Na-S Battery: Low-cost with four times the capacity of lithium
The key word that's almost submerged in the article is <i>molten</i>.<p>Like previous sodium-sulphur batteries this one relies on a molten salt electrolyte, meaning you won't see it in your phone or laptop any time soon!<p>However, as it's being developed with the idea of grid-scale smoothing/backup, that's much less of a problem. (The square-cube law means that as you increase the volume of your molten salt cell, the surface area grows more slowly -- and thermal losses scale with surface area, so really big cells are cheaper to maintain at operating temperature.)