Electrochemical properties of LiNiO2 substituted by Al or Ti for Ni via the combustion method

LiNi0.995Al0.005O2, LiNi0.975Al0.020Ti0.005O2, and LiNiO2 samples were synthesized using the combustion method. The starting materials, in desired proportions, were dissolved in distilled water and mixed with urea using a magnetic stirrer. The mixture was calcined at 750 °C for 36 h in an O2 stream after preheating at 400 °C for 30 min in air. The electrochemical performances of the synthesized samples at 0.1 C rate were investigated. Among LiNi0.995Al0.005O2, LiNi0.975Al0.020Ti0.005O2, and LiNiO2, LiNi0.975Al0.020Ti0.005O2 had the largest first discharge capacity of 181 mA h/g with the capacity deterioration rate of 1.07 mA h/g/cycle. LiNi0.995Al0.005O2 had a capacity deterioration rate of 0.65 mA h/g/cycle with the first discharge capacity of 164 mA h/g. LiNi0.995Al0.005O2 had the largest value of I003/I104 and the smallest unit cell volume and R-factor.