Improve First-Cycle Efficiency and Rate Performance of Layered-Layered Li1.2Mn0.6Ni0.2O2 Using Oxygen Stabilizing Dopant

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• 作者：Jinfeng Li ; Chun Zhan ; Jun Lu ; Yifei Yuan ; Reza Shahbazian-Yassar ; Xinping Qiu ; Khalil Amine
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：July 29, 2015
• 年：2015
• 卷：7
• 期：29
• 页码：16040-16045
• 全文大小：363K
• ISSN：1944-8252

文摘

The poor first-cycle Coulombic efficiency and rate performance of the Li-rich layered-layered oxides are associated with oxygen gas generation in the first activation charging and sluggish charge transportation along the layers. In this work, we report that barium doping improves the first-cycle efficiency of Li-rich layered-layered Li_1.2Mn_0.6Ni_0.2O₂ via suppression of the oxidation of O^{2鈥?/sup> ions in the first charging. This effect can be attributed to the stabilizing effect of the barium cations on the oxygen radical intermediates generated during the oxidation of O2鈥?/sup>. Meanwhile, because the stabilized oxygen radicals likely facilitate the charge transportation in the layered-layered structure, the barium-doped Li_1.2Mn_0.6Ni_0.2O₂ exhibits significant improvement in rate performance. Stabilizing the oxygen radicals could be a promising strategy to improve the electrochemical performance of Li-rich layered-layered oxides.}