Calcination Temperature Effect on Citrate‐Capped Iron Oxide Nanoparticles as Lithium‐Storage Anode Materials

Abstract

In this work, citrate‐capped magnetites (cit‐Fe3O4) are facilely synthesized according to a modified co‐precipitation method, and the resulting cit‐Fe3O4 underwent thermal calcination under N2 flow for 2 h. The calcined cit‐Fe3O4 at 500 °C, so‐called C‐Fe3O4 (500 °C), exhibits the XRD patterns attributed mainly to the fcc crystalline phases of magnetite (Fe3O4). On the other hand, the calcined cit‐Fe3O4 at 700 °C, so‐called C‐Fe2O3 (700 °C), exhibits the X‐ray diffraction (XRD) patterns attributed mostly to hexagonal crystalline phases of hematite (α‐Fe2O3). The iron oxides calcined at different temperatures (500, 600, 700 °C) are employed as active anode materials for Li‐ion batteries. After 80 cycles at the current rate of 0.1 C, the C‐Fe2O3 (700 °C) exhibits the higher reversible capacity by ≈200% than that of the C‐Fe3O4 (500 °C). The improved reversible capacity of the C‐Fe2O3 (700 °C) is attributed to the transformation of magnetite phases into hematite phases with higher crystallinity, which is more beneficial for faster transfer of charge carriers and structural stability.

Nano-synthesis of solid acid catalysts from waste-iron-filling for biodiesel production using high free fatty acid waste cooking oil

“…The hematite contaminated with alumina obtained from the WIF was calcined at 500, 700 and 900 °C according to Won Jung et al 28 to synthesize RBC500, RBC700 and RBC900 respectively. Thereafter, sulfonated to obtain the kind of catalysts as shown in Eq.…”

Perspective—Enhancing Active Anode Material Performance for Lithium-Ion Batteries via Manipulation of Interfacial Chemistry

“…These results suggest that π-conjugation as well as electron affinity of functional groups affect the interfacial characteristics of the particle which can help dictate battery transport performance. As it pertains to the electronic environment on the particle surface, non-electronically conductive small-molecule capping agents such as citrate 41 and oleic acid 42 have been attached to the surface, however in comparison to π-conjugated small molecules, these capping agents tend to provide an insulating layer that hampers charge transfer even if volume changes leading to catastrophic electrode failure are mitigated. As a result, proper identification of a capping agent is needed so as to avoid hampering charge transfer mechanics by adding an insulating layer.…”

Separation of TiO2 and Fe2O3 from Indonesia Ilmenite Minerals and their Application as Photocatalysts for Eriochrome Black‐T Dye Degradation

“…[17] In nature, generally, iron oxide is in the form of wustite (FeO), which can be synthesized into hematite (α-Fe 2 O 3 ), maghemite (γ-Fe 2 O 3 ), and magnetite (Fe 3 O 4 ). [18] These compounds have been synthesized by various methods that have been reported, including chemical precipitation, sol-gel, hydrothermal, surfactant-mediated precipitation, emulsion deposition, microemulsion precipitation, electro-precipitation, and microwave-assisted hydrothermal techniques. [19] However, not all methods can be used to obtain both compounds sequentially.…”

“…The content of chemical compounds in ilmenite, reaching 30–65 %, is titanium dioxide (TiO 2 ), and the rest is oxide compounds, including iron oxide (FeO) in the form of hematite [17] . In nature, generally, iron oxide is in the form of wustite (FeO), which can be synthesized into hematite (α‐Fe 2 O 3 ), maghemite (γ‐Fe 2 O 3 ), and magnetite (Fe 3 O 4 ) [18] . These compounds have been synthesized by various methods that have been reported, including chemical precipitation, sol‐gel, hydrothermal, surfactant‐mediated precipitation, emulsion deposition, microemulsion precipitation, electro‐precipitation, and microwave‐assisted hydrothermal techniques [19] .…”