LiNi0.6Co0.2Mn0.2O2 (NCM) is a highly potential cathode material for lithium-ion batteries (LIBs). However, its poor rate capability and cycling performance at high cutoff voltages have seriously hindered further commercialization. In this study, we successfully design an ultra-thin lithium aluminum oxide (LiAlO2) coating on NCM for LIBs. Compared to Al2O3, the utilization of lithium-ion conducting LiAlO2 significantly improves the NCM performance at high cutoff voltages of 4.5/4.7V. The study reveals that the LiAlO2-coated NCM can maintain a reversible capacity of more than 149mAhg−1 after 350 cycles with 0.078% decay per cycle. Furthermore, LiAlO2-coated NCM exhibits higher rate capacities [206.8mAhg−1 at 0.2C (50mAg−1) and 142mAhg−1 at 3C] than the Al2O3-coated NCM (196.9mAhg−1 at 0.2C and 131.9mAhg−1 at 3C). Our study demonstrates that the ultra-thin LiAlO2 coating is superior to Al2O3 and significantly improves the capacity retention and rate capability of NCM for LIBs.