A new strategy to quickly synthetize true nanoparticles of the spinel LiMn2O4 by using a microwave-assisted hydrothermal route

• Published in: Journal of alloys and compounds Vol. 911; p. 164856
• Main Authors: Silva, Daiane Piva B., Falqueto, Juliana Bruneli, Bocchi, Nerilso, Biaggio, Sonia R., Rocha-Filho, Romeu C.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05-08-2022; Elsevier BV
• Subjects: Crystal structure; Discharge; Electrochemical analysis; Electrodes; Emission analysis; Energy storage material; Energy-saving microwave-assisted hydrothermal route; Genuinely nanostructured spinel LiMn2O4; High resolution electron microscopy; Hydrothermal reactions; Inductively coupled plasma; Li-ion battery; Lithium manganese oxides; Low temperature; Nanoparticles; Reaction time; Reagents; Spinel; Energy storage material; Li-ion battery; Genuinely nanostructured spinel LiMn2O4; Energy-saving microwave-assisted hydrothermal route
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.164856

Based on a microwave-assisted hydrothermal reaction, a new route is proposed to prepare highly pure true nanoparticles (≤15 nm) of the single-phase spinel LiMn2O4 (LMO) at a low temperature (140 °C) and short reaction time (5 min), using exclusively water-soluble reagents. The obtention of this material was confirmed by using different techniques such as X-ray diffractometry, Rietveld crystal structure refinement, inductively coupled plasma-atomic emission spectroscopy and high-resolution transmission electron microscopy. Electrochemical evaluations were performed by using cyclic voltammetry and galvanostatic charge and discharge tests. Only electrodes prepared from spinel LMO nanoparticles with an average size of ~15 nm showed electrochemical activity. From charge and discharge tests at a constant rate of C/5, the electrodes prepared from this active material exhibited an initial specific capacity of 128 mA h g–1 with a capacity retention of 95% after the 27th cycle. The hallmark of the synthesis route here described is the saving of energy while preparing truly nanoparticulate LMO with excellent chemical, structural and promising electrochemical properties.
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•Highly pure nanoparticles (≤15 nm) of LiMn2O4 (LMO) are prepared by a new route.•The LMO preparation is based on a microwave-assisted hydrothermal reaction (MWH).•Low temperature, short time and water-soluble reagents are used in the MWH reaction.•LMO nanoparticles show excellent chemical, structural and electrochemical properties.