Enhancing high-voltage performance of LiNi0.8Co0.1Mn0.1O2 by coating with NASICON fast ionic conductor Li1.5Al0.5Zr1.5(PO4)3

Abstract The Li1.5Al0.5Zr1.5(PO4)3-coated LiNi0.8Co0.1Mn0.1O2 cathode material has been successfully fabricated by a sol-gel method. Combined with the results of XRD, SEM, TEM and XPS, the LAZP is coated closely on the surface of NCM and forms a film with a thickness of approximately 4 nm. The LAZP coating layer can significantly facilitate the Li+-ion diffusion rate at the interface of electrolyte/electrode on the NCM particle surface, decrease the degree of Li+/Ni2+ cation mixing, and preserve the structural stability of cathode material. The NCM@LAZP-1 cathode material maintains 78.3% after 300 cycles at 1C in voltage of 2.8–4.3 V. Furthermore, at the high cutoff voltage of 4.5 V, the modified NCM@LAZP-1 cathode is discovered to realize a sustained reversible capacities of 179.3 mA h g−1, corresponding to capacity retention of 84.8% after 200 charge/discharge cycles, while the pristine NCM cathode delivers only 112.1 mA h g−1, matching with capacity retention rate of 52.3%.