Improvement of high voltage electrochemical performance of LiNi0.5Co0.2Mn0.3O2 cathode materials via Li2ZrO3 coating

Abstract LiNi 0.5 Co 0.2 Mn 0.3 O 2 is successfully coated with Li 2 ZrO 3 through a simple sol–gel method. The formation of a uniform Li 2 ZrO 3 coating layer on the surface of the bare sample is confirmed by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS). Similar discharge capacities are delivered by both bare and Li 2 ZrO 3 -coated samples. However, the capacity retention of Li 2 ZrO 3 -coated sample is much higher than that of the bare one at 1 C after 100 charge–discharge cycles under a high cutoff voltage of 4.6 V. Meanwhile, the rate performances of Li 2 ZrO 3 -coated sample are dramatically enhanced especially at high rates. Furthermore, the increase of impedance during charge–discharge process is suppressed by Li 2 ZrO 3 coating layer.