Research Overview:
Understanding how ions move through solids is one of the central challenges in developing next-generation solid-state batteries. Ion transport is governed not only by crystal structures but also by grain boundaries, domains, and heterogeneous interfaces over multiple length and time scales. However, no single experimental technique can fully capture these complex transport processes.

Our research develops and applies quantitative measurement methods to reveal ion transport in solids. Rather than relying on a single technique, we combine PFG-NMR, lithium isotope tracer TOF-SIMS, impedance spectroscopy, and operando SIMS, each providing complementary information on ionic motion. By integrating these independent measurements, we aim to obtain a consistent and quantitative picture of ion transport from bulk crystals to interfaces.

One of our particular interests is establishing quantitative relationships between tracer diffusion, self-diffusion, and ionic conductivity in a wide variety of solid-state battery materials. Such cross-validation enables us to evaluate ion transport with greater confidence than is possible using any single technique alone.

Our ultimate goal is to establish reliable measurement methodologies that provide a scientific basis for designing safer, longer-lasting, and higher-performance solid-state batteries.

Prospective Students:
We welcome applications from students interested in pursuing a Ph.D. through the Hokkaido University–NIMS Joint Graduate Program. Financial support is available through the NIMS Junior Researcher Program, which provides a salary while conducting research.

Research topics include solid-state batteries, solid electrolytes, ion transport, interfacial phenomena, NMR, TOF-SIMS, isotope tracer techniques, and electrochemical measurements. Previous experience with NMR or SIMS is not required.

We welcome students with backgrounds in chemistry, physics, materials science, electrochemistry, and computational science who are interested in developing a quantitative understanding of ion transport in solids.

During the Ph.D. program, students are encouraged to develop independence by experiencing the entire research process—from defining research questions and designing experiments to publishing scientific papers. If you are interested in joining our group, please feel free to contact us to discuss potential research projects and admission opportunities.

Figure 1. Schematic illustration of ion transport in solid-state battery materials over multiple length and time scales. Quantitative understanding of ion transport requires complementary experimental techniques to investigate bulk crystals, grain boundaries, domains, and interfaces.