Facile preparation of hierarchical micro-nano FeF₃·0.33H₂O by a one-pot method with dual surfactants

To prepare a hierarchical micro-nano structure FeF₃·0.33H₂O simply and economically, a one-pot method with dual surfactants was used. Scanning electron microscopy and a Fourier transformation infrared spectrometer revealed that polyvinyl pyrrolidone (PVP) regulates the morphology of the material, while cetyltrimethylammonium bromide (CTAB) can reshape FF@PVP, it can not only remove PVP at room temperature, but also obtain a hierarchical micro-nano structure. The electrochemical results show that the hierarchical micro-nano structure FF(1.5CTAB 0.5PVP) has the best electrochemical performance. It maintained a high specific capacity of 109.4 mAh g^-1 after 100 cycles at 1 C. In particular, under the ultra-high rate discharge of 20 C, the ultra-high specific discharge capacity of 66.4 mAh g^-1 was reached. The FF(1.5CTAB 0.5PVP)'s excellent electrochemical performance is mainly due to a large contact area between the electrolyte and active materials.