The Super-iron battery is a moniker for a proposed class of rechargeable
electric battery. Such batteries feature cathodes composed of
ferrate salts, commonly
potassium ferrate (K 2FeO 4) or
barium ferrate (BaFeO 4).[1][2][3] One attraction to the proposed device is that the spent cathode would consist of a
rust-like material, which is preferable to batteries based on toxic
cadmium,
manganese and
nickel.[1][2][3] Another attraction is potentially higher energy capacity.[1]