Characterization of the interface between LiCoO2 and Li7La3Zr2O12 in an all-solid-state rechargeable lithium battery
Characterization of the interface between LiCoO2 and Li7La3Zr2O12 in an all-solid-state rechargeable lithium battery
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DOI：
10.1016/j.jpowsour.2010.07.073
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发表时间：
2011-01-15
影响因子：
9.2
通讯作者：
Ogumi, Zempachi
中科院分区：
文献类型：
--
作者：
Kim, Ki Hyun;Iriyama, Yasutoshi;Ogumi, Zempachi
使用显微镜和电化学测量技术的组合，其特征在于在薄膜沉积期间在锂离子传导固体电解质Li 7 La 3 Zr 2 O 12（LLZ）和LiCoO 2之间形成的界面层。循环伏安法证实，锂提取发生在第一次循环的界面上，虽然不对称的氧化还原峰表明电化学性能差。使用分析型透射电子显微镜，分析反应层（类似于50 nm）。能量色散X射线光谱显示，一些元素（Co，La和Zr）的浓度在整个层中逐渐变化。该层的纳米束电子衍射显示，该层既不含LiCoO 2也不含LLZ，但一些斑点对应于La 2CoO 4的晶体结构。实验还表明，由于相互扩散，LLZ和LiCoO 2之间容易在界面处形成反应相。在高温处理过程中形成的反应层可能是LLZ/LiCoO 2界面处锂嵌入/提取不良的主要原因之一。(C)2010 Elsevier B. V.保留所有权利。
The interfacial layer formed between a lithium-ion conducting solid electrolyte, Li7La3Zr2O12 (LLZ), and LiCoO2 during thin film deposition was characterized using a combination of microscopy and electrochemical measurement techniques. Cyclic voltammetry confirmed that lithium extraction occurs across the interface on the first cycle, although the nonsymmetrical redox peaks indicate poor electrochemical performance. Using analytical transmission electron microscopy, the reaction layer (similar to 50 nm) was analyzed. Energy dispersive X-ray spectroscopy revealed that the concentrations of some of the elements (Co, La, and Zr) varied gradually across the layer. Nano-beam electron diffraction of this layer revealed that the layer contained neither LiCoO2 nor LLZ, but some spots corresponded to the crystal structure of La2CoO4. It was also demonstrated that reaction phases due to mutual diffusion are easily formed between LLZ and LiCoO2 at the interface. The reaction layer formed during high temperature processing is likely one of the major reasons for the poor lithium insertion/extraction at LLZ/LiCoO2 interfaces. (C) 2010 Elsevier B.V. All rights reserved.