Li2Mn03 stabilized LiNil /3 CO1 /3 Mn1/3 02 cathode materials are discussed by xLi2Mn03 (1 - x)LiNiii3C01/3Mni/302 (x=0.3 and 0.7) solid solutions. The solid solutions were synthesized by annealing the mixing LiNO3, Mn(NO3)2 and LiNiii3Coli3Mni /3 02 powder at 900 C for 12h, and it was found that the cathode particle size increased from 200-300 to 300-500 nm. The pristine LiNi113 C0113 Mn11302 showed the 30th discharge capacity of 174.5 mAh g-1. Our results indicated that the introduction of Li2Mn03 in the cathode could increase performance. 0.3Li2Mn03 0.7LiNiii3Coli3Mni /302 cathode shows higher discharge of 182.0 mAhg-1 in the 30th cycle. And the discharge capacity of 214.1 mAh g-1 was obtained when the Li2Mn03 content increased to 0.7. Moreover, the cyclic performance at 55 C was also increased by Li2Mn03. For instance, the discharge capacities were 191.2 mAh g-1 (x = 0.3) and 229.3 mAh g-1 (x=0.7) and the capacity retentions are 94.9% and 91.4% after 40 cycles, respectively. The DFT calculations show that stable Li2Mn03-enriched layer is as a result of enhanced performance. Crown Copyright 2013 Published by Elsevier B.V. All rights reserved.