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Regulation of Breathing CuO Nanoarray Electrodes for Enhanced Electrochemical Sodium Storage
Author(s) -
Ni Jiangfeng,
Jiang Yu,
Wu Feixiang,
Maier Joachim,
Yu Yan,
Li Liang
Publication year - 2018
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201707179
Subject(s) - materials science , faraday efficiency , anode , electrochemistry , electrode , nanowire , sodium , chemical engineering , nanotechnology , metallurgy , chemistry , engineering
Abstract Cupric oxide (CuO) represents an attractive anode material for sodium‐ion batteries owing to its large capacity (674 mAh g −1 ) associated with multiple electron transfer. However, the substantial volume swelling and shrinking (≈170%) upon Na uptake and release, which mimics an electrode breathing process, disturbs the structural integrity, leading to poor electrochemical durability and low Coulombic efficiency. Here, a structural strategy to regulate the breathing of CuO nanoarray electrodes during Na cycling using an atomic layer deposition of cohesive TiO 2 thin films is presented. CuO nanoarrays are electrochemically grown on 3D Cu foam and directly used as anodes for sodium storage. The regulated CuO electrode arrays enable a large reversible capacity (592 mAh g −1 ), a high cycle efficiency (≈100%), and an excellent cycling stability (82% over 1000 cycles), which are some of the best sodium storage performance values reported for CuO systems. Electrochemical impedance and microscopic examination reveal that the enhanced performance is a direct outcome of the efficient regulation of the breathing of CuO nanowires by TiO 2 layer.