LiNi1-yMyO2 (M = Ga, In and Tl, y = 0.010, 0.025 and 0.050) with small y were synthesized by the combustion method by calcining in an O2 stream at 750 °C for 36 h. XRD analyses, SEM observation and measurement of the variation of discharge capacity with the number of cycles were carried out. All the samples had the R
The transition metal oxides such as LiMn2O4 [1–3], LiCoO2 [4–6] and LiNiO2 [7–16] have been investigated as cathode materials for lithium secondary batteries. LiMn2O4 is very cheap and does not bring about environmental pollution, but its cycling performance is not good. LiCoO2 has a large diffusivity and a high operating voltage, and it can be easily prepared. However, it has a disadvantage that it contains an expensive element Co. LiNiO2 is a very promising cathode material since it has a large discharge capacity and is relatively excellent from the viewpoints of economics and environment. However, its preparation is very difficult as compared with LiCoO2 and LiMn2O4.
