TY - JOUR
T1 - Intermediate honeycomb ordering to trigger oxygen redox chemistry in layered battery electrode
AU - Mortemard De Boisse, Benoit
AU - Liu, Guandong
AU - Ma, Jiangtao
AU - Nishimura, Shin Ichi
AU - Chung, Sai Cheong
AU - Kiuchi, Hisao
AU - Harada, Yoshihisa
AU - Kikkawa, Jun
AU - Kobayashi, Yoshio
AU - Okubo, Masashi
AU - Yamada, Atsuo
N1 - Funding Information:
This work was financially supported by the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; Grant-in-Aid for Specially Promoted Research No. 15H05701. This work was also supported by MEXT, Japan under the 'Elemental Strategy Initiative for Catalysis and Batteries (ESICB)'. M.O. was financially supported by MEXT, Japan; Grant-in-Aid for Challenging Exploratory Research No. 15K13798. M.O. was also supported by the Hattori Hokokai Foundation. The synchrotron XRD experiment was performed under approval of Photon Factory Program Advisory Committee (Proposal No.2013G670) and the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2015A1503, 2014A1196 and 2013A1665). The SAED patterns were recorded at Nanotechnology Platform of MEXT (No. A-14-NM-0064). The synchrotron X-ray absorption experiments at SPring-8 were performed with the approval of the Japan Synchrotron Radiation Research Institute (Proposal No. 2015B1471) and by the joint research in the Synchrotron Radiation Research Organization and the Institute for Solid State Physics, the University of Tokyo (Proposal No. 2015A7403).
PY - 2016/4/18
Y1 - 2016/4/18
N2 - Sodium-ion batteries are attractive energy storage media owing to the abundance of sodium, but the low capacities of available cathode materials make them impractical. Sodium-excess metal oxides Na2MO3 (M: transition metal) are appealing cathode materials that may realize large capacities through additional oxygen redox reaction. However, the general strategies for enhancing the capacity of Na2MO3 are poorly established. Here using two polymorphs of Na2RuO3, we demonstrate the critical role of honeycomb-type cation ordering in Na2MO3. Ordered Na2RuO3 with honeycomb-ordered [Na1/3Ru2/3]O2 slabs delivers a capacity of 180 mAh g-1 (1.3-electron reaction), whereas disordered Na2RuO3 only delivers 135 mAh g-1 (1.0-electron reaction). We clarify that the large extra capacity of ordered Na2RuO3 is enabled by a spontaneously ordered intermediate Na1RuO3 phase with ilmenite O1 structure, which induces frontier orbital reorganization to trigger the oxygen redox reaction, unveiling a general requisite for the stable oxygen redox reaction in high-capacity Na2MO3 cathodes.
AB - Sodium-ion batteries are attractive energy storage media owing to the abundance of sodium, but the low capacities of available cathode materials make them impractical. Sodium-excess metal oxides Na2MO3 (M: transition metal) are appealing cathode materials that may realize large capacities through additional oxygen redox reaction. However, the general strategies for enhancing the capacity of Na2MO3 are poorly established. Here using two polymorphs of Na2RuO3, we demonstrate the critical role of honeycomb-type cation ordering in Na2MO3. Ordered Na2RuO3 with honeycomb-ordered [Na1/3Ru2/3]O2 slabs delivers a capacity of 180 mAh g-1 (1.3-electron reaction), whereas disordered Na2RuO3 only delivers 135 mAh g-1 (1.0-electron reaction). We clarify that the large extra capacity of ordered Na2RuO3 is enabled by a spontaneously ordered intermediate Na1RuO3 phase with ilmenite O1 structure, which induces frontier orbital reorganization to trigger the oxygen redox reaction, unveiling a general requisite for the stable oxygen redox reaction in high-capacity Na2MO3 cathodes.
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U2 - 10.1038/ncomms11397
DO - 10.1038/ncomms11397
M3 - Article
AN - SCOPUS:84973321184
SN - 2041-1723
VL - 7
JO - Nature Communications
JF - Nature Communications
M1 - 11397
ER -