阴极
材料科学
锂(药物)
电极
化学工程
透射电子显微镜
纳米技术
电气工程
化学
医学
工程类
内分泌学
物理化学
作者
Feng Lin,Dennis Nordlund,Yuyi Li,Matthew K. Quan,Lei Cheng,Tsu‐Chien Weng,Yijin Liu,Huolin L. Xin,Marca M. Doeff
出处
期刊:Nature Energy
[Springer Nature]
日期:2016-01-11
卷期号:1 (1)
被引量:212
标识
DOI:10.1038/nenergy.2015.4
摘要
In technologically important LiNi1−x−yMnxCoyO2 cathode materials, surface reconstruction from a layered to a rock-salt structure is commonly observed under a variety of operating conditions, particularly in Ni-rich compositions. This phenomenon contributes to poor high-voltage cycling performance, impeding attempts to improve the energy density by widening the potential window at which these electrodes operate. Here, using advanced nano-tomography and transmission electron microscopy techniques, we show that hierarchically structured LiNi0.4Mn0.4Co0.2O2 spherical particles, made by a simple spray pyrolysis method, exhibit local elemental segregation such that surfaces are Ni-poor and Mn-rich. The tailored surfaces result in superior resistance to surface reconstruction compared with those of conventional LiNi0.4Mn0.4Co0.2O2, as shown by soft X-ray absorption spectroscopy experiments. The improved high-voltage cycling behaviour exhibited by cells containing these cathodes demonstrates the importance of controlling LiNi1−x−yMnxCoyO2 surface chemistry for successful development of high-energy lithium ion batteries. Advanced batteries require careful control over the interfacial properties of their constituent materials. This study designs hierarchically structured cathode materials that are resistant to surface reconstruction, leading to improved cycling performance.
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