J-STAGE Data
Browse
IMAGE
advpub_21-00123.jpg (342.39 kB)
DOCUMENT
6_SuplementalInformation_Ele_final.docx (510.57 kB)
1/0
2 files

Electrochemical Properties and Crystal and Electronic Structures of Spinel αMgCo2−xMnxO4-(1 − α)Mg(Mg0.33V1.67−yNiy)O4 for Magnesium Secondary Batteries (Supporting Information)

dataset
posted on 2022-01-20, 02:55 authored by Yasushi Idemoto, Ren OKADA, Naoya ISHIDA, Chiaki ISHIBASHI, Toshihiko MANDAI, Naoto KITAMURA
In the present study, αMgCo1.5Mn0.5O4-(1 − α)Mg1.33V1.57Ni0.1O4 was synthesized by a reverse co-precipitation method. The products were assigned to a spinel structure with a space group Fd3m based on powder X-ray diffraction analysis. Inductively coupled plasma-atomic emission spectroscopy revealed that the composition was not close to the target composition; the Mg content was higher and the V content was lower than expected. Charge/discharge cyclic tests showed that the discharge capacity exceeded 180 mAh g−1 and that the cyclability was reversible up to 60 cycles at 90 °C with a cut-off voltage of 0.945 to −1.055 V vs. Ag/Ag+ (3.545–1.545 V vs. Mg/Mg2+) for α = 0.3. The electronic structure was analyzed using the maximum-entropy method based on a Rietveld analysis, and it was found that Mg insertion was easier for α = 0.3, 0.5, 0.9 than for MgCo1.5Mn0.5O4 and Mg1.33V1.57Ni0.1O4. The strain in MO6 octahedra for α = 0.1, 0.3, 0.5, 0.7 was smaller than that for MgCo1.5Mn0.5O4 and Mg1.33V1.57Ni0.1O4, which suggests that the host structure was stabilized by forming a solid solution. A Rietveld analysis after the first discharge and second charge confirmed a partly reversible phase transition from the spinel phase to a rock-salt phase. The valence of the transition metals was examined by X-ray absorption fine structure (XAFS) measurements, and the Co and Mn K-edge spectra revealed that Co and Mn were present as Co2.67+ to Co2+ and Mn4+ to Mn3+ species for α = 0.3. Both Co and Mn redox processes are considered to contribute to Mg intercalation. Extended XAFS (EXAFS) Co K-edge and Mn K-edge spectra for the powder specimens and after the first discharge and second charge showed that bonds between Co, V atoms and nearest-neighbor O atoms were distorted after the first discharge, and that this distortion was relaxed after the second charge.

Funding

3D integration engineering by vertical BC-MOSFET and application development

Japan Science and Technology Agency

Find out more...

Advanced storage battery research and development base

Japan Science and Technology Agency

Find out more...

History

Manuscript title

Electrochemical Properties and Crystal and Electronic Structures of Spinel αMgCo2−xMnxO4-(1 − α)Mg(Mg0.33V1.67−yNiy)O4 for Magnesium Secondary Batteries

Corresponding author email address

idemoto@rs.tus.ac.jp

Copyright

© 2022 The Author(s)

Usage metrics

    Electrochemistry

    Categories

    Licence

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC