Structural modification of isomorphous SO -doped KFeO for remediating the stability and enhancing the discharge of super-iron battery.

In the paper, the isomorphous doped KFeO, aimed at the remediation of the discharge and stability of the super-iron battery, was first synthesized for doping and reforming the KFeO crystalline structure via a facile co-precipitation and mechanochemistry. Afterwards, the compared cathodes were assembled by the undoped and doped KFeO for an evaluation of the discharge and stability in the AAA super-iron battery system. The results show that the small amounts of KSO were doped into the KFeO in the calculated form of KFeSO by the isomorphous substitution. The doped KFeO cathodes/batteries exhibited an excellent discharge with a normal discharge profile. The cathodes doped by two techniques had significantly enhanced the discharge capacity of the super-iron battery with an increase of 10-30% compared to the undoped KFeO. Moreover, the stability of the KFeO cathodes was obviously remediated by the isomorphous doping. The shelf time of the doped KFeO cathodes was prolonged by an increase of about 10% in comparison of the undoped KFeO cathode. The desirable enhancements could be attributed to doping and reforming the similar building block and isomorphous into the tetrahedral and crystalline in the form of the isomorphous substitution and filling vacancies.