Electrochemical Properties of Natural and Modified Pyrite
Pyrite utrafine powder was yielded through processing natural pyrite, including gravity separation, flotation and airflow grinding, which the contents of Fe and S are 45.30wt% and 50.95wt% respectively and the mean grain size is 13μm. Pyrite powder modified by fatty acid salt A was investigated by TG/DSC, XPS and XRD. The results indicate that the phase of powder is mostly pyrite FeS2 coating with organic modifier, and S exists in the form of [S2]2- principally on modified pyrite surface. Furthermore, electrochemical impedance spectroscopy, cyclic voltammetry measurement and galvanotactic current charge and discharge methods were applied to exhibit the electrochemical performance of pyrite sample. The results show that modified pyrite has lower charge transfer resistance and higher conductivity than that of natural pyrite, and the specific discharge capacity is as high as 850mAh/g under 0.354A current at room temperature and the cutoff of 0.5V closing to the theoretical specific capacity of pyrite (890mA•h/g), and the voltage plateau is 1.44V.