Sodium structure powers solid-state batteries below freezing temps

Researchers at the University of Chicago Pritzker School of Molecular Engineering have developed a new sodium-based solid-state battery technology that performs effectively at room temperature and below freezing, marking a significant advance for sodium batteries which have historically struggled under real-world conditions. The breakthrough centers on stabilizing a previously unreported metastable structure of sodium hydridoborate, achieved by heating and rapidly cooling the material to lock in a crystal form. This structure exhibits ionic conductivity at least an order of magnitude higher than previously reported sodium electrolytes, enabling better battery performance. The team combined this metastable electrolyte with an O3-type cathode coated with a chloride-based solid electrolyte, allowing for thick, high-loading cathodes that increase the theoretical energy density by packing more active material into the battery. This design contrasts with traditional thin cathodes that contain more inactive material, thus improving energy storage capacity. The innovation not only enhances sodium battery performance but also offers a more cost-effective and sustainable alternative to lithium-based batteries, potentially enabling gig