Domi Yasuhiro, Doi Takayuki, Tsubouchi Shigetaka, Yamanaka Toshiro, Abe Takeshi, Ogumi Zempachi
Office of Society-Academia Collaboration for Innovation, Kyoto University, Gokasho, Uji, Kyoto 611-0011, Japan.
Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan.
Phys Chem Chem Phys. 2016 Aug 10;18(32):22426-33. doi: 10.1039/c6cp03560d.
The degradation mechanism of a graphite negative-electrode in LiPF6-based electrolyte solution was investigated using the basal plane of highly oriented pyrolytic graphite (HOPG) as a model electrode. Changes in the surface morphology were observed by in situ atomic force microscopy. In the initial cathodic scan, a number of pits appeared at around 1.75 V vs. Li(+)/Li, and fine particles formed on the terrace of the HOPG basal plane at about 1.5 V vs. Li(+)/Li. The fine particles were characterized by spectroscopic analysis, such as X-ray photoelectron spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy. We added one of the components to LiClO4-based electrolyte solution, and successfully reproduced the formation of pits and fine particles on the basal plane of HOPG. Based on these results, the formation mechanisms of pits and fine particle layers were proposed.
以高度取向热解石墨（HOPG）的基面作为模型电极，研究了基于LiPF6的电解液中石墨负极的降解机理。通过原位原子力显微镜观察表面形貌的变化。在初始阴极扫描中，相对于Li(+)/Li，在约1.75 V处出现了许多凹坑，并且在相对于Li(+)/Li约1.5 V处的HOPG基面台面上形成了细颗粒。通过X射线光电子能谱和衰减全反射傅里叶变换红外光谱等光谱分析对细颗粒进行了表征。我们向基于LiClO4的电解液中添加了其中一种成分，并成功地在HOPG基面再现了凹坑和细颗粒的形成。基于这些结果，提出了凹坑和细颗粒层的形成机理。
