Nanocrystalline and thin film germanium electrodes with high lithium capacity and high rate capabilities
Nanocrystalline and thin film germanium electrodes with high lithium capacity and high rate capabilities
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DOI：
10.1149/1.1697412
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发表时间：
2004-01-01
影响因子：
3.9
通讯作者：
Fultz, B
中科院分区：
文献类型：
--
作者：
Graetz, J;Ahn, CC;Fultz, B
制备了锗纳米晶（平均直径12 nm）和非晶薄膜（厚度60-250 nm）作为锂二次电池的阳极。在平面镍基板上制备的非晶薄膜电极在60次循环中表现出1700 mAh/g的稳定容量。锗纳米晶体显示出高达1400 mAh/g的可逆重量容量，50次循环后容量保持率为60%。发现两个电极在完全锂化状态下都是结晶的。纳米相锗的容量、倍率性能（1000 C）和循环寿命优于块状结晶锗，这归因于活性材料的高表面积和短扩散长度以及纳米相材料中不存在缺陷。(C)2004年电化学学会。
Germanium nanocrystals (12 nm mean diam) and amorphous thin films (60-250 nm thick) were prepared as anodes for lithium secondary cells. Amorphous thin film electrodes prepared on planar nickel substrates showed stable capacities of 1700 mAh/g over 60 cycles. Germanium nanocrystals showed reversible gravimetric capacities of up to 1400 mAh/g with 60% capacity retention after 50 cycles. Both electrodes were found to be crystalline in the fully lithiated state. The enhanced capacity, rate capability (1000C), and cycle life of nanophase germanium over bulk crystalline germanium is attributed to the high surface area and short diffusion lengths of the active material and the absence of defects in nanophase materials. (C) 2004 The Electrochemical Society.