Article ID Journal Published Year Pages File Type
8000211 Journal of Alloys and Compounds 2015 8 Pages PDF
Abstract
Mg doping and zirconium oxyfluoride (ZrOxFy) coating are introduced simultaneously to improve the high-voltage performance of LiCoO2 cathode material. XRD, TEM and XPS analysis confirm that the doping element (Mg) is incorporated into the lattices of the modified samples and there is a compact ZrOxFy coating layer on the surface of the co-modified sample. In addition, DSC results indicate that the modified samples show better thermal stability at the charged state. Electrochemical tests demonstrate that the cycling capability of co-modified sample is enhanced apparently, which maintains 76.3% of its initial capacity after 100 cycles at 1 C in the voltage range of 3.0-4.6 V. That is much more than 19.5% for the pristine sample. Moreover, EIS, XRD, TEM and Co dissolution tests of the cycled electrodes reveal that Mg-doping stabilizes the crystal structure of LiCoO2 and ZrOxFy-coating alleviates unwanted interfacial side reactions between the cathode and electrolyte, thereby suppressing Co dissolution and the impedance growth during prolonged cycling.
Related Topics
Physical Sciences and Engineering Materials Science Metals and Alloys
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