Yolk-shell structured Sb@C anodes for high energy Na-ion batteries
Yolk-shell structured Sb@C anodes for high energy Na-ion batteries
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DOI：
10.1016/j.nanoen.2017.08.051
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发表时间：
2017-10-01
期刊：
影响因子：
17.6
通讯作者：
Li, Xiaolin
中科院分区：
文献类型：
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作者：
Song, Junhua;Yan, Pengfei;Li, Xiaolin
尽管钠离子电池的发展取得了很大进展，但寻找高能、稳定的负极材料仍然是一个挑战。合金或转换型负极材料具有较高的比容量和较低的电压，但其体积膨胀大，电化学可逆性差，容量衰减快，阻碍了其应用。在这里，我们以锑(Sb)为例，演示了蛋黄壳结构阳极在高能钠离子电池中的应用。通过控制还原和选择性脱除Sb_2O_3制备的Sb@C蛋黄壳结构能够适应Sb在碱化过程中的膨胀，并改善结构/电完整性，防止粉化。它具有接近554mAhg(-1)的高比容量、良好的倍率性能(10C速率下为315 mHAg(-1))和长循环能力(200次循环的容量保持率为92%)。O_3-Na-0.9[Cu0.22Fe0.30Mn0.48]O~(-2)和Sb@C-硬碳复合阳极在2.0-4.0V的电压范围内，比能量高达130Wh kg(-1)(以阴阳极总质量计)，与类似设计的硬碳阳极电池的1.5倍相近。
Despite great advances in sodium-ion battery developments, the search for high energy and stable anode materials remains a challenge. Alloy or conversion-typed anode materials are attractive candidates of high specific capacity and low voltage potential, yet their applications are hampered by the large volume expansion and hence poor electrochemical reversibility and fast capacity fade. Here, we use antimony (Sb) as an example to demonstrate the use of yolk-shell structured anodes for high energy Na-ion batteries. The Sb@C yolk-shell structure prepared by controlled reduction and selective removal of Sb2O3 from carbon coated Sb2O3 nano-particles can accommodate the Sb swelling upon sodiation and improve the structural/electrical integrity against pulverization. It delivers a high specific capacity of similar to 554 mAh g(-1), good rate capability (315 mhA g(-1) at 10 C rate) and long cyclability (92% capacity retention over 200 cycles). Full-cells of O3-Na-0.9[Cu0.22Fe0.30Mn0.48] O-2 cathodes and Sb@C-hard carbon composite anodes demonstrate a high specific energy of similar to 130 Wh kg(-1) ( based on the total mass of cathode and anode) in the voltage range of 2.0-4.0 V, similar to 1.5 times energy of full-cells with similar design using hard carbon anodes.