Effects of Chemical versus Electrochemical Delithiation on the Oxygen Evolution Reaction Activity of Nickel-Rich Layered LiMO2

详细信息    查看全文

• 作者：Veronica Augustyn ; Arumugam Manthiram
• 刊名：The Journal of Physical Chemistry Letters
• 出版年：2015
• 出版时间：October 1, 2015
• 年：2015
• 卷：6
• 期：19
• 页码：3787-3791
• 全文大小：402K
• ISSN：1948-7185

文摘

Nickel-rich layered LiMO₂ (M = transition metal) oxides doped with iron exhibit high oxygen evolution reaction (OER) activity in alkaline electrolytes. The LiMO₂ oxides offer the possibility of investigating the influence of the number of d electrons on OER by tuning the oxidation state of M via chemical or electrochemical delithiation. Accordingly, we investigate here the electrocatalytic behavior of LiNi_0.7Co_0.3O₂ and LiNi_0.7Co_0.2Fe_0.1O₂ before and after chemical delithiation. In addition to varying the oxidation state of the transition-metal ions, we find that chemical delithiation also affects the local chemical environment and morphology. The electrochemical response differs depending on whether the delithiation occurred ex situ chemically or in situ during the electrocatalysis. The results point to the important role of in situ transformation in LiMO₂ in alkaline electrolytes during electrocatalytic cycling.