Pyrite FeS₂ nanospheres was synthesized through a simple solvothermal method in one step, and the electrochemical performance as the electrode material of supercapacitor was studied. The structure, morphology, specific surface area and pore volume of the material were characterized and measured experimentally, and its supercapacitor performances in three common electrolytes (6 M KOH, 6 M NaOH and 1 M Na₂SO₄) were tested by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the product is homogeneous pyrite FeS₂ nanospheres with a diameter of about 300?600 nm, showing obvious pseudocapacitance characteristics in all three electrolytes. When the electrolyte is KOH, it shows the highest specific capacitance, reaching 732.9 F/g at the current density of 2 A/g and 307.1 F/g at the current density of 20 A/g with the capacity retention rate of 41.9%. It is demonstrated that the synthesized FeS₂ nanospheres is an excellent electrode material for supercapacitors. 

By means of optical microscope, field emission scanning electron microscope, X-ray diffraction and laser Raman spectroscopy, the mineralogical characteristics of cryptocrystalline graphite in Yantongshan, Jilin Province and its indication significance for the genesis of the deposit are studied. The diameter of graphite microcrystals is L_a=59?175 nm, and the stacking height is L_c=32?93 nm. The graphitization degree value ranges from 0.573 to 1.000, and the interval (002) layers vary from 0.3352 to 0.3370 nm. The intensity ratio of D₁ peak and G peak arranges between 0.07 to 0.28. On the base above, the metamorphic temperature range was calculated as 526℃ to 622℃, with the average is 561℃, indicating that the metamorphic degree could reach the amphibolite facies in its formation. The graphitization degree varied greatly, and much higher near Fe bearing minerals, indicating that the crystallization process of graphite could be catalyzed with the different spots of one graphite ore slice by Fe containing compounds.