Applied Surface Science, Vol.351, 209-215, 2015
Electrochemical performance of layer-spinel composite cathode materials at elevated temperature and high rate
xLiNi(1/3)Co(1/3)Mn(1/3)O(2)-LiMn1.95Ni0.05O3.98F0.02 composite cathode materials with various mass ratios (x = 5.0%, 7.5%, and 10.0%) are prepared by the Pechini method. The relationship between the structural and electrochemical properties of the layerspinel composite cathode materials is investigated. XRD shows the composite materials still possess cubic spinel structure of the pristine matrix (space group of View the Fd (3) over barm). SEM and TEM show that a uniform coating layer of polycrystalline LiNi1/3Co1/3Mn1/3O2 was formed on the surface of the octahedral spinel grains. 10.0% LiNi1/3Co1/3Mn1/3O2-90.0%LiMn1.95Ni0.05O3.98F0.02 cathode exhibits better cycle performance and rate capability at elevated temperature (i.e., 55 degrees C) arising from the protective role of layer of LiNi1/3Co1/3Mn1/3O2. The coating material, LiNi1/3Co1/3Mn1/3O2, is one of most widely applied cathodes for lithium-ion batteries as well, which possesses high capacity retention, rate ability and discharge capacity at elevated temperatures, not only protect spinel LiMn1.95Ni0.05O3.98F0.02 from electrolyte corroding but also enhance Li-ion transport compared with inert coatings. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Cathode material;Lithium manganese oxide spinel;Layer-spinel composite;Cyclicity at elevated temperature;Rate performance