Variation of discharge capacities with C-rate for LiNi1−yMyO2 (M = Ni, Ga, Al and/or Ti) cathodes synthesized by the combustion method

LiNiO2, LiNi0.995Al0.005O2, LiNi0.975Ga0.025O2, LiNi0.990Ti0.010O2 and LiNi0.990Al0.005Ti0.005O2 specimens were synthesized by preheating at 400 °C for 30 min in air and calcination at 750 °C for 36 h in an O2 stream. The variation of the discharge capacities with C-rate for the synthesized samples was investigated. LiNi0.990Al0.005Ti0.005O2 has the largest first discharge capacities at the 0.1 and 0.2 C rates. LiNi0.990Ti0.010O2 has the largest first discharge capacity at the 0.5 C rate. In case of LiNiO2 and LiNi0.990Ti0.010O2, the first discharge capacity decreases slowly as the C-rate increases. LiNiO2 has the largest discharge capacities at n = 10 (after stabilization of the cycling performance) at the 0.1, 0.2 and 0.5 C rates. This is considered to be related with the largest value of I0 0 3/I1 0 4 and the smallest value of R-factor (the least degree of cation mixing) among all the samples. LiNi0.975Ga0.025O2 exhibits the lowest discharge capacity degradation rates at 0.1, 0.2 and 0.5 C rates.