TY - JOUR
T1 - Redox-Driven Spin Transition in a Layered Battery Cathode Material
AU - Watanabe, Eriko
AU - Zhao, Wenwen
AU - Sugahara, Akira
AU - Mortemard De Boisse, Benoit
AU - Lander, Laura
AU - Asakura, Daisuke
AU - Okamoto, Yohei
AU - Mizokawa, Takashi
AU - Okubo, Masashi
AU - Yamada, Atsuo
N1 - Funding Information:
We acknowledge the financial supports from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; the Grant-in-Aid for Specially Promoted Research no. 15H05701; and “Elemental Strategy Initiative for Catalysts and Batteries (ESICB).” E.W. was financially supported by Grant-in-Aid for Young Scientists (B). M.O. was financially supported by MEXT, Japan; Grant-in-Aid for challenging Exploratory Research, and the Iketani Science and Technology Foundation. B.M.dB. and L.L. are grateful to the Japan Society for the Promotion of Science (JSPS) for their respective fellowship. The synchrotron X-ray absorption experiments at Photon Factory were performed under the approval of the Photon Factory Program Advisory Committee (proposal nos. 2016G031, 2018G082, and 2016G108). A part of X-ray absorption spectra was measured by the joint research in Synchrotron Radiation Research Organization and the Institute for Solid State Physics, the University of Tokyo (proposal no. 2015B7500). The computation in this work was performed at the Supercomputer Center, Institute for Solid State Physics, The University of Tokyo.
Funding Information:
We acknowledge the financial supports from the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan; the Grant-in-Aid for Specially Promoted Research no. 15H05701; and “Elemental Strategy Initiative for Catalysts and Batteries (ESICB).†E.W. was financially supported by Grant-in-Aid for Young Scientists (B). M.O. was financially supported by MEXT, Japan; Grant-in-Aid for challenging Exploratory Research, and the Iketani Science and Technology Foundation. B.M.dB. and L.L. are grateful to the Japan Society for the Promotion of Science (JSPS) for their respective fellowship. The synchrotron X-ray absorption experiments at Photon Factory were performed under the approval of the Photon Factory Program Advisory Committee (proposal nos. 2016G031, 2018G082, and 2016G108). A part of X-ray absorption spectra was measured by the joint research in Synchrotron Radiation Research Organization and the Institute for Solid State Physics, the University of Tokyo (proposal no. 2015B7500).
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/4/9
Y1 - 2019/4/9
N2 - A spin transition between high-spin (HS) and low-spin (LS) states in a solid can occur when the energies of two spin configurations intersect, which is usually caused by external perturbations such as temperature, pressure, and magnetic fields, with substantial influence to its physical and chemical properties. Here, we discover the electrochemical "redox reaction" as a new driving force to induce reversible HS-LS spin transition. Although reversible solid-state redox reaction has been thoroughly investigated as the fundamental process in battery electrode materials, coupling between redox reactions and spin transitions has not been explored. Using density functional theory calculations, we predicted the existence of redox-driven spin transition occurring exclusively for the Co 3+ /Co 2+ redox couple in layered transition-metal oxides, leading to a colossal potential hysteresis (>1 V) between the cathodic (LS Co 3+ to LS Co 2+ ) and anodic (HS Co 2+ to HS Co 3+ ) reactions. The predicted potential hysteresis associated with the spin transition of Co was experimentally verified for Na x Ti 0.5 Co 0.5 O 2 by monitoring the electrochemical potential, local coordination structure, electronic structure, and magnetic moment.
AB - A spin transition between high-spin (HS) and low-spin (LS) states in a solid can occur when the energies of two spin configurations intersect, which is usually caused by external perturbations such as temperature, pressure, and magnetic fields, with substantial influence to its physical and chemical properties. Here, we discover the electrochemical "redox reaction" as a new driving force to induce reversible HS-LS spin transition. Although reversible solid-state redox reaction has been thoroughly investigated as the fundamental process in battery electrode materials, coupling between redox reactions and spin transitions has not been explored. Using density functional theory calculations, we predicted the existence of redox-driven spin transition occurring exclusively for the Co 3+ /Co 2+ redox couple in layered transition-metal oxides, leading to a colossal potential hysteresis (>1 V) between the cathodic (LS Co 3+ to LS Co 2+ ) and anodic (HS Co 2+ to HS Co 3+ ) reactions. The predicted potential hysteresis associated with the spin transition of Co was experimentally verified for Na x Ti 0.5 Co 0.5 O 2 by monitoring the electrochemical potential, local coordination structure, electronic structure, and magnetic moment.
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U2 - 10.1021/acs.chemmater.8b04775
DO - 10.1021/acs.chemmater.8b04775
M3 - Article
AN - SCOPUS:85063520525
VL - 31
SP - 2358
EP - 2365
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 7
ER -