Электрохимические свойства композитных электродов, содержащих наночастицы солей меди

The energetic properties of the new composite electrode materials suitable for electrochemical capacitors were investigated. Composite electrodes were made using Norit A activated carbon and synthesized sparingly soluble copper salts such as copper iodide(I) and hexacyanoferrates (II), etc. (III). The composition of the salts was confirmed by elemental analysis and the particle size was determined by the Scherrer equation using the data of X­-ray phase analysis.

Pyrolized polyacrylonitrile as a feasible electrode material for electrochemical power sources

In the current paper electrospun nanofiber mats were derived from polyacrylonitrile (PAN). The temperature influence on the volumetric and surface composition of the resulting pyropolymers was studied by means of elemental analysis and X-ray photoelectron spectroscopy. Rotating disc electrode (RDE) and rotating ring disc electrode (RRDE) methods were used to determine the catalytic properties of PAN pyropolymers, derived at carbonization temperature interval of 600–1200°C, as well as composite PAN/support catalysts, carbonized at 900°C, in the oxygen reduction reaction in H2SO4 и KOH solutions. The methods of cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic polarization were utilized to characterize the charge capacitive properties. An equivalent scheme modeling the electrochemical response of PAN pyropolymer in H2SO4 solution was proposed. An assumption was made of interrelation between the PAN-T catalytic activity and the occurrence of condensed parquet aromatic structure comprising of nitrogen-carbon bonds. Evidence was given that Fe atoms play the key role in the synthesis of active non-precious catalysts with high selectivity towards the 4-electron O2 reduction. The possibility of the catalysts synthesis for 2-electron ORR without the use of metal precursors was evidently shown. Prominent correlation of capacitive and catalytic properties for these materials was observed in H2SO4 solution. The optimal PAN pyropolymers synthesis temperature was determined to be in the range of 750–950°C. The mats of PAN-T were shown to be feasible as the negative electrodes of supercapacitors.