CAJ | 학술논문

Iron disulfide (FeS2) cathode active material was prepared from iron and sulfur at room temperature by high energy mechanical alloying. Modified FeS2 composites containing Co or Ni transition metal powders as additives were also prepared by the same method. Lithium cells with these FeS2 cathodes were studied for charge-discharge properties at room temperature using 0.5M LiTFSI in tetra(ethylene glycol) dimethyl ether (TEGDME) solvent. Cyclic voltammetry showed two anodic oxidation peaks at 1.8 and 2.5V and two cathodic reduction peaks at 2.0 and 1.3 V for FeS2 with metal additives. The addition of 5wt% Co and 3wt% Ni resulted in an enhancement of the first discharge capacity giving 571 and 844mAh/g respectively at 0.1C-rate. The cycle performance was also enhanced remarkably by the addition of these electrically conductive transition metals in the active material. FeS2 with 5wt% Co exhibited a stable cycle performance delivering a reversible capacity of 338mAh/g (37.8% of theoretical capacity) after 20 cycles.