Zn2SnO4 Nanowires versus Nanoplates: Electrochemical Performance and Morphological Evolution during Li-Cycling
Zn2SnO4 Nanowires versus Nanoplates: Electrochemical Performance and Morphological Evolution during Li-Cycling
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DOI：
10.1021/am400802j
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发表时间：
2013-07-15
影响因子：
9.5
通讯作者：
Sow, Chorng Haur
中科院分区：
文献类型：
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作者：
Cherian, Christie T.;Zheng, Minrui;Sow, Chorng Haur
采用气相传输法在不锈钢衬底上直接合成了Zn_2SnO_4纳米线。利用X射线衍射仪（XRD）和透射电子显微镜（TEM）对样品的结构和形貌进行了表征。通过恒电流循环和循环伏安法（CV）测试了Zn 2SnO 4纳米线在两个不同电压窗口（0.005-3和0.005-1.5 V vs Li）下的电化学性能，并与水热法制备的Zn 2SnO 4纳米片进行了比较。Zn 2SnO 4纳米线在0.005-3 V电压范围内、120 mA g（-1）电流下的恒电流循环研究显示，1000（+/-5）mAh g（-1）的可逆容量，前10次循环的容量几乎稳定，此后通过60次循环衰减至695 mAh g（-1）。在相对于Li在0.005- 1.5V的电压范围内循环时，对于前10次循环观察到680（+/-5）mAh g（-1）的稳定可逆容量，在10-50次循环之间的容量保持率为58%。另一方面，Zn 2SnO 4纳米片显示出剧烈的容量衰减高达10个循环，然后显示出80%和70%的容量保持率之间的10和50个循环时，在0.005-1.5和0.005-3 V的电压范围内循环，分别。研究了Zn 2SnO 4纳米线在循环过程中的结构和形态演变及其对Li循环行为的影响。还阐明了电压范围和活性物质初始形态的选择对锂循环性能的影响
Zn2SnO4 nanowires have been synthesized directly on stainless steel substrate without any buffer layers by the vapor transport method. The structural and morphological properties are investigated by means of X ray diffraction (XRD) and transmission electron microscopy (TEM). The electrochemical performance of Zn2SnO4 nanowires is examined by galvanostatic cycling and cyclic voltammetry (CV) measurements in two different voltage windows, 0.005-3 and 0.005-1.5 V vs Li and compared to that of Zn2SnO4 nanoplates prepared by hydrothermal method. Galvanostatic cycling studies of Zn2SnO4 nanowires in the voltage range 0.005-3 V, at a current of 120 mA g(-1), show a reversible capacity of 1000 (+/- 5) mAh g(-1) with almost stable capacity for first 10 cycles, which thereafter fades to 695 mAh g(-1) by 60 cycles. Upon cycling in the voltage range 0.005-1.5 V vs Li, a stable, reversible capacity of 680 (+/- 5) mAh g(-1) is observed for first 10 cycles with a capacity retention of 58% between 10-50 cycles. On the other hand, Zn2SnO4 nanoplates show drastic capacity fading up to 10 cycles and then showed a capacity retention of 80% and 70% between 10 and 50 cycles when cycled in the voltage range 0.005-1.5 and 0.005-3 V, respectively. The structural and morphological evolutions during cycling and their implications on the Li-cycling behavior of Zn2SnO4 nanowires are examined. The effect of the choice of voltage range and initial morphology of the active material on the Li-cycleabilty is also elucidated