NANOSTRUCTURED FЕ-PT/C COMPOSITE ELECTRODE MATERIALS FOR SUPERCAPACITORS BASED ON THE CARBON MATRIX FROM ANTHRACITE

Nanostructured Fе-Pt/С composites based on a carbon matrix with a filler content of 1 wt%, and the molar ratio of Pt/Fe components equal to 9 : 1 have been obtained by the joint reduction of aqueous solutions of the precursors (hydrogen hexachloroplatinate(IV) and iron(II) sulphate) with an alkaline solution of hydrazine hydrate at a temperature of 90-95 °C. The carbon matrix was mainly a microporous carbon sorbent (SAK) synthesized by the high-temperature alkaline activation of anthracite from the Kuznetsk coal basin. The formation of the Fе-Pt filler nanophase at the initial stages of synthesis has been studied. For this purpose, along with the standard synthesis method (5 min), the syntheses with the interruption of the reaction at the initial stage (after 10 and 30 s) have been carried out by introducing a dilute HCl solution cooled to a temperature of 2 °C into the reaction medium. It has been found that, according to X-ray diffraction and sorbtometry data, the formation of finely dispersed filler nanoparticles decorating the matrix surface occurs within the first 10 s, while minimal blocking of the matrix pores is observed, and the highest electrical capacity characteristics for nanocomposites are recorded. It has been determined that with an increase in process duration, the filler particles become larger, which causes a decrease in the specific surface of nanostructured composites and, as a consequence, deterioration of the electrical capacitance properties. It is shown that the highest specific electrical capacitance (1.5-1.7 times higher than the capacity for a cell with electrodes made of SAK) was achieved in an asymmetric cell with a working nanocomposite Fе-Pt/C electrode obtained under the conditions of synthesis interruption after 10 s. The reasons for these considered effects are discussed