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Suppressing the P2–O2 Phase Transition of Na 0.67 Mn 0.67 Ni 0.33 O 2 by Magnesium Substitution for Improved Sodium‐Ion Batteries
Author(s) -
Wang PengFei,
You Ya,
Yin YaXia,
Wang YueSheng,
Wan LiJun,
Gu Lin,
Guo YuGuo
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201602202
Subject(s) - cathode , sodium , magnesium , materials science , nickel , phase transition , ion , electrochemistry , transition metal , phase (matter) , stoichiometry , inorganic chemistry , chemical engineering , chemistry , electrode , metallurgy , thermodynamics , organic chemistry , physics , engineering , catalysis
Room‐temperature sodium‐ion batteries (SIBs) have shown great promise in grid‐scale energy storage, portable electronics, and electric vehicles because of the abundance of low‐cost sodium. Sodium‐based layered oxides with a P2‐type layered framework have been considered as one of the most promising cathode materials for SIBs. However, they suffer from the undesired P2–O2 phase transition, which leads to rapid capacity decay and limited reversible capacities. Herein, we show that this problem can be significantly mitigated by substituting some of the nickel ions with magnesium to obtain Na 0.67 Mn 0.67 Ni 0.33− x Mg x O 2 (0≤ x ≤0.33). Both the reversible capacity and the capacity retention of the P2‐type cathode material were remarkably improved as the P2–O2 phase transition was thus suppressed during cycling. This strategy might also be applicable to the modulation of the physical and chemical properties of layered oxides and provides new insight into the rational design of high‐capacity and highly stable cathode materials for SIBs.