Electrochemical Properties for Co-Doped Pyrite with High Conductivity

In this paper, the hydrothermal method was adopted to synthesize nanostructure Co-doped pyrite (FeS2). The structural properties and morphology of the synthesized materials were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. Co in the crystal lattice of FeS2 could change the growth rate of different crystal planes of the crystal particles, which resulted in various polyhedrons with clear faces and sharp outlines. In addition, the electrochemical performance of the doping pyrite in Li/FeS2 batteries was evaluated using the galvanostatic discharge test, cyclic voltammetry and electrochemical impedance spectroscopy. The results showed that the discharge capacity of the doped material (801.8 mAh·g−1) with a doping ratio of 7% was significantly higher than that of the original FeS2 (574.6 mAh·g−1) because of the enhanced conductivity. Therefore, the doping method is potentially effective for improving the electrochemical performance of FeS2.