TY - JOUR
T1 - Electrochemical performance and thermal stability of iron oxyfluoride (FeOF) for sodium-ion batteries
AU - Kitajou, Ayuko
AU - Zhao, Liwei
AU - Nagano, Rintaro
AU - Inoishi, Atsushi
AU - Kobayashi, Eiji
AU - Okada, Shigeto
N1 - Funding Information:
This research was funded by the Elements Strategy Initiative for Catalysts and Batteries Project of MEXT, Japan.This work was financially supported by the Elements Strategy Initiative for Catalysts and Batteries Project of MEXT, Japan. The XANES spectra were obtained on the BL11 beamline with the approval of the Kyushu Synchrotron Light Research Center (Proposal No. 1212129R).
Publisher Copyright:
© 2018 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2018/12
Y1 - 2018/12
N2 - Self-synthesized rutile iron oxyfluoride (FeOF) was studied as a cathode material for Na-ion batteries. The highly crystalline FeOF provided an initial discharge capacity of 246 mAhg-1 in a voltage range of 1.0–4.0 V, followed by 88% of capacity retention after 20 cycles. This discharge-charge reaction of FeOF between 0.8 and 4.0 V are advanced by the Fe2+ /Fe3+ redox reaction. That is, no conversion reaction was involved in the application of FeOF as a cathode material for Na-ion batteries because of the low potential of Na-insertion. In addition, the structure change of FeOF from rutile to cubic during Na ion insertion, which was similar to that in Li-ion batteries. No remarkable HF release was detected even up to 700°C, indicating a low toxic risk of the FeOF cathode. The thermal properties of sodiated and desodiated FeOF electrodes in the associated electrolyte were investigated by DSC (Differential scanning calorimetry) up to 500°C. Sodiated FeOF electrodes showed larger exothermic heat generation than desodiated ones, especially at a temperature higher than 380°C. Finally, the thermal stability of FeOF cathodes in the associated Li-and Na-ion battery electrolytes was quantitatively compared with variations of the electrode/electrolyte ratio.
AB - Self-synthesized rutile iron oxyfluoride (FeOF) was studied as a cathode material for Na-ion batteries. The highly crystalline FeOF provided an initial discharge capacity of 246 mAhg-1 in a voltage range of 1.0–4.0 V, followed by 88% of capacity retention after 20 cycles. This discharge-charge reaction of FeOF between 0.8 and 4.0 V are advanced by the Fe2+ /Fe3+ redox reaction. That is, no conversion reaction was involved in the application of FeOF as a cathode material for Na-ion batteries because of the low potential of Na-insertion. In addition, the structure change of FeOF from rutile to cubic during Na ion insertion, which was similar to that in Li-ion batteries. No remarkable HF release was detected even up to 700°C, indicating a low toxic risk of the FeOF cathode. The thermal properties of sodiated and desodiated FeOF electrodes in the associated electrolyte were investigated by DSC (Differential scanning calorimetry) up to 500°C. Sodiated FeOF electrodes showed larger exothermic heat generation than desodiated ones, especially at a temperature higher than 380°C. Finally, the thermal stability of FeOF cathodes in the associated Li-and Na-ion battery electrolytes was quantitatively compared with variations of the electrode/electrolyte ratio.
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U2 - 10.3390/batteries4040068
DO - 10.3390/batteries4040068
M3 - Article
AN - SCOPUS:85068388760
SN - 2313-0105
VL - 4
JO - Batteries
JF - Batteries
IS - 4
M1 - 68
ER -