A Swedish company has announced a lithium-free sodium-ion battery that is supposed to be cheaper and more sustainable. It has an energy density of 160 Wh/kg.
It will require more development before becoming commercially competitive. Energy density and cost considerations vary from application to application so this sodium-ion battery development is still a good step forward.
Lithium-ion battery densities have improved enormously in the last decade, see this article. (Note, the bar chart shows volumetric energy density, Wh/l, and not mass energy density Wh/kg).
In early 2023 a record of just over 700 Wh/kg (1650 Wh/l) was set for Li-ion batteries. A comparison of energy densities for various battery chemistries is shown here. A history of Li-ion batteries can be found here.
