Effect of a surface treatment for LiNi1/3Co1/3Mn1/3O2 cathode material in lithium secondary batteries

LiNi1/3Co1/3Mn1/3O2 cathode material was surface-treated to improve its electrochemical performance. A1 2O3 nanoparticles were coated onto the surface of LiNi1/3Co1/3Mn1/3O2 powder using a sol-gel method. The as-prepared Al2O3 nano-particle was identified as the cubic structure of A12O3. XRD showed that the LiNi1/3Co1/3Mn1/3O2 structure was not affected by the A12O3 coating. With a coating of 3 wt.% A12O3 on LiNi1/3Co 1/3Mn1/3O2, the cyclic-life performance and rate capability were improved. However, heavier coatings (5 wt%) on LiNi 1/3Co1/3Mn1/3O2 resulted in a considerable decrease of the discharge capacity and rate capability. The thermal stability of LiNi1/3Co1/3Mn1/3O2 materials was greatly improved by the 3 wt.% Al2O3 coating.open3