LiNiO2 and Ba-doped LiNiO2 were synthesized by a simple solid state reaction, and used as cathode active materials for lithium rechargeable batteries. Physical properties of the synthesized products are discussed in the light of structural (TG/DTA, XRD, TEM, SEM with EDAX) and spectroscopic (FTIR) measurements. XRD results show that the compounds are similar to LiNiO2 in structure. TEM and SEM analyses were used to examine the particle size, nature and morphological aspects of the synthesized oxides. The composition of the materials was explored by EDAX analysis. Performances of lithiated oxides as cathode materials in lithium-ion batteries and substitutive effect on electrochemical properties have been investigated by cyclic voltammetry and galvanostatic charge–discharge cycling. By substitution of Ni with Ba, in LiNi0.8Ba0.2O2 has yielded better cycling results compared to all other materials revealed through charge–discharge studies.