Researchers crack safer battery chemistry for sodium-ion cells
Scientists have engineered non-flammable electrolytes that could make sodium-ion batteries commercially viable for energy storage and electric vehicles. The breakthrough combines ether and phosphate solvents to eliminate fire risk while maintaining the ionic conductivity needed for practical applications—addressing a major safety barrier holding back sodium-ion adoption.
Originaltitel: Non-flammable ether and phosphate-based liquid electrolytes for sodium-ion batteries
<p>This study investigates a group of electrolytes containing NaPF<sub>6</sub> or NaBF<sub>4</sub> salts in phosphate- and ether-based solvents for high-mass loading sodium-ion batteries. It explores physicochemical properties such as ionic conductivity, dynamic viscosities, and non-flammability. The combination of experimental with computational studies reveals detailed insights into the physicochemical properties of the non-flammable liquid electrolytyes. Diglyme-based electrolytes become non-flammable with 50 vol.% phosphate solvents, while tetraglyme-based electrolytes require 70 vol.%. The solvation structure has been investigated using NMR and is combined with computational studies to provide information about properties such as solvation structure, ionic conductivity and viscosity. The molecular dynamic simulations confirm the enhanced solvation in diglyme based liquid electrolytes observed experimentally by <sup>23</sup>Na-NMR. Despite lacking sufficient electrochemical stability, this work provides fundamental understanding of the solvation structure and physicochemical properties of a novel electrolyte system. This is an important contribution to be applied in future electrolyte design rationale.</p>