A significant breakthrough in all-solid-state sodium battery technology has been achieved by researchers at Osaka Metropolitan University. This development holds promise for more affordable and safer energy storage solutions, as sodium-based batteries offer advantages over current lithium-ion technology. Led by Associate Professor Atsushi Sakuda and Professor Akitoshi Hayashi, the research team developed a new process for mass producing sodium-containing sulfides, a key component for high-performance solid electrolytes.
The pursuit of greener energy also requires efficient rechargeable batteries to store that energy. All-solid-state sodium batteries are garnering interest due to the abundance of sodium compared to lithium, despite lithium-ion dominance. Processing challenges hinder widespread production of safer solid-state batteries, potentially reducing sodium battery costs, making them more accessible.
The team utilized sodium polysulfides, compounds comprising two or more sulfur atoms, for both material and flux purposes. This promotes fusion, leading to the creation of a solid sulfide electrolyte with the world’s highest reported sodium ion conductivity—about 10 times higher than required for practical use. Additionally, they developed a glass electrolyte with high reduction resistance.
Mass synthesis of such electrolytes with high conductivity and formability is key to the practical use of all-solid-state sodium batteries.
“This newly developed process is useful for the production of almost all sodium-containing sulfide materials. It includes solid electrolytes and electrode active materials,” Professor Sakuda said. “This process makes it easier to obtain materials that display higher performance. We anticipate that compared to traditional approaches, this process will be mainstream for future all-solid-state sodium battery material development.”
