Lithium-ion conductive coating layer on nickel rich layered oxide cathode material with improved electrochemical properties for Li-ion battery

Abstract

In this work, an excellent ionic conductor Li3PO4 was deposited on the surface of LiNi0.8Mn0.1Co0.1O2 by a hydrothermal treatment method. This method avoided contact between the active material and water, and required only one step of calcination to obtain the product. The X-ray photoelectron spectroscopy (XPS) results indicated that the Li3PO4 coating layer had a protective effect which can greatly suppress the reaction of active material with the air and the electrolyte. Besides that, the Li3PO4 layer provided fast channels for lithium ions migration, and effectively inhibited the growth of SEI film and decreased the charge transfer resistance at the interface between the electrode and electrolyte. Therefore, the coated materials had excellent rate capability and cycle performance. The lithium ions diffusion (DLi+) of H-LPO&NMC was enhanced to the range of 10−13-10−12 cm2 s−1, while that of the bared material was only about 10−15-10−13 cm2 s−1.