LiNi0.6Co0.2Mn0.2O2(abbreviated as NCM622)is a highly promising cathode materials for use in lithium ion batteries.However,its poor cycling performance and capacity rate at high cutoff voltages hinder its commercialization.Our previous reports indicate that surface modification is an effective approach to improve the electrochemical performances for secondary batteries.Herein,we successfully design two different coatings of Al2O3 and LiAlO2 onto NCM622 by a hydrolysis-hydrothermal method in an attempt to provide the NCM622 greater capacity rate,stabilities and energy densities with enhanced specific capacities and higher voltage outputs.Compare to the Al2O3-coated NCM622,our results indicate that the utilization of lithium ion conductors(LiAlO2,as a coating material)significantly improves the performance of NCM622 at high cutoff voltages(4.5/4.7V).The NCM622 with less than 1 nm LiAlO2 coating layer exhibits a higher discharge capacity of 206.8mAh g-1 at 0.2C(50mA g-1)and 142mAh g-1 at 3C(750mA g-1)than the Al2O3 coated(196.9mAh g-1 at 0.2C and 131.9mAh g-1 at 3C)at cutoff voltages of 4.5V.The different impact of Al2O3 and LiAlO2 coatings on NCM622 performance was compared in details.