Rajendra S. Dhaka

A piggy bank where coins slip in easily but can only be retrieved by smashing it. Something similar happens with a new material for sodium batteries. It readily accepts sodium ions during charging, but during discharge, it gives back almost nothing.

Tiny particles, smaller than a hundredth of the thickness of a human hair, can be magnets that don't lose their strength even at 600 degrees Celsius. These particular particles were made from a nickel-iron-aluminum alloy. The alloy has been known for a long time, but in nanoparticle form it was produced without templates — simply by mixing solutions of metal salts.

Sodium is lithium's neighbor on the periodic table, but it's hundreds of times more abundant in the Earth's crust and much cheaper. So sodium batteries could replace lithium ones in electric vehicles and energy storage.