Prussian white

— Prussian blue (PB) and its analogues are promising materials for sodium-ion battery cathodes because of their high working potentials, high theoretical capacity, and low toxicity. Prussian white (PW), which is the fully reduced and sodiated form of PB, could significantly improve the manufacturability of commercial batteries as it circumvents the requirement of a reactive sodium-loaded anode in cell assembly. However, previous preparations of PW require a high-temperature, high-pressure, and oxygen-free environment, and their reported performance in battery cathodes have been modest so far.