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 À 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.

High‐Throughput Production of Cheap Mineral‐Based Heterostructures for High Power Sodium Ion Capacitors

“…Ilmenite shows a trigonal crystal structure in the R‐3 space group with oxygen atoms arranged hexagonally and cations occupying two‐thirds of the octahedral positions, where Fe and Ti are interlaced in the octahedron along the 001 direction. [ 16 ]…”

“…Ilmenite shows a trigonal crystal structure in the R-3 space group with oxygen atoms arranged hexagonally and cations occupying two-thirds of the octahedral positions, where Fe and Ti are interlaced in the octahedron along the 001 direction. [16] To investigate the effect of heterojunction formation on the electronic structures, their energy bandgap structures were calculated. Since the bandgap structure of FS/TO@C cannot be calculated directly, it was substituted by calculating the bandgap structures of TiO 2 and FeS 2 , separately.…”

Understanding the Predominant Potassium-Ion Intercalation Mechanism of Single-Phased Bimetal Oxides by in Situ Magnetometry

“…29−31 Over the past five years, experimental studies have contributed to show superior Li/Na-ion storage performance of FeTiO 3 . 29,32,33 However, materials that are electrochemically active toward Li/Na ions are not necessarily active for the K-ion, which is because the ionic radii of the latter (K-ion, 1.38 Å) is much larger than that of the former two (0.76 and 1.02 Å for Li-and Na-ions, respectively). 34,35 The extension of these works toward K-ion storage, however, remains to be done, which is paramount to deciding whether the objective of highperformance KEES with low cost can be implemented with FeTiO 3 material.…”

“…Metal oxides show interesting properties and promising performance in a wide range of applications. The presence of a foreign metal cation in the matrix of a metal oxide to form a single-phased bimetal oxide, in particular, has modified electrochemical activities because of the synergic effects of different metal species, complex chemical composition, and interfacial effects. − Multiple single-phased bimetal oxides have previously been reported in energy storage devices, with varying degrees of success. ,, The high energy-to-price ratios, which enable the use of ilmenite (FeTiO 3 ) for potential large-scale applications, result from its high theoretical capacity, chemical stability, abundant reserves, and low cost. − Over the past five years, experimental studies have contributed to show superior Li/Na-ion storage performance of FeTiO 3 . ,, However, materials that are electrochemically active toward Li/Na ions are not necessarily active for the K-ion, which is because the ionic radii of the latter (K-ion, 1.38 Å) is much larger than that of the former two (0.76 and 1.02 Å for Li- and Na-ions, respectively). , The extension of these works toward K-ion storage, however, remains to be done, which is paramount to deciding whether the objective of high-performance KEES with low cost can be implemented with FeTiO 3 material.…”

Highly graphited carbon-coated FeTiO3 nanosheets in situ derived from MXene: an efficient bifunctional catalyst for Zn–air batteries

“…[19][20][21][22] Among the titaniumbased perovskite-type oxides, FeTiO 3 stands out due to its low price, abundant reserve, wide band gap and high activity, [23][24][25] however, it suffers from poor conductivity. 26 To solve this problem, FeTiO 3 is often compounded with highly conductive materials, such as recently reported FeTiO 3 @C nanoparticles, 27 porous TiO 2 -FeTiO 3 @carbon nanocomposites, 28 etc. Although these hybridizing methods can improve the conductivity of FeTiO 3 to some extent, the problems of low graphitization and uneven dispersion of carbon always exist.…”