期刊
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
卷 16, 期 27, 页码 13838-13842出版社
ROYAL SOC CHEMISTRY
DOI: 10.1039/c4cp01436g
关键词
-
资金
- NSERC
- NRC
- CIHR
- University of Saskatchewan
- National Natural Science Foundation of China [51272051]
- Academic Expert Program of Harbin [RC2012XK017008]
The electronic structure at the Ni, Mn and O sites and their evolution upon the electrochemical lithiation of Li1-xNi0.5Mn1.5O4 (LNMO) in a lithium ion battery has been explored using comprehensive X-ray absorption near edge structure spectroscopy (XANES) at the Ni and Mn L-3,L-2-and O K-edges, with both surface-sensitive and bulk-sensitive detection. It has confirmed that Ni reduction from Ni4+ to Ni2+ plays the leading role in charge compensation when the lithiation voltage is above 4.5 V. Our study also unveils the participation of oxygen in the charge compensation. Furthermore, the enhanced difference in the electronic structures of the surface and bulk in electrochemically cycled samples, and the different surface electronic structures of the fully discharged LNMO and the pristine one, highlight the importance of electrochemical activation. These findings are critical for a better understanding of the electrochemical reaction of LNMO and the influence of structural modifications to the surface region upon its performance, and will assist further efforts to improve this high-voltage cathode material for its application in lithium ion batteries.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据