In Situ Reactive Coating of Fast Ionic Conductor LiTi₂(PO₄)₃ on LiNi_0.8Co_0.1Mn_0.1O₂ Cathode Materials for High-Performance Li-Ion Batteries

A uniform fast ionic conductor LiTi2(PO4)(3) (LTP) coating layer on the surface of Ni - rich layered metal oxide LiNi0.8Co0.1Mn0.1O2 (LNCM811) cathode material, was constructed via an in situ reaction of the residual LiOH and Li2CO3 on the LNCM811 surface with the added C8H20O4Ti and (NH4)H2PO4. This in situ reactive coating approach is favorable to remove the undesired LiOH and Li2CO3 which are residual on the LNCM811 surface. Moreover, the obtained uniform LTP coating layers could not only protect the LNCM811 cathode materials from the sidereaction with the electrolytes, but also ensure the fast Li+ conductivity for the LNCM811 cathode materials during the charge and discharge cycling. Therefore, owing to the multifunctional effects of the LTP coating, the LTP coated LNCM811 cathode materials exhibited excellent cyclic stability and rate performances with a high initial capacity of 200.1 mAh.g(-1) at 0.2C, the high reversible capacities of 155.7 mAh.g(-1) after the 200th cycle at 0.2C, 126.4 mAh.g(-1) at 2C and 111.9 mAh.g(-1) at 5C.