Home >

news Help

Publication Information


Title
Japanese: 
English:Oxidation behaviour of lattice oxygen in Li-rich manganese-based layered oxide studied by hard X-ray photoelectron spectroscopy 
Author
Japanese: Keiji Shimoda, 湊 丈俊, Koji Nakanishi, Hideyuki Komatsu, Toshiyuki Matsunaga, Hajime Tanida, 荒井 創, Yoshio Ukyo, 内本 喜晴, Zempachi Ogumi.  
English: Keiji Shimoda, Taketoshi Minato, Koji Nakanishi, Hideyuki Komatsu, Toshiyuki Matsunaga, Hajime Tanida, Hajime Arai, Yoshio Ukyo, Yoshiharu Uchimoto, Zempachi Ogumi.  
Language English 
Journal/Book name
Japanese:Journal of Materials Chemistry A 
English:Journal of Materials Chemistry A 
Volume, Number, Page Vol. 4        pp. 5909
Published date Mar. 18, 2016 
Publisher
Japanese: 
English: 
Conference name
Japanese: 
English: 
Conference site
Japanese: 
English: 
DOI https://doi.org/10.1039/c6ta01152g
Abstract The oxidation/reduction behaviours of lattice oxygen and transition metals in a Li-rich manganese-based layered oxide Li[Li0.25Ni0.20Mn0.55]O1.93 are investigated by using hard X-ray photoelectron spectroscopy (HAX-PES). By making use of its deeper probing depth rather than in-house XPS analyses, we clearly confirm the formation of O ions as bulk oxygen species in the active material. They are formed on the 1st charging process as a charge compensation mechanism for delithiation and decrease on discharging. In particular, the cation–anion dual charge compensation involving Ni and O ions is suggested during the voltage slope region of the charging process. The Ni ions in the material are considered to increase the capacity delivered by a reversible anion redox reaction with the suppression of O2 gas release. On the other hand, we found structural deterioration in the cycled material. The O species are still observed but are electrochemically inactive during the 5th charge–discharge cycle. Also, the oxidation state of Ni ions is divalent and inactive, although that of Mn ions changes reversibly. We believe that this is associated with the structural rearrangement occurring after the activation process during the 1st charging, leading to the formation of spinel- or rocksalt-like domains over the sub-surface region of the particles.

©2007 Tokyo Institute of Technology All rights reserved.