Particle size effects on the electrochemical performance of copper oxides toward lithium
Particle size effects on the electrochemical performance of copper oxides toward lithium
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DOI：
10.1149/1.1353566
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发表时间：
2001-04-01
影响因子：
3.9
通讯作者：
Tarascon, JM
中科院分区：
文献类型：
--
作者：
Grugeon, S;Laruelle, S;Tarascon, JM
在可再充电锂电池中测试了根据多元醇方法制备的定制Cu 2 O或CuO粉末的电化学反应性。令我们惊讶的是，我们证明了CuO（一种众所周知的用于原锂电池的材料）和Cu 2 O可以分别与每个化学式单元1.1个Li和2个Li离子可逆地反应，导致在3-0.02 V范围内高达400 mAh/g的可逆容量。氧化铜为基础的锂电池的能力，以保持其容量后，许多周期被发现是强烈依赖于颗粒的大小，并获得最好的结果（100%的总容量高达70个周期）与1妈妈CuO和CuO颗粒。非原位透射电子显微镜数据和原位X-射线实验表明，还原机制的氧化铜锂首先涉及到形成的铜纳米颗粒分散到氧化锂（Li 2 O）矩阵，随后由有机涂层的生长，部分溶解后，随后的收费，而铜转换回氧化铜纳米颗粒。我们认为，铜氧化物或其他过渡金属氧化物对锂的可逆反应性机制的关键是在第一次放电期间电化学驱动形成高反应性金属纳米颗粒，这使得在随后的循环中能够形成-分解Li 2 O。(C)2001年电化学学会。All rights reserved.
The electrochemical reactivity of tailor-made Cu2O or CuO powders prepared according to the polyol process was tested in rechargeable Li cells. To our surprise, we demonstrated that CuO, a material well known for primary Li cells, and Cu2O could reversibly react with 1.1 Li and 2 Li ions per formula unit, respectively, leading to reversible capacities as high as 400 mAh/g in the 3-0.02 V range. The ability of copper oxide-based Li cells to retain their capacity upon numerous cycles was found to be strongly dependent on the particle size, and the best results (100% of the total capacity up to 70 cycles) were obtained with 1 mum Cu2O and CuO particles. Ex situ transmission electron microscopy data and in situ X-ray experiments show that the reduction mechanism of Cu2O by Li first involved the formation of Cu nanograins dispersed into a lithia (Li2O) matrix, followed by the growth of an organic coating that partially dissolved upon the subsequent charge while Cu converted back to Cu2O nanograins. We believe that the key to the reversible reactivity mechanism of copper oxides or other transition metal oxides toward Li is the electrochemically driven formation of highly reactive metallic nanograins during the first discharge, which enables the formation-decomposition of Li2O upon subsequent cycles. (C) 2001 The Electrochemical Society. All rights reserved.