Effects of Cr2O3-modified LiNi1/3Co1/3Mn1/3O2 ncathode materials on the electrochemical performance of lithium-ion batteries

Cr2O3-modified LiNi1/3Co1/3Mn1/3O2 composites are prosperously synthesized through a high-temperature solid-state method. From scanning electron microscopy and transmission electron microscopy analyses, it can be observed that the structures of Cr2O3-modified LiNi1/3Co1/3Mn1/3O2 materials were converted to polycrystalline. An appropriate amount of Cr2O3 could reduce the electrochemical polarization of electrode and enhance the electrochemical reaction kinetics of Li+ insertion/deinsertion. Consequently, the discharge capacity of 2 wt% Cr2O3-modified LiNi1/3Co1/3Mn1/3O2 material is 186.7, 185.5, 174.1, and 171.7 mAh/g, at 0.1, 0.2, 0.5, and 1 C rates, in the voltage range of 2.6-4.6 V, respectively, which are higher than those of other samples. In particular, the rate capacity of 2 wt% Cr2O3-modified LiNi1/3Co1/3Mn1/3O2 material remains 90% even after 63 cycles. Cyclic voltammetry measurements indicate that the materials have favorable structural stability and cycle performance. The enhancement of rate capacity of LiNi1/3Co1/3Mn1/3O2 material was attributed to Cr2O3 modification, which increased the conductivity of the material.