Wet-chemical synthesis of phase-pure FeOF nanorods as high-capacity cathodes for sodium-ion batteries.

It is challenging to prepare phase-pure FeOF by wet-chemical methods. Furthermore, nanostructured FeOF has never been reported. In this study, hierarchical FeOF nanorods were synthesized through a facile, one-step, wet-chemical method by the use of just FeF3⋅3H2O and an alcohol. It was possible to significantly control the FeOF nanostructure by the selection of alcohols with an appropriate molecular structure. A mechanism for the formation of the nanorods is proposed. An impressive high specific capacity of approximately 250 mAh g(-1) and excellent cycling and rate performances were demonstrated for sodium storage. The hierarchical FeOF nanorods are promising high-capacity cathodes for SIBs.