IEA: Global EV Outlook 2026 - Emerging battery chemistry and designs

[eppur_se_muova]

1. Interesting progress report. It's worth noting that batteries based on magnesium have been explored and could ...

... have about twice the energy density of sodium batteries, because Mg undergoes 2-e redox while Na only does 1-e, yet Mg atoms and sodium have nearly equal weight.

https://www.ecoticias.com/en/magnesium-battery-electric-vehicles/11434/

(The article in the OP cites sodium batteries as having a lower volume energy density than Li cells. In automotive applications, it is the mass energy density that matters most, since a lower value means heavier batteries are necessary to do the same job, and hence lower mileage. I can imagine the volume energy density matters for ships (low values mean more hull capacity turned over to batteries), and especially air- and spacecraft, which tend to be pretty cramped). Since ships are buoyant, moderate differences in mass density should not be much of an issue.