State of Manganese Atoms during the Mechanochemical Synthesis of LiMn2O4

✍ Scribed by N.V. Kosova; I.P. Asanov; E.T. Devyatkina; E.G. Avvakumov

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 142 KB
• Volume: 146
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8329

✦ Synopsis

It has been established using X-ray photoelectron spectroscopy in combination with other physical methods that the initial stages of mechanochemical synthesis of LiMn 2 O 4 in mixtures of MnO 2 with LiOH and Li 2 CO 3 are considerably di4erent. In the 5rst case the 99smearing:: of LiOH, having a 6aky structure, on the surface of MnO 2 and the formation of an amorphous layer take place. The reaction is accompanied by a redox process, with the participation of OH groups and Mn 4؉ ions and with di4usion of lithium ions to the interior of the particles, and is completed by formation of Li+O+Mn bonds. No change in the valence state of manganese was detected, in Li 2 CO 3 , only brittle fracture was observed. Formation of defect spinel-like Li 2 O ' yMnO 2 (2.54y44) on the surface is proposed.