Li Diffusion in Thin-Film LiySi Electrodes: Galvanostatic Intermittent Titration Technique and Tracer Diffusion Experiments
Li Diffusion in Thin-Film LiySi Electrodes: Galvanostatic Intermittent Titration Technique and Tracer Diffusion Experiments
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DOI：
10.1021/acs.jpcc.0c08294
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发表时间：
2020-12-24
影响因子：
3.7
通讯作者：
Schmidt, Harald
中科院分区：
文献类型：
--
作者：
Uxa, Daniel;Hueger, Erwin;Schmidt, Harald
LiySi是锂离子电池负极材料中的一种有趣材料。我们进行了测量与恒电流间歇滴定技术（GITT）上的离子束溅射的非晶LiySi（y近似为0.02和0.25）薄膜，以确定在室温下的锂扩散系数。结果进行了比较，在我们的实验室进行的二次离子质谱（西姆斯）的Li示踪剂扩散实验。西姆斯测量产生Li扩散率几个数量级低于GITT测量Li0.02Si膜。相比之下，这两种方法都给出了约10（-20）m（2）/s的Li 0.25Si膜的扩散率。这一结果可以用电极材料的非均相电化学锂化机理来解释。
LiySi is an interesting material for negative electrodes in Li-ion batteries. We carried out measurements with a galvanostatic intermittent titration technique (GITT) on ion-beam-sputtered amorphous LiySi (y approximate to 0.02 and 0.25) films to determine Li diffusivities at room temperature. The results are compared to Li tracer diffusion experiments conducted in our laboratory by secondary ion mass spectrometry (SIMS). SIMS measurements yield Li diffusivities several orders of magnitude lower than GITT measurements for Li0.02Si films. In contrast, both methods give a diffusivity of about 10(-20) m(2)/s for Li0.25Si films. The results can be explained by a heterogeneous electrochemical lithiation mechanism of the electrode material.