Iron, an abundant element in nature, typically occurs in the valence states of Fe (0), Fe (Ⅱ) and Fe (Ⅲ). Due to their high oxidation, multiple electron transfer, and high intrinsic energy, we refer to the cells containing Fe (Ⅵ) compounds as“super-iron”batteries with more energy capacity compared to conventional alkaline batteries. The three charge reduction of Fe (Ⅵ) represents a high energy and capacity source of cathodes, and the ferric oxide have been considered as an environmentally benig...