FeTiO3 as Anode Material for Sodium‐Ion Batteries: from Morphology Control to Decomposition

Abstract Ilmenite, general formula FeTiO 3 , has been proposed as possible conversion anode material for lithium‐ and sodium‐ion batteries, with theoretical capacity of 530 mAhg −1 . Experimentally, the observed specific capacity for pristine ilmenite is far away from the theoretical value; for this reason, the control of morphology via alkaline hydrothermal treatment has been proposed as possible strategy to improve the electrochemical performance. At the same time FeTiO 3 is prone to react with sodium and potassium hydroxide, as already demonstrated by studies on the degradation of ilmenite for the extraction of TiO 2 . In this paper we demonstrate that the alkaline treatment does not induce a morphological modification of the FeTiO 3 powders but involved the degradation of the precursor material with the formation of different phases. A complete physicochemical and electrochemical characterization is performed with the aim of correlating structural and functional properties of the obtained products.