Modification of LiNi0.5Co0.2Mn0.3O2 cathode material using nano TiO2 to enhance the cycle stability in high-voltage ranges

Nano TiO2 with low crystallinity is employed to improve the high-voltage cycling performance of LiNi0.5Co0.2Mn0.3O2 cathode material. Nano TiO2 is homogeneously distributed on the surface by EDS and TEM analysis. TiO2-modified sample delivers capacity retentions of 86.9% (200 cycles) and 87.2% (100 cycles) in 3.0-4.4 V and 3.0-4.6 V, respectively, which are much greater than that of unmodified sample (75.6% and 74.1%). The morphology, structure and impedances changes of the cycled electrodes are detailedly discussed. Nano TiO2 modification contributes to stabilize the layered structure, remit the particles pulverization and suppress the impedance growth and the formation of microcracks, resulting in the excellent high-voltage cycling performance of the material.