Highly Reversible Oxygen-Redox Chemistry at 4.1 V in Na4/7− x[□1/7Mn6/7]O2 (□: Mn Vacancy)

Benoit Mortemard de Boisse, Shin ichi Nishimura, Eriko Watanabe, Laura Lander, Akihisa Tsuchimoto, Jun Kikkawa, Eiichi Kobayashi, Daisuke Asakura, Masashi Okubo, Atsuo Yamada*


研究成果: Article査読

161 被引用数 (Scopus)


Increasing the energy density of rechargeable batteries is of paramount importance toward achieving a sustainable society. The present limitation of the energy density is owing to the small capacity of cathode materials, in which the (de)intercalation of ions is charge-compensated by transition-metal redox reactions. Although additional oxygen-redox reactions of oxide cathodes have been recognized as an effective way to overcome this capacity limit, irreversible structural changes that occur during charge/discharge cause voltage drops and cycle degradation. Here, a highly reversible oxygen-redox capacity of Na2Mn3O7 that possesses inherent Mn vacancies in a layered structure is found. The cross validation of theoretical predictions and experimental observations demonstrates that the nonbonding 2p orbitals of oxygens neighboring the Mn vacancies contribute to the oxygen-redox capacity without making the Mn−O bond labile, highlighting the critical role of transition-metal vacancies for the design of reversible oxygen-redox cathodes.

ジャーナルAdvanced Energy Materials
出版ステータスPublished - 2018 7月 16

ASJC Scopus subject areas

  • 再生可能エネルギー、持続可能性、環境
  • 材料科学一般


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