Super-iron battery

The Super-iron battery is a moniker for a proposed class of rechargeable electric battery. Such batteries feature cathodes composed of ferrate salts, either potassium ferrate (K
₂FeO₄) or barium ferrate (BaFeO₄). 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 cadmium, manganese and nickel.