Radially aligned hierarchical columnar structure as a cathode material for high energy density sodium-ion batteries
Radially aligned hierarchical columnar structure as a cathode material for high energy density sodium-ion batteries
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DOI：
10.1038/ncomms7865
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发表时间：
2015-04-01
影响因子：
16.6
通讯作者：
Sun, Yang-Kook
中科院分区：
文献类型：
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作者：
Hwang, Jang-Yeon;Oh, Seung-Min;Sun, Yang-Kook
在开发可再充电钠离子电池的阴极时，提供高容量和良好的保持力是一个挑战。在这里，我们提出了一个径向排列的分层柱状结构的球形颗粒与不同的化学成分从内端（Na [Ni0.75Co0.02Mn0.23] O-2）的结构的外端（Na[ www.example.com ]O-2）。Ni0.58Co0.06Mn0.36使用这种阴极材料，我们表明基于Ni 2 +/3+/4+的电化学反应可容易地提供157 mAh（g-氧化物）（-1）的放电容量。（15 mA g（-1）），容量保持率为80%（125 mAh g（-1）），以及132.6 mAh g（-1）（1，500 mA g（-1），10摄氏度速率）的速率容量。该阴极即使在-20 ° C下也表现出良好的温度性能。这些结果源于阴极材料的相当独特的化学性质，其使得Ni氧化还原反应能够进行并且使接触腐蚀性电解质的表面积最小化。
Delivery of high capacity with good retention is a challenge in developing cathodes for rechargeable sodium-ion batteries. Here we present a radially aligned hierarchical columnar structure in spherical particles with varied chemical composition from the inner end (Na[Ni0.75Co0.02Mn0.23]O-2) to the outer end (Na[Ni0.58Co0.06Mn0.36]O-2) of the structure. With this cathode material, we show that an electrochemical reaction based on Ni2+/3+/4+ is readily available to deliver a discharge capacity of 157 mAh (g-oxide)(-1) (15 mA g(-1)), a capacity retention of 80% (125 mAh g(-1)) during 300 cycles in combination with a hard carbon anode, and a rate capability of 132.6 mAh g(-1) (1,500 mA g(-1), 10 degrees C-rate). The cathode also exhibits good temperature performance even at -20 degrees C. These results originate from rather unique chemistry of the cathode material, which enables the Ni redox reaction and minimizes the surface area contacting corrosive electrolyte.