Preparation and performance of LiNi_0.8Co_0.15Al_0.05O₂ cathode material of lithium ion battery

By means of coprecipitation, the precursor Ni_0.8Co_0.15Al_0.05(CO₃)_x (OH)_y with about 10 μm particle size was prepared. The cathode material of lithium ion battery, LiNi_0.8Co_0.15Al_0.05O₂ (LiNCA) was fabricated successfully with the precursor and LiOH·H₂O, and the effects of calcination atmosphere, calcination temperature and calcination method on electrochemical performances were studied. The results show that the discharge specific capacity of the LiNCA calcined in oxygen reaches 170 mAh·g^-1, and the capacity retention ratio after 50 cycles reaches 95%, which is better than the LiNCA calcined in air. In the oxygen atmosphere, the LiNCA obtains the best performance when the calcination temperature is in range of 700 to 750℃. If the calcination temperature is too high or too low, the performance of LiNCA decreases significantly. When the precursor is precalcined at 450℃ in oxygen atmosphere, and then calcined with mixed LiOH·H₂O at 700 to 750℃, the LiNCA discharge specific capacity reaches 190 mAh·g^-1, which increases significantly.