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Highly Efficient Sodium Storage in Iron Oxide Nanotube Arrays Enabled by Built‐In Electric Field
Author(s) -
Ni Jiangfeng,
Sun Menglei,
Li Liang
Publication year - 2019
Publication title -
advanced materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.707
H-Index - 527
eISSN - 1521-4095
pISSN - 0935-9648
DOI - 10.1002/adma.201902603
Subject(s) - anode , materials science , cathode , energy storage , oxide , electrode , electric field , nanotechnology , lithium (medication) , heterojunction , optoelectronics , chemical engineering , electrical engineering , power (physics) , chemistry , medicine , physics , quantum mechanics , endocrinology , metallurgy , engineering
High‐power sodium–ion batteries capable of charging and discharging rapidly and durably are eagerly demanded to replace current lithium–ion batteries. However, poor activity and instable cycling of common sodium anode materials represent a huge barrier for practical deployment. A smart design of ordered nanotube arrays of iron oxide (Fe 2 O 3 ) is presented as efficient sodium anode, simply enabled by surface sulfurization. The resulted heterostructure of oxide and sulfide spontaneously develops a built‐in electric field, which reduces the activation energy and accelerates charge transport significantly. Benefiting from the synergy of ordered architecture and built‐in electric field, such arrays exhibit a large reversible capacity, a superior rate capability, and a high retention of 91% up to 200 cycles at a high rate of 5 A g −1 , outperforming most reported iron oxide electrodes. Furthermore, full cells based on the Fe 2 O 3 array anode and the Na 0.67 (Mn 0.67 Ni 0.23 Mg 0.1 )O 2 cathode deliver a specific energy of 142 Wh kg −1 at a power density of 330 W kg −1 (based on both active electrodes), demonstrating a great potential in practical application. This material design may open a new door in engineering efficient anode based on earth‐abundant materials.