TiO2–LiF composite coating for improving NCM622 cathode cycling stability: one-step construction

The Ni-rich NCM622 is a promising cathode material for future high energy lithium ion batteries, but unstable electrochemical performance of NCM622 hinder its large scale commercial application. The cycling peformance of nickel-rich LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode materials can be improved by surface coating. Here, a one-step approach based on TiF4 is used to successfully manufacture modified NCM622 cathode materials with a TiO2–LiF coating. The TiO2–LiF coated NCM622 preserves 79.7% capacity retention which is higher than the pure NCM622 (68.9%) at 1C after 200 cycles within 2.7–4.3 V. This material serves as the cathode for lithium-ion batteries (LIBs). The uniform TiO2–LiF coating layer can alleviate structural degradation brought on by unfavorable side reactions with the electrolyte has been validated. TiO2–LiF coated on NCM622 cathode materials can be modified easily by one-step approach.