Abstract
This research is about LiNi0.8Co0.15Mn0.05O2 cathode material of lithium ion secondary batteries made by nickel, cobalt, and manganese. First we changed the conditions of calcination such as temperature (750℃, 800℃ and 850℃) and calcination time (8hr and 12hr). X-ray diffractometer (XRD) and scanning electron microscope (SEM) can help us to analyze and compare morphologies of LiNi0.8Co0.15Mn0.05O2. Comparison of C-Rate, cycle life, cyclic voltammetry (CV) test of the final coin cells can let us know which conditions are the best for LiNi0.8Co0.15Mn0.05O2.Surface modifications were done in the second half of this research. Base on the applicable synthesis conditions, different ratios of Al2O3(2%, 3%), MgO(2%, 3%) and ZrO2(1%, 2%) are used to coat on LiNi0.8Co0.15Mn0.05O2. From the results we found that capacities of the batteries decrease little and cycle life performances were similar with the bare LiNi0.8Co0.15Mn0.05O2. 2wt% Al2O3 coated LiNi0.8Co0.15Mn0.05O2 shows the best cycle ability when the voltage increases to 4.5V. It is the potential material.