Sodium Power That Works From Frost to Heat

A new design tweak in the tiny molecules of ether solvents lets sodium metal batteries stay reliable from -40 to 70°C. Scientists found that the usual weakly solvating ethers are too volatile, which makes them unsafe at high temperatures. By reshaping the ether molecules, they strengthened the bonds between solvent molecules themselves. This change raises boiling points while keeping the solvation power low, so sodium ions can leave their solvent shells more easily even in cold air. The result is a battery that can deliver at least 0. 5 mA cm⁻² without losing capacity across a huge temperature band.Lab tests show that the key to this improvement is not just how ions interact with solvent, but also how solvent molecules talk to each other. When these intermolecular forces are tuned right, the energy needed for ion desolvation drops sharply at low temperatures. The study points to a simple route: tweak the solvent’s internal interactions instead of chasing new chemistries. Such an approach could make sodium batteries safer and more versatile for extreme‑weather gear, deep‑sea probes, or even spacecraft power supplies.