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A Stable Layered Oxide Cathode Material for High‐Performance Sodium‐Ion Battery
Author(s) -
Xiao Yao,
Zhu YanFang,
Yao HuRong,
Wang PengFei,
Zhang XuDong,
Li Hongliang,
Yang Xinan,
Gu Lin,
Li YongChun,
Wang Tao,
Yin YaXia,
Guo XiaoDong,
Zhong BenHe,
Guo YuGuo
Publication year - 2019
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201803978
Subject(s) - materials science , cathode , electrochemistry , sodium ion battery , battery (electricity) , intercalation (chemistry) , chemical engineering , thermal stability , oxide , scanning electron microscope , electrode , analytical chemistry (journal) , inorganic chemistry , composite material , chemistry , faraday efficiency , thermodynamics , power (physics) , physics , engineering , metallurgy , chromatography
As one of the most promising cathode candidates for room‐temperature sodium‐ion batteries (SIBs), P2‐type layered oxides face the challenge of simultaneously realizing high‐rate performance while achieving long cycle life. Here, a stable Na 2/3 Ni 1/6 Mn 2/3 Cu 1/9 Mg 1/18 O 2 cathode material is proposed that consists of multiple‐layer oriented stacking nanoflakes, in which the nickel sites are partially substituted by copper and magnesium, a characteristic of the material that is confirmed by multiscale scanning transmission electron microscopy and electron energy loss spectroscopy techniques. Owing to the optimal morphology structure modulation and chemical element substitution strategy, the electrode displays remarkable rate performance (73% capacity retention at 30C compared to 0.5C) and outstanding cycling stability in Na half‐cell system couple with unprecedented full battery performance. The underlying thermal stability, phase stability, and Na + storage mechanisms are clearly elucidated through the systematical characterizations of electrochemical behaviors, in situ X‐ray diffraction at different temperatures, and operando X‐ray diffraction upon Na + deintercalation/intercalation. Surprisingly, a quasi‐solid‐solution reaction is switched to an absolute solid‐solution reaction and a capacitive Na + storage mechanism is demonstrated via quantitative electrochemical kinetics calculation during charge/discharge process. Such a simple and effective strategy might reveal a new avenue into the rational design of excellent rate capability and long cycle stability cathode materials for practical SIBs.