For the preparation of the La2Ni0.75Co0.25O4.08 cathode composite, 30 wt-% of as-synthesized La2Ni0.75Co0.25O4.08 was mixed with 60 wt-% of La0.9Ba0.1F2.9 and 10 wt-% of dried carbon black to improve the ionic and electronic conductivity of the cathode material. The mixture was then ball milled for 3 hrs at the rotational speed of 250 rpm. The reduced rotation frequency is necessary to avoid amorphization and destruction of the layered structure.