Defect chemical studies on oxygen release from the Li-rich cathode material Li 1.2 Mn 0.6 Ni 0.2 O 2-δ

Takashi Nakamura, Hongze Gao, Kento Ohta, Yuta Kimura, Yusuke Tamenori, Kiyofumi Nitta, Toshiaki Ina, Masatsugu Oishi, Koji Amezawa

研究成果: Article査読

28 被引用数 (Scopus)

抄録

Oxygen release from oxide-based cathode materials is a key phenomenon for the realization of high performance and highly reliable next-generation batteries, because it can be a trigger for a thermal runaway and closely related to electrochemical performances. In this study, the mechanism of oxygen release from Li 1.2 Mn 0.6 Ni 0.2 O 2-δ and the corresponding electronic and crystal structural changes were studied. Li 1.2 Mn 0.6 Ni 0.2 O 2-δ showed oxygen deficient nonstoichiometry until δ ≈ 0.042, and further oxygen extraction resulted in the reductive decomposition to MnNi 6 O 8 and Li-Mn enriched Li(Li,Mn,Ni)O 2-δ′ . The oxygen vacancy formation mechanism was investigated by the defect chemical and thermodynamic analyses, and the oxygen vacancy formation energy was calculated from the nonstoichiometric data (ca. 2.03 eV). It was clearly confirmed that the lattice parameters and the distances of Mn-O and Ni-O were increased by the oxygen vacancy formation, which is known as the reduction expansion in nonstoichiometric compounds. Cooperative reduction of Ni, Mn and O due to the oxygen vacancy formation was observed from Ni-L, Mn-L and O-K edge X-ray absorption spectra. The charge compensation of the oxygen vacancy formation was maintained mainly by the reduction of Ni 3+ to Ni 2+ and mildly by the reduction of Mn 4+ and O 2- .

本文言語English
ページ(範囲)5009-5019
ページ数11
ジャーナルJournal of Materials Chemistry A
7
9
DOI
出版ステータスPublished - 2019

ASJC Scopus subject areas

  • 化学 (全般)
  • 再生可能エネルギー、持続可能性、環境
  • 材料科学(全般)

フィンガープリント

「Defect chemical studies on oxygen release from the Li-rich cathode material Li <sub>1.2</sub> Mn <sub>0.6</sub> Ni <sub>0.2</sub> O <sub>2-δ</sub>」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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