In recent years, energy engineers have been trying to design new reliable batteries that can store more energy and allow electronics to operate for longer periods of time before they need to be charged. Some of the most promising among these newly developed batteries are solid-state batteries, which contain solid electrolytes instead of liquid ones.
Compared to batteries with liquid electrolytes that are widely used today, solid-state batteries could exhibit higher energy densities (i.e., could store more energy) and longer lifetimes. However, many of these batteries have been found to be unstable, due to unwanted chemical reactions that occur between their high-voltage cathodes (i.e., positive electrodes) and solid electrolytes, which can speed up the degradation of the batteries’ performance over time.
These undesirable side reactions are particularly common in sodium-ion (Na+) solid-state batteries, which use Na+ ions to store and release electrical energy. This is because while Na is more abundant and cheaper than lithium, Na-ion batteries are inherently more chemically reactive than Li-ion batteries.








