Microwave Plasma Chemical Vapor Deposition of Carbon Coatings on LiNi_1/3Co_1/3Mn_1/3O₂ for Li-ion Battery Composite Cathodes

In this paper we report results of a synthesis method of thin-film conductive carbon coatings on LiNi_1/3Co_1/3Mn_1/3O₂ cathode active material powders for lithium-ion batteries. Thin layers of graphitic carbon were produced from a solid organic precursor, anthracene, by a one-step microwave plasma chemical vapor deposition (MPCVD) method. The structure and morphology of the carbon coatings were examined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The composite LiNi_1/3Co_1/3Mn_1/3O₂ electrodes were electrochemically tested in lithium half coin cells. The composite cathodes made of the carbon-coated LiNi_1/3Co_1/3Mn_1/3O₂/C powder showed superior electrochemical performance and increased capacity compared to standard composite LiNi_1/3Co_1/3Mn_1/3O₂ electrodes.