Li2MnO3 stabilized LiNi1/3Co1/3Mn1/3O2 cathode with improved performance for lithium ion batteries

Abstract

Li2MnO3 stabilized LiNi1/3Co1/3Mn1/3O2 cathode materials are discussed by xLi2MnO3·(1 − x)LiNi1/3Co1/3Mn1/3O2 (x = 0.3 and 0.7) solid solutions. The solid solutions were synthesized by annealing the mixing LiNO3, Mn(NO3)2 and LiNi1/3Co1/3Mn1/3O2 powder at 900 °C for 12 h, and it was found that the cathode particle size increased from 200–300 to 300–500 nm. The pristine LiNi1/3Co1/3Mn1/3O2 showed the 30th discharge capacity of 174.5 mAh g−1. Our results indicated that the introduction of Li2MnO3 in the cathode could increase performance. 0.3Li2MnO3·0.7LiNi1/3Co1/3Mn1/3O2 cathode shows higher discharge of 182.0 mAh g−1 in the 30th cycle. And the discharge capacity of 214.1 mAh g−1 was obtained when the Li2MnO3 content increased to 0.7. Moreover, the cyclic performance at 55 °C was also increased by Li2MnO3. 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 Li2MnO3-enriched layer is as a result of enhanced performance.