Electrochemical Properties and In-situ XAFS Observation of Li2O-V2O5-P2O5-Fe2O3 Quaternary-glass and Crystallized-glass Cathodes

Takuya Aoyagi, Tadashi Fujieda, Tatsuya Toyama, Kazushige Kono, Daiko Takamatsu, Tatsumi Hirano, Takashi Naito, Yamato Hayashi, Hirotsugu Takizawa

研究成果: Article査読

8 被引用数 (Scopus)

抄録

Electrochemical properties of Li2O-V2O5-P2O5-Fe2O3 quaternary-glass and crystallized-glass cathodes were compared in terms of the local structural changes of vanadium and iron ions with increasing discharge capacity by in-situ X-ray absorption fine structure (XAFS) measurements. 10.3Li2O-69.2V2O5-10.2P2O5-10.3Fe2O3 glass was prepared by the melt-quenching method. The crystallized glass was produced by heat treatment of the glass at 375 °C in air. The crystal phase of the crystallized glass was found to be a single phase of β-vanadium bronze. The glass exhibited a discharge capacity of around 300 mAh g− 1 and a capacity retention of 66% after 100 cycles. On the other hand, the crystallized glass exhibited a capacity of around 340 mAh g− 1 and a capacity retention of 68% after 100 cycles. In the cases of glass and crystallized glass, in-situ X-ray absorption near-edge spectroscopy (XANES) spectra revealed that a redox reaction of vanadium and iron ions occurs as a compensation reaction for lithium-ion insertion. In addition, the absorption-energy shift of the vanadium and iron K-edges in the case of glass was larger than that in the case of crystallized glass despite the same discharge capacity. The analysis of pre-edge peak intensities and extended X-ray absorption fine structure (EXAFS) analysis revealed that the vanadium and iron coordination symmetry of the glass can transform more easily than that of the crystallized glass under lithium-ion insertion. These results imply that the origin of good cycleability differs in the cases of glass and crystal-phase cathodes.

本文言語English
ページ(範囲)28-35
ページ数8
ジャーナルJournal of Non-Crystalline Solids
453
DOI
出版ステータスPublished - 2016 12 1

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Condensed Matter Physics
  • Materials Chemistry

フィンガープリント 「Electrochemical Properties and In-situ XAFS Observation of Li<sub>2</sub>O-V<sub>2</sub>O<sub>5</sub>-P<sub>2</sub>O<sub>5</sub>-Fe<sub>2</sub>O<sub>3</sub> Quaternary-glass and Crystallized-glass Cathodes」の研究トピックを掘り下げます。これらがまとまってユニークなフィンガープリントを構成します。

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