TY - JOUR
T1 - Charge/discharge mechanism of a new Co-doped Li2O cathode material for a rechargeable sealed lithium-peroxide battery analyzed by X-ray absorption spectroscopy
AU - Ogasawara, Yoshiyuki
AU - Hibino, Mitsuhiro
AU - Kobayashi, Hiroaki
AU - Kudo, Tetsuichi
AU - Asakura, Daisuke
AU - Nanba, Yusuke
AU - Hosono, Eiji
AU - Nagamura, Naoka
AU - Kitada, Yuta
AU - Honma, Itaru
AU - Oshima, Masaharu
AU - Okuoka, Shin Ichi
AU - Ono, Hironobu
AU - Yonehara, Koji
AU - Sumida, Yasutaka
AU - Mizuno, Noritaka
N1 - Funding Information:
This work was supported by the Japan Society of the Promotion of Science (JSPS) through its “Funding Program for World-Leading Innovative R&D on Science and Technology (FIRST Program)”. A part of this work was supported by JSPS Grants-in-Aid for Scientific Researches (B) Grant Number 26289371 . The XANES measurements were carried out under the approvals of the Photon Factory Program Advisory Committee (Proposal Nos. 2013Y031, 2013Y033, 2013G169 and 2014G100).
Publisher Copyright:
© 2015 Elsevier B.V. All rights reserved.
PY - 2015/8/1
Y1 - 2015/8/1
N2 - Abstract Soft X-ray absorption spectroscopic studies are carried out to clarify the charge/discharge reaction mechanism of Co-doped Li2O (CDL, Co/Li = 0.1 molar ratio) as a cathode material for a new rechargeable lithium-peroxide battery. Upon charging CDL in an aprotic electrolyte, a drastic change can be seen in the O K-edge spectra, with a new, strong peak assignable to σ∗(O-O) of peroxide at photon energy of 531.0 eV. This peak is reduced during subsequent discharging, causing the spectrum to essentially return to that of pristine CDL recorded in total fluorescence yield mode. The Co L2,3-edge spectra do not show a remarkable change during charging, with the exception of the disappearance of a Co2+ shoulder peak. The spectrum of charged CDL is in reasonable agreement with the calculated spectrum, assuming that the fraction of Co3+-L (where L indicates a hole state in the oxygen 2p band) is dominant in the electronic configuration of the ground state. This suggests that, to a certain extent, a redox reaction involving a ligand hole state (Co3+-L) participates in generation of the capacity.
AB - Abstract Soft X-ray absorption spectroscopic studies are carried out to clarify the charge/discharge reaction mechanism of Co-doped Li2O (CDL, Co/Li = 0.1 molar ratio) as a cathode material for a new rechargeable lithium-peroxide battery. Upon charging CDL in an aprotic electrolyte, a drastic change can be seen in the O K-edge spectra, with a new, strong peak assignable to σ∗(O-O) of peroxide at photon energy of 531.0 eV. This peak is reduced during subsequent discharging, causing the spectrum to essentially return to that of pristine CDL recorded in total fluorescence yield mode. The Co L2,3-edge spectra do not show a remarkable change during charging, with the exception of the disappearance of a Co2+ shoulder peak. The spectrum of charged CDL is in reasonable agreement with the calculated spectrum, assuming that the fraction of Co3+-L (where L indicates a hole state in the oxygen 2p band) is dominant in the electronic configuration of the ground state. This suggests that, to a certain extent, a redox reaction involving a ligand hole state (Co3+-L) participates in generation of the capacity.
KW - Cathode material
KW - Lithium battery
KW - Lithium oxide
KW - Oxygen redox
KW - X-ray absorption spectroscopy
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U2 - 10.1016/j.jpowsour.2015.04.050
DO - 10.1016/j.jpowsour.2015.04.050
M3 - Article
AN - SCOPUS:84927539601
VL - 287
SP - 220
EP - 225
JO - Journal of Power Sources
JF - Journal of Power Sources
SN - 0378-7753
M1 - 21026
ER -