TY - JOUR
T1 - Determining the crystal and electronic structures of the magnesium secondary battery cathode material MgCo2−xMn xO4 using first-principles calculations and a quantum beam during discharge
AU - Ishibashi, Chiaki
AU - Ishida, Naoya
AU - Kitamura, Naoto
AU - Idemoto, Yasushi
N1 - Publisher Copyright:
© 2020, Springer Science+Business Media, LLC, part of Springer Nature.
PY - 2020/10/1
Y1 - 2020/10/1
N2 - Abstract: The stable structures of the spinel compounds MgCo2O4 and MgCo1.5Mn0.5O4 following the insertion of Mg atoms into vacant 16c sites during discharge were investigated using first-principles calculations. During this insertion, Mg atoms at 8a sites were found to migrate to other vacant 16c sites, such that the spinel form transitioned to a rock salt structure. The structural change from the standard spinel phase to a rock salt form was minimal in the case of MgCo2O4, since this change required the insertion of numerous Mg atoms. In contrast, a more pronounced structural change from the normal spinel to a rock salt form occurred in the MgCo1.5Mn0.5O4, as this change required fewer Mg atom insertions. The data suggest that the electron density and bond length between Mg atoms at 8a sites and O atoms in MgCo1.5Mn0.5O4 are both reduced compared to that in MgCo2O4. The Mg atoms in MgCo1.5Mn0.5O4 were determined to readily undergo intercalation as a result of the substitution of Mn atoms. Graphic abstract: [Figure not available: see fulltext.]
AB - Abstract: The stable structures of the spinel compounds MgCo2O4 and MgCo1.5Mn0.5O4 following the insertion of Mg atoms into vacant 16c sites during discharge were investigated using first-principles calculations. During this insertion, Mg atoms at 8a sites were found to migrate to other vacant 16c sites, such that the spinel form transitioned to a rock salt structure. The structural change from the standard spinel phase to a rock salt form was minimal in the case of MgCo2O4, since this change required the insertion of numerous Mg atoms. In contrast, a more pronounced structural change from the normal spinel to a rock salt form occurred in the MgCo1.5Mn0.5O4, as this change required fewer Mg atom insertions. The data suggest that the electron density and bond length between Mg atoms at 8a sites and O atoms in MgCo1.5Mn0.5O4 are both reduced compared to that in MgCo2O4. The Mg atoms in MgCo1.5Mn0.5O4 were determined to readily undergo intercalation as a result of the substitution of Mn atoms. Graphic abstract: [Figure not available: see fulltext.]
UR - http://www.scopus.com/inward/record.url?scp=85086868177&partnerID=8YFLogxK
U2 - 10.1007/s10853-020-04979-8
DO - 10.1007/s10853-020-04979-8
M3 - Article
AN - SCOPUS:85086868177
SN - 0022-2461
VL - 55
SP - 13852
EP - 13870
JO - Journal of Materials Science
JF - Journal of Materials Science
IS - 28
ER -