title: Progress of the conversion reaction of Mn3O4 particles as a function of the depth of discharge.
abstract: A comprehensive investigation of the morphological and interfacial changes of Mn3O4 particles at different lithiation stages was performed in order to improve our understanding of the mechanism of the irreversible conversion reaction of Mn3O4. The micronization of Mn3O4 into a Mn-Li2O nanocomposite microstructure and the formation of a solid electrolyte interphase (SEI) on the Mn3O4 surface were carefully observed and characterized by combining high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and in situ X-ray absorption fine structure (XAFS) measurements. Accumulation of a thin SEI film of 2-5 nm thickness on the surfaces of the Mn3O4 particles due to their catalytic decomposition was observed at a depth of discharge (DOD) of 0%. As the DOD increases from 25% to 75%, the SEI layer composed of Li2CO3 and LiF continues to grow to 20-30 nm, and Li2O nanoparticles are clearly observed. At 100% DOD, the Mn-Li2O particles with diameters of 2-5 nm become totally encapsulated within a huge organic-inorganic coating structure, while the overall starting shape of the particles remains.
authors.affiliation: Department of Applied Chemistry, Tokyo University of Agriculture & Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8558, Japan. k-naoi@cc.tuat.ac.jp.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yonekura
authors.forename: Etsuro
authors.initials: E
authors.lastname: Iwama
authors.forename: Naoki
authors.initials: N
authors.lastname: Ota
authors.forename: Masanori
authors.initials: M
authors.lastname: Muramatsu
authors.forename: Morihiro
authors.initials: M
authors.lastname: Saito
authors.forename: Yuki
authors.initials: Y
authors.lastname: Orikasa
authors.forename: Wako
authors.initials: W
authors.lastname: Naoi
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Naoi
mesh_terms: D011211:Electric Power Supplies; D004566:Electrodes; D007477:Ions / Q000737:chemistry; D008094:Lithium / Q000737:chemistry; D017895:Manganese Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D053761:Nanocomposites / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy
chemical_list: D007477:Ions; D017895:Manganese Compounds; D010087:Oxides; C027424:manganese oxide; D008094:Lithium