The role of yttrium content in improving electrochemical performance of layered lithium-rich cathode materials for Li-ion batteries

被引：130

作者：

Li, Ning ^{[1
]}

An, Ran ^{[1
]}

Su, Yuefeng ^{[1
,2
]}

Wu, Feng ^{[1
,2
]}

Bao, Liying ^{[1
,2
]}

Chen, Lai ^{[1
]}

Zheng, Yu ^{[1
]}

Shou, Haofang ^{[1
]}

Chen, Shi ^{[1
,2
]}

机构：

[1] Beijing Inst Technol, Beijing Key Lab Environm Sci & Engn Beijing, Sch Chem Engn & Environm, Beijing 100081, Peoples R China

[2] Natl Dev Ctr High Technol Green Mat, Beijing 100081, Peoples R China

来源：

JOURNAL OF MATERIALS CHEMISTRY A | 2013年 / 1卷 / 34期

基金：

中国国家自然科学基金;

关键词：

SURFACE MODIFICATION; HIGH-VOLTAGE; OXYGEN LOSS; Y2O3; MN; NI;

D O I：

10.1039/c3ta11665d

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The promising layered lithium-rich cathode materials, Li1.2Mn0.6-xNi0.2YxO2 (0 <= x <= 0.05), have been synthesized by substituting Mn4+ in Li1.2Mn0.6Ni0.2O2 with unusually large Y3+ ions, in order to improve their cycling performance and rate capability. An oxalate co-precipitation method is adopted in the synthetic process. X-ray diffraction (XRD) patterns show that, other than as a dopant, the yttrium element is found to become Y2O3 or LiYO2 in excess Y3+-doped samples. The effects of yttrium content on the electrochemical properties of the lithium-rich materials are investigated by electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge tests as well. It demonstrates that the high capacity retention (240.7 mA h g(-1) after 40 cycles at 0.1 C rate) and superior rate capability (184.5 mA h g(-1) after 40 cycles at 1 C rate) have been achieved by the lithium-rich materials with a suitable amount of Y3+ doping. The "super-large" Y3+ can expand Li+-diffusing channels in the layered structure and stabilize the material structure.

引用

页码：9760 / 9767

页数：8

共 30 条

[1] Nanostructured materials for advanced energy conversion and storage devices [J].