Influence of Manganese Dissolution on the Degradation of Surface Films on Edge Plane Graphite Negative-Electrodes in Lithium-Ion Batteries
Influence of Manganese Dissolution on the Degradation of Surface Films on Edge Plane Graphite Negative-Electrodes in Lithium-Ion Batteries
复制标题
DOI：
10.1149/2.031207jes
复制
发表时间：
2012
影响因子：
3.9
通讯作者：
M. Ochida;Y. Domi;T. Doi;S. Tsubouchi;Hiroe Nakagawa;T. Yamanaka;T. Abe;Z. Ogumi
中科院分区：
文献类型：
--
作者：
M. Ochida;Y. Domi;T. Doi;S. Tsubouchi;Hiroe Nakagawa;T. Yamanaka;T. Abe;Z. Ogumi
利用端面高取向热解石墨（HOPG），通过循环伏安法、电化学阻抗谱和原位原子力显微镜（AFM）研究了电解液中溶解的Mn离子对石墨负极电化学性能的影响。随着循环次数的增加，边缘平面 HOPG 电极上锂离子的嵌入和脱嵌反应导致的氧化还原电流显着降低。在锰离子存在下，特别是在低于 0.6 V 的电位下，表面膜和界面的锂离子传输电阻均显着增加，表明应该发生一些不可逆反应。 X射线光电子能谱表明，Mn金属沉积在端面HOPG上，然后在开路条件下氧化成二价（或更高价）Mn。这些结果表明，沉积的Mn金属应该被氧化以还原性地分解电解质本身和/或原始表面膜。电化学AFM观察表明，在含有Mn离子的电解液中，在初始电位循环中，端面HOPG上形成了小于0.1μm的非常细小的颗粒，然后在进一步的电位循环后观察到更大的颗粒。还研究了成膜添加剂对端面 HOPG 电极上 Mn 沉积的影响。
The influence of Mn-ion dissolved in electrolyte solution on the electrochemical properties of graphite negative-electrodes was investigated using edge plane highly oriented pyrolytic graphite (HOPG) by cyclic voltammetry, electrochemical impedance spectroscopy, and in situ atomic force microscopy (AFM). Redox currents due to intercalation and de-intercalation reactions of Li-ion at an edge plane HOPG electrode significantly decreased with an increase in the cycle number. Both the surface film and interfacial Li-ion transfer resistances remarkably increased in the presence of Mn-ion, and particularly at potentials below 0.6 V, indicating that some irreversible reactions should occur. X-ray photoelectron spectra indicate that Mn metal was deposited on the edge plane HOPG, and then oxidized into divalent (or higher) Mn under open-circuit conditions. These results suggest that the deposited Mn metal should be oxidized to decompose the electrolyte itself and/or the original surface film reductively. Electrochemical AFM observation showed that very fine particles smaller than 0.1 μm were formed on edge plane HOPG in the initial potential cycle in electrolyte containing Mn-ion, and then larger particles were observed after further potential cycles. The effects of film-forming additives on the deposition of Mn on the edge plane HOPG electrode were also investigated.