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Dual‐Role Surface Modification of Layered Oxide Cathodes for High‐Power Sodium‐Ion Batteries
Author(s) -
Yang Ying,
Feng Yuzhang,
Ma Cheng,
Huang Qun,
Zhou Liangjun,
Wang Peng,
Wei Weifeng
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.202000002
Subject(s) - spinel , cathode , materials science , oxide , ion , chemical engineering , ionic radius , dissociation (chemistry) , sodium , diffusion , electrochemistry , ionic bonding , limiting , nanotechnology , electrode , chemistry , thermodynamics , metallurgy , organic chemistry , engineering , mechanical engineering , physics
P2‐type layered oxides have attracted extensive attentions due to their high reversible capacity and operating voltage when applied as cathode materials for sodium‐ion batteries (SIBs). However, the large ionic radius of Na + and restricted 2D diffusion channels account for the inferior Na + conductivity, limiting their practical application under large current densities. Herein, a facile dual‐role surface treatment on oxide precursors using KMnO 4 solution is employed to generate K + pillar and spinel‐like surface nanolayer in the layered oxide cathodes simultaneously. The substantial enhancement of Na kinetics is ascribed to the enlarged interlayer spacing in the lattice induced by K + pillar and the formation of coherent spinel‐like surface structure derived from the decomposition of KMnO 4 , which satisfies the timely Na + insertion/extraction and improves the rate performance. It is anticipated that this dual‐role strategy may provide a promising pathway for the development of the high‐power‐capability SIBs.