The Univ. of Tokyo
Condensed Matter
Physics Theory,
Computational Physics

Mission and Members

A02 AdvancedAnalysis

5

Physico-Chemical Analysis of Solid-State Ionics Interfaces
by Integrating Advanced Measurement Techniques
Principal Investigator

Co-Investigators

Koji AMEZAWA

Kazutaka IKEDA		 KEK, Neutron Science
Koji OHARA		JASRI, Structural Analysis for
Amorphous Materials

Tohoku Univ., SolidState Ionics

Akichika KUMATANI		Tohoku Univ., Surface
ScienceExperimental
Analysis

Naoaki KUWATA		 NIMS, Physical ChemistryYukio TAKAHASHI		Tohoku Univ., Synchrotron
X-ray Imaging
Shigeo MORI		Osaka Prefecture Univ.,
Materials Physics

perim

Materials

entalAnalys
isKazuo YAMAMOTO		 JFCC, Electron Microscopy

Dev
ices&ExweN

islysaAn
alci
reteohT

A04 Design of
Functional
Interface

Development of Novel Functional
Interfaces of Solid-State Ionics Devices andNew Solid-State Ionics Materials
Principal Investigator

Co-Investigators

Naoaki YABUUCHI

Masashi OKUBO			The Univ. of Tokyo, Solid-State

Yokohama National
Univ., Solid-StateElectrochemistry

ChemistryDaisuke KAN			Kyoto Univ., Solid-State Chemistry
Ayuko KITAJOU			Yamaguchi Univ., Inorganic
Chemistry

Akitoshi HAYASHI		Osaka Prefecture Univ., Inorganic
Materials Chemistry

orytheNewObservers
Shu YAMAGUCHI

Kohei UOSAKISpecially Appointed
Professor
National Institution for
Academic Degrees andQuality Enhancement ofHigher Education
Solid-State Ionics

Fellow
National Institute forMaterials Science
Surface Physical
Chemistry

Kiyoshi
KANAMURA
Professor
Tokyo Metropolitan
Univ.
Electrochemistry,Battery, Energy
Chemistry

Hideki IBA
Advanced Material
Engineering Div. CPE
Toyota MotorCorporation
New Generation
Batteries, IndustryAcademiaCollaboration

6Missions and Members

Gp-A01 Model Interface
Gp-A01 develops model interface systems such as electrode/solid electrolyte interfaces, inorganic/organic solid electrolyte interfaces, and grainboundaries. Interfacial ion dynamics play important roles in the design ofsolid-state ionics devices such as all-solid-state batteries and capacitors.
Gp-A01 uses thin-film technologies (e.g., pulsed laser deposition, atomic
layer deposition, and sputtering) and single crystalline materials, amongothers, to develop model interfaces as well as investigate their interfacial iontransfer and ion accumulation properties using electrochemical methods.
The resultant model interfaces are analyzed in Gp-A02.

Thin-film materials

wet process

epitaxial

amorphous

Preparation of model materials

Ion charge interface

atomic layer

metal/solid electrolyte (blocking)semiconductor/solid electrolyte
grain boundary

Tailored interface

Fundamental analysis ofinterfacial ion dynamics

Single crystalline
LixLa(1-x)/3NbO3(LLNbO)
single crystal
poly crystalorganic solid
Epitaxial La(2/3-x)Li3xTiO3 (LLTO) thin film

Bulk materials

Insertion electrode/solid electrolyte
metal/solid electrolyte (non-blocking)hetero solid electrolyte interface

Ion transfer interface

Members
Principal Investigator

Co-Investigators

Yasutoshi IRIYAMA
Nagoya Univ.
Electrochemistry

Tsuyoshi OHNISHI
NIMS
Thin-Film Growth

Toshinori TAISHI
Shinshu Univ.
Bulk Crystal Growth

Yumi TANAKATokyo Univ. of Science
Solid-State Ionics

Kaoru DOKKO
Yokohama National
Univ.
Electrochemistry

Masaki MATSUIKobe Univ.
Inorganic Materials
Chemistry

Missions and Members

Gp-A02 Advanced Analysis
Unique ion transport/storage phenomena at solid-state interfaces areoften attributed to anomalous physical/chemical states modulated locallyat interfaces. Gp-A02 comprehensively reveals the physical/chemical characteristics of anomalous and local states such as ion concentration, electric/chemical/electrochemical potentials, micro/local structures, strain/
distortion, and ion diffusion from multiple viewpoints by combining various
novel and advanced analytical techniques. Through systematic analyses of
Gp-A01’s and Gp-A04’s model interfaces together with Gp-A03’s theoretical
calculation, scientific principles to design high performance solid-stateinterfaces are established based on theoretical rationales.

Members
Principal Investigator

Co-Investigators

Koji AMEZAWA
Tohoku Univ.
Solid-State Ionics

Kazutaka IKEDA
KEK
Neutron Science

Koji OHARA
Akichika KUMATANI
JASRI
Tohoku Univ.
Structural Analysis for Surface Science
Amorphous Materials

Naoaki KUWATA
NIMS
Physical Chemistry

Yukio TAKAHASHI
Tohoku Univ.
Synchrotron X-ray
Imaging

Shigeo MORI
Osaka Prefecture
Univ.
Materials Physics

Kazuo YAMAMOTOJFCCElectron Microscopy

78Missions and Members

Gp-A03 Computational & Data Science
To construct a theory for “Interface IONICS,” Gp-A03 introduces twostrategies; computational and data science approaches. For the former,
equilibrium/steady states and dynamics of electrons and ions aroundsolid-solid interfaces are investigated using multiscale computational
approaches through DFT (density functional theory) level calculations andcontinuum models. In addition, data-driven AI science approaches are
implemented to elucidate large-scale structure-property relations in theobserved images and spectra. Through these findings and deep collaborations with the other groups (Gp-A01, A02 and A04), a new theoreticalframework for “Interface IONICS” is established.

Members
Principal Investigator

Co-Investigators

Yoshitaka TATEYAMANIMS
ComputationalInterface Science

Gen INOUE
Kyushu Univ.
Macro-Transport
Simulation

Hieu Chi DAM
JAIST
Data-Driven AI

Masanobu NAKAYAMA
Nagoya Institute ofTechnology
Materials Simulation

Shunsuke MUTO
Nagoya Univ.
Properties ofNanomaterials

Missions and Members

Gp-A04 Design of Functional Interface
Gp-A04 studies solid-state ionics materials and realizes new functionalities through interface engineering. For instance, charge accumulation andmigration of charge carriers are highly dependent on the interface structures of materials. Nevertheless, the origin is not clearly understood. One
example of an electrode material for lithium storage is LiMnO2. Although
LiMnO2 prepared by a conventional route shows an insufficient ability forcharge accumulation, LiMnO2 with enriched grain boundaries shows a muchbetter functionality as an electrode material. Gp-A04 establishes the basic
science related to the interface structures of solid-state ionics materials,
which will be the foundation for innovative solid-state energy storage systems and other functional solid-state devices.

Design of New Solid-State Ionics MaterialsEnriched Grain Boundary ➡ Better Functionality(Inorganic, Organic, Polymer, and Complex Materials)

Conventional LiMnO 2Interface Engineering

Nano/Amorphous Materials

E/VNew Materials

New Functionality through Interface Engineering ofSolid-State Ionics Materials

LiMnO2 with Enriched Grain Boundary

Q / mAh/g

Members
Principal Investigator

Co-Investigators

Naoaki YABUUCHI
Yokohama National
Univ.
Solid-StateElectrochemistry

Masashi OKUBOThe Univ. of Tokyo
Solid-State Chemistry

Daisuke KAN
Kyoto Univ.
Solid-State Chemistry

Ayuko KITAJOU
Yamaguchi Univ.
Inorganic Chemistry

Akitoshi HAYASHI
Osaka Prefecture Univ.
Inorganic Materials
Chemistry910Research Achievements

Research Achievements(Jul.2019 - Dec.2019)
Peer-reviewed Papers and Proceedings (8)Keynote/Invited lectures (36)Highlight from Interface IONICS

A sodium-ion sulfide solid electrolyte with unprecedented conductivity
at room temperature
A. Hayashi, N. Masuzawa, S. Yubuchi, F. Tsuji, C. Hotehama, A. Sakuda and M. Tatsumisago
Nature Communications, 10: 5266 (2019).
DOI: https://doi.org/10.1038/s41467-019-13178-2
Published on November 20, 2019
Abstract
A key material for realizing all-solid-state rechargeable batteries is an excellent inorganic superionic conductor. Here, we demonstrate a sulfide superionicconductor, Na2.88Sb 0.88W0.12S4, with conductivity superior to that of the benchmark electrolyte, Li10 GeP2S12.
Partial substitution of antimony in Na3SbS4 with tungsten induces the generation of sodium vacancies andtetragonal to cubic phase transition, resulting in thehighest room-temperature conductivity of 32 mS cm−1for a sintered body, Na2.88Sb 0.88W0.12S4. Moreover, thissulfide has additional advantages: it generates a negligible amount of harmful hydrogen sulfide in humid
atmosphere and it can be densified at much lower sintering temperatures than those (>1000°C) of typicaloxide sodium ion conductors, Na3Zr2Si2PO12 andβ-alumina. The discovery of the superior sodium ion
conductor boosts the ongoing research for solid-state
rechargeable battery technology with high safety,cost-effectiveness, large energy, and power density.

Osaka Prefecture University press release URL (Japanese)
https://www.osakafu-u.ac.jp/press-release/pr20191121/
Group URL
http://www2.chem.osakafu-u.ac.jp/ohka/ohka2/english/index.html

11Highlight from Interface IONICS

Li+ Transport Mechanism at Heterogeneous Cathode/Solid Electrolyte
Interface in All-Solid-State Battery via First-Principles Structure Prediction
SchemeBo Gao, Randy Jalem, Yanming Ma, Yoshitaka Tateyama
Chem. Mater. 32, 85-96 (2020).
DOI: https://doi.org/10.1021/acs.chemmater.9b02311
Published on November 20, 2019
Abstract
High interfacial resistance between a cathode andsolid electrolyte (SE) has been a long-standing problem
for all-solid-state batteries (ASSBs). Though thermodynamic approaches suggested possible phase transformations at the interfaces, direct analyses of the ionicand electronic states at the solid/solid interfaces arestill crucial. Here, we used our newly constructed scheme
for predicting heterogeneous interface structures via
the swarm-intelligence-based crystal structure analysis
by particle swarm optimization method, combined withdensity functional theory calculations, and systematically investigated the mechanism of Li-ion (Li+) transport at the interface in LiCoO2 cathode/β-Li3PS4 SE, a
representative ASSB system. The sampled favorable
interface structures indicate that the interfacial reaction layer is formed with both mixing of Co and P cations

and mixing of O and S anions. The calculated sitedependent Li chemical potentials μ Li(r) and potential
energy surfaces for Li+ migration across the interfaces
reveal that interfacial Li+ sites with higher μ Li(r) values
cause dynamic Li+ depletion with the interfacial electron transfer in the initial stage of charging. The Li+depleted space can allow oxidative decomposition ofSE materials. These pieces of evidence theoreticallyconfirm the primary origin of the observed interfacial
resistance in ASSBs and the mechanism of the resistance decrease observed with oxide buffer layers (e.g.,LiNbO3) and oxide SE. The present study also provides
a perspective for the structure sampling of disorderedheterogeneous solid/solid interfaces on the atomicscale.

NIMS press release URL (Japanese)
https://www.nims.go.jp/news/press/2019/11/201911210.html
Group URL
https://www.nims.go.jp/group/cs/en/

Newsletter vol.1
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: March 2020