Structural and Electrochemical Properties of Low-Cobalt-Content LiNi0.6+xCo0.2-xMn0.2O2 (0.0 ≤ x ≤ 0.1) Cathodes for Lithium-Ion Batteries.
作者:He, Li-Po; Li, Kun; Zhang, Yao; Liu, Jun
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ACS applied materials & interfaces
卷:12 期:25 页:28253-28263
DOI:10.1021/acsami.0c06824
出版年: 2020-Jun-24 (Epub 2020 Jun 16)
文献类型:Journal Article
摘要
The layered oxides LiNi0.6+xCo0.2-xMn0.2O2 are promising cathode materials for Li-ion batteries (LIBs) owing to their moderate energy densities and structure stabilities. In this study, we systematically investigate the effects of substitution of Co by Ni on the structures, morphologies, and electrochemical properties of LiNi0.6+xCo0.2-xMn0.2O2 (0.0 ≤ x ≤ 0.1). The physical characteristics of these materials are studied by particle size analysis, scanning electron microscopy, inductively coupled plasma-atomic emission spectroscopy, Rietveld refinement of X-ray diffraction data, and X-ray photoelectron spectroscopy. The electrochemical properties are investigated by charge-discharge cycling, galvanostatic intermittent titration, and electrochemical impedance spectroscopy. As the Co content decreases and the Ni content increases, the discharge capacity and voltage platform are slightly improved, while the initial efficiency, cycling performance, rate capability, and thermal stability gradually decrease. The decreased kinetic performance is attributed to the increased degree of cation mixing and resistance, which decreases the Li+ diffusivity. Moreover, the activation energy gradually increases with the decrease in the Co content, which decreases the low-temperature performance. Considering its cost, energy density, cycling lifetime, kinetic performance, and safety properties, LiNi0.65Co0.15Mn0.2O2 is a promising cathode candidate for use in LIBs.
关键词
关键词列表:activation energy; cathode; layered oxide; lithium-ion battery; low cobalt content
作者信息
地址:Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials, South China University of Technology, Guangzhou 510641, P. R. China.
Cell Technology Research Center, Sunwoda Electronic Co., Ltd., Shenzhen 518000, P. R. China.