A research team led by Professor Akitoshi Hayashi of the Graduate School of Engineering and Associate Professor Atsushi Sakuda of Osaka Metropolitan University developed a process for the mass synthesis of sodium-containing sulfides.
The team produced a solid sulfide electrolyte with the highest reported sodium ion conductivity in the world—approximately ten times higher than needed for practical use—and a glass electrolyte with high reduction resistance. They used sodium polysulfides, or sulfides with two or more sulfur atoms, as the material and the flux, which encourages fusion.
Developing high-conductivity, formable electrolytes in large quantities is essential for successfully applying all-solid-state sodium batteries.
This newly developed process is useful for the production of almost all sodium-containing sulfide materials, including solid electrolytes and electrode active materials. Also, compared to conventional methods, this process makes it easier to obtain materials that display higher performance, so we believe it will become a mainstream process for the future development of materials for all-solid-state sodium batteries.
Atsushi Sakuda, Associate Professor, Osaka Metropolitan University
Funding
Energy Storage Materials
The study was funded by JSPS KAKENHI.
Inorganic Chemistry
The research was funded by JSPS KAKENHI and the 2023 Osaka Metropolitan University (OMU) Strategic Research Promotion Project (Priority Research).
Advantages and Challenges in Solid-State Sodium Battery Production
Journal References:
Nasu, A., et al. (2024). Utilizing reactive polysulfides flux Na2S for the synthesis of sulfide solid electrolytes for all-solid-state sodium batteries. Energy Storage Materials. doi.org/10.1016/j.ensm.2024.103307.
Otono, T., et al. (2024). High-Sodium-Concentration Sodium Oxythioborosilicate Glass Synthesized via Ambient Pressure Method with Sodium Polysulfides. Inorganic Chemistry. doi.org/10.1021/acs.inorgchem.3c04101.