Enhanced Electrochemical Performance of Fast Ionic Conductor LiTi2(PO4)3-Coated LiNi1/3Co1/3Mn1/3O2 Cathode Material.

Layered LiNi1/3Co1/3Mn1/3O2 (NCM333) is successfully coated by fast ionic conductor LiTi2(PO4)3 (LTP) via a wet chemical method. The effects of LTP on the physicochemical properties and electrochemical performance are studied. The results reveal that a highly layered structure of NCM333 can be well maintained with less cation mixing after LTP coating. LTP of about 5 nm thickness is coated on the surface of NCM333. Such an LTP coating layer can effectively suppress the side reactions between NCM333 and electrolyte but will not hinder the lithium ion transmission. As a result, LTP-coated NCM333 owns an improved capability and cyclic performance, for example, NCM333/LTP delivers an initial capacity as high as 121.0 mA h g-1 with a capacity retention ratio of 82.3% after 200 cycles at 10 C, whereas NCM333 only has an initial capacity of 120.4 mA h g-1 with a very low capacity retention ratio of 66.4%. This method of using a fast ionic conductor like LTP as a coating material may provide a simple and effective strategy to modify those electrode materials with poor cyclic performance.