title: Air-Stable Copper-Based P2-Na7/9Cu2/9Fe1/9Mn2/3O2as a New Positive Electrode Material for Sodium-Ion Batteries.
abstract: An air-stable copper-based P2-Na7/9Cu2/9Fe1/9Mn2/3O2is designed and synthesized by a simple solid-state method and investigated as a positive electrode material for sodium-ion batteries. The attractive long cycling stability is demonstrated by the capacity retention of 85% after 150 cycles at 1 C rate without phase transformation. The reversible Cu2+/Cu3+redox couple in P2 phase oxides is proved for the first time.
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Yunming
authors.initials: Y
authors.lastname: Li
authors.affiliation: Laboratory for Advanced Materials and Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Zhenzhong
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Shuyin
authors.initials: S
authors.lastname: Xu
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Linqin
authors.initials: L
authors.lastname: Mu
authors.affiliation: Laboratory for Advanced Materials and Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Hu
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Key Laboratory for Renewable Energy Beijing Key Laboratory for New Energy Materials and Devices Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China.
authors.forename: Liquan
authors.initials: L
authors.lastname: Chen
keywords: Na7/9Cu2/9Fe1/9Mn2/3O2; copper redox couple; grid storage; layered oxides; sodium‐ion batteries