Scientists Invent a New Type of Battery – The Oxygen-Ion Battery

Promising but for this:

“The new battery concept is not intended for smartphones or electric cars, because the oxygen-ion battery only achieves about a third of the energy density that one is used to from lithium-ion batteries and runs at temperatures between 200 and 400 °C. The technology is, however, extremely interesting for storing energy.”

https://scitechdaily.com/scientists-invent-a-new-type-of-battery-the-oxygen-ion-battery/