We opted for a conventional solid-state reaction method with a slight modification to synthesize cathode active materials calcined at 950 °C. Cation disordered rocksalt (DRX) cathode materials precisely Li1.22Ru0.61Ni0.16O2 (1) and Li1.22Ru0.61Na0.05Ni0.10O2 (2), were synthesized. The powders of LiNO3, NaNO3, Ni(CH3COO)2.4H2O, and RuO2 were stoichiometrically calculated and thoroughly homogenized using mortar and pestle for around 10 minutes. Subsequently, the powders were mixed with acetone, followed by ball milling for the next four hours. To avoid loss during high-temperature synthesis, an excess of 5 wt % of LiNO3 and NaNO3 over was taken. The homogenized mixture was then dried overnight in a vacuum oven at 100 °C. The powders were again mortar-pestled and finally, powers were transferred in an alumina crucible for sintering at 950 °C for 12 h at a ramp rate of 5 °C/min in a tube furnace in the ambient atmosphere. Subsequently, the furnace was cooled to room temperature and samples were grounded manually to obtain a fine powder.